REFERENCE

AlllOb D3T730

NBSIR 81-1655 NIST

PUBLICATIONS

ESTIMATED UNCERTAINTY OF CALIBRATIONS

OF FREESTANDING PRISMATIC LIQUEFIED

NATURAL GAS CARGO TANKS

J. D. Siegwarth

J. F. LaBrecque

Thermophysical Properties Division

National Engineering Laboratory

National Bureau of Standards

U.S. Department of Commerce

Boulder, Colorado 80303

January 1982

Supported by

LNG Custody Transfer Measurements Supervisory Committee

and the Maritime Administration

(00

- Vfib

Vr\rf>

EPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

AL BUREAU OF STANDARDS, Ernest Ambler, Director

NBSIR 81-1655

ESTIMATED UNCERTAINTY OF CALIBRATIONS

OF FREESTANDING PRISMATIC LIQUEFIED

NATURAL GAS CARGO TANKS

J. D. Siegwarth

J. F. LaBrecque

National Bureau of Standards

U.S. Department of Commerce

Boulder, Colorado 80303

January 1982

Supported by

LNG Custody Transfer Measurements Supervisory Committee

and the Maritime Administration

Contents

Page

1. Introduction 1 2. Description of the Tanks 2 3. The Photogrammetric Calibration Method 9 4. Accuracy of the Photogrammetric Calibration Method

as Applied to the Freestanding Prismatic Tanks 11

5. Accuracy of Tanks in Service 14

6. References 17

Appendix A - Accuracy and Precision of Photogrammetric Dimensioning of

Freestanding Prismatic Cargo Tanks

by J . F. LaBrecque, C. L. Carroll, and J. D. Siegwarth

Appendix B - Uncertainty in Tank Volume Determination Introduced by

the Calculation Method

by J. F. LaBrecque

Appendix C - Uncertainties Due to Temperature Effects

by J. D. Siegwarth and J. F. LaBrecque

Appendix D - A Laser-Based Calibration of Tank //3 on the

Tanker El Paso Columbia

by W. C. Haight, F. Scire, R. G. Hartsock, and R. J. Hocken

Appendix E - Deformation Measurements on Freestanding LNG Cargo Tanks

by W. C. Haight, B. Borchardt, R. G. Hartsock, R. C. Veale,

and R. J. Hocken

Appendix F - Hydrostatic Deformation of Freestanding LNG Cargo Tanks

by W. C. Haight, F. Scire, R. G. Hartsock, and R. J. Hocken

Appendix G - Deadwood Survey Data El Paso Columbia, Hull 2266, Tank 3

by W. C. Haight, R. G. Hartsock, and R. J. Hocken

Appendix H - Bottom Surveys of Freestanding LNG Cargo Tanks

by W. C. Haight, F. Scire, R. G. Hartsock, C. Johnson,

and R. J. Hocken

iii
Estimated Uncertainty of Calibrations of Freestanding

Prismatic Liquefied Natural Gas Cargo Tanks

J. D. Siegwarth and J. F. LaBrecque

Thermophysical Properties Division

Center for Chemical Engineering

National Engineering Laboratory

National Bureau of Standards

Boulder, Colorado 80303

The accuracy of the tank calibrated by the photogrammetric technique was examined during the calibration of fifteen freestanding prismatic LNG transport

tanks. This examination indicated that the calibration accuracy of the tanks

calibrated in the storage position was better than + 0.1%. Additional factors

influencing the accuracy of the calibration of the tanks, such as the effects of

installing the tanks into the ship and loading the ships with LNG, were examined

in the course of this work and the results are reported here. The various

measurements used by various NBS personnel to analyze the calibration accuracy

are detailed in the eight Appendices included in this report.

Key words: calibration accuracy; laser calibration; LNG ship tanks;

photogrammetry ; volume calibration.
Estimated Uncertainty of Calibrations

of Freestanding Prismatic Liquefied Natural Gas Cargo Tanks

J. D. Siegwarth and J. F. LaBrecque

1. Introduction.

The National Bureau of Standards has done preliminary studies [1] to

establish an upper limit for the tank volume uncertainty of a spherical

transport tank calibrated by photogrammetry [2,3]. The Maritime Administration

of the Department of Commerce and the LNG Custody Transfer Measurements

Supervisory Committee [4] have provided funds both to test the accuracy of the

present state of the art of tank calibration and to develop new methods of

calibrating tanks that are suitable for industrial use. This additional

support has made possible an expanded study of the calibration uncertainties of

freestanding prismatic LNG transport tanks. The objectives of this work are

two fold. The first objective is to make more extensive measurements to

provide an independent verification of the uncertainty of the photogrammetric

method of determining spatial coordinates of points on the surface of the

tanks. The second objective is to provide an upper limit for the uncertainty

of the calibration of these particular tanks. This latter objective contains

the first, but additional factors must be considered. As in the case of the

spherical tanks, the photogrammetric survey is done before the tanks are transported to and installed in the ship. In addition, the photogrammetry is

done with the tank empty. Effects of lifting, installing, cooling, and loading

the tanks should be included in the calibration uncertainty.

In this work, we have examined by independent measurements and calculations the photogrammetric calibration method and effects on the tank volume of

events following the tank calibration. The photogrammetric calibration has

been analyzed for each of the tanks using length standards. The NBS has tested

the calibration of one tank by a completely independent volume determination

method. The laser plane method developed by NBS for the conformation of the

volume tables of membrane tanks [5] was modified and used on the exterior of

the tank.

The method of volume calculations has also been tested for accuracy by

independent calculations using the photogrammetrically determined coordinate

data for points on the tank surface. The dimensions of the aluminum in the

tank walls and internal structure were measured for one tank to obtain an

estimate of the error induced when using the blueprint dimensions in the

correcting for volume taken by the tank walls and structure.

1
The same tank dimensioned by laser planes was also dimensioned while

filled with the maximum amount of water during the hydrostatic tests. A

distortion study was done based on these results.

In other measurements, the tank bottoms were resurveyed after the tanks were installed to determine whether the tank support blocks were properly

shimmed so that the constructed bottom contour of the tank was retained.

Finally, two of the early tanks were surveyed, both before and after they were lifted into place aboard the ship, to investigate the effects the lifting

might have on the tank volume calibration.

The methods used and the results obtained from the various measurements by

NBS are detailed in the reports contained in the appendices. The authors of

the various appendices identify those who did that particular part of the

project. An estimate of just the uncertainty of the photogrammetric survey

technique as applied to this particular calibration problem is provided.

2. Description of the Tanks.

Each ship contains five tanks similar to the tank shown in figure 1.

Counting from the bow, the third and fourth tanks are identical; the second

tank is nearly the same in capacity as tanks three and four but the sides taper

slightly towards the bow. Tank five is shorter and tapered slightly toward the

stern. Tank one is again shorter and heavily tapered towards the bow. The

outer walls of the tanks are flat planes, eight in all. The bottoms and tops

are horizontal planes; the ends are vertical planes. The sides are composed of

two planes each. The top most plane is vertical and connects to the bottom

via a chine plane that slopes in toward the center line of the tank at the

bottom. This narrowing of the bottom provides clearance for the curved corners between the sides and bottom of the hull. The larger of the tanks have widths

and lengths of about 36 m; all have heights of about 23 m, and are constructed

of rectangular plates of 5083 aluminum varying in thickness from approximately

1.5 to 3 cm. These plates are edge welded to form panels. These panels are

2
3

Figure

1.

Exterior

view

ofa

completed

tank

waiting

to

be

loaded

aboard

the

ship.
preassembled complete with the vertical stiffening channels and horizontal

girders. The panels are lifted by crane, fitted into place and welded. The

tanks are divided internally into four quadrants by vertical walls. The fore

to aft wall is liquid tight. The port to starboard wall or swash bulkhead is

not liquid tight. The external and internal walls of the tank are heavily

braced internally first by vertical 23 cm wide L shaped ribs at roughly 2/3 m intervals. These ribs in turn are attached to seven wide flanged horizontal

girders at intervals from the bottom to the top of the tank. Stiffening ribs are also welded to the top plates inside and I-beam girders brace the floor

panels at the same intervals as the ribs on the walls. These in turn are welded to heavy girders in both the floor and ceiling. Numerous triangular

braces are fit between the various stiffening girders. Figures 2 and 3 are photographs of this internal structure. The corners between the planes composing the tank surface are radiused. The radius is approximately 30.5 cm on the

inside. The volume of the aluminum comprising the tank amounts to between one

and two percent of the total volume of the tank. Figure 4 is a diagram of the

tank showing the interior structure.

The tanks, after the assembly is complete or nearly complete, are transported from the assembly area to a hydrotest stand. The tanks are transported

by four crawler tractors, one under each corner lifting the tank by means of

lifting brackets. The tank is hydrotested by filling it a little more than

half full with water. The tank is then pressurized with air to 0.14 bar (2

psi). After hydrotesting, the tank is transported again by the crawlers to the

storage area and placed on three rows of concrete pillars. The photogrammetr ic

calibration usually takes place while the tanks are in this storage area. One

tank of each ship set has been calibrated while on the hydrotest stand. Only

the sides of the tanks are actually dimensioned photogrammetrically . The top

and bottom of the tanks are profiled using conventional theodolite techniques.

These surveys supply the top and bottom data used in the tank table calculation. This bottom survey is used to shim the surfaces of the support blocks on

the ship located in the bottom of the tank socket so the tank is uniformly supported. The tank and contents are supported completely on these blocks.

The ship is brought to the tank construction site to load the tanks. The

tanks are moved up one at a time via the crawlers, then lifted, swung out over

the ship and lowered into the insulated tank socket by a 1.36 x 10^ kg (1500

ton) capacity crane. Figure 5 shows a tank being lifted aboard the ship.

4
Figure 2. Interior photograph showing ceiling and upper wall structure

of a tank.

5
Figure 3. Interior photograph showing the floor and chine surfaces of a tank.

6
Figure 4. Cutaway drawing of two quadrants of a cargo tank showing the

internal bracing configuration.

7
Figure 5. Tank //5 being loaded on the Columbia. From the time the tank left

the crawlers until it was in place on the ship, slightly over an hour had elapsed.

8
The tank is connected to a horizontal lifting beam of the crane by a large number of cables supported by interconnected hydraulic cylinders such that the tank

load is equally supported on all the cables. Insulation is placed over the top

of the tank; then the deck section covering of the tank socket is replaced. The

walls of the tank are then accessible only from the inside of the tank.

3. The Photogrammetric Calibration Method

The photogrammetric process is employed to determine x,y,z coordinates of

a number of points distributed over the surface, in this case the outside

surface, of the tank. These points are, physically, 19 mm diameter white dots

placed on a black background or 19 mm diameter white balls placed on the tank

prior to photography. The white dots and background are either painted on the

tank wall or are printed on adhesive-backed paper and placed on the tank wall.

The white balls are offset a known distance from the walls. The number and

placement pattern are quite flexible and generally chosen to give sufficient

detail of any wall variations with the minimum number of targets. The x,y,z

coordinates of the points on the tank can be in any arbitrary coordinate system.

This coordinate system is later translated and rotated such that the z axis is

perpendicular to the gravitational plane when the tank is on the ship and the x axis is parallel to the center of the ship in the gravitational plane; hence,

the y axis is transverse to the ship and in the gravitational plane.

The photogrammetric method of determining the coordinates of the tank

surfaces is closely related to the method of determining the coordinates of the

tank surfaces is closely related to the method of using a theodolite to locate

identifiable points on the surface by measuring vertical angles to the points

from horizontal and horizontal angles from a baseline of known length at both

ends of the baseline. The axes of the theodolite determined coordinate system

might be the horizontal baseline, the gravitational field direction and the axis

perpendicular to both. One such theodolite set-up or station can be related to

the next by repeating measurements of some of the targets located from the

adjacent stations. The theodolite must be aimed twice at each point to be

located : once from each end of the baseline , or one aimed from each end of the

baseline if two theodolites are used.

In the photogrammetric method, the eyepiece of the theodolite is replaced

by a camera employing a very flat photographic plate. A photograph of the

complete surface from each of the two ends of the baseline contains the same

9
information as all the theodolite readings since all the point images off the

optical axis are recorded in each photograph. The angle data from a theodolite

aimed at a point is contained in the position of the photographic image of the

point. The x,y coordinates of these photographic images can be measured to + 3 micrometers. Sufficient photographic image data are acquired such that not

only x,y,z coordinates of each target spot can be calculated but also the camera positions and orientations, a lens correction and an uncertainty for the

coordinate position. In practice, the calibrated base line used with the

theodolite can be replaced by a few known target spacings on the tank surfaces.

Although many of the details of the stereo-triangulation methods used by the

photogrammetr ic consultants are proprietary, the general approach here is

explained in references [2] and [3].

10
4. Accuracy of the Photogrammetric Calibration Method

as Applied to the Freestanding Prismatic Tanks

The accuracy of calibration of the tanks has been independently estimated

from a number of measurements made by NBS personnel. The various measurements

and the results are described in detail in Appendices A through H.

The method used to verify the accuracy and precison of the

photogrammetrically determined coordinates of designated points on the tank

exterior walls is described in Appendix A, and the results are presented for all

fifteen tanks of the three ship sets.

In Appendix B, gaging tables, calculated at NBS using the

photogrammetrically determined coordinate data, and gaging tables, calculated by

the photogrammetrist from the same data, are compared in order to examine the

computational method. The computational method and results for all fifteen

tanks are also given. The results are for the total volumes of the tank to the

outside surfaces.

The photogrammetric measurements are made on the tank under conditions

assumed nearly isothermal and at ambient conditions. The tank volume is then

mathematically sized at the normal operating condition using the thermal

expansion coefficient for 5083 Aluminum [7]. Possible errors introduced by lack

of isothermal conditions, uncertainty of the expansion coefficient and incorrect

determination of temperature are discussed in Appendix C.

Tables A, B, and C give summaries of the estimated maximum errors of the

volume determined by the photogrammetric method. Details are in the first three

Appendices. Tables A through C are for the Savannah, the Cove Point, and the

Columbia, respectively.

The random errors are represented by 95% confidence limits for the random error source in question. While the errors due to volume calibration, scale

factor, and target spacing are considered random, the thermal expansion

coefficient error is systematic, but unknown; the limits for this error are based on the bounds for the thermal expansion coefficient [6]. All errors are given in percent. In the tables a plus sign signifies an overestimate and a minus sign an underestimate.

11
TABLE I: Error Summary (percent) for the Savannah Tanks

Limits of

Systematic | 1 Scale bias

Random Uncertainty Error for j 1 + systematic

Volume | Target | Scale | RMS | Thermal ) Scale | and random

Tank | Calculation spacing j factor | total | coef

.

bias | error

1 | + .01 1 ±-014 | + .01 | +.020 | + .03 | -.04 | -.04 + .050

2 1 + .01 | +.014 | + .01 | +.020 | + .03 | -.06 | -.06 + .050

3 1 + .01 | .00 | + .01 | +.014 | + .03 | .00 | 0 + .044

4 | + .01 | .00 | + .Oi | +.014 | + .03 | -.03 | -.03 + .044

5 | + .01 | .00 | + .0! | + .014 | + .03 | -.03 | -.03 + .044

TABLE II : Error Summary (percent) r or the Cove Point Tanks

Limits of

Systematic | 1 Scale bias

Random Uncertainty Error for | 1 + systematic

1 Volume | Target | Scale j RMS | Thermal | Scale ) and random

Tank | Calculation spacing 1 factor | total j coef

.

bias | error

1 | + .01 | +.014 | + .015 | +.023 | + .03 | .00 | .00 + .053

2 | + .01 1 ±*014 | + .009 | +.019 | + .03 | .00 | .00 + .049

3 1 + .01 | .014 | + .005 | +.018 | + .03 | -.02 | -.02 + .048

4 | + .01 | .014 | + .011 | +.020 | + .03 | .01 | .01 + .050

5 + .01 .014 1 + .007 1 +.019 1 + .03 1 .00 I .00 + .049

TABLE III: Error Summary (percent) for the Columbia Tanks

Limits of

Systematic

Random Uncertainty Error for | Systematic

1 Volume | Target | Scale | RMS Thermal | and random

Tank | Calculation spacing | factor 1 total coef

.

| error limit

1 | + .01 | +.014 | + .025 | + .03 + .03 1 ± .06

2 | + .01 | +.014 1 ± - 025 1 + .03 + .03 1 ± .06

3 1 + .01 | .014 | + .025 | + .03 + .03 1 ± .06

4 | + .01 | .014 | + .025 | + .03 + .03 1 ± .06

5 + .01 .014 1 + .025 1 + .03 + .03 1 + .06

12
The second column in the tables gives the estimate of the random

uncertainty in the volume introduced by the computational method. The third

column gives an estimate of the random uncertainty introduced when the number of

identifiable points or targets on the tank used for the photogrammetric survey

is reduced to half those used on tanks 3, 4, and 5 of the Savannah. The fourth

column gives the random uncertainty associated with the magnitude of the scale

factor required to convert coordinate number data to true lengths as determined

from the NBS tape results. Column five gives the rms sum of these random

errors

.

A systematic error results from the uncertainty in the coefficient of

thermal contraction for the aluminum tank cooled to operating temperature. The

estimated limits of this error are given in column six. The seventh column of

Tables I and II give the systematic error in the tank volume resulting from

systematic errors in the photogrammetric scale factor, which is discussed

Appendix A. Detectable scale factor systematic errors were observed only for some of the calibrations of the tanks of the Savannah and Cove Point. No scale

factor systematic error was discernable for the tanks of the Columbia, so that

column has been deleted. The scale-factor systematic error can be eliminated by

applying a multiplying factor to the gage table volumes.

The last column of the three tables shows a combined value of the

uncertainty of the tank calibration for each tank.

Some photogrammetrically-determined numbers were used in this error estimate in combination with some independent measurements. A gaging table for

tank 3 of the Columbia was calculated by NBS personnel using a completely

independent measurement method. This method consisted of erecting a laser plane

defined solid exterior to the tank wall, then measuring the offset from the

laser-defined planes to the walls at a large number of points. The spatial

relationship of the planes was measured using tapes and theodolites. The method

was adapted from a tank volume measurement method used internally on membrane-type LNG tanks [5]. The results of the measurements of tank 3 of the

Columbia are given in Appendix D. These results agree with the

photogrammetrically-determined gaging tables and agree in total volume at

22.445 m height to 0.7 m3 or 0.003%. The largest difference is 3.0 m

3 in

the region of 15 m height.

13
5. Accuracy of Tanks in Service

The results of the last section are consistent with the tanks being calibrated within the accuracy claimed by the photogrammetrist . The tanks, however,

are constructed and calibrated on shore and while empty. The procedures of

loading the tanks aboard ship, or the hydrostatic loading of the cargo could

change the volume of the tank. Furthermore, the volumes discussed in the previous section were external; so that the volume of aluminum in the walls and

internal framing must be subtracted from the external volume to obtain the

actual liquid volume. This deadwood correction is 1.3% for the smallest tank

(tank 1) and ranges down to 0.9% for the largest tank. The distortion of the

tank caused by lifting it into the ship, the hydrostatic distortion and the

deadwood have been studied by NBS personnel to determine what errors may be

introduced into the gaging tables.

To test for lifting distortion, flatness surveys as described in Appendix E were done on the top and bottom surfaces of tanks 4 and 5 of the Savannah. The

tanks were surveyed in the storage yard and then immediately after being placed

in the ship. The root mean square differences of the surveyed points from a fitted plane were calculated for each survey. Appendix E argues that, as there

was no significant change in the rms values of any of the before and after surveys, there could not be significant change in tank volume. Also, it was assumed that since the top and bottom of the tank, which would be most affected

by the move, did not distort, then the walls did not distort either.

The hydrostatic pressure on the bottom of the tank when filled with LNG is

about 1 bar. Since the tanks were hydrostatically tested by filling them

half-full of water, it was possible for NBS personnel to measure hydrostatic deformation of the tank. Flatness measurements were made on the walls of tank 3

of the Columbia both with and without water in the tank. The results of these

measurements are given in Appendix F. The rms differences of the surveyed

points from a fitted plane were calculated and compared for the survey done

before the hydrostatic test and for the survey made during the test. As no significant differences were detected for the rms values, it was inferred that no significant volume change had occurred.

The tank volume comparisons given in Appendix B are for the outside dimensions of the tank. To obtain the liquid volume, the volume of aluminum in the

walls and internal structure must be calculated as a function of height. The

deadwood volume at height h must be subtracted from the external tank volume at

height h to get the liquid volume at this height. The photogramme trie contractor determined deadwood volume as a function of height from drawings of the

tanks and the nominal dimensions of the various plates. In measurements made by

14
NBS on tank 3 of the Columbia, it was found that the deadwood dimensions are generally slightly larger than nominal. For this tank, the larger dimensions

decrease the total liquid volume by about 8 m^ or 0.03%. The measurements are reported in Appendix G.

In Appendix H, the survey effort and the results obtained for the tank bottom surveys of the 10 tanks of the first two ships are presented. The desired

measurement accuracy was not achieved with these measurements because the shipyard continued work during the measurements, which caused both constant movement

and permanent changes of the list and trim. The flatness surveys of the four

tank quadrants could not be satisfactorily correlated by the water tube measurements. The flatness surveys by quadrant did suggest however that little bottom

distortion had resulted from placing the tanks. The motions of the ship during

the surveys also precluded accurate measurement of the orientation of the tank

with respect to the draft marks. The third ship was not completed because the

gas trials of the Savannah showed the Insulation system used was unsatifactory

for LNG service.

Because of the central location of the gage in these tanks, the volume er- ror is not a strong function of list or trim. For example, a 5 cm list adds an error of +3 m^ to the volume of the largest tanks, the sign depending on whether the list is to starboard (positive) or to port. The attempt to measure the

tank and gage orientations with respect to the draft marks was done when the

ships were essentially complete. This measurement could be repeated anytime in

the future when the ship tanks are brought up to air during the periodic inspections. This could best be done in a non-floating drydock. The measurements

might also be done with the ship afloat in a ^uiet body of water when no other

work is being done either on the ship or nearby.

Of the three sources of error considered in the section - lifting distortion, hydrostatic distortion, and errors in deadwood specification - only errors

in the deadwood corrections are seen to be significant. For the lifting and hydrostatic distortions, no bounds have been calculated for how much change in

volume could have occurred without having been detected by the methods of meas- urement used. The study by NBS on tank 3 of the Columbia showed the deadwood

volume to be 2.9% larger than the deadwood volume calculated from the tank's

nominal dimensions.

The uncertainty of this 2.9% value has been calculated to be approximately

+0.2%. While it is not possible to predict what the error in the deadwood volume due to oversized dimensions would be for the remaining fourteen tanks, the

material from which the other tanks were constructed is likely to be similar in

sizing to the material for this tank, and it is not expected that this deadwood

volume error would exceed 5%.

15
In conclusion, the NBS verification of the photogrammetric method of

determining the external tank volumes found the uncertainty of this method to be

within +0.1% of total volume. This includes the errors in the use of the

temperature coefficient to calculate the volume at operating temperature and in

the deadwood calculation, but not the errors in the bottom survey or the effects

of lifting, installing, and loading the tanks. The deadwood calculation error

is expected to be within +0.04% for the largest tank and within + 0.06% for the

smallest. We have no good estimate of the bottom survey error. We have no indication of any distortion due to hydrostatic loading or to moving the tanks,

and no estimate of how much volume change could have occurred without being

detected by the techniques used in this study.

16
6. References

[1] Jackson, R.H.F., R.S. Collier, S. Haber, R.V. Tryon, et al . 1979. Custody

Transfer Systems for LNG Ships: Tank Survey Techniques and Sounding

Tables. NBSIR 79-1751

[2] Brown, D.C., 1958. A Solution to the General Problem of Multiple Station

Analytical Stereoangulation. Air Force Missile Test Center Report No.

58-8, Patrick AFB, Florida

[3] Kenefick, J.F., 1971. Ultra-Precise Analytics. Photograrametric

Engineering Vol . 37, p. 1167.

[4] The members of the LNG Custody Transfer Measurements Supervisory

Committee are Ivan W. Schmitt, Chairman, El Paso Marine Company; Bland

Osborn, Columbia LNG Corporation; Howard S. Joiner, Consolidated Systems

LNG Company; and Ed Crenshaw, Southern Energy Company

[5] Hocken, R.J. and Haight, W.C., 1978; "Multiple Redundancy in the

Measurement of Large Structures", Annals of the International Institution

of Production Engineering Research (CIRP), Volume 27, p. 1.

[6] Brown, D.C., Application of Close-Range Photogramme try to Structures in

Orbit, Vol. 1 and 2, GSI Technical Report # 2 0—0 12. Available from

Geodetic Services incorporated, 1511 South River View Drive, Melbourne,

Florida 32901.

[7] Mann, D. B., Editor, 1977. LNG Materials and Fluids . Thermophysical

Properties Division, National Bureau of Standards, Boulder, Colorado.

17

Appendix A

Accuracy and Precision of the

Photogrammetric Dimensioning of

Freestanding Prismatic Cargo Tanks

By

J. F. LaBrecque, C. L. Carroll, and J. D. Siegwarth
Contents for Appendix A

Page

1. Test Method A-l

2. Tape Installation A-2

3. Tape Calibration A-3

4. Results of the Photogrammetric Calibration Tests A-5

4.1 El Paso Savannah Tape Results A-5

4.2 El Paso Cove Point Tape Results A-16

4.2a Tape Descriptions and Locations A-16

4.2b Method of Analyzing Tape Data A-22

4.2c Results of Analysis A-23

4.3 El Paso Columbia Tape Results A-29

4.3a Tape Descriptions and Locations A-29

4.3b Method of Analyzing Tape Data A-32

4.3c Results of Analysis A-33

5. Tape Data Summary and Comments A-41

6. References A-44
Accuracy and Precision of the Photogrammetric Dimensioning

of Freestanding Prismatic Cargo Tanks

J. F. LaBrecque, C. L. Carroll and J. D. Siegwarth

1. Test Method

Since the resolution of the photogrammetric survey method can be as high as

1 part in 100,000, even for large objects, confirmation of the accuracy of the

method is difficult. The most straightforward method is to measure the spacing

between pairs of reference targets with sufficient accuracy so that the measured

distances and the distances calculated from the photogrammetrically determined

target coordinates can be compared. The first test by NBS of the

photogrammetric method was done during the survey of a 36-1/2 meter diameter

spherical tank.

Because of the high accuracy required in the spherical tank calibration,

measuring the distance between pairs of the photogrammetric targets on the tank

walls was not sufficient. Accurate taping was precluded because of the curved

walls. Even if some tank wall target spacings could be accurately measured,

wall temperature changes and gradients would probably alter the distances a measurable amount between the taping and the photography.

To provide some measured target spacings for the spherical tanks, reference

targets of similar optical quality to the photogrammetric targets were placed on each end of a number of approximately 4 m long aluminum rods. These rods

attached to the tank wall by suction cups were placed at various locations on

the accessible, i.e. the lower, portion of the tank wall. These lengths were made as long as they could be and still be handled and transported. The only

place greater reference target spacings were possible was tapes with targets

hung along the central tower. The tower locations, however, were already

occupied by the photogrammetrists calibration tapes. The comparison of the NBS

measured and the photogrammetrically measured target spacings on the calibration

rods gave values for the random uncertainty in reasonable agreement with the

uncertainty predicted by the photogrammetrist • Unfortunately, these test rods

give only limited information on bias errors, since to test the resolution, the

separation of the NBS reference targets should be as large as the major

dimensions of the tank.

A-l
The rectangular geometry of the free standing prismatic tanks made reference

target spacings approaching the tank dimensions realizable. Surveyor’s tapes

could be hung parallel to the vertical sides and ends of the tank and aligned

horizontal tapes could be supported along the straight sides. Since the

calibrations of all fifteen tanks were tested, a much larger amount of length

data was obtainable with no great increase in hardware over that used in the

spherical tank test.

These tapes became the NBS length standards by clamping targets, again

having properties similar to those used by the photogrammetrist , directly to

them. The position of a target edge was referenced to the scribe mark, either

by scribing the tape at the reference edge of the target for new positions or by measuring to 0.1 mm with a metric scale the location of the target placed

within a few centimeters of an existing scribe line. The distance from the

reference edge of the target to the target center was measured in the

laboratory. This distance was around 3.2 or 4.5 cm depending on type of

target

.

Since the photography on these tanks was to be done in the open air under

varying weather conditions, we chose iron-36% nickel alloy tapes to minimize

thermal effects. The thermal expansion coefficient of this material is assumed

to be 0.4 x 10“6 cm/cm°C [1] and since the maximum difference between the

temperature of the photography and the tape calibration at NBS is about 7°C, the

maximum temperature correction never exceeded 3 ppm. These tapes are unruled

making it impossible to determine target separations by examining the tape.

2. Tape Installation

Sufficient time elapsed between tanks, and a sufficient number of tank

calibrations were tested, to allow comparison of results and modifications to

the techniques as the work progressed. The vertical tapes were hung from the

top of the tank, allowed to slide through aluminum foil guides at the bottom of

the tank and tensioned by 5 kg weights hung on the bottom end. We found on the

first tank that the targets, consisting of a 19 mm diameter white spot on an

87 mm square black aluminum plate, could only be placed near the top and bottom

ends because of the frequent wind in the area. The tapes were immune to all but

the strongest winds with targets only at the ends. The tapes were pulled up

from the bottom on the first two tanks but lowered from the top on all

subsequent tanks. No other changes in the vertical tape installation were effected over the course of the work.

A2
On the first four tanks, a horizontal tape was placed near ground level in a catenary suspension between two roller supports with one end fixed and the other

tensioned by a 10 kg weight attached to the tape end via a string through a pulley. One target was placed on each short horizontal section between the end

of the tape and support roller. This tape was discontinued because wind and

moisture were probably affecting the target spacing. Horizontal tapes were

placed on most of the subsequent tanks by supporting the tapes on aligned

brackets with about 3 m separations. The brackets were first aligned by visual

sighting, then later by laser beam. At first, the tapes were placed on edge

with the vertical tape targets clamped on. The targets had to be placed near

support brackets. The tape was free to slide over the supports but fixed at one

end and tensioned by a 5 kg weight attached to the other via a string and

pulley. Later, the tapes were laid flat with 19 mm diameter white balls

attached to black anodized aluminum plates clamped to the tape. These balls

present a circular cross section from any angle above the plane of the tape. On

a few of the later tanks, horizontal tapes were passed under the tank, supported

at 3 m intervals, with ball targets at each end. These tape installations

differed from the other tapes in that no one photographic plate contained images

of targets on more than one end of the tape. These were time consuming to apply

and often construction work on the tank prevented their installation.

The positions of the targets relative to the scribe marks on the tape were measured before and again after photography. Only in two instances had the

target moved. In those cases the clamp screws were loosened by the wind

rattling the target against the tank wall.

During the photography, the air temperature was monitored to determine tape

temperature.

3. Tape Calibration

The tape calibration consisted of measuring the separations between the

scribe marks on the tapes. The tapes were sent to NBS at Gaithersburg,

Maryland, for calibration. All distances between the scribe lines were determined at 20 degrees Celsius on a horizontal flat surface with 5 and 10

kilograms tension applied. An interferometric laser system was used with the

measuring leg of the interferometer designed and built by NBS. It consists of a

three wheel dolly carrying a corner cube for the laser and a 10 power micrometer

microscope for viewing the scribe lines. The dolly travels over the tapes on a

61 m bench that slightly sags between its 1.22 m points of support, but

A-3
straight and flat enough for the laser beam. A spirit level and adjustable

support for the dolly's third wheel corrects the plumb of the microscope. Ten

vial scale divisions produces 0.0076 millimeter change in length. The level

vial is so sensitive that any on-scale reading of the vial is acceptable. But

if the level is not adjusted for on-scale reading, as much as 0.1 millimeter

error has been noted.

The pooled standard deviation of the difference between repeated

measurements of the scribe mark spacings was 0.0129 millimeters with 28 degrees

of freedom. The maximum difference being 0.042 millimeters.

From the lengths determined for the two tensions applied during the tape

calibration at NBS, the tape lengths at Mobile were computed. The effective

tension of a tape hanging vertically is one-half the weight of the tape ribbon

of the desired interval, plus the weight of all objects that hung below the

interval. The tapes weigh 0.027 kg/m, the targets weigh 0.071 kg, and the

eye-bolts and attachments weigh 0.040 kg.

Adding up the weights, the effective tension is about 5.5 kg, and a 1/2

kg change for the tapes produces about 0.05 mm change in length. The

uncertainty of the calibration of the tapes is about 0.03 mm, and using these

tapes at Mobile the uncertainty in the distance between targets should be less

than 0.3 mm which includes the error of positioning the targets. The

calibration report and data has been included at the end of this Appendix.

A-4
4. Results of the Photogrammetric Calibration Tests

The tape results were analyzed and reported as each ship set was completed.

These results are presented in this section in the same way.

4.1 El Paso Savannah Tape Results

a. Tape Descriptions and Locations

Each calibration tape used on the Savannah tanks had two or three

reference targets attached. The positions of these reference targets, as determined by the survey, are contained in the coordinate data supplied

to NBS by the photogrammetrist . Three targets on a tape represent three

distances, but only two distances can be considered independent. The

largest and smallest of the three distances are used. If targets 1 and 2 on a tape had photogrammetric coordinates (x]_, y^, zi) and (X2 ,

y 2 , Z 2 ), then the distances between them as determined from the

coordinate data, assuming an orthogonal coordinate system, is

d 12 “ 1 " x 2> 2 + (7 1 “ y 2> 2 + < z

1 ~ z 2> 1,2

'

The temperature of the air near some of the calibration tapes was measured

during the course of the photography and the target separations in table I are determined at the average of these temperatures. The values d^g are the

reference target spacings determined by NBS. The target separations determined

by the photogrammetric survey, dp, appear in the next to the last column of

table I. The invar calibration tapes are labeled If 1 through if 5 in table I.

The targets are in the same positions for tanks 3 and 4 for all but tape

#3, but have been moved for tank 5. For tanks 3 and 4, tape if 1 was

placed vertically on the bow end and tapes if 2 and if 4 were placed

vertically on the stern. Tape If 3 was placed vertically on the port side

of tank 3 and the starboard side of tank 4. These tapes were all hung

about 5 meters from the corners of the tanks. Tape if 5, installed

horizontally along the length of the tanks, hung in a catenary between

two pulleys about 30 meters apart. Because wind was stirring this tape

during the survey, this measurement may be less accurate than the

vertical tape measurements.

For the photogrammetric survey of tank 5, tape #1 was installed

horizontally across the stern end and supported at intervals so that no

sag correction was needed. Tapes if3, #4, and 05 were positioned as on

tank 4, and tape if

2

was hung on the bow end.

A-5
TABLE I. Comparison of NBS Determined Target Spacings and Photogrammetrically

Measured Target Spacings on the Tanks of the El Paso Savannah.

Tape # and Location NBS Photogramme trie d - d (mm)

Length (m) Length (m)

NBS P

Tank #3 Temperature

,

21.3°C 11-8-77

1 For. Vert. 1.7127

20.6311

2 Aft Vert. 1.2626 1.2625 -0.1

21.0533 21.0535 +0.2

3 Port Vert. 16.6249 16.6247 -0.2

4 Aft Vert. 2.6416 2.6416 0

20.8542 20.8548 +0.6

5 Port Horiz. 31.9933

Tank #4 Temperature

,

17 . 8 °C 11-7-77

1 For. Vert. 1.7127 1.7135 +0.8

20.6311 20.6303 -0.8

2 Aft Vert. 1.2626 1.2629 +0.3

21.0533 21.0514 -1.9

3 Stbd. Vert. 16.5769 16.5764 -0.5

4 Aft Vert

.

2.6416 2.6424 40.8

20.8542

5 Stbd. Horiz. 31.9932 31.9909 -2.3

Tank #5 Temperature

,

12.0°C 1-5-78

1 Aft Horiz. 20.6309 20.6278 -3.1

2 For. Vert. 1.2684 1.2678 -0.6

20.5906 20.5893 -1.3

3 Aft Vert. 16.6249 16.6233 -1.5

4 Aft Vert. 2.6307 2.6310 40.3

20.1892 20.1867 -2.5

5 Stbd. Horiz. 23.1234 23.1224 -1.0

Tank #2 Temperature

,

21.0°C 4-6-78

1 For. Vert. 20.6311 20.6266 -4.5

0.4453 0.4455 +0.2

2 Aft Vert. 21.0533 21.0485 -4.8

0.4681 0.4680 -0.1

3 Stbd. Vert. 16.5770 16.5742 -2.8

4 Aft Vert. 20.8545 20.8500 -4.5

0.6656 0.6655 -0.1

5 Stbd. Horiz 31.9933

A6
TABLE I (Continued)

Tape # and Location NBS Photogramme trie d-d

P NBS

Length (m) Length (m)

d

NBS

d

P

Tank #1 Temperature , 19.1°C 4-22-78

1 For . Vert

.

1.7507 1.7504 -0.3

18.8578 18.8538 -4.0

2 Aft Vert

.

1.3070 1.3070 0

20.6193 20.6174 -1.9

3 Stbd. Vert. 15.9697 15.9678 -1.9

4 Aft Horiz. 2.6045 2.6047 -0.2

20.8172 20.8148 -2.4

A7

(mm)
Figure

1.

Deviation

6

of

photogrammetrically

determined

test

tape

lengths

from

NBS

determined

lengths,

djqgg

,

versus

djqgg

for

Tank

3

of

the
I I I

mm ‘^® N p-

£l p = 9

A9

Figure

2.

Deviation

6

of

photogrammetr

ically

determined

test

tape

length

from

NBS

determined

lengths

d

NB

c;

versus

d

NBg

for

Tank

4

of

the

Savannah.
E

u~) CO D

Ullil ‘ S 8 Wj

A-10

Figure

3.

Deviation

6

of

photogrammetrically

determined

test

tape

lengths

from

NBS

determined

lengths,

d

NBg

versus

d

NBg

for

Tank

A

of

the
A-ll

Figure

4.

Deviation

6

of

photogrammetrically

determined

test

tape

lengths

from

NBS

determined

lengths,

d

NBS

,

versus

d

NBS

for

tank

2

of

th
A-12

Figure

5.

Deviation

6

of

photogrammetrically

determined

test

tape

lengths

from

NBS

determined

lengths,

d^S

,

versus

djjgg

for

Tank

1

of

the
On tank 2, tape #2 and #4 were placed on the aft end of the tank

with tape #4 near the port and #2 near the starboard corner. Tape #3 was placed near the forward corner on the starboard side and #1 was placed near the port corner of the forward end of the tank. Tape #5 was placed

along the starboard side.

On tank 1, the placements were: tape #3 near the aft corner of the

starboard side, tape #2 on the aft end near the port corner, tape #1 on

the forward end near the starboard corner and tape ItU horizontally across

the aft end of the tank. Tape #5 was not placed on the tank since the

tank lifting brackets were still attached and in the way.

b. Method of Analyzing Tape Data and Results

The data in Table I for each tank were fit by the equation:

where 6" d - d^^, c represents a constant error in all values

of 6, and s represents a scaling error. The above equation was fit by

least squares for each tank and the results are shown in figures 1 through 5. A non-zero value for c means the targets used as the

reference are offset. Tank 4 shows a value of c of 0.8 mm which is

statistically significant at the 1% level. The values of c on the other

four tanks are not statistically different from zero.

The first column of table II gives the observed values of s with a 95% confidence interval for each of the five tanks. The second column

gives the estimated standard deviation of 8 for each tank.

In the last column of table II, volume bias with 95% confidence

intervals are given for the percentage error in the tank volume because

of the scale error. The largest of these is the 0.06% underestimate on tank 2.

Since no intermediate target spacings were checked by tapes, it must

be assumed that s does represent a scale error. Only tank 3 shows a value for s small enough to be statistically insignificant. All the

observed values of s for the remaining tanks are negative, and all are comparable in magnitude except for tank 2 which has an observed value of

s about twice the magnitude of the others. The photogrammetric

consultant uses six 15 1/4 meter lengths to determine the scale factor

for each tank survey. If we assume that the standard deviation for the

A-13
Table II

Tank

s value

with

95% C.I .*

Standard deviation

for

length measurements d.f

.

Volume Bias

with

95% C.I.

1 -13.4 + 3.2 (10~ 5

) 0.72 mm 6 -0.04% + 0.01%

2 -21.1 + 3.1 (io~ 5

) 0.36 mm 6 -0.06% + 0.01%

3 1.1 + 3.6 (io

-5

) 0.28 mm 4 0.00% + 0.01%

4 -9.8 + 3.6 (10"5

) 0.43 mm 5 -0.03% + 0.01%

5 -9.2 + 2.7 (10

-5

) 0.82 mm 6 -0.03% + 0.01%

confidence intervals based on overall observed standard deviations of 0.58 mm

with 27 degrees of freedom.

A- 14
measurement of such lengths to be 1 mm—which is conservative based on our information from the photogrammetric consultant —the standard

deviation for the scale factor would be 2.7 x 10

~ 5 . For 99% of the

time, we should then expect values of s in the interval + 6.9 x 10“^.

The values observed for s for tanks 1, 2, 4, and 5 fall outside this

interval

.

NBS estimates a standard deviation for the tape lengths of 0.3 mm. This includes all errors of laboratory length measurement, catenary

correction, temperature correction, and errors in positioning the targets

with respect to the tape markings. The photogrammetric consultant gives

standard deviations for these lengths from 0.4 mm to 0.8 mm. The

combined overall standard deviation from all tanks has a value of 0.58 mm

(27 degrees of freedom) which is in good agreement with these values.

A-15
4.2 El Paso Cove Point Tape Results

4.2a Tape Descriptions and Locations

Each calibration tape used on the Cove Point tanks had two or more

targets attached. The positions of these targets, as determined by the

survey, are contained in the coordinate data supplied to NBS by the

photogrammetrist . The n targets on a tape represent only n-1 independent

distances. An end target on a tape was chosen as target 1 and the

distances to the other targets were determined from this target. If

targets 1 and i on a tape had photogrammetric coordinates (x^, y^,

z ]_ ) and (x^, y^, zj), then the distances between them as determined from the coordinate data, assuming an orthogonal coordinate

system, is

d i " {(*i xi> 2 + (yi yi > 2 + < 2

i " z i>

2

}

The temperature of the air near 6ome of the calibration tapes was measured during the course of the photography and the target separations

in table II are determined at the temperature of the photogrammetric

survey. The values d^g are the target spaclngs determined by NBS.

The target separations determined by the photogrammetric survey, dp,

appear in the next to the last column of table II.

The invar calibration tapes are labeled #1 through #8 in table II. On

tank 3, the vertical tapes #1, #2, and #3 were placed near the port corner of the forward end of the tank, near the port corner of the aft

end of the tank and on the starboard side near the forward end of the

tank respectively. Tape If 4 with six targets was placed on edge

horizontally across the forward end of the tank and supported at 3 m

intervals on aligned brackets. Tape #5 was similarly mounted along the

port side again with six targets. Tape #7 was mounted crosswise under

the tank with two ball targets on each end. The tape was laid flat on aligned wire hangers placed at 3 m intervals. Tape Nos. 6 and 8 were

similarly mounted but ran diagonally under the tank. Tape #8 extended

from the after starboard corner to the forward port corner. The targets

on one end of tape #6 which laid on the opposite diagonal was obscured by

something and no photogrammetric length was obtained.

A-16
On tank 4, the vertical tapes #1, #2 and #3 were placed on the

forward end of the tank near the port corner, aft near the port corner,

and on the starboard side near the forward corner respectively. Tape #4 was placed horizontally on the forward end with five targets and #5 was placed horizontally on the starboard side with seven targets. The

mounting and support methods were the same as for these tapes on tank 3.

Tapes #2 and #3 were placed at the same locations on tank 5 as on tank 4. Tape #1 was placed on the forward end of the tank near the

starboard corner. Tapes #4 and #5 were placed in the same positions as on tank 4 with six targets each. Tapes #6 and #8 were installed

diagonally underneath the tank with the forward ends near the centerline

of the tank and the after ends near the starboard and port corners respectively. Two ball targets were attached at each end. The

horizontal tape Installations were the same as those for tanks 3 and 4

but the supports were aligned for the first time by means of laser beam.

Tape #7 was installed horizontally along the port side of the tanks and

mounted with five ball targets. This tape was, for the first time,

installed flat rather than on edge and ball targets were used because

this tape was located on the side adjourning tank 4.

For the photography on tank 2, tape #1 was mounted horizontally on

the forward end of the tank. This tape was mounted flat with some new

3/4" diameter ball targets on 2.5 by 6.4 mm plates. Again, the supports

were aligned by a laser beam. Tapes #2, #3, and #4 were placed

vertically toward the starboard side of the forward end, on the port side

toward the aft end of the tanks and on the aft end near the port corner respectively.

On tank 1, tapes #1, #2, and #3 were placed vertically on the aft of

the tank toward the port corner, on the forward end of the tank near the

starboard quarter, and on the port side of the tank toward the aft end

respectively. No other tapes were Installed.

The number of tapes installed and the positions they are placed is

dictated not only by the information desired, but also by the location of

the tanks, the tank construction work underway at the time, and the

installation time available.

A-17
The difference in the NBS determined and the photogrammetrically

determined target spacings shown in Table III were generally less than 2 mm with a few exceptions. The exceptions involve one target on each of

two tapes and perhaps tape #5 on tank 4 completely. The single target

position errors on tape #1 of tank 4 and tape #7 of tank 5 cannot be

attributed definitely to either the photogrammetric length determination

or the NBS length determination; though, in the case of the tape #1

target position error, the photogrammetric uncertainty in the vertical

direction given by the photogrammetrist is twice that of the other

targets on vertical tapes suggesting the possibility that the error is in

the photogrammetry. For tape #7, no such clue exists. These two data were not used in the analysis. Tape #5 on tank 4 (see Table III) shows

length errors that increase with length to 6 mm for the longest length

indicating a scale factor error. Such an error is not indicated by any

other tape on that tank, however. If the tape was under tensioned, this

result could be obtained. Though the 5 kg tensioning weight does not

elongate the tape more than about 3 mm for the entire length, sag between

supports could account for the additional decrease in the

photogrammetrically determined length as the weight is decreased below

5 kg. The weight was placed on the tape, but if the tape hung up on something on the weight end thus reducing the tape tension, the tape may

not have been stretched the amount assumed in the NBS length

determination. Laboratory tests showed that the required tape sag to

account for the observed shortening is slight enough that it could have

gone unnoticed during the photography. Since this apparent scale factor error showed up in only one of the 11 horizontal tapes used on these five

tanks, a slacked tape seems the more likely cause of error rather than a horizontal scale error in the photogrammetry on one side of the tank.

Two of the diagonal tapes beneath the tank, tape #8 on tank 3 and

tape #6 on tank 5, showed errors of nearly 1 cm and 9 cm respectively in

the original photogrammetric target coordinate data. The four targets,

two on each end of the tape, should lie on a straight line. An

examination of the coordinate data of both tapes showed that one target

location on one end of each tape was well off a line through the

remaining three targets. An examination of the detailed photogrammetric

data showed that in both cases, the location of the target was determined

A-18
TABLE III. Comparison of NBS Determined Target Spacings and Photogrammetr ical ly

Measured Target Spacings on the Tanks of the El Paso Cove Point.

Tape # and Location NBS Photogrammetric dp ^ XTT> C Length (m) Length (m)

Dob

d d

NBS P

Tank #3 Temperature, 26.8°C 8-17-78

1 For. Vert. 1.7188 1.7182 -0.6

20.5985 20.5969 -1.6

2 Aft Vert. 1.2673 1.2674 +0.1

20.5812 20.5801 -1.1

3 Port Vert. 0.5826 Target center out

16.0113 16.0105 -0.8

4 For. Horiz. 2.6679 Target obscured

13.0921 13.0906 -1.5

16.0220 16.0210 -1.0

20.2112 20.2095 -1.7

20.8869 20.8851 -1.7

5 Port Horiz. 5.9795 5.9798 +0.3

Target not recorded 7.0734

12.0630 12.0626 -0.4

19.7401 19.7388 -1.3

Target not recorded 20.4795

25.7966 25.7953 -1.3

31.9756 31.9736 -2.0

6 Diag. Horiz. .3278 Target obscured

38.9965

" " 39.1896 " "

7 Trans. Horiz. 0.1989 0.1985 -0.4

30.1526 30.1493 -3.3

30.4457 30.4428 -2.9

8 Diag. Horiz. 0.1690 0.1690 0

39.6625 39.6599 -2.6

39.8910 39.8887 -2.3

Tank #4 Temperature, 26°C 9-15-78

1 For. Vert. 1.7256 1.7252 -0.4

20.6195 20.6144 -5.1

2 Aft Vert. 1.2304 1.2301 -0.3

20.9810 20.9808 -0.2

3 Stbd. Vert. 0.5672 0.5673 +0.1

16.6537 16.6532 -0.5

4 For. Horiz. 2.6532 2.6537 +0.5

13.0551 13.0562 +1.1

15.9874 15.9890 +1.6

20.8413 20.8430 +1.7

5 Stbd. Horiz. 6.0658 6.0645 -1.3

7.0668 7.0650 -1.8

12.1546 12.1521 -2.5

19.7142 19.7108 -3.4

25.7845 25.7800 -4.5

32.0028 31.9968 -6.0

A- 19
TABLE III (continued)

Tape if and Location NBS

Length (m)

d

NBS

Tank if5 Temperature

1 For. Vert. 1.7407

20.1578

2 Aft Vert. 1.3327

21.1277

3 Stbd. Vert. 0.5746

16.6067

4 For. Horiz. 2.6450

13.0582

15.9717

20.1938

20.8499

5 Stbd. Horiz. 5.9948

7.0890

12.0673

19.7514

23.0463

6 Diag. Horiz. 0.3263

29.2902

29.6015

7 Port Horiz. 6.0835

12.0287

21.2385

24.1893

8 Diag. Horiz. 0.1652

29.5943

29.8706

Tank if 2 Temperature

1 For. Horiz. 1.7128

8.9399

14.0045

20.1844

20.6216

2 For. Vert. 1.2420

20.5848

21.0513

3 Port Vert. 0.5550

16.5642

4 Aft Vert. 0.6678

20.8501

Photogrammetric d

p - dNB g(mm) Length (m)

10-12-78

1.7410 +0.3

20.1580 +0.2

1.3331 +0.4

21.1271 -0.6

0.5747 +0.1

16.6077 +1.0

2.6449 -0.1

13.0581 -0.1

15.9714 -0.3

20.1933 -0.5

20.8498 -0.1

5.9949 +0.1

7.0894 +0.4

12.0679 +0.6

19.7523 +0.9

23.0469 +0.6

0.3264 +0.1

29.2919 +1.7

29.6033 +1.9

6.0836 +0.1

12.0192 -9.5

21.2358 -2.8

24.1913 +2.0

0.1652 0

29.5933 -1.0

29.8719 +1.3

C 11-20-79

1.7139 +1.1

8.9405 +0.6

14.0052 +0.7

20.1844 0

20.6222 +0.6

1.2424 +0.4

20.5849 +0.1

21.0517 +0.4

0.5547 -0.3

16.5645 +0.3

0.6674 -0.4

20.8516 +1.5

A-20
TABLE III (continued)

Tape # and Location NBS Photogramme trie d

P

" d

NBS Length (m) Length (m)

dNBS d

P

Tank #1 Temperature , 18.7°C 11-21-79

1 Aft Vert

.

1.7224 1.7223 -0.1

20.1815 20.1819 +0.4

20.6383 20.6389 +0.6

2 For

.

Vert

.

1.2825 1.2823 -0.2

20.5991 20.5982 -0.9

21.0468 21.0463 -0.5

3 Port Vert

.

0.5545 0.5548 +0.3

16.7708 16.7720 +1.2

(mm)

A-21
by the intersection of only two rays. This fact, coupled with the difficulty of

positively identifying the targets on the photographs placed in these locations,

suggested that the targets had been incorrectly identified on one plate and the

other two intersections of the four rays (from the two plates to the two targets)

might be the actual target positions. We used the appropriate camera and

coordinate positions to derive the coordinates of the other two intersections for

both tapes, and found in terms of both length and alignment, these intersections were the true target positions.

Of the 27 tapes and well over 100 targets used in the analysis of

these five tanks, the only length disagreements between the NBS and photogrammetric length determinations of any consequence occurred on one tape and two

other targets. Since an erroneous measurement, especially when only a few occur,

is of much less significance than a correct measurement, the evidence that the

photogrammetric method accurately determines the target coordinates is

overwhelming

.

4.2b Method of Analyzing Tape Data

The photogrammetrically determined ith length from the jth tape on a particular tank is assumed to be related to the corresponding NBS length

in the following way:

ij ki +

*tj ( 2 )

where a is a constant which ideally would be 1, and have been

substituted for the symbols (d

p ) and (d ). , respectively, and «. is a

r NBo lj lj

random error associated with the photogrammetric technique. However, because

any error in the position of target 1 is part of the for all the i^j,

it may appear as a significant offset and hence affect the estimate for a. To

avoid this, equation 2 was modified to the following relationship and fitted

to the l± y.

?' -L-c+s. (L. - L J.) + (3) ij i J 'ij

where /j is the average of the /jj for the jth tape. For this relationship

s (”a-l) would ideally be 0, as would the value for c(=sjj). In this form the

estimate for s is unaffacted by the error in the position of target 1.

The information derived from the /jj data are: an estimated value for

s, an estimate of how this s value would affect the volume and an estimated value

for the standard deviation (std. dev.) of the A.j.

A-22
are

4.2c Results of Analysis

Table IV gives this derived information for the vertically suspended

targeted tapes by tank. Ninety-five percent confidence intervals (C.I.)

given for the s values and volume biases. The column headed d.f. (degrees of

freedom) give the relative information available for estimating the std. dev.;

the larger the d.f., the better the estimate. Only tank 3 shows a value of s that is judged to be different from zero. The 95% C.I. for the volume bias

resulting from this s value is taken to be -0.017% + 0.012%. Figure 6 is a plot of versus - ij for all the tapes of tank 3. The point

symbols are numbers giving the tape from which was derived. This plot

clearly indicates a value for s different from zero. The set of points for

each of the three vertically suspended and four horizontally supported tapes

(tape /6 targets were obscured) used for tank 3 each show a slightly different

value of s. Table V gives the results for each of the horizontally supported tapes.

Each of these tapes are analyzed separately because they usually have more than

four targets and have more problems to consider. Of the horizontal tapes of

tank 3, only tape #5 shows a value for s significantly different from zero, but

taken as an ensemble (see table VI), the case is clear.

As mentioned in the previous section, tape #5 on tank 4 gives data that are suspect and will not be considered in this analysis. The tape #5 data show

a large value for s, but tape #3 hung on the same side shows no scale error

(value of s not different from zero). However, tape it 4 also shows a scale

error, but of different sign from that of tape #5. Unfortunately, the vertical

tape #1 hung on the same side as tape it 4 and could not be used to shed any

additional information on a non-zero value for s. Tape #4 Is on the forward

end of the tank and there are no tapes on the port side. Since the tapes on

the other two sides show no scale error, it is assumed that half the tank has a

scale error and other half does not. A 95% C.I. for the volume bias due to the

scale error is taken to be 0.010% + 0.007%.

As also discussed in the previous section, one of the values on tape #7 of tank 5 is judged to be in error and not included in the analysis.

The results for the remaining three contain a large estimated std. dev.

considered to be atypical. The tape was on the side adjacent to another tank.

This higher uncertainty is expected since the camera positions are definitel>

A-23
A-24

Figure

6.

Deviation

of

the

photogrammetrically

determined

test

tape

length

from

the

NBS

determined

length

versus

NBS

length

less

the

NBS

average

length,

-

for

all

tapes

used

on

Tank

3

of

the

Cove

Point.

The

symbols

refer

to

tape

numbers

given

in

Table

III.
Table IV. Results From tne Analyses of the Photogrammetrically Measured

Target Spacings of the Vertically Hung Tapes on the Cove Point Tanks

s value with Std. dev. for Volume Bias with

Tank 95% C.I. length measurements d.f

.

95% C.I.

-5

1 1.4 + 5.0 (10 ) 0.63 mm 8 0.004 + 0.015%

-5

2 3.8 + 4.1 (10 ) 0.65 mm 7 0.011 + 0.012%

3 -5.8 + 4.1 (10

-5

) 0.34 mm 3 -0.017 + 0.012%

4 -1.2 + 2.9 (10“ 5

) 0.33 mm 3 -0.004 + 0.009%

5 -0.7 + 5.0 (10“ 5

) 0.53 mm 5 -0.002 + 0.015%

Combined 0.55 mm 28

A-25
Table

Tank

2

3

3

3

3

4

4

5

5

5

5

5

V. Results From Analyses of the Photogrammetrically Measured Target

Spacings for Each of the Horizontally Supported Tapes of the Cove

Point Tanks.

s value with Std. dev. for

Tape 95% C.I. length measurements

Volume Bias with

d.f. 95% C.I.

1 -3.9 + 5.6 (10~ 5

) 0.40

4 -5.7 + 24. (10“ 5

) 0.50

5 -8.4 + 3.5 (10

-5

) 0.32

7 -9.0 + 16. (10~ 5

) 0.43

8 -6.2 + 8.7 (10~ 5

) 0.31

4 7.0 + 5.1 (10~ 5

) 0.22

5 -16.7 + 3.0 (10

-5

) 0.35

4 -1.2 + 3.9 (10~ 5

) 0.25

5 3.0 + 3.9 (10~ 5

) 0.42

6 5.7 + 3.1 (10~ 5

) 0.08

7 2.81

8 0.56 + 6.7 (10“5

) 0.95

mm 3 0.011 + 0.017%

mm 3 -0.017 + 0.072%

mm 3 -0.025 + 0.010%

mm 1 -0.027 + 0.047%

mm 1 -0.017 + 0.026%

mm 2 0.021 + 0.015%

mm 4 -0.050 + 0.009%

mm 4 -0.004 + 0.012%

mm 4 0.009 + 0.012%

mm 1 0.017 + 0.009%

mm 3 —

mm 3 0.002 + 0.02%

A-26
Table VI. Results From Analyses of the Photogrammetrically Measured Target

Spacings for the Vertical and Horizontal Tapes of Each of the Cove

Point Tanks.

s value with Std. dev. for Volume Bias with

Tank Tape 95% C.I . length measurements d.f

.

95% C.I .

1 All 1.4 + 5.0 do"5

) 0.63 mm 8 0.004 + 0.015%

2 All 1.5 + 3.0 (io“

5

) 0.58 mm 11 0.004 + 0.009%

3 All -7.2 + 1.8 (10~ 5

) 0.59 mm 18 -0.022 + 0.005%

4 1,2,3 -1.2 + 2.9 (10“ 5

) 0.33 mm 3 -0.004 + 0.009%

4 4 7.0 ±

5 ' 1 (10' 5

) 0.22 mm 2 -0.021 + 0.015%

5 1,2,3 1.7 + 2.4 (10

-5

) 0.73 mm 20 0.005 + 0.007%

4,5,6

8

Combined 0.65 mm 57
not optimum because of the narrow gap between the tanks in the storage area.

The camera positions are close to the extended plane of the tank wall which is

required to obtain a view of the full tank wall and dictates that the

photogrammetrist must use ball targets. This camera positioning reduces the

resolution of the target positions in the horizontal component parallel to the

tank wall, but not the other two components. The increased uncertainty in

target positions in this direction contributes negligibly to the tank volume

uncertainty. The data for tape #7 are excluded from further analysis of tank

5.

Table VI is a summary combining the results for the vertical and

horizontal tapes for each tank. Tank 4 is a special case and has been given

two lines in the table. The combined std. dev. is based on all the tanks

except 4, and will be the value used to represent the random error of the

photogrammetric technique in this set of tanks.

The photogrammetric consultant uses six 15 1/4 meter lengths to determine

the scale factor for each tank survey. If we assume that the standard

deviation for the measurement of such lengths to be 1 mm, which is conservative

based on our information from the photogrammetric consultant, the standard

deviation for the scale factor would be 2.7 x 10“^. For 99% of the time, we should then expect values of s in the interval + 6.9 x 10

“ 5 . The values

observed for s for tank 3 falls outside this interval.

NBS estimates a standard deviation for the tape lengths of 0.3 mm. This

includes all errors of laboratory length measurement, catenary correction,

temperature correction, and errors in positioning the targets with respect to

the tape markings. The photogrammetric consultant gives standard deviations

for these lengths from 0.4 mm to 0.8 mm. The combined overall standard

deviation for the length measurements from all tanks has a value of 0.65 mm (57

degrees of freedom) which is in good agreement with these values.

A-28
4.3 El Paso Columbia Tape Results

4.3a. Tape Descriptions and Locations

Each calibration tape used on the Columbia tanks had two or more targets

attached. The positions of these targets, as determined by the survey, are contained in the coordinate data supplied to NBS by the photogrammetrist

.

The n targets on a tape represent only n-1 independent distances. One target

on a tape was chosen as target 1 and the distances to the other targets were determined from this target. If targets 1 and i on a tape had

photogrammetric coordinates (x]_, y]_, z^) and (x^, y^ , z^), then

the distances between them as determined from the coordinate data, assuming

an orthogonal coordinate system, is given by equation (1).

The temperature of the air near some of the calibration tapes was measured during the course of the photography and the target separations in

table VII are determined at the temperature of the photogrammetric survey.

The values dNgg are the target spacings determined by NBS. The target

separations determined by the photogrammetric survey, dp, appear in the

next to the last column of table VII.

The invar calibration tapes are labeled //I through #6 in table VII. On

tank 3, the vertical tapes #1, #2, and # 3 were placed near the starboard corner of the forward end of the tank, near the port corner of the aft end of

the tank and on the port side near the aft end of the tank respectively.

Tape II 4 with six targets was placed on edge horizontally alongs the port side

of the tank and supported at 3 m intervals on laser aligned brackets. Tape

II 5 was similarly mounted along the starboard side again with seven targets.

Tape II 6 was mounted diagonally under the tank with ball targets on each end.

The tape was laid flat on laser aligned wire hangers placed at 3 m intervals

and extended from the after port corner to the forward center. Tape II 3 fell

from the tank and was destroyed before the photography.

A-29
TABLE VII. Comparison of NBS Determined Target Spacings and Photogrammetrically

Measured Target Spacings on the Tanks of the El Paso Columbia.

Tape // and Location NBS Photogramme trie d

P

d

NBS Length (m) Length (m)

d

NBS

d

P

Tank #3 Temperature

,

16 . 2 °C 3-7-79

1 For. Vert. Target slipped 1.7293

19.3188 19.3208 2.0

2 Aft Vert. 1.3097 1.3097 0.0

21.0939 21.0957 1.8

4 Port Horiz. 2.7010 2.7018 0.8

13.0541 13.0544 0.3

16.0187 16.0200 1.3

20.2495 20.2496 0.1

20.9134 20.9133 -0.1

5 Stbd. Horiz. 5.9329 5.9331 0.2

7.0678 7.0670 -0.8

12.0095 12.0091 -0.4

20.4700 20.4686 -1.4

25.7629 25.7606 -2.3

29.2678 29.2651 -2.7

6 Diag. Horiz. 38.2304 38.2252 -5.2

Tank #4 Temperature 20. 8 °C 3-26-79

1 Aft Vert. 1.7282 1.7287 0.5

20.1726 20.1741 1.5

20.6686 20.6693 0.7

2 For. Vert. 1.2993 1.2996 0.3

2.0679 2.0680 0.1

20.0884 20.0879 -0.5

21.0865 21.0861 -0.4

5 Port. Horiz. 7.6633 7.6571 -6.2

(between tanks) 12.6909 12.6890 -1.9

13.7533 13.7541 0.8

19.8007 19.7968 -3.9

0.7533 0.7542 0.9

3.1924 3.1937 1.3

6.0586 6.0620 3.4

9.4419 9.4429 1.0

12.2814 12.2810 -0.4

A-30
TABLE VII —continued

Tank #5 Temperature, 18.5°C 3-28-79

1 For. Vert. 0.9297 0.9297 0.0

1.7593 1.7595 0.2

20.1349 20.1361 1.5

2 Aft Vert. 2.0328 2.0325 -0.3

20.1108 20.1126 1.6

21.0181 21.0200 1.9

4 For. Horiz. 2.6784 2.6791 0.7

13.0876 13.0874 -0.2

16.0188 16.0199 1.1

20.1990 20.1993 0.3

Tank #1 Temperature, 24.7°C 5-23-79

1 Aft Vert. 1.7386 1.7383 -0.3

20.1699 20.1692 -0.7

20.6586 20.6575 -1.1

2 For. Vert. 1.2819 1.2821 0.2

2.0652 2.0653 0.1

20.1041 20.1037 -0.4

21.0747 21.0741 -0.6

4 Aft Horiz. 2.6252 2.6256 0.4

13.0695 13.0693 -0.2

15.8852 15.8861 0.9

20.1759 20.1764 0.5

20.8753 20.8759 0.6

Tank #2 Temperature 26.2°C 5-24-79

1 For. Vert. 1.6832 1.6834 0.2

20.1539 20.1527 -1.2

20.6307 20.6292 -1.5

2 Aft Vert. 1.2717 1.2718 0.1

2.0356 2.0360 0.4

20.5514 20.5524 1.0

21.0639 21.0648 0.9

5 Stbd. Horiz. 6.0299 6.0298 -0.1

7.1261 7.1265 0.4

12.0906 12.0900 -0.6

19.7938 19.7942 0.4

20.4345 20.4347 0.2

23.0050 23.0047 -0.3

23.1019 23.1021 0.2

25.8528 25.8529 0.1

29.3218 29.3211 -0.7

32.0650 32.0648 -0.2

A-31
On tank 4, the vertical tapes //I and #2 were placed, respectively, on

the forward end of the tank near the starboard corner with four targets and

on the after end of the tank near the starboard corner with five targets.

Tape #5 was placed horizontally along the port side of the tank.

Tape #1 was placed on forward end of tank 5; while tape #2 was placed on

the aft end near the starboard corner. The tapes held five and four targets,

respectively. Tape #4 with five targets was placed horizontally across the

forward end.

On tank 1, tape #1 with four targets was placed near the starboard

corner on the aft end and tape #2 with five targets was placed near the

starboard corner on the forward end. Tape #4 was installed horizontally

across the aft end of the tank with six targets attached.

On tank 2 tape #1 with four targets was placed on the forward end near

the starboard corner and tape // 2 with five targets was placed near the

starboard corner on the aft end. Tape #5 with eleven targets was installed

horizontally along the starboard side.

The differences of the NBS and the photogrammetry determination of reference

target spacings is, again for this shipset , generally less than 2 mm. The

diagonal tape on tank 3, tape #6, shows a difference exceeding 5 mm and tape

#5 on tank 4 shows differences larger than 2 mm. In the case of the latter

tape, this higher uncertainty is expected since it was located again in the narrow gap between the tanks in the storage area. The extra uncertainty in

target positions in this direction contributes negligibly to the tank volume

uncertainty. Only one ball target was placed on each end of tape //6; so insufficient information exists to determine whether the difference between

the measured lengths is random or systematic. More information is available

on the calibration of tank 3 in Appendix D. This tank has been dimensioned

by a modification of the laser plane method developed by NBS for membrane

tank calibration.

4.3b Method of Analyzing Tape Data

The method used on the Columbia tanks is the same as used on the Cove

Point tanks, section 4.2b.

A-32
4.3c Results of Analysis

A 95% confidence interval is given in Table VIII for the s value of each

tape. The corresponding estimated standard deviations for length

measurements, shown in the third column, are based on the best linear fit for

that tape. The column headed "degrees of freedom" give the relative

information available for estimating the standard deviation; the larger the

degrees of freedom, the better the estimate. The data for vertical tapes //I and #2 on tank 3 were combined to give an estimate for s. There are only

three length measurements between them, and the plot of these measurements

suggest that s is approximately the same for both; the alternative would have

been to discard these data.

A test of these estimated standard deviations shows them to be

consistent with the assumption that the standard deviation for length

measurements is the same for all tapes. There was one exception to this. As

explained earlier, tape //5 on tank 4 is expected to have a larger standard

deviation because of the oblique angles at which it was photographed. The

data from this tape was not used in determining the overall, combined

estimated standard deviation of 0.37 mm (34 degrees of freedom) for length

measurements. This estimate is in good agreement with that of the

photogrammetrist , who states the standard deviations for length measurements

to be from 0.4 mm to 0.8 mm. The 95% confidence intervals in table VIII for the various s values show

evidence contrary to the assumption that each tank has a single value for s. Figures 7-11 are plots of the

j versus for tanks

1-5, respectively. These plots illustrate the variability in the values of s for the various tapes on each tank. We assume for this set of tanks that the

values for s are randomly variable from place to place on a tank. There are three estimated values for s for each tank. Each is given equal weight in

estimating the average value of s for each tank and its standard deviation.

The average value of s computed for each tank and is given in table IX

with a 95% confidence interval (C.I.). This 95% C.I. is based on pooling the

five estimates of the standard deviations of s derived from the values of s obtained for each tank. These five values, also given in the table, were judged not statistically different. The last column of table IX gives the

volume bias attributed to each of the averaged s values. None of the biases

are judged to be significant, but the variability in the estimates for s introduce an uncertainty in the tank volumes of + 0.025%.

A-33
Table VIII. Results from Analyses of the Photogrammetrically Measured

Target Spacing for the Invar Tapes on the Columbia Tanks.

Tank

1

1

1

2

2

2

3

3

3

4

4

4

5

5

5

liEL

8 value with

95% C.I.*

1 -4.5 + 2.7 (10

_5

)

2 -2.4 + 2.7 (10~5

)

4 2.7 + 2.2 (10

-5

)

1 -6.6 + 2.6 (l(f5

)

2 4.6 + 2.5 (lCf

5

)

5 -0.4 + 1.1 (10~5

)

1&2 9.9 + 4.8 (10~5

)

4 -3.8 + 5.1 (10

-5

)

5 -10.8 + 3.5 (10~5

)

1 5.4 + 2.6 (10~5

)

2 -3.4 + 4.0 (10"5

)

5 -6.6 + 2.3 (10"5

)

1 6.6 + 2.7 (10~ 5

)

2 11.6 + 5.2 (10“5

)

4 2.7 + 2.7 (10

-5

)

Std . dev. for

length measurements

0.24 mm

0.17

0.42

0.26

0.19

0.38

0.27

0.57

0.40

0.50

0.11

2.7

0.12

0.004

0.63

degrees of

freedom

1

2

2

1

2

8

1

3

5

1

2

7

3

1

2

*Confidence Intervals based on overall observed standard deviations of 0.37 mm with 34 degrees of freedom.

A-34
o

A-35

Figure

7.

Deviations

of

photogrammetrically

determined

test

tape

lengths

from

NBS

determined

lengths

versus

length

for

Tank

1

of

the

Columbia-
o

A- 3 6

Figure

8.

Deviations

of

photogrammetrically

determined

test

tape

lengths

from

NBS

determined

test

tape

lengths

from

NBS

determined

length

versus

length

for

Tank

2

of

the

Columbia.
A-37

Figure

9.

Deviations

of

photogrammetr

iral

ly

determined

test

tape

lengths

from

NBS

determined

lengths

versus

length

for

Tank

3

of

the

Columbia.
o

A-38

Figure

10.

Deviations

of

photogrammetrically

determined

test

tape

lengths

from

NBS

determined

lengths

versus

length

for

Tank

4

of

the

Columbia.
o

A-3 9

Figure

11.

Deviations

of

photogrammetrically

determined

test

tape

lengths

from

NBS

determined

lengths

versus

length

for

Tank

5

of

the

Columbia.
Table IX. Scale Error Estimates for Each of the Five Tanks of the El Paso

Columbia

s value with Std. dev. for Number of Volume Bias with

Tank 95% C.I.* s value of a tape tapes 95% C.I.

1 -1.4 + 8.4 (io“5

) 3.7 (10“5) 3 -0.004 + 0.025 (%)

2 -0.8 + 8.4 (io

-5

) 5.6 (io"5

) 3 -0.002 + 0.025 (%)

3 -1.6 + 8.4 (10~5

) 10.5 (10

-5

) 3 -0.005 + 0.025 (%)

4 -1.5 + 8.4 (10

-5

) 6.2 (IO

-5

) 3 -0.004 + 0.025 (%)

5 7.0 + 8.4 (10~5

) 4.5 (10“5

) 3 0.021 + 0.025 (%)

Confidence intervals are based

values for each tank, i.e., 6.6

on the combined standard deviations of the s (10~5) with 10 degrees of freedom.

A-40
NBS estimates a standard deviation for the tape lengths of 0.3 mm. This

includes all errors of laboratory length measurement, catenary correction,

temperature correction, and errors in positioning the targets with respect to the tape markings.

5. Tape Data Summary and Comments

In these analyses of the length measurement data, the basic model has

been

*13 A + B

A'j

where t. . and 1. . are the corresponding length values as determined

3 ^

1 t h t h by the photogrammetrist and NBS for the l length on the j tape

for a particular tank, and where A ideally has the value 0 and B the value 1.

The constant A reflects any error in the reference target coordinates. For

the analyses of the tape data for the ship sets 1 and 2, it had been assumed

that B can change magnitude from tank to tank, but is a constant for all

tapes on a particular tank. The analysis of the data showed no reason to

alter this assumption. However, the data for ship set 3 (El Paso Columbia)

suggested B might vary from tape to tape, and the data were handled

accordingly.

As discussed in section 4.3, a separate value of B was estimated for

each tape used on ship set 3 and the appropriate values averaged for each

tank to obtain the estimated scale correction for the tank, see table IX.

For the other two ship sets, where B was estimated on the assumption that it was not random from tape to tape but only from tank to tank, the uncertainty

of the scale factor is smaller than estimated using the model for ship set 3.

Larger uncertainties are obtained for the scale factor because the amount of

information available to estimate uncertainties is now proportional to the

number of tapes rather than the number of lengths, as was the case for ship

sets 1 and 2. If we handle the Savannah (ship set 1) tape data as we did the

Columbia (ship set 3), we get the estimates in table X for the average

s (= B-l) for each tank, rather than those shown in table II.

The major change in table X over table II is that the uncertainties

(width of the 95% confidence intervals) are now twice as large because we now

have only one-fourth the information with which to estimate uncertainty. We

see no reason, therefore, to substitute a new analysis for the tape data from

the Savannah.

A-41
Table X. Values of s When Allowed to Vary for Each Tape on the Tanks of

the Savannah.

s Value Number Volume Bias

with of with

Tank 95% C.I.

* Tapes 95% C.I.

1 -14.5 + 6.4 (10“ 5

) 3 -0.04% + 0.02%

2 -22.6 + 6.4 (io

-5

) 3 -0.06% + 0.02%

3 2.4 + 7.9 (10"5

) 2 0.01% + 0.02%

4 -9.8 + 7.9 (10“5

) 2 -0.03% + 0.02%

5 -9.8 + 7.9 (10"5

) 2 -0.03% + 0.02%

* -5

confidence intervals based on overall standard deviation of 4.8 (10 ) with 7 degrees of freedom.

Table XI. Values of s When Allowed to Vary for Each Tape on the Tanks of

the Cove Point.

s Value Number Volume Bias

with of with

Tank 95% C.I. Tapes 95% C.I.

1 2.0 + 5.5 (10

-5

) 3 0.006 + 0.016%

2 2.1 + 4.8 (10~5

) 4 0.006 + 0.014%

3 -6.7 + 1.7 (10~5

) 6 -0.021 + 0.005%

4 -7.6 + 16.1 (10~ 5

) 5 -0.024 + 0.050%

5 1.3 + 3.4 (10"5

) 8 0.004 + 0.010%

A-42
Table XI gives the results of analyzing the Cove Point (ship set 2) tape

data as we did that of the Columbia replacing table VI. The confidence

intervals for s for tanks 1, 2, 5 are based on an estimated standard

deviation of 4.4 x 10 ^ (12 d.f.) that combines the individual estimates

from the three tanks. For tank 3 the standard deviation is too small to be

considered like those of the above three tanks, and was not combined with

them. For tank 4 the estimated standard deviation is too large. Also, in

the analysis of the tank 4 data in section 4.2, the tape 5 data was not used

and one length from tape 1 was not used. However, in this analysis, all the

data were used. The new results are little different from the results in

section 4.2 except for those of tank 4. The new method of analysis allows us

to treat all the tape data in the same way as in the analysis of tank 4 and

not exclude data as in the previous analysis. The uncertainty in the

determination of scale factor for tank 4 is about three times larger for the new analysis, but the uncertainties of the scale factor for the other four

tanks remain as they are in section 4.2

The random uncertainty in length measurements as determined by the

photogrammetr ic survey has been estimated for each of the three ship sets as follows

Standard deviation Degrees of

Ship of length measurement freedom

Savannah 0.58 mm 27

Cove Point 0.65 mm 57

Columbia 0.37 mm 34

The difference in standard deviations between the first two ship sets and the

last may result from the method used to analyze the data. For the first tuo

ship sets, the length measurements for a tank were analyzed without regard to

what tape they came from, and so no allowance was made for different tape^

having different scale factors; this method increases the apparent random

scatter in the length measurements.

A-43
The imprecision of the length measurements and, indirectly, of the

target locations should have little effect on the uncertainties of the tank

calibrations. When determining the height of each of the levels of targets,

the actual deviations of targets from the average may be several centimeters,

and the deviation of the tank wall between targets may also be several

centimeters

.

In trying to predict the uncertainty due to scale error on future

photogrammetric surveys of large tanks, we have pooled our three estimates of

the standard deviation for s: 6.6 x 10 ^ with 10 degrees of freedom for

the Columbia from section 4.3, 4.8 x 10 ^ (7 d.f.) for the Savannah, and

4.4 x 10

5 (12 d.f.) for the Cove Point, the last two from this section.

The pooled value is 5.3 x 10 ^ with 29 degrees of freedom. A two-sided

99% confidence interval for the true standard deviation of s is 3.9 x

10 ^ to 7.8 x 10 ^. If, as we have assumed in similar exercises in

the previous sections, the standard deviation of the length measurements is

1 mm, then the standard deviation for s obtained by the photogrammetrist

using his vertical tapes should be 6.6 x 10 which is certainly within

this confidence interval. However, from the tape data it appears that his

standard deviation for length measurements is actually smaller than 1 mm. Using the tapes the way the photogrammetrist uses them, a value of 0.6 mm may

be more correct. This would give a standard deviation for s of

3.9 x 10 \ the lower end of the interval.

Taking the upper end of the 99% confidence interval as our prediction

for the standard deviation s, and assuming the use of six calibration tapes

in the manner we have employed there, the uncertainty in volume calibration

due to scale uncertainty would be + 0.025% (99% confidence interval) —it is

0.035% if only three tapes were used, as was done by the photogrammetrist.

6. References

[1] Hidnert , D. and Kirby, R. K., 1953. A New Method for Determining

Thermal Expansion of Invar Geodetic Surveying Tapes. J.Res., NBS 50, 179.

A-44
UNITED STATES DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

WASHINGTON, D.C. 20234

REPORT OF CALIBRATION

M 1 4 6 5

page 1 of 4 For: Eight Invar Length Measuring Tapes

Submitted by: National Bureau of Standards

Center for Chemical Engineering

Thermophysical Properties Division

Boulder, Colorado 80303

The tapes were calibrated using a helium-neon laser interferometer as the length standard while under tension and uniformly

supported on a horizontal flat surface. The distances between

the terminal points of the indicated intervals at 20 degrees

Celsius (68 degrees Fahrenheit) under 5 kilograms tension are

given on the following pages. The terminal points of the

indicated intervals are the centers of the graduations at the

edge of the tape ribbon nearest the observer when the zero

graduation is to his left.

All measurements were made in a controlled envirnoment near 20

degrees Celsius and an assumed coefficient of thermal

expansion of 0.0000004 per degree was used to correct the

lengths to 20 degrees.

The linear density and AE values were determined and are given

on the following pages. The AE value is the product of the

average cross-sectional area of the tape ribbon and its

Young's Modulus of Elasticity.

The uncertainty of the reported lengths is 0.000005 meter per

meter and is taken to be the sum of the random and systematic

components of error. The random component is taken to be

three times the observed standard deviation. The systematic

component consists solely of the uncertainty of the laser

interferometer and is estimated to be 0.000002 meter per

meter

Measurements were made by

/ Date: April 13, 1981

A-45
Report continued, page 2 of 4

20-Meter Invar Tape

Interval

(g radua tions )

A to B

A to E

A to F

A to G

A to C

A t o D

Feb 7 8 Length

frnill imeters

)

1712. 8 5

20185. 5 3

20631. 02

Feb 79 Length

(m ill imeters

)

865. 96

1712. 86

8936. 27

14 00 7. 4 7

2018 5. 54

2 0631. 01

The linear density is 0.026918 kilogram/meter

is 49499 kilograms for tape 14811.

21-Meter Invar Tape

Interval

(g raduat ions

)

A t o B

A to E

A TO F

A to C

A to D

Feb 7 8 Length

(mill imeters ) 1262. 48

20585. 07

21053. 10

Feb 79 Length

(m ill imeters ) 1262. 50

2042. 85

20113. 47

2058 4. 9 3

21052. 91

The linear density is 0.026961 kilogram/meter

is 49097 kilograms for tape 14812. **************

16-Meter Invar Tape

In te rval

(g raduat ions

)

A to B

A to E

A to F

A to G

A to C

A to D

Feb 7 8 Length

frn il 1 imeters

)

553. 36

16576. 9 8

16624. 9 3

Feb 79 Length

(mill imeters

)

553. 43

1079. 34

15709. 98

16174. 44

16577. 01

16624. 9 9

The linear density is 0.026923 kilogram/meter

is 49656 kilograms for tape 14813.

M 14 6 5

NBS No. 14811

Jul 8 0 Length

(millimeters )

and the AE value

NBS No. 14812

Jul 8 0 Length

(mill imeters

)

21052. 67

and the AE value

NBS No. 14813

Jul 8 0 Length

(mill imeters )

16622. 08

and the AE value

A-46
Report continued, page 3 of 4 M1465

20-Meter Invar Tape

Interval

(g raduat ions )

A to B

A t o E

A t o G

A to F

A to C

A t o D

Feb 7 8 Le ngth

(mill imeters ) 2641. 90

20188. 90

20854. 30

Feb 7 9 Length

frn ill imeters

)

2641. 94

13048.44

15890. 82

15979. 84

20188. 9 3

20854. 34

The linear density is 0.027063 kilogram/meter

is 48771 kilograms for tape 14814.

3

2 -Me ter Invar Tape

In terval

(g raduations

)

A to S

A to E

A t o B

A to F

A to G

A to H

A to I A to J

A to K

A to L

A to M

A to S

A to C

A to D

Feb 7 8 Length

&n ill imeters

)

23035. 63

31999. 32

Mar 7 9 Length

(millimeters)

128. 15

5969. 11

7063. 30

12052. 66

19729. 28

20469. 28

22941. 33

23034. 82

25786. 50

29179. 92

29262. 54

31782. 03

31909. 72

31998. 36

The linear density is 0.027043 kilogram/meter

is 47702 kilograms for tape 15815.

NBS No. 14814

Jul 80 Length

(mill imeters ) 2642. 03

13048. 50

15890. 94

15979. 92

20189. 05

20854. 50

and the AE value

NBS No. 14815

Jul 8 0 Length

(mill imeters )

31998. 34

and the AE value

A-47
Report continued, page 4 of 4 M 146 5

39-Meter Invar Tape

Interval

(g raduat ions

)

A to B

A to E

A to F

A to C

A to D

Fe b 7 8 Le ng t h

fan ill imeters

)

Feb 79 Length

fan ill imeters

)

328. 33

29209. 82

29521. 08

38917. 69

39110. 9 3

The linear density is 0.026762 kilogram/meter

is 48513 kilograms for tape 14916.

30-Meter Invar Tape

Interval

(g raduations

)

A to B

A to E

A to F

A to G

A to H

A to I A to C

A to D

Feb 78 Length

(mill imeters

)

Mar 79 Length

fan ill imeters

)

198. 93

6278. 48

12223. 08

16729. 43

21433. 55

2438 3. 88

30074. 29

30367. 46

The linear density is 0.027020 kilogram/meter

is 48666 kilograms for tape 14917. ******   ** **

40-Meter Invar

Interval

(g rad ua t ions )

A to B

A to E

A to F

A to C

A to D

Ta pe

Feb 7 8 Length

(mill imeters ) Mar 7 9 Length

(mill imeters ) 168.75

29514. 73

29790. 67

39583. 23

39811. 76

The linear density is 0.027100 kilogram/meter

is 48386 kilograms for tape 14918.

NBS NO. 14916

Jul 80 Length

(mill imeters )

39110. 98

and the A- . aiue

NBS No. 14917

Jul 80 Length

(mill imeters )

and the AE value

NBS No. 14918

Jul 80 Length

(mill imeters

)

39811. 73

and the AE value

A-48
Appendix B

Uncertainty in the Tank Volume Determination

Introduced by the Calculational Method

By

J. F. LaBrecque
Contents for Appendix B

Page

Volume Calculation from Coordinate Data B-l

Comparisons of Volume Determination B-3

Target Distribution on Tank B-19

References B-21
Uncertainty in the Tank Volume Determination

Introduced by the Calculational Method

J. F. LaBrecque

The photogrammetric surveys of the freestanding prismatic tanks for the

Savannah, Cove Point, and Columbia provide representations of each tank in the

form of the X, Y, Z coordinates of the photogrammetric targets attached to the

external tank walls. From these coordinate points, a mathematical model of the

tank must be contrived from which the tank volume as a function of height can be

calculated. In this report, the methods used by both the photogrammetrist and by

NBS are outlined and the results of the two methods compared at selected

elevations for all fifteen tanks of these three ships.

Volume Calculation from Coordinate Data

The photogrammetric consultant calculates the volume of a tank from a height times area relationship. Using the target coordinate data, he approximates the horizontal cross sectional area of the tank at various heights; the

volume between two such adjacent areas is then their average times the distance

between them. A linear interpolation is used to obtain the tank volume at a height falling between two adjacent cross sections. These volumes include the

walls and internal support structure of the tank since the targets are located

on the outer walls. To obtain the actual cargo volume, the volume of the

structural materials or "deadwood" must be subtracted.

To check this calculation technique, we have separately calculated the

external volume using the target coordinate data supplied by the photogrammetric

consultant. The uncertainty in deadwood corrections are examined in a later

section of this report.

Targets on a tank are arranged along each side in horizontal rows with

vertical separations of about 1.5 m. Sixteen such rows span the approximate

23 m height of each tank. The bottom row of targets is just above the rounded

B-l
bottom edge and the top most row is just below the rounded top edge. The row

of targets approximately the same height on all sides defines the boundary of

a horizontal cross section of the tank. In our calculations, the height of

each cross section is taken as the average height of all targets defining the cross section. The error introduced by this approximation should be small

since deviations from the average level are small. Of course, on the

chines, virtual adjustment in the z (vertical) direction must be accompanied

by a virtual adjustment in the y direction (starboard to port).

We calculated the area of a cross section by summing the areas of

triangles with vertices (o,o,z), (x^, yf,z), (xi+l»yi+l) z ) > w*iere

z is the average height of targets for that cross section, i represents a perimeter point (target), i+1 is the next adjacent point on the perimeter and

(o,o,z) is a point on the vertical axis through the center of the tank. As

there are no targets defining the cross sectional areas at the corners of the

tank wall, virtual corner points for each cross section were determined by

fitting least squares lines to the rows of targets defining a cross section

and then solving for the intersections of these lines. The virtual corners were then included in the points defining the cross section. As a test of

this point-to-point method, the area defined by the lines joining the virtual

corners was also calculated. As a rule, these two values for the area differed only by small amounts. The point-to-point integration value should

generally be closer to the true value.

As with the photogrammetrist ’ s method, the volume between two cross sections is assumed to be the product of the average of the two areas and the

vertical distance between them. This assumes that any volume effects of the

variations in the tank walls between the two levels cancel. However, at the

top of the chines there is sharp change with no level of targets to help

define the cross sectional area at this height. To get a value for both the area and height at the top of the chines, planes were fit by the method of

least squares to the coordinate data, six planes for each tank. Using those

planes , a vertical height z was determined for the chine intersection with

the vertical sides at each of the four corners of a tank. The average of

these four values was taken as the height of the area at the top of the

chine. For the El Paso Savannah and El Paso Cove Point the area

B-2
corresponding to this height was also determined using the six planes. This,

however, is an overall average, and the determined areas closest to the top

of the chines should be more predictive of what could be expected at the top

of the chines. For the third ship, the El Paso Columbia, a linear

extrapolation to the value of height as described above, from the two

determined areas directly below was averaged with the linear extrapolation

from the two determined areas directly above. For these ships the two

methods for chine area determination produce values that are a little

different. Fitting the planes to the tank walls allows us to check the

conformance of the tank walls to planes, as well as provide another test of

the volume calculation. This second volume calculation again uses the cross sectional areas and separations as discussed in the preceedings paragraph but

the areas are now defined by the planes fitted to the walls. The difference

in the volumes obtained using the two methods was less than 0.04% of total

volume for each of the five tanks of the Savannah, 0.03% for those of the

Cove Point and 0.015% for those of the Columbia.

Comparisons of Volume Determinations

Our volume tables are compared with those of the photogrammetrist in

tables 1 through 5 for the tanks of the Savannah, in tables 6 through 10 for

the tanks of the Cove Point, and in tables 11 through 15 for those of the

Columbia. These tables give the outside volume of the tanks at -160°C only

[6]. No deadwood corrections have been made to these volumes. The volume

between the bottom of a tank and the first level of targets has been

subtracted out, as that part of the volume involves corrections for the

bottom survey which we have not made. The temperature adjustments are

presumed the same for both methods; so any differences in results cannot be

attributed to this factor. The differences between the methods are generally

0.01% or less except for some values of volume toward the bottom of the

tanks. The correction used by the photogrammetrist for the rounded tank

corners amounts to 1.8 m3 per tank. This correction is in the form of a

0.08 m2 subtraction for each cross section. This correction is alread\

accounted for in the volume comparisons for the tanks of the Cove Point and

Columbia, but not for the Savannah. Subtracting 1.8 m 3 from each of the

NBS total volumes gives the following differences beteen the two methods for

tanks 1-5 of the Savannah, respectively; -0.072 m 3

, .010 m

3

, 0.431 m3

,

B-3
TABLE 1

COMPARISON OF VOLUME CALCULATION

FOP

tank 1 - savannah

HEIGHT VI (PC) V2 (NBS) %DIF

.398 0.000 -.000 0.0000

1.238 466.900 466.854 • 0098

2.750 1373.200 1373.574 -.0272

4.288 2383.200 2383.283 -.0035

4.981 2867.000 2866.813 • 0065

5.828 3469.600 3469.713 -.0033

7.353 4554.600 4555.215 -.0135

8.871 5635.200 5635.904 -.0125

10.388 6715.200 6715.710 -.0076

11.908 7796.700 7797.274 -.0074

13.427 8876.900 8877.756 -.0096

14.947 9957.800 9958.665 -.0087

16.463 11034.900 11036.335 -.0130

17.982 12114.300 12115.802 -.0124

19.502 13194.500 13195.844 -.0102

21.022 14274.300 14275.865 -.0110

22.460 15295.800 15297.672 -.0122

B-4
TABLE 2

COMPARISON OF VOLUME CALCULATION

FOR

TANK 2 - savannah

HEIGHT VI (PC) V2(N0S) *DIF

.390 0.000 -.000 0.0000

1.257 965.600 965.667 -.0070

2.756 2725.800 2726.219 -.0154

4.303 4663.600 4663.480 • 0026

4.991 5563.100 5563.757 -.0118

5.826 6669.400 6669.439 -.0006

7.346 8681.500 8682.406 -.0104

8.865 10694.600 10694.683 -.0008

10.385 12708.400 12708.413 -.0001

11.904 14718.900 14720.245 -.0091

13.422 16729.300 16730.257 -.0057

14.941 18740.900 18741.258 -.0019

16.456 20748.000 20749.038 -.0050

17.975 22754.900 22756.143 -.0055

19.494 24764.600 24765.378 -.0031

21.014 26774.500 26776.009 -.0056

22.454 28679.600 28681.390 -.0062

B-5
TABLE 3

COMPARISON OF VOLUME CALCULATION

FOR

tank 3 - savannah

HEIGHT VI (PC) V2(NBS) *DIF

• 404 0.000 -.000 0.0000

1*236 957.700 957.803 -.0108

2.754 2796.600 2797.321 -.0258

4*280 4764.300 4765.671 -.0288

4.973 5697.600 5696.311 -.0125

5*815 6846.300 6846.944 -.0094

7.333 6917.200 8916.084 -.0099

8*852 10990.700 10990.929 -.0021

10*370 13061.100 13062.371 -.0097

11*890 15135.100 15136.171 -.0071

13*406 17205.600 17207.012 -.0082

14*927 19278.300 19279.165 -.0046

16*445 21348.800 21349.617 -.0038

17*964 23419.500 23420.802 -.0056

19*483 25490.400 25491.559 -.0045

21*002 27560.200 27561.962 -.0064

22*520 29630.000 29631.368 -.0046

B-6
TABLE 4

COMPARISON OF VOLUME CALCULATION

FOR

TANK 4 - savannah

HEIGHT VI (PC) V2(NBS) %DIF

.395 0,000 .000 0.0000

1.251 984,800 984.767 • 0034

2.782 2839.700 2039.705 -.0002

4.294 4789.100 4789.106 -.0001

4.988 5723.700 5722.973 .0127

5.832 6874.600 6874.653 -.0008

7.351 8946.800 @947.096 -.0033

8.870 11018.900 11019.349 -.0041

10.385 13085.100 13085.789 -.0053

11.903 15155.700 15155.746 -.0003

13.421 17225.300 17225.288 • 0001

14.940 19295.100 19296.009 -.0047

16.456 21361.700 21362.161 -.0022

17.975 23431.100 23431.795 -.0030

19.494 25499.800 25501.160 -.0053

21.008 27563.300 27563.711 -.0015

22.531 29637.900 29639.044 -.0039

B-7
TABLE 5

COMPARISON OF VOLUME CALCULATION

FOR

TANK 5 - savannah

HEIGHT VI (PC) V2CNBS) %DIF

.398 0.000 • 000 0.0000

1.256 703.400 703.683 -.0402

2. 79* 2033.200 2033.673 -.0233

4.314 3434.600 3434.653 -.0015

4.992 4087.400 4086.876 • 0128

5.816 4891.200 4891.025 • 0036

7.335 6373.200 6373.503 -.0047

8.853 7854.600 7855.047 -.0057

10.370 9335.900 9335.438 • 0049

11.889 10817.600 10817.268 • 0031

13.408 12298.600 12298.512 • 0007

14.927 13779.400 13779.380 • 0001

16.445 15258.900 15258.973 -.0005

17.963 16738.000 16736.211 -.0013

19.483 18218.800 18219.108 -.0017

20.999 19696.100 19695.965 • 0007

22.447 21106.000 21106.482 -•0023

B-8
table 6

COMPARISON OF VOLUME CALCULATION

FOR

tank i - cove point

HEIGHT VI < ®C

)

V2CNB5) %D1F

.401 0.000 «.ooo 0.0000

1*302 501.500 501.463 • 0075

2.745 1368. 500 1368.512 -.0009

4.277 2375.900 2375.901 -.0000

4.979 2867.000 2 R66.427 • 0200

5.928 3472.300 3471.526 .0223

7.351 4557.900 4557.109 .0173

B. 86? 5635.400 5634.591 .0144

10.380 6716.500 6715.746 • 0112

11.902 7800.000 7799.256 .0095

13.420 8880.500 8879.659 t .0095

14.935 9958.300 9957.464 • 0084

16.453 11038.700 11037.850 • 0077

17.975 12120.800 12119.943 • 0071

19.485 13195.200 13194.406 • 0060

21.011 14280.700 14279.903 • 0056

22.449 15305.500 15304.741 • 0050

B-9
TABLE 7 COMPARISON OF VOLUME CALCULATION

FOR

TANK 2 - COVE POINT

HEIGHT VI (PC) V2 (N9S) %DIF

.399 0.000 .000 0.0000

1.187 875.500 875.496 • 0004

2.663 2602.000 2602.015 -.0006

A. 249 4581.000 4581 .022 -.0005

4.964 5516.100 5516.122 -.0004

5.763 6574.400 6574.434 -.0005

7.281 8586.800 8586.752 • 0006

8.802 10602.700 10602.745 -.0004

10.310 12601.300 12601.265 • 0003

11.838 14626.100 14626.110 -.0001

13.356 16635.500 16635.522 -.0001

14.877 16650.000 18650.048 -.0003

16.393 20656.400 20656.430 -.0001

17.909 22662.400 22662.411 -.0000

19.426 24668.900 24668.866 • 0001

20.946 26679.900 26679.921 -.0001

22.451 28671.300 28671.320 -.0001

B-10
TABLE 8

COMPARISON OF VOLUME CALCULATION

FOR

TANK 3 - COVE POINT

HEIGHT VI (PC) V2(NBS) %D1F

.427 0.000 • 000 0.0000

1.307 1013.900 1013.859 • 0041

2.731 2739.400 2739.459 -.0021

4.262 4712.000 4712.059 -.0013

4.977 5674.100 5673.948 • 0027

5.B32 6840.100 6839.697 • 0059

7.351 8910.800 8910.453 • 0039

8.865 10974.400 10974.030 • 0034

10.387 13050.000 13049.650 • 0027

11.905 15121.000 15120.623 • 0025

13.422 17189.200 17188.871 • 0019

14.941 19261.100 19260.722 • 0020

16.457 21327.400 21327.060 • 0016

17.975 23396.700 23396.385 • 0013

19.494 25466.000 25465.647 • 0014

21.011 27534.600 27534.298 • 0011

22.450 29498.000 29497.74

2

• 0009

B-ll
TABLE 9

COMPARISON OF VOLUME CALCULATION

FOR

TANK A - COVE POINT

HEIGHT VI (PC) V2CNBS) %DIF

.431 0.000 .000 0.0000

1.240 932.600 932.648 ‘-•0051

2.753 2764.900 2764.927 -.0010

4.286 4742.900 4742.920 -.0004

4.981 5679.000 5678.433 • 0100

5.832 6838.900 6838.620 • 0041

7.351 8911.000 8910.653 • 0039

8.866 10977.800 10977.511 • 0026

10.386 13050.700 13050.377 .0025

11.902 15118.900 15118.589 • 0021

13.422 17191.200 17190.914 • 0017

14.939 19260.500 19260.303 • 0010

16.460 21334.100 21333.851 • 0012

17.975 23399.600 23399.40

2

• 0008

19.492 25466.000 25465.776 • 0009

21.013 27541.000 27540.844 • 0006

22.445 29494.900 29494.686 • 0007

B-12
TABLE 10

COMPARISON OF VOLUME CALCULATION

FOR

TANK 5 - COVE POINT

HEIGHT VI <PC> V2(NBS) %DIF

• 410 0.000 -.000 0.0000

1.263 698.300 698.304 -.0005

2.740 1973.300 1973.320 -.0010

4.302 3411.100 3411.190 -.0026

4.986 4069.400 4070.047 -.0159

5.841 4903.900 4903.865 • 0007

7.365 6390.000 6389.939 • 0u09

8.882 7868.800 7868.645 • 0020

10.403 9351.300 9351.114 • 0020

11.917 10827.700 10827.475 • 0021

13.438 12309.700 12309.465 • 0019

14.954 13787.400 13787.060 • 0025

16.474 15268.400 15268.058 • 0022

17.990 16744.700 16744.331 • 0022

19.509 18224.100 18223.674 • 0023

21.029 19705.300 19704.806 • 0025

22.467 21107.600 21107.114 • 0023

B-13
TABLE. 11

COMPARISON OF VOLUME CALCULATION

FOR

TANK 1 - COLUMBIA

HEIGHT VI (PC) V2 (NBS) %DIF

• 40! 0.000 • 000 0.0000

1*233 462.200 462.222 -.0048

2.698 1339.800 1339.718 • 0062

4.259 2363.400 2363.193 • 0088

4.973 2862.400 2862.307 • 0032

5.808 3457.300 3456.946 • 0102

7.323 4536.000 4535.694 • 0067

8.622 5603.100 5602.771 • 0059

10.366 6702.000 6701.669 • 0049

11.684 7782.200 7781.669 • 0043

13.401 8660.700 6860.328 • 0042

14.915 9937.300 9936.895 • 0041

16.437 11019.800 11019.370 • 0039

17.952 12096.200 12095.613 • 0032

19.466 13171.500 13171.096 • 0031

20.984 14250.300 14249.611 • 0034

22.473 15308.600 15308.368 • 0027

B-14
TABLE 12

COMPARISON or VOLUME CALCULATION

FOR

TANK 2 - COLUMBIA

HEIGHT VI <PC> V2(NBS) %DIF

.39? 0.000 -.000 0.0000

1 • 2?8 929.900 929.925 -.0027

2.672 2620.900 2620.882 • 0007

<.260 4602.900 4602.911 -.0002

4.975 5537.700 5537.904 -.0037

5.622 6659.800 6659.913 -.0017

7.336 8665.700 8665.855 -.0018

6.641 10660.300 10660.366 -.0006

10.374 12690.600 12690.951 -.0012

11.691 14701.600 14701.677 -.0005

13.410 16712.300 16712.427 - # 0008

14.929 18723.900 18723.994 -.0005

16.444 20730.100 20730.222 -.0006

17.964 22742.200 22742.309 -.0005

19.462 24750.400 24750.574 -.0007

20.999 26759.000 26759.233 -.0009

22.480 26720.500 28720.732 -.0008

B-15
table. 13

COMPARISON OF VOLUME CALCULATION

FOR

TANK 3 - COLUMBIA

HEIGHT VI (PC) V2 (NBS) %DIF

• 39B 0.000 -.000 0.0000

1*218 943.400 943.412 -.0013

2.567 2570.900 2570.896 • 0001

4,274 4764.600 4764.667 -.0014

4.973 5704.800 5705.393 -.0104

5.708 6817.600 6817.579 • 0003

7.306 8889.800 8869.650 -.0006

B.B23 10959.600 10959.664 -•0006

10.342 13033.200 13033.301 -•0008

1 1 .864 15109.400 15109.437 -•0002

13.362 17180.700 17180.618 -.0007

14.900 19251.600 19251.711 -•0006

16.416 21317.500 21317.677 -•0008

17.935 23389.100 23389.324 -.0010

19.454 25459.500 25459.704 -.0008

20.972 27527.500 27527.769 -•0010

22.446 29537.300 29537.522 -.0006

B-16
table 14

COMPARISON OF VOLUME CALCULATION

FOR

TANK 4 - COLUMBIA

HEIGHT VI (PC) V2(NBS) %D IF

.432 0.000 -.000 @®oooo

1*231 920.500 920.507 -.0008

2.672 2663.200 2663.255 -.0020

4.309 4771.900 4771.869 @0007

4.986 5683.000 5683.636 -.0112

5.832 6837.600 6837.567 ®©005

7.349 8907.600 8907. 7M .0007

8.659 10968.700 10968.672 @0003

10.384 13050.700 13050.646 • 0004

11.901 15121.300 15121.238 • 0004

13.420 17194.000 17193. 936 • 0003

14.937 19264.200 19264.166 • 0002

16.454 21333.200 21333.202 -.0000

17.973 23404.700 23404.714 -.0001

19.491 25474.000 25473.991 • 0000

21.010 27546.100 27546.1 22 -.0001

22.492 29568.400 29568.437 -.0001

B-17
TABLE 15

COMPARISON OF VOLUME CALCULATION

FOR

TANK 5 - COLUMBIA

HEIGHT VI (PC) V2 (NBS) *D1F

• 410 0.000 -.000 0.0000

1.247 665.300 685.311 -.0017

2.741 1974.500 1974.491 • 0005

4.310 3420.300 3420.164 • 0034

4.987 4071.600 4072.117 -.0127

5. 837 4901.600 4901.493 • 0022

7.347 6375.600 6375.437 • 0026

8.657 7850.100 7849.925 • 0022

10.387 9343.000 9342.852 • 0016

11.907 10825.600 10825.374 • 0021

13.422 12303.900 12303.744 • 0013

14.940 13783.700 13783.494 • 0015

16.467 15272.500 15272.305 • 0013

17.978 16745.800 16745.562 • 0014

19.493 18222.900 18222.679 • 0012

21.013 19704.600 19704.312 • 0015

22.492 21147.600 21147.368 • 0011

B-18
0.656 m3 and 1.318 m 3 . The increase in the differences with tank number

is considered coincidental. The major differences occur in the volumes

adjacent to the chine top because of the difference in the methods used to determine the height and area at the top of the chines. The remaining

differences are attributed to round off error.

The largest source of error arising from the volume calculation results

from having to estimate the height and area at the chines where there are no targets. We judge that the height should be good to + 5 cm and the area to

within + 1 m2 . These together produce an uncertainty in total volume of +

01%. Other sources of error in these calculations are judged to be

negligible

.

Target Distribution on Tank

The targets placed on the tanks for photographic reference are uniformly

distributed on the tank surfaces. Again, in the vertical direction, the rows

or targets are spaced about 1.5 meters apart with the first two rows only

abut half that distance apart, for a total of sixteen rows; and in the

horizontal direction, the spacing between columns of targets is about 3 meters with the two columns at the right edge, left edge and in the middle

being 1.5 meters apart. As discussed above, rows or targets at the same nominal height form the boundary of a horizontal cross section, and the

height of the cross section is taken to be the average height of these

targets. In computing tank volume tables, the photogrammetrist assumes that

the targets on the boundary of a horizontal cross section are close enough

together to give a good definition of the shape of the cross section, and

that the computation of the cross sectional area is unaffected by the any

smaller intermediate variations in the tank wall, since the area contributions of these variations tend to cancel. In the same way, he assumes that the effect on the volume of the variations in the tank walls

between cross sections also cancel. To test the adequacy of the 3 meter

spacing between columns of targets, additional targets were placed on tanks

3, 4 and 5 of the Savannah such that the spacing between columns of targets

on these tanks was generally 1.5 m. On the larger tanks (3 or 4), the more dense spacing results in twenty-five columns of targets per side, rather than

the fifteen per side of the less dense spacing. Tables 16, 17, and 18 show

B-19
the average heights and the areas for the sixteen levels (rows) for tanks 3,

4, and 5, respectively, for both the more and the less dense target spacings.

The area calculation method was as described above. As can be seen, in

only one instance is the area difference for the two target densities as large as 0.01%. The volume error at the highest level of targets is: for

tank 3, 0.66 m^ larger for the dense survey; for tank 4, 0.41 m^ larger

for the dense survey; and for tank 5, 0.27 m^ smaller for the dense

survey. These differences are very small. The largest difference, tank 3,

is 0.002% of total volume.

The number and placement of targets on the tanks seem adequate from two

standpoints. The closer spaced targets used on tanks 3, 4 and 5 yield a difference in total volume over the wider spaced targets of less than 1.0

and the volume calculations that assumed the tank sides to be planes

differed from those of the cross sectional method by at most 9 m^ — this was for tank 3 — for the other tanks it was 3 m^ or less. So for these

tanks, increasing the number of targets would likely yield little results in

terms of increased accuracy.

While it is not known exactly how the tank wall deviates from a flat

surface between targets 3 m apart, a study of the 1.5m horizontal spacings

for tanks 3, 4 and 5 of the Savannah gave the standard deviations at the

midpoint between 3m spacings of 5.7 mm, 4.7 mm and 5.3 mm, respectively. For

tanks 1 and 2, the standard deviations for midpoints for 6 to 8 m spacings were 7.1 mm and 6.4 mm, respectively; we expect that these would be larger

because of the larger spacings. A study of the vertical spacings for all

five tanks gave standard deviations at the midpoint of 3 m spacings in the

range of 2.5 mm to 3.2 mm. This would suggest that the deviations between 3 m spacings for tanks 1 and 2 are much like those for tanks 3, 4 and 5. Using

a simplified model similar to that used for volume calculations, we estimate

that the use of the 3 m spacings over the 1.5m spacings contributes an uncertainty of + 1.0 m^ for the larger tank volumes. We must point out,

however, that the systematic differences shown in tables 16, 17, and 18

indicate that the 3 m spacings do miss tank features that are the same for

all or many levels of the tank; i.e., a vertical wrinkle would effect more

than one level. Another way of looking at this is to consider as random the

B-20
percentage differences between the volume determinations for the 1.5 m spacings

and the 3.0 m spacings for tanks 3, 4 and 5. These are, respectively, 0.00223%,

0.00183% and -0.00128%. The standard deviation based on these three values is

0.0018%. The prediction for tanks 1 and 2 of the Savannah and tanks of the

other two ships is that the percentage differences would be in the interval +

0.014% [1]. This interval is rather large, but the prediction is based on only

three numbers. Since tanks 3, 4 and 5 had the more dense spacings, the

uncertainty from target placement for these tanks is taken to be negligible.

References

[1] Natrella, M. B., 1963. Experimental Statistics . National Bureau of

Standards Handbook 91.

B-21

Appendix C

Uncertainties Due to Temperature Effect

By

J. D. Siegwarth and J. F. LaBrecque

Uncertainties Due to Temperature Effects

J. D. Siegwarth and J. F. LaBrecque

1. INTRODUCTION

Since the measurements required to provide the volume of an LNG transport tank as

a function of height are done at ambient temperature, a significant correction is

required to adjust the tank volume to the operating temperature of 110 K. If the

tank is not isothermal during the calibration measurements, not only is the

temperature from which the correction is made uncertain, but the actual shape of

the tank may likewise be altered from the shape at operating temperature. The

portion of the tank in contact with the liquid cargo can be expected to be nearly

isothermal except in the event that the contents stratify.

2. VARIOUS TEMPERATURE RELATED UNCERTAINTIES

Below is a discussion of the various ways temperature contributed to the volume

uncertainty of the prismatic free standing tanks. An estimate of the maximum

error is included in each case.

2.1 Uncertainty of the thermal expansion coefficient of the aluminum.

The uncertainty in the thermal expansion coefficient for 5083 aluminum is estimated to be +3% [1], The tanks are surveyed in the temperature range of 5 to

25°C and the volume is adjusted to ~160°C. For this adjustment, the —3.- uncer

tainty in the expansion coefficient translates into a volume uncertaint> of

—0.03%.

2.2 Uncertainty contributed by the interior wall temperatures.

A small systematic error in tank volume arises due to the temperaturt distribu

tion in the tank structure at the time of the photogrammetric survey. Measurements of the temperature of the outer walls of the tanks suggest tht>

relatively isothermal though the degree of uniformity certainly depends on the

wind, cloud cover and rate of change of ambient temperature. The inner quadrant

C-l
walls of the tank, however, can be as much as 8°C warmer than the outer walls

because the temperature of the large volume of air within the tank lags the

outside temperature. This difference will vary with the difference between day

and night time temperatures and the rate of change of the external temperature.

The higher temperature of the internal walls should cause a bulge in the side

walls of the tank. If the quadrant walls are 8°C warmer, the outer walls should

bulge 3.4 mm on the largest tanks assuming no constraining forces reduce this

strain. The temperature distribution on the quadrant walls of tank 4 of shipset

#3 were measured at the time of the survey to estimate this effect on volume.

The internal temperatures gradually increased from values within 1°C of the

outside wall temperature at the bottom of the tank to 8°C warmer at the top.

Measurements of the top and bottom outside temperatures on a number of points on

the curved edge of the tank on tank 5 of the third shipset showed that, on that

night, top and bottom temperatures were the same to about —1°C.

To estimate the effect of the internal quadrant wall temperature on volume, assume that the bulge in a wall is an isosceles triangle with an amplitude of zero at the bottom and 3,4 ran at the top. The volume, AV, added for all four

sides is then

.0034 x 22.9 x 36.6 x 4 AV =

z z = 2.85 m

3

,

where 22.9 m and 36.6 m are the height and width of the tank respectively.

Hence, the actual volume of the tank is about 0.01% less than the volume given by

the calibration. The tank height is similarly increased during the survey

resulting in an additional decrease in volume of a similar amount but this does

not affect the liquid content as determined from tank tables.

The magnitude of this systematic error should be the worst case estimate since

the top of the tank must constrain the sides at the quadrant walls so they cannot move out. Also, the internal wall temperatures do decrease toward the outside wall

.

C-2
2.3 Uncertainty contribution from tank wall temperature measurements.

An error of 1 C in the measurement of tank wall temperature generates an 0.007%

error in tank volume assuming a temperature coefficient of 23 x 10"^ K.

During the time period of the photography, we noted a tank wall temperature

change of 3

c C maximum. Generally, the temperature change was much smaller over

the course of the photography. Temperatures of the top plates were found to be

as much as 1°C warmer. We estimate the temperature uncertainty of the tank to be

+2°C maximum so the tank temperature uncertainty at the time of the photogrammetric survey results in a volume uncertainty of +0.014%.

2.4 Error from calibration tape temperature differences.

The temperature of the NBS calibration tapes differed as much as -5°C from the

tank wall temperature. The photogrammetric calibration tapes like the NBS tapes were suspended in the air away from the tank walls thus, may have differed from

the tank wall temperature by -5°C also. The iron-36% nickel tapes used by NBS were corrected to the air temperature, though the correction is negligible, while

the photogrammetrists ' tapes. were corrected to tank temperature. Assuming the

photogrammetrists 1 tapes were steel, we assume stainless steel, with a coefficient of 16 x 10 “6 per °C the tank volume would be over estimated by

0.024% if the tapes were indeed 5°C cooler.

3. DISCUSSION

Though it is possible to reduce the magnitude of the volume uncertainties caused

by temperature uncertainties, it is not easy to do so in most cases. The volume

uncertainty resulting from the coefficient of expansion of aluminum (section -.1)

could be reduced by carefully measuring the thermal contraction of samples of the

aluminum plates comprising the tank walls and structure. Reducing the volume

uncertainties due to tank temperature distribution and uncertainty (section

and 2.3) is difficult under the conditions of the measurement. The most stable

conditions could probably be obtained on a cloudy windless night and around the

time the tank reached the minimum temperature. A vigorous circulation

C-3
of air through the interior to bring the inside temperatures down to the exterio

temperature is desirable.

The elimination of the three contributions discussed above, generally, will

increase tank calibration costs. The uncertainty in volume resulting from tape

temperature uncertainty can be eliminated at little additional cost by using a low thermal expansion alloy like iron-36% nickel for the calibration tapes rathe

than stainless steel.

4. REFERENCES

[1] Mann, D. B., Editor, 1977. LNG Materials and Fluids . Thermophysical

Properties Division, National Bureau of Standards, Boulder, Colorado.
Appendix D

A Laser-Based Calibration of Tank //3

on the

LNG Tanker El Paso Columbia

By

W. C. Haight, F. Scire, R. G. Hartsock, and R. J. Hocken
!

I

ji
A Laser-Based Calibration of Tank it 3 on the LNG Tanker El Paso Columbia

This Appendix presents the results of a dimensional calibration of Tank it 3 on the LNG tanker Columbia conducted by NBS personnel while the tank was in

storage at the construction yard in Mobile, Alabama. This calibration is

completely independent, both metrologically and computationally, of any other

surveys conducted on this same tank.

The NBS measurement method is similar to the technique described in

references [1] and [2] for membrane-type LNG tanks, with the exception being

that all measurements were made from the tank exterior rather than the

interior. All reference gage points were established by laser planes just

outside the tank surfaces, and marked on aluminum plates attached to the

exterior tank surface with high-strength epoxy. The dimensions of the

laser plane solid were measured with an invar tape, and angles between

planes were measured with a first-order theodolite. Offsets from the

laser planes to the tank walls were measured on a 3 x 3 m grid, that is, on every other photogrammetr ic target whenever possible. An ultrasonic

thickness gage was used to record the wall thickness at every offset

point. The survey was conducted at night to minimize the effects of

non-uniform temperature distributions on the tank surfaces caused by solar

heating.

The following information is provided for this tank:

a. A calibration report providing the measurement conditions and error estimate;

b. Two summary main gaging tables showing the tank volume as a function of gage height at selected intervals;

° Table 1 presents the tank interior volume as a function

of gage height, exclusive of internal structural deadwood,

0 Table 2 presents the tank exterior volume as a function

of gage height, exclusive of internal structural deadwood.

c. A comparison of the NBS exterior main gaging table at

selected intervals to the gaging table provided by the

calibration contractor.

D-l
FORM NBMU

(REV. U-W)

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

WASHINGTON, D.C. 20234

REPORT OF CALIBRATION

For: Tank // 3 on the LNG Tanker

El Paso Columbia

Requested by: El Paso Marine Company

2919 Allen Parkway

P.0. Box 1592

Houston, TX 77001

The following tables have been calculated from dimensional measurements on tank number 3 of the liquified natural gas tanker El Paso Columbia while

the tank was in storage at the Kaiser Aluminum Company construction yard in

Mobile, Alabama. These tables represent the volume of a liquid enclosed in

the tank as a function of the height of the liquid surface, measured along a straight line, fixed with respect to the tank. This line is defined as being

located at the longitudinal center line of the tank's capacitance gage. Both

the measurement method and the computational algorithms are outlined in the

paper "Multiple Redundancy in the Measurement of Large Structures", Annals

of the International Institution of Production Engineering Research (CIRP)

,

Volume 27/1, 1978.

All measurements relating to this survey were made from the tank exterior

except those needed to locate the capacitance gage. The tank wall thickness

at each survey point was measured with an ultrasonic thickness gage and

these values are used to report the volume relative to the tank interior

surfaces as a function of gage height in Table 1. Table 2 presents the

corresponding relationship relative to the tank exterior surfaces. No

correction has been made in either case for the volume occupied by internal

structures (deadwood).

The tank was measured empty while at an average temperature of 13. 5°Celsius.

The tabulated volumes and the error estimates apply to the tank under these

conditions

.

The measurement method used includes geometrically redundant cross checks

which allow assessment of the random error in the measurement process. For

this tank, the total volume, excluding the vapor dome, was

3

° Interior volume = 30821.5 m^

° Exterior volume = 30929.5 m

D-2
3 The uncertainty of these values is 3.1 m (0.01% of total volume) at the

three standard deviation limit of random error. Including an analysis

of probable systematics by adding the absolute magnitude of the error

sources, we estimate that the total uncertainty, at the 99% confidence

level, is +0.05% of the total volume. No estimates of the errors in the

individual table entries are included, since without an estimate of the

height error introduced by the liquid level gage such estimates of

necessity would be incomplete. y .

*

/

Automated Production Technology Division

Centi-r for Manufacturing Engineering

Date: March 5-8, 1979

D-3
TABLE 1

EL PASO COLUMBIA

CARGO TANK NO. 3, HULL 2266

MAIN VOLUME VS. HEIGHT TABLE, INTERIOR VOLUME

TANK TEMPERATURE: 13.5°C

GAGE HEIGHT

(meters)

VOLUME

(cubic meters)

.000

.050

.100

.200

.300

.400

.500

1.000

2.000

3.000

4.000

5.000

6.000

7.000

8.000

9.000

10.000

11.000

12.000

13.000

14.000

15.000

16.000

17.000

18.000

19.000

20.000

21.000

22.000

22.500

23.000

8.3

64.1

120.1

232.4

345.3

458.7

572.6

1149.7

2342.4

3586.4

4881.8

6228.4

7599.2

8970.0

10340.8

11711.6

13082.3

14453.0

15823.7

17194.4

18565.1

19935.7

21306.4

22677.0

24047.6

25418.1

26788.7

28159.2

29529.7

30215.0

30821.5

TOTAL INTERIOR VOLUME OF TANK = 30821.5 cubic meters

D-4
TABLE 2

EL PASO COLUMBIA

CARGO TANK NO. 3, HULL 2266

MAIN VOLUME VS. HEIGHT TABLE, EXTERIOR VOLUME

TANK TEMPERATURE: 13.5°C

GAGE HEIGHT

(meters)

VOLUME

(cubic meters)

.000

.050

.100

.200

.300

.400

.500

1.000

2.000

3.000

4.000

5.000

6.000

7.000

8.000

9.000

10.000

11.000

12.000

13.000

14.000

15.000

16.000

17.000

18.000

19.000

20.000

21.000

22.000

22.500

23.000

32.5

88.5

144.6

257.3

370.5

484.2

598.4

1177.2

2373.4

3620.8

4919.7

6269.9

7643.8

9017.6

10391.4

11765.1

13138.7

14512.3

15885.8

17259.2

18632.5

20005.7

21378.9

22752.0

24125.0

25497.9

26870.8

28243.6

29616.3

30302.6

30929.5

TOTAL EXTERIOR VOLUME OF TANK - 30929.5 cubic meters

D-5
Comparison of the NBS and

Photogrammetric Exterior Calibrations

of Tank 3 of the Columbia

Table 3 shows the photogrammetrically-determined external tank volume as a function of height compared to the NBS volume measured by the laser plane

survey. The tables have been adjusted so the volume is zero at the zero of the

level gage, which is the point on the internal floor of the tank immediately

under the gage. This eliminates the tank bottom profile. Since the

photogrammetric coordinate origin was at the inside surface of the lowest point

of the tank, an additional 6.37 m^ has been added to the photogrammetric

volume in the vertical wall region. This correction drops linearly to zero from

Z=5 to Z=0 m, which is the chine region. A value of 29.08 m^ is added to all

the photogrammetric volume table entries since that much volume was removed to

correct for undulations of the bottom. With these adjustments, the bottom is now a horizontal gravitational plane through the zero of the gage and at the

time the tank yard bottom survey was done.

The volume table derived from the laser survey is referenced to a horizontal

plane containing the same zero point by subtracting 32.5 m^ from each of the

volume readings in table 2 of the calibration report at the end of this

Appendix. This plane is, however, the best fit plane to the bottom survey

rather than a gravitational plane. Neither plane offers advantages for the

volume calculation since the orientation of the tank in the ship relative to the

surveys is the one needed. For small relative tilts of these planes with

respect to each other, a few centimeters makes no detectable error in the tank

volume when the bottom is subtracted out, but could if the bottom is left in.

Thus the two survey methods are best compared with the bottom effects removed.

The photogrammetric volume versus height tables are derived from planes fit to

each level of targets as described in Appendix B and the volume versus external

height data supplied by the photogrammetrist is given at each target level in

table 3 for 16.2°C. The laser plane volume versus height table is given at

meter intervals and since the horizontal cross sectional areas at each level are defined by planes fit to each surface of the tank, the laser measurements are D-6
Table 3

Volume Versus Height Table

Columbia, Tank #3

Height (m) Volume

Laser Planes (m^)

Volume

Photogrammetry (m^)

0.0 0.0 0.0

0.398 449.5 448.7

1.218 1401.3 1399.8

2.567 3042.2 3041.5

4.274 5252.7 5251.8

4.973

5.788 7320.9 7320.0

7.306 9406.6 9406.8

8.823 11490.8 11491.1

10.342 13577.5 13579.2

11.864 15668.3 15670.0

13.382 17753.4 17755.8

14.900 19838.3 19841.3

16.415 21918.9 21921.7

17.935 24006.2 24007.8

19.454 26091 .9 26092.7

20.971 28174.8 28175.2

22.445 30198.4 30199.1

D-7
easier to extrapolate to the photogrammetrists levels than vice-versa. The

laser-determined volume from Z=0 to 4.8m given in table 3 is:

V(Z) = 1119Z + 25. 7Z 2 + 0.15Z (m3

)

and from Z=5.2 to 22.5 m as

V(Z) = -163.26 + 1374. 314Z - 0.0368Z2 + 0.17Z - .09 (m 3

)

The last term of the first equation and the last two terms of the second convert

the volumes at 13.5°C to the volumes at 16.2°C so the photogrammetric and laser

surveys can be compared with the tank at the same temperature. A gap between Z values of about 4.8 to 5.2 m exists where neither expression is correct because

the wall actually rounds into the chine with a radius of about 15 cm rather than

meeting it at a sharp angle.

The two calibrations shown in table 3 agree in volume to within 2 m 3 over the

height of the tank except for the 13 to 17 m range where the disagreement is

less than 3 m

3 .

If the tank bottom shape is included, then 8.3 m

3 must be added to the laser

volumes given in table 3. The photogrammetrists volume with the bottom included

is 30,198.2 m

3 at 22.445 m height. This is 8.5 m3 or about 0.03% less than

the NBS value. This is well within the estimated uncertainty of both

calibrations. This difference probably arises from differences in the zero location, approximately 1 m

3 /mm and the different choices of reference plane

which when coupled with the offset of the level gage, horizontally adds 1.2 m

3

of difference per centimeter of tilt. The best fit plane was used as the level

plane for the NBS calibration and the gravitational plane was used for the

photogrammetric calibration. The offset from the coordinate origin of the best

fit plane supplied the bottom correction for former calibration while numerical

integration supplied the correction for the latter. The orientation of the

tanks to the level ship is the information needed to finally determine the

volume to be included in the tank bottom.

The close agreement between the volume tables calculated by the two independent

D-8
surveys indicates that the uncertainty estimates given for the two surveys,

+0.05% of total volume for the laser method and 0.1% for the photogrammetric

method, are conservative.

i
REFERENCES

[1] Hocken, R.J. and Haight, W.C., 1978; "Multiple Redundancy in the

Measurement of Large Structures", Annals of the International

Institution of Production Engineering Research (CIRP)

,

Volume 27, p. 1.

[2] Haight, W.C., R.J. Hocken, B.R. Borchardt, C.L. Carroll, R.G. Hartsock,

C.P. Reeve, F.E. Scire, and R.C. Veale, 1981; "Estimated Accuracy of

Calibration of Some Membrane-Type LNG Transport Tanks", NBSIR 80-2141.

D-10
Appendix E

Deformation Measurements on

LNG Cargo Tanks

By

W. C. Haight, B. Borchardt, R

Freestanding

G. Hartsock,

R. C. Veale, and R. J. Hocken

NBSIR 81-2332

DEFORMATION MEASUREMENTS ON

FREESTANDING LNG CARGO TANKS

W. C. Haight, B. Borchardt, R. G. Hartsock,

R. C. Veale and R. J. Hocken

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Manufacturing Engineering

Automated Production Technology Division

Washington, DC 20234

October 1981

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards
Table of Contents Page

Abstract 1

I. Introduction 2

II. The Measurement Method 5

11. 1 Top Survey 5 11. 2 Bottom Survey S

III. Data Analysis 12

111.1 General Comments 12

111. 2 Tank Top Data 12

111. 3 Tank Bottom Data 13

111. 4 Calculation of Distortion 13

IV. Error Analysis 14

V. Results and Conclusions 17

VI. Tables of Survey Data 20

VII References 39
List of Figures Page

Figure 1 - LNG Tank Schematic 4

Figure 2 - Laser Level Schematic 6

Figure 3 - LNG Tank Top Plan 7

Figure 4 - LNG Tank Bottom Plan 10

List of Tables

Table 1 - Random Error Sources 14

Table 2 - Temperature Profile Summaries 16

Table 3 - RMS Distortion Results 19

Deformation Measurements on Freestanding

LNG Cargo Tanks

W. C. Haight, B. Borchardt, R. G. Hartsock

R. C. Veale, and R. J. Hocken

ABSTRACT

Large Liquid Natural Gas (LNG) cargo tanks in a variety of configurations are presently under construction worldwide. Metrologists are being

called upon to measure their capacity, their deformation under load, and their

mechanical deformation due to handling after calibration. In this paper,

we present the results of a series of measurements made on aluminum tanks

to determine the extent of permanent distortion caused by loading them

into a ship with a large crane. These measurements are intended to be used

to determine the validity of land-based photo gramme trie calibrations conducted

prior to installation of the tanks in the ships.

It is shown that the permanent tank deformation is insignificant to

the level of accuracy of the measurement method used, and that the volumetric

change can be no more than 0.02% of the total tank volume when the technique

described herein is employed.

1
I. Introduction

Measurement of LNG cargo volume determines one of three essential quantities upon which the dollar value of LNG shipments is based, the other two

being LNG composition and density. The volume of a shipboard cargo is

typically determined from a measurement of the liquid-gas interface level

relative to the tank bottom in each tank. This measurement, in conjunction

with a prior determination of the tank size and shape can be used to compute

a liquid volume at the time of gaging.

Metrologists are being challenged by the LNG industry to develop a

variety of measurement techniques for parameters affecting total cargo

volume. The most fundamental of these, tank size and shape, has been

studied for certain container types and reported by Hocken and Haight [1]

and by Jelffs [2]. The rising price of LNG is motivating a futher extension of such measurement accuracy to parts in 10^ over distances of

30 meters and beyond.

A second study area is the effect of cryogenic temperatures on container

size and shape. Since methane liquifies at -162°C, this effect can be

substantial. The present literature is limited to physical property data

for various container materials and fluids at cryogenic temperatures [3]

but no field measurements of tank dimensional changes at cryogenic temperature

are known to have been made.

A third area is the hydrostatic deformation of tanks under the load of

their cargo. Even though the density of liquid methane is approximately

3 3 0.5 g/cm , the average volume of 25,000 m per tank can lead to potentially

significant distortions that may introduce errors in gaging tables based on

empty tank calibrations. This effect has been investigated by Haight et.

al. for large freestanding prismatic tanks and reported in reference [4].

2
The area of study for this paper is distortion of freestanding

prismatic tanks due to a lifting procedure used to place them in a ship

after construction. The ship under study contained 5 cargo tanks, with

a typical tank shown schematically in Figure 1. They are constructed

from aluminum plate up to 25 mm thick. All tank structural support is

provided by a complex structure of internal beams, and when installed in

the ship the tank is uniformly supported on wood blocks at its base and

is clamped to the ship’s deck at the top to prevent movement. Insulation

is provided by a polyurethane foam, sprayed directly onto the inner hull

of the ship, and covered with layers of fiberglass.

When tank construction is completed on land, the ship’s deck plates

are removed and the tanks are lifted into the ship’s hull with a large

crane. All lifting is along the longitudinal centering of the tank using

multiple hydraulically equalized cables, with lifting hooks attached to

brackets on the tank top.

Primary tank calibrations are done photogrammetrically while the tanks

are in a storage yard prior to loading into the ship. It is the desire of

the sponsor to know if the photogrammetric calibrations remain valid after

the tanks have been loaded into the ship and are resting on a base other

than the one on which they were calibrated. To meet this end, two sets of

measurements have been made by NBS. One set is made when the tanks are in

the storage yard in the same position in which they were photographed. The

second set is a repeat of the first set but is made after tank loading into

the ship is complete. A comparison of the two data sets yields an estimate

of the permanent distortion due to the loading process.

3
Figure 1 - A typical LNG tank of the freestanding prismatic type. The

tank is internally divided into quadrants and is uniformly

supported on the bottom while in the ship. The coordinate

system used to report the measurement data is shown here.

(View from Aft)

4
II. The Measurement Method

In order to characterize permanent distortion due to lifting the freestanding LNG cargo tanks, the following technique is used. Two "flatness"

surveys are conducted on each tank, one on the tank exterior top and one

on the tank interior bottom. Each survey is conducted both before and

after the tank is loaded into the ship's hull.

The flatness surveys utilize a rotating laser, schematized in Figure 2,

to define a plane fiat to +1.0 sec of arc and approximately parallel to the

tank surface. This laser has a self leveling feature that permits the plane

to be established perpendicular to the earth's gravitational field. For the

surveys reported herein, the laser is always allowed to self-level after

initial setup, and is then locked to insure that the reference plane remains

fixed throughout the survey. Offsets from this swept plane are measured to

the actual tank surface using a beam seeking laser rod. These commercially

available rods have been refitted with higher accuracy scales, kinematic

base plates, and a circular bubble level to insure the rod is perpendicular

to the survey plane. The laser rod contains an active detector that searches

for the laser beam, averages a large number of readings, and then locks

so a reading can be taken. The offset measurements are made at a large

number of points on a uniform two-dimensional grid to fully characterize

the contours of the surface being surveyed.

II. 1 Top Survey

The top survey details will be presented first. A grid approximately

3 m x 3 m (actually 10 ft x 10 ft) is marked off on the tank top by placing

small aluminum markers around the tank perimeter at the grid interval.

5
Rotation Axis

Figure 2 - Schematic of laser level with beam seeking laser rod.

The rotating pentaprism causes the beam to be swept in

a plane. Manufacturer's specifications are ±10 seconds

of arc flatness. Resolution of rod is 0.1 mm.

6
3

5

7

9

11

13

(

15

17

19

21

23

25(

3 - Top plan of a typical LNG tank showing grid point definitions,

^^represents laser set-up points and(+)represents tie-in points.

The shaded area is not visible from the aft laser set-up, but

is instead measured from the forward laser set-up. One grid

unit equals approx. 1.5m (5 feet).

7
This is shown in detail in Figure 3. Markers are placed at every other

one of the photogrammetric targets along the tank edge so the top survey

can be referenced to an independent exterior photogrammetric survey. The

grid is measured from tank centerlines, since not all tanks are rectangular

in plan.

A uniform grid spacing is chosen since the tank is constructed from

large aluminum plates braced internally by a cross section of beams.

The plate size and support spacing lead to periodic variations in the

top profile due to welding the various members together. The uniform

3 m grid spacing avoids the periodicity of these supports, with grid

point positions sometimes lying on high ridges over a beam, dips between

beams, or at various intermediate points. (Transverse beams are spaced

at 0.65 m, longitudinal beams are spaced at 3.66 m and top plates are

half the length of the tank long by approximately 3.60 m wide.)

No point on the surface exists from which all other points are

visible because of the rectangular vapor dome in the center of the tank.

To survey the grid points in the laser shadow, we chose to make two

laser set-ups, one on the aft lifting bracket and one on the forward

lifting bracket. In addition, 10 points on the tank top were carefully

marked (see Figure 3) so that they could be included in both the aft and

forward surveys. The aft survey is conducted first, and includes all

visible grid points and the 10 tie-in points. The laser is then moved

to the forward set-up point and all remaining grid points are surveyed

and the 10 tie-in points are included. These tie-in points are used in

the analysis to reference the entire tank top to a single plane.

Characterizing the thermal profile of the tank top during the

survey presents a problem. When the tanks are in the storage yard, top

8
surveys are conducted at night when the tanks are in a near isothermal

state. When the tanks are loaded into the ship, top surveys must be

conducted immediately after loading since insulation on the tank top is

installed within a few hours after loading is complete. This survey is

often conducted in direct sunlight with surface temperatures as high as

48 °C. A temperature profile on a 5 x 5 point grid over the entire tank

top was recorded first while the tank was in the storage yard, and was

then repeated at the start of the in-ship survey and again when the

laser was moved from the aft to the forward set-up point during the inship survey. Since the tank walls were not accessible after the tanks

were loaded into the ship, no temperature readings were taken there,

even though gradients in the side walls could distort the top nonuniformly. The results of these thermal profiles and the thermal distortion

error introduced into the flatness surveys will be discussed in Section IV.

II. 2 Bottom Survey

The bottom survey is conducted in a manner similar to the top, but

is complicated by the fact that the tank is divided into quandrants with

a longitudinal liquid tight bulkhead and a transverse swash bulkhead.

It is further complicated by the fact that floor beams up to 1.4 m high

are present. A schematic of the tank bottom is shown in Figure 4. The

method used is as follows: Four separate flatness surveys are conducted,

one in each tank quandrant, using a nominal 2 m x 2 m grid spacing.

These surveys may be done on four different days if necessary. The

laser is mounted on the top flange of a floor beam and the intersection

of the laser plane with the wall beam flanges is marked at the four

9
FORWARD

1 5 8 13 16 18 20 3 5 8 13 16 20 24

Figure 4 - Bottom plan of a typical LNG tank showing grid point

definitions. Points marked^) are water tube tie-in

points. Grid numbers are based on small floor and

wall beam locations. One grid unit equals approx. 0.6 m

(2 feet).

3

6

9

12

15

18

21

24

27

29

3

6

9

12

15

18

21

23

26

10
extremes of each quadrant. The laser level is locked after initially

allowing the unit to self-level. Offsets from the laser plane to the

tank floor are measured with the beam seeking level rod in the usual

manner. Extreme care is taken to insure the rod is perpendicular to the

laser plane since the offset measurements are approximately 1.9 m in

length and the chance of a significant cosine error is substantial. A

circular bubble level on the rod is used for this purpose.

Once the four quadrant surveys are complete, water tubes are used

as a differential level to define a level plane throughout the tank.

Then, short offset measurements from laser plane locations in each

quadrant can be used to reference the four quadrant surveys to a single

surface. The water tube technique involves establishing a reference

point in one quadrant by keeping one end of the tube fixed at that

point. The other end of the tube is then moved to 15 additional points

in the appropriate quadrants. The approximate location of these points

is shown in Figure 4. At each point, a mark is made at the same height

as the reference mark, based on the water level. It is important for

this procedure to be completed as quickly as possible on all 15 points.

Access to various quadrants is through a valve in the liquid tight

bulkhead and through manways in the swash bulkhead. The water tubes

used for this survey are made from tygon and have aluminum scales

attached to each end for clamping to the tank beams.

Finally, a number of angular measurements were made on the tank

interiors in the event that the top and bottom survey data showT ed signit leant

distortions. These are not reported, since they add no new information

to the tank distortion profiles.

11
III. Data Analvsis

111.1 General Comments

Field data for any tank surface consists of a set of deviation measurements from a plane, typically a gravitational plane defined by a rotating laser

or by a set of water tube readings. Since the tank surface is likely to be

tilted with respect to the gravitational plane, it is more convenient to

reference the surface deviations to the hypothetical plane which best fits the

surface in the least squares sense. It is reasonable to compute such a plane

because at least four data points will always be available. In fact, there

will usually be many more available so that no single data point has undue

influence on the location of the fitted plane.

111. 2 Tank Top Data

The basic raw data from one complete top survey consists of two sets of

X, Y, and Z coordinates. The X and Y values are approximate and are expressed

as index numbers. The Z values, measured with the beam seeking laser rod, have

] a resolution of 0.1 mm.

Before any further analysis can be made, the forward survey data must be

tied-in to the aft survey data. This is accomplished by fitting separate least

li

squares planes to each set of data using only the ten points common to both

sets. All of the Z values from the forward survey are the rotated until the

least squares planes are coincidental. This completes the tie-in procedure.

The differences between the pairs of Z values at the ten tie-in points provides

a measure of the closure of the process. The root-mean-square (rms) value of

these differences was typically about 2 mm.

12
The final adjustment is made by fitting a least squares plane to the

combined Z values and then computing the deviations of the Z values from that

plane. These deviations, which describe the profile of the tank surface, are

reported in Section VI. The rms value of the deviations from the plane are

also reported in Table 3 as a measure of the "flatness" of the surface.

111. 3 Tank Bottom Data

The problem is only slightly more complicated with the bottom survey data.

There are five gravitational planes; one for each quadrant, generated by the

rotating laser, and the fifth, for the entire tank, generated by the water

tube measurements. The water tube plane is taken to be absolute and uniform

throughout the tank.

In each quadrant there are four tie-in points where the offset from the

laser plane to the water tube plane has been measured. A least squares plane

is fit to these four offset values, and corrections are obtained for converting

Z values. The set of deviations of the Z values from this plane then describes

the profile of the bottom surface of the tank.

111. 4 Calculation of Changes

On both the bottom and top planes, the individual data points are carefully

selected to be at the same positions for both the before and after surveys. ihus,

the problem of the change in the shape reduces to one of subtraction at each data

point. It is only necessary to decide which set of deviations is most likely

to be representative of the tank itself. The best fit least squares plane

through the whole surface was chosen as the best reference to use. A pointby-point subtraction is made, the rms value for the differences is found, and

the differences are reported in Section VI.

13
IV. Error Analysis

Errors associated with the flatness surveys used to quantify mechanical

deformation due to loading LNG tanks into a ship are of several types. We

will discuss 3 types in this paper; random, systematic, and model errors.

The random errors currently identified in tank flatness surveys are

shown in Table 1.

Table 1 - Random Errors in Free-Standing Tank Measurements

Physical Source

Laser plane

Error Value

+1 . 5mm

Error Source

Manufacturer

Spec (1)

Laser rods

Reading Error

Cosine error

Grid point definition

+0.3 nan +0. 6 mm

+4 . 0 mm

Estimated (2)

Computed (3)

Estimated (4)

Total Random Error +4 . 3 ram Sum of errors

in quadrature

Notes for Table 1

(1) Specifications on the laser plane ’include wobble, lack of flatness, and

deviation from level when self-leveling feature is used. The manufacturer

specifies that the sum of these errors will not exceed +10 arc sec. For

the maximum length of a tank, L * 30 m, this error is +1-5 mm.

14
(2) Scales on the laser rods are blank lines in mm increments on a light

background. The random error estimate for this type of scale is based on

years of laboratory experience.

(3) For an absolute displacement measurement, a rod cosine error is

systematic. For relative measurements, this becomes random. For a discussion of the calculation method used to predict this error, see Reference 1.

(4) For comparison of the "before" and "after" survey data, the same grid

point must be repeated. Due to local surface curvature around some points,

an error can result from inability to remeasure exactly the same point.

This estimate is based on remeasurement at a number of points.

It must be noted that the laser rod calibration cannot contribute an error

in this survey since only relative displacement from flatness of two planes

is being computed.

The major systematic error in this type of survey is the thermal

distortion due to uneven heating of the tank surfaces from the sun. The

worst case observed was on the top of Tank 5 after it was loaded into the

ship. Gradients of up to 18 °C were recorded on the top, which over a 30 m

length in aluminum amount to a dimensional change of 11 mm. Gradients in

the tank walls are equally important in establishing this error, however

it was not possible to measure these. Table 2 presents a summary of the

thermal profiles recorded on each surface surveyed, with bottom profiles

15
being based on a 16 point grid and top profiles being based on 25 or

more points. A clear picture of the thermal distortion effect is not

presently available.

Table 2

El Paso Savannah

Temperature Profile Summaries - Readings in °C

TOP PLANES BOTTOM PLANES

Tank A Tank A

Avg. Range Avg. Range

Before lifting 26.1 21.3-29.7 Before lifting 18.7 18.1-19.3

After lifting 31.3 27.0-37.0 After lifting 22.8 21.9-23.5

Tank 5 Tank 5

Before lifting 6.8 6.2- 7.

A

Before lifting 13.3 13. 2-13.

A

After lifting 39.8 30.0-A8.0 After lifting 25.9 25. 6-26.

A

Finally, model errors will be considered. The previous discussion dealt

with expected errors in measurement, but one must also examine how well the

model of flat planes represents the true tank surface. In performing this

distortion survey, we measured two tanks of the El Paso Savannah, both

before and after loading into the ship, and top and bottom surfaces of each

tank. This yielded 8 flatness surfaces, and the rms deviations from the

"best fit" plane for each case is shown in Table 3. These deviations vary

from 7.9 mm to 23.0 mm for surfaces up to 37 m square. We therefore conclude

that the tank surfaces are modeled sufficiently well by a plane.

16
V. Results and Conclusions

The results of lifting distortion measurements on Tanks 4 and 5 of

the El Paso Savannah are presented in Table 3. Two planes per tank for

two tanks were measured, both before and after lifting, yielding 8 data

sets. The rms deviations of each of these 8 data sets from a "best fit"

plane are reported, and most importantly the rms values of the before and

after differences taken on a point-by-point basis for each surface are

given. From this table, it is seen that these rms differences range from

3.4 mm to 5.1 mm, with the exception of the bottom of Tank 5. The difference value for Tank 5 is invalid because of a failure of the water

tube survey to successfully tie the four quadrant surveys together before

tank lifting. A true measure of tank bottom flatness is given by the

"flatness from underneath" value, but because different survey points

were used inside and outside the tank these two data sets cannot be

differenced. The failure of the water tube apparatus was probably due

to an undetected constriction of the tubing while level points were being

marked on the tank.

The estimated random error of this survey technique, exclusive of

thermal effects, is +4.3 mm at the one— standard deviation limit of

uncertainty, and +13.0 mm at the three-standard deviation limit. Systematic

distortion would therefore be indicated by any rms difference value

exceeding 13.0 mm. Since no surface, except the one on which the measurement method failed, exceeds this value, we conclude the effect of lifting

distortion on land-based tank calibrations is negligible.

17
An estimate of the volume error caused by a systematic deformation

of the tank bottom can be made as follows. Consider the largest tank.

Tank 4, with bottom dimensions of approxiamtely 30 m x 37 m. Assume that

the edges of the bottom surface are constrained and only the center

deflects. Further assume that the deflection profile is parabolic s.o

that the deformed bottom is a paraboloid with a rectangular base. If

the center of the paraboloid is 13.0 mm from the plane formed by the base,

3 the enclosed volume is 6.4 m . Alternatively, if it is assumed that the

interior bulkhead constrains the bottom in quandrants, that is four surfaces

15 m x 18.5 m each are deflected, then the total enclosed volume remains

3 3

6.4 m . For a tank with a total volume of approximately 30,800 m , this

represents an uncertainty of only 0.02% of total volume.

18
Table 3

El Paso Savannah

Deviations (RMS) from "best fit" Plane

TOP PLANES BOTTOM PLANES

Tank 4 Tank 4

Before lifting

After lifting

23.0 mm Before lifting 9.8 mm

22.2 mm After lifting 8.2 mm

RMS value of differences 3.4 mm RMS value of differences 5.1 mm

Tank 5 Tank 5

Before lifting

After lifting

18.0 mm Before lifting 13.7 mm*

18.5 mm After lifting 7.9 mm

RMS value of differences 4.6 mm RMS value of differences 13.8 mm

* Flatness from underneath 7.7 mm

19
VI . Tables of Survey Data

For completeness, tables of the actual deviations of each data

point from the "best fit" plane applicable to that surface are included

here. Also included are the difference tables for each point of each

surface in the before and after surveys. All deviations are reported in

millimeters. The composition of each table is as follows:

Table Contents

A1 Tank A, Top before lifting

A2 Tank A, Top after lifting

A3 Tank A, Top differences

A4 Tank A, Bottom before lifting

A5 Tank A, Bottom after lifting

A6 Tank A, Bottom differences

A7 Tank 5, Top before lifting

A8 Tank 5, Top after lifting

A9 Tank 5, Top differences

A10 Tank 5, Bottom before lifting

All Tank 5, Bottom after lifting

A12 Tank 5, Bottom differences

Any point on the top surfaces with a entry of "******" is one that

could not be measured either because the laser was mounted too close to

the point or the vapor dome was installed where the point would have

been.

The coordinate system orientation used for reporting data in these

tables is shown in Figure 1. The X-Y origin is at the forward port

corner of each surface, as shown in Figures 3 and 4 for top and bottom

surfaces respectively. The Z-axis is positive downward, and the Z=0

point is defined by the best fit plane.

20
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38
VII. References

1. Hocken, R. J. and Haight, W. C., "Multiple Redundancy in the

Measurement of Large Structures," Annals of the CIRP (1978).

2. Jelffs, P. A., "Calibration of Containers and Gages," J. Inst. Pet.,

Vol . 58, No. 561, p 117-25 (May 1972).

3. Mann, D. B., Editor, "LNG Materials and Fluids. A User's Manual

of Property Data in Graphic Format - 1st Edition," NBS Cryogenic

Data Center (1977)

.

4. Haight, W. C., Scire, F., Hartsock, R. G., and Hocken, R. J.,

"Hydrostatic Deformation of Freestanding LNG Cargo Tanks,"

NBSIR (in preparation).

39

Appendix F

Hydrostatic Deformation

of

Freestanding LNG Cargo Tanks

By

W. C. Haight, F. Scire, R. G. Hartsock, and R. J. Hocken

Tables of Tank Surface Flatness Data

The following tables present the results of the hydrostatic distortion survey conducting on Tank 3 of the El Paso Columbia. The following plane numbering

scheme is used:

Pi ane #

1

2

3

4

5

6

78

Location

Tank Bottom

Starboard Chine

Starboard Wall

Tank Top

Port Wall

Port Chine

Aft Wall

Forward Wall

The coordinate system orientation for each surface is as follows:

Plane # Plane Location

X-Y Origin

Location

Starboard Chine

Starboard Wall

Port Wall

Port Chine

Aft Wall

Fwd Wall

Bottom Aft

Bottom Aft

Bottom Aft

Bottom Aft

Bottom Port

Bottom Port

X-Axis

Bottom to Top

Bottom to Top

Bottom to Top

Bottom to Top

Bottom to Top

Bottom to Top

Y-Axis

Aft to Fwd

Aft to Fwd

Aft to Fwd

Aft to Fwd

Port to Stbd

Port to Stbd

For all planes, a smaller Z value indicates an outward displacement of

the surface as referenced to the tank interior. The X-Y coordinate spacing is

approximately 1524 mm (5 feet) per unit of X or Y. The bottom row of targets

on the forward and aft walls starts approximately 914 mm (3 feet) from the

weld seam joining the wall to the curved section at the tank bottom.

For this survey, planes 2, 3, 5, 6, 7 and 8 were measured twice; first

while the tank was under hydrostatic test and later when the tank was empty in

the storage yard. Plane 1 was not measured because the presence of concrete

supports beneath the tank in the hydrotest area completely obscured the tank

bottom. Plane 4 was not measured because the tank was not completely filled

with water and top deformation does not contribute to the tank capacity, error

in normal tank usage, that is, the tank is not filled with cargo to 1005: capacity.

FI
Table 1 presents a summary of the rms deviations from flatness for each

tank surface measured, and also reports the rms deviations from flatness for

the surfaces comparing the tank containing water vs. not containing water.

From an examination of Table 1, it is concluded that no systematic distortion

of the tank occurred during the hydrotest. The reasoning used is as follows.

The estimated random error of the survey technique is +2.2 mm (refer to Table 1

of "Deformation Measurements on Freestanding LNG Cargo Tanks"). This means the

three-standard deviation limit of uncertainty of the survey is +6.6 mm.

Systematic distortion would be indicated by any rms difference value exceeding

this value. Since only one surface exceeded that value, namely plane 6, and

since that surface had unique characteristics discussed below, we conclude that

systematic distortion due to hydrotesting does not exist.

Tables 2 through 31 present flatness data for each plane measured. Two

unique cases exist.

a) Plane 3, the starboard wall, is reported from Y=1 to Y=20, not to Y=25

as in the case of the other surfaces. This was caused by the laser

plane being too close to the wall from Y=21 to Y=25 for the detector

rod to function. This surface was not re-measured with a new laser

setup because of the hazardous working conditions and time pressure

from the tank construction crew for NBS to clear the tank.

b) Plane 6, the port chine, shows an rms difference deviation 9.0 mm.

A closer examination of Table 21 shows that the largest deviations

occur at the forward and aft extremes of the surface. For the survey

conducted on the hydrostand (reported in Table 19), these end points

could not be surveyed because of the tank lifting brackets. The

F2
construction yard staff would not allow these brackets to be removed

for the NBS survey, so the points were dropped. Therefore, a detailed

comparison of before and after survey data in these regions is invalid.

F3
Table 1

El Paso Columbia - Summary of Flatness Measurements

Flatness Flatness Flatness

Plane without water, ram with water, mm differences

,

2 9.9 11.5 4.8

3 7.7 8.6 3.8

5 6.2 7.9 3.5

6 10.3 11.9 9.0

7 11.1 10.2 5.0

8 12.9 14.5 4.8

NOTE: All table entries represent the rms deviations from flatness in

mm

millimeters
Table 2

El Paso Columbia

Plane 2

Flatness data without water - Z is normal to the plane.

X Y Z (mm)

5. 1 . 165. 40

w' • 1

.

1 5£. 6 0

1

.

1

.

1 35. £0

5. c 155. 70

cr • w • 1 6 0

.

0 0

3

.

—1 m 1 5£. 1 0

1

.

•W* • 147. 30

5. cr

• 16£

.

70

V* • 5. 156. 6 0

1. 5. 1 4£. 30

crJ 1*’ 175. 0 0

• I 151

.

4 0

1

.

l • 139. 3 0

5. 9. 1 7 0

.

50

•»' • 9. 1 6 0

.

80

1. 9. 1 48

.

3 0

1 1

.

181

.

0 0

1 11. 165. 3 0

1

.

11. 153. £0

C*

• 13. 184. 3 0

J • 13. 163. 30

cr

• 14. 145. 30

w • 14. 149. 0 0

1. 14. 151. 10

5. 16. 151

.

10

3. 16. 148. 40

1. 16. 149. 30

5

.

18. 161. 0 0

3. 18. 155. 90

1. 18. 157. 30

5

.

£ 0

.

163. 50

3. £0. 1 6£

.

30

1

.

£ 0

.

161. £0

5. ££. 168. 60

3. ££. 168. 90

1. ££ 166., £0

5. £4. 171., 00

3 £4. 17£., 00

i. £4. 167., 0 0

5. £5. 191..£0

—' • £5. 1 96

.

.90

1. £5. 180..70

RMS deviation from flatness 9.9 mm

F5
Table 3

El Paso Columbia

Plane 2

Flatness map without water.

Y/X 1 2 3 4 5

1 -11. -5. 1. 4. 8.

2 -6. -3. -0. C a “C a 3 -1. -1. -1. -0. 1.

4 -4. —c • o. 1. 2

.

5 r’ • -3. C a C a 2

.

6 -10. —6

.

“ C a

"i 8.

7 -IE*. -9. -5. 4. 13.

8 -8. -5. -1. 4. 1 0.

9 -4. -1. 5. I' a 10 -3. 1. 4. 3. 11.

11 -1. 2

.

8

.

11. 16.

12 “ r* • — c

.

4. 1 0. 17.

13 -14. -6. 2

.

1 0. 18.

14 -6. -9. -13. -18. “*C C a 15 ““ l' a -11. -14. -17. -20.

16 -9. -12. -15. -17. -18.

17 -6. -9. -12. -13. -14.

18 ““C • -6. —9

.

-9. -1 0.

19 -1

.

-4. — r’ a - 8 . -9.

20 -0. a -4. -6. -9.

21 C a -0. “"C a -4. “ 1*' a 22 3. 2

.

1. C. a -5.

23 •i C • 1 . ~ C a -5.

24 kl a C a -1. -4.

25 15. £ 1 • £6. 21. 15.

F6
Table 4

El Paso Columbia

Plane 2

Flatness data with water - Z is normal to the plane.

X Y Z (mm)

3. 1

.

334. 00

O —' 888. 90

846. 00

3. 5. £14.40

1 . 5. 194. 00

er “7 J . • • £44. 00

J* • * • £ 04 . 8 0

1 . 7. 185. 00

J -* • £35.80

3 . 9

.

808. 00

1 . 9. 187.80

5. 11. 841 . 00

3. 11. 806. 70

1 . 11. 184. 8

0

5. 13. 888. 30

3. 13. 8 0 0 . 4 0

5. 14. 198.50

3. 14. 181. 8

0

1. 14. 174.50

5. 16. 1 9 0 . 8 0

3 . 16. 178.70

1 . It-. 171.0 0

5. 18. 186.40

3 . 18. 17 0. 0 0

1 . 18. 171.50

5 . 8 0. 188.80

3. £0. 170. 8

0

1 . 8 0

.

169.60

3. 88

.

173. 00

3 . 84. 174.80

3. 85. 198. 00

RMS Deviation from flatness 11.5 mm
Table 5

El Paso Columbia

Plane 2

Flatness map with water.

Y/X 1 2 3 4 5

1 -£. 0. 3. 3. £

2 -4. -£. 1. £. 4

3 -6. -4. -£. £. 6

4 -7. -5. -3. £. 8

5 -9. -7 • -5. £. 10

6 -11. -9. -7. £. 1£

7 -1£. -11. -9. £. 13

8 -9. -7. -5. 3. 1£

9 -5. -3. -0. 5. 10

10 -3. -1. £. 9. 16

11 -1. 1. 4. 13. ££

12 -£. 1. 4. 9. 15

13 -£. 1. 3. 6. 9

14 -3. -8. -13. -16. -18

15 -£. -8. -14. -16. -17

16 -1. -9. -16. -16. -15

17 £. -6. -15. -14. -14

18 5. -4. -13. -13. -13

19 7 . —£

.

-10. -10. —9

20 9. 1. -7 —6. -5

21 11. 4. -4. —£. -1

22 1£. 6. 1 . 1 . 23 14. 9. a

5. 7

24 16. 11. 8. 8. 11

25 18. 14. 35. 1£. 15

F8
Table 6

El Paso Columbia

Plane 2

Difference between "with water" and "without water" - Z heights in mm.

Y/X 1 2 3 4 5

1 9. cr

• C • "C* — ' a 2 iZ • C 1

.

0. t*' • 3 -5. "" tZ. • -1. J • 5.

4 " j a Z' •' a 1. 8.

5 iZ • -4. •’ • 0. r • 6 -1

.

— J • -5. -1. 4.

7 -1

.

“ c. • -4. ~ iZ 0.

8 -0. “ iZ • -4. -1

.

C • 9 -0. — c‘ • J • 0. j a 10 -0. -1. c. 1. 4.

11 - 0

.

-1

.

“~tZ ® c! ® 8.

12 6. J • - 0

.

-i. “"C • 13 11. 6. 1. -4. -9.

14 iZ. • 1. 0. c° • 4.

15 5. •Z • -0. 1

.

•>' a 16 8

.

-J • -1. 1

.

a 17 8. ““iZ • -1. -1.

18 r • c • -4. -4. -4.

19 • c. • "" J' i ” tZ • -0.

20 9. J • — c. • 0. Z1 a 21 9. 4. “C a c

.

8.

22 9. 4. 0. w1 . a 23 11. 6. 8

.

8. 11.

24 14. 9. 8. 9. 15.

25 c — f‘ • C;

'J • -9. -0.

RMS deviation from flatness 4.8 mm

F9
Table 7

El Paso Columbia

Plane 3

Flatness data without water - Z is normal to the plane.

X Y Z (mm) X Y Z (mm)

1£. 1

.

1 £ 0 . 9 0 C a 1 1 a 153. 70

1 0. 1 . 1 38 . 3

0

1. 1 1 a 156. 90

1. 14 0. 0 0 1 0 . 13 . 156. 1

0

6. 1. 148. 00 • a 13 a 154. 50

4. 1 . 147. 10 6. 13 a 157. 90

C. • 1

.

149. 70 4. 13 a 158. 00

1. 1

.

144.90 C a 13 a 154.30

1 0. d a 119. 0

0

1. 13 a 154.90

u 8

.

189. 3

0

1 0. 14 159. 70

6. cl a 1 46 . 8 0 a 14 a 1 6 0 . 5 0

4. Cl a 1 48 . 9 0 6. 14 a 166. 5

0

C • Cl a 141.0

0

4. 14 a 164. 90

1

.

C a 133.50 Cl a 14 a 159. 10

1 0. —1 a 180. 70 1. 14 a 1 6 0 . 3 0

a 1 33. 80 18. 16 a 1 3 1 . 3 0

6. —' a 144.50 1 0. 16 a 149.80

4. •J a 141.40 ' a 16 a 151.90

C • a 141.30 6. 16 a 155. 30

1

.

a 140. 8 0 4. 16 a 156. 80

1 0. 5. 1 c‘ u‘ . J 1.1 Cl a 16 a 1 56. 60

• 5. 1 3 1 . 8 0 1. 16 a 156. 1

0

6. 5. 1 39 . 3

0

18. 18 a 181. 0

0

4. 5. 1 4 0 . 4 0 1 0

.

18 a 145. 90

d a 5. 1 48.30 C1 a 18 a 158.30

1. 5. 141 . 50 6. 18 a 156. 3 0

1 0

.

I'* a 184. 3

0

4. 18 168. 80

8. 1 a 189.50 Cl a 18 a 161. 8

0

6. —

j

1' a 139.80 1. 1

8

a 168. 00

4. I’’ a 148. 70 18. 80 a 185. 0

0

C a

1*’ a 143. 3

0

1 0. 8 0 a 146. 00

1. 1*’ a 141.8

0

a 8 0 a 153. 90

1£. 9. 181. 3

0

6. 80 . 160. 00

1 0. 9 „ 184. 3

0

4. 80 a 161. 8

0

8. 9. 134. 70 d a 80 a 163. 1

0

6. 9. 141 . 30 1. 8 0 a 164. 70

4. 9. 144.90

C a 9. 146. 90

1. 9. 151.30

1£. 11. 119. 30

1 0. 11. 135.90

8. 1

1

. 143. 70

6. 11. 146.80

4. 11. 151.80

RMS deviation from flatness 7.7 mm

F10
Table 8

El Paso Columbia

Plane 3

Flatness map without water.

Y/X 1 2 3 4 5 6 7 8 9 10 11 12

1 -2

.

cr

w' 6. r* 1 0. 13. 11. 9. 11. 12. 6. -1

2 -10. -5. -1. 3 m r • 10. 4. ' • -5. — 8

.

-11. -14

3 -9. —6

.

-3. -1. l" • 4. 1. ~ j —8. -12. -16

4 -9. -6. -4. —2

.

0. o 1

.

-1. -5. -8. -11. -14

5 - 1 0

.

“ • -5. -4. —2

.

-0. -2. -4. -6. — 8

.

-10. -12

6 -11. * f a -6. -4. —2. -l. -3. -6. ““ 1** • —8. -9. - 1 0

7 -12. -8. -6

.

-4. -3. “C w -5. -8. -8. -8. -8. -9

8 —8

.

-7. -5. -4. -3. “C -4. -6. —8

.

-9. -9. — C|

•• 9 -4. -6. -5. -4. -3. -4. -5. -7. -1 0. -9. -9

10 -2. -4. w* • -2. -1

.

-i

.

-1. -1. •—1 -5. -8. -1

1

11 -1

.

-2. -1. 1. 0. 0. 1. 2. 1. -1. -7. -13

12 -2. 0. w1 • 4. 5. 6. r* • 8. 8. 7 5

13 -5. -3. 1. 5. 8. 10. 1 0. li. 14. 17. 20. 24

14 -0. 1. 6. 11. 14. 17. 17. 16. 18. 20. 22

.

24

15 -4. -2. 2 6. 8. 11. 11. 11. 12. 14. 11. 9

16 -7. -4. -2. 0. 2

.

4. 5. 5. 6. 7. 1. -6

17 -5. -2. 0. 2

.

3. 4. 4. 4. 5. 5. -4. — 1

2

18 -3. -1

.

2. 4. 4. w* 4. 3. 2

.

-8. -18

19 — *T* w -1. 1. I' • . w* • 4. 4. •—9 2

.

1. -8. -17

20 -2. -2. 0. dm 5. 4. I' • 2. -0. -8. -16

Fll
Table 9

El Paso Columbia

Plane 3

Flatness data with water - Z is normal to the plane.

X Y Z (mm) X Y Z (mm)

12. 1. 159. 30 CL a 11 • 135.90

1 0. 1. 171.40 1. 11 • 137.30

8. 1. 171 . 70 10. 12 144.70

6. 1. 175.90 o i a 140. 2

0

4. 1. 178. 00 6. i: a 142. 00

c

.

1. 171.30 4. 12 a 1 36 . 0

0

18. 2. 134. 1

0

C a 12 a 1 28 . 3 0

10. 2

.

149.50 1. 12 a 129. 00

3. 2. 159. 90 12. 14. 123.30

6. 2 171.20 10. 14. 144. 00

4. 8. 165. 20 8

.

14. 141.10

C • 2 1 6 0 . 1 0 6. 14. 144.80

18. o. 135.80 4. 14. 1 38 . 1

0

10. ow( • 148. 90 c. • 14. 128.50

8. • 158.40 1. 14. 1 c! f' • 2 0

6. o e 165. 70 12. 16. 112. 0

0

4. ' 159.10 1 0. 16. 125.30

c. • Z" a 157.40 O • 16. 125. 10

18. 5. 135.30 6. 16. 185.30

1 0. 5. 141. 10 4. 16. 123. 1

0

8. 5. 148.30 C 16. 118. 00

6. 5. 153.90 1

.

16. 112.20

4. cr

•J ® 150. 1

0

1 0. 1 I1 a 113.30

c • 5. 149.10 O • 1 3. 118. 1

U

1. 5. 148. 90 6. 1 Z1 a 118.50

18. 1* • 122. 00 4. 1 3

.

118.30

1 0. 7I • 137. 00 C e 18. 112.1

0

o • r • 138. 00 6. C 0. 114.20

6. 7. 144.70

4. 7. 141.40

8. 1** a 132.90

1. 1* • 138.50

18. 9. 1 28 . 3 0

10. 9. 128.30

8. 9. 132.90

6. 9. 133. 00

4. 9. 137. 90

8. 9. 141.10

1. 9. 138. 50

12. 11. 118. 00

1 0. 11. 133.80

8. 11. 136.1

0

6. 11. 136. 00

4. 11. 135. 10

RMS Deviation from flatness 8.6 mm
Table 10

El Paso Columbia

Plane 3

Flatness map with water.

Y/X 1 2 3 A 5 6 7 8 9 10 11 12

1 4. 6. 1*’ • 8. 11. 14. 13. 12. 12. 13. 8

.

2 -6. -3. 0. 4. o • 12. •** • 2. -2 . -6. -13. -20.

3 -5. -3. -1. 1. 5. 9. 6. 4. -0. -4. -10. -16.

4 -6. -5. -3. -1. 2. 6. 4. 1. —2 . -5. -9. -13.

5 “ r -6. -5. -3. -0. 2* • 1. -1. -4. -6. O m -10.

6 - 1 0. -11. -8. -5. “C • 1. -1 . -4. -5. -6. -10. -14.

7 - 12. -17. -12. -6. -4. -1. -4. -6. -6. -5. — 1 2. -18.

8 -9. -10. -8. -6. -4. —2. -4. -6. -6. l’ a -1 0. -12.

9 “ l • -3. -4. -5. -4. a -4. -6. “ f a -9. -8. —7

.

10 -5. — 3 . •J >' —2. -1. -1. “ C • —£• -3. -6. -9.

11 -3. -3. -3. “c • -1. 1. CL • j s •j • 2 . _e;

•J • -12.

12 -4. -4. -2. 1. 4. 6. 7. r* • 9. 1 0. 9. i

' m 13 -6. -5. -1. 4. 8. 12. 12. 12. 15. 19. 22 25.

1A -5. -3. —' • 9. 13. 18. 17. 16. 18. 21. 11. 2 . 15 - 1 0. -5. -0. 4. 7. 1 0. 1 0. 1 0. 12. 14. 6. -1.

16 - 14. -8. -4. -1. 1. • 4. Cj 6. 7

.

1

.

-4.

17 - 13. -8. -4. -0. 1. • 4. 4. 4. 0. “ j! ^ 18 - 12. -8. -4. -0. 1. C • 2

.

1. -1

.

““C • 19 - 11. -8. -4. 0. 1. 1. C • 0. - 3

.

-1

.

20 - 10. -9. -4. 0. 0. •j • 1. c • —c

.

-6. -1

.

FI 3
Table 11

El Paso Columbia

Plane 3

Difference between "with water" and 'without water " - z height s in mm.

Y/X 1 2 3 4 5 6 7 8 9 10 11

1 6. 1

.

1. 1. 1. 1. £

.

C a C a 1

.

C a 2 £

.

C! a 1. 1. flZ a •Z' a Cj 4. H a c. 3 4. 8

.

C a 1. £

.

C a C! a a -• a 4. 2.

4 Z* a cl . 1. 1. c • Z* a

• *' s j . a j a C a 5 1. 1. 1. £

.

j s •J* a •Ja s C a C. a C a 6 1. -4. e=’ -1 a -1. 0. C a £• C a C a C a -1 . 7 -1. -9. -6. -3. -1. 1. 1. C a C. a 3. -3.

8 “C • -3. ““C a “lZ a -1

.

0. 0. 0. 1 . lT a -1.

9 -3. 3. 1. -1. -0. 0. -1. -1. 0. C a C a 10 —c! • 1. -1. “C a -1. 0. -0. -0. 1

.

C a C a 11 ““

c. tZ • —£

.

- 3 . -1. 1. 0. 0. C a

“i C. a 12 -i. “ c • — c • “C a -0. 1

.

1. 1

.

1 . C. a C a 13 -i. ““C • —£

.

-1. 1. C. a £

.

1. 1 . 1. 1 . 14 -4. -3. w* . “C a -1. 0. 0. -0. 0. 1. -11.

15 -6. — ~cl . -£. -1. -0. -0. -0. 0. 0. -5.

16 -8. -4. -£. -i. -1

.

-1. -0. -0. -0. - 0

.

1.

17 -8. -6. -4. -3. — c. -1

.

-1

.

- 0

.

- 0

.

-1

.

4.

18 -9. “ r* a -6. -4. -3. -1

.

-1

.

-0. -1

.

-1

.

1* a 19 -7. -5. -3. -3. -3. C a -1 . C. a -4. 6 a 20 -8. l‘* a -4. -1. -3. ""C a -3. -1. -4. -6. cr

RMS deviation from flatness 3.8 mm

12

4

ij

1

c. -4

-

1

0

-4

11

1

!

F14
Table 12

El Paso Columbia

Plane 5

Flatness data without water - Z is normal to the plane.

X Y Z (mm) X Y Z (mm)

18. 1 . 145.70 6. 11. 119.90

12. 1 . 144.30 4. 11. 119.50

8. 1 . 1 4 0 . 3 0 c 11. 121. 3 0

6 . 1 . 1 3 2 . 6 0

1 . 1

1

. 122. 8

0

4. 1 . 127. 20 12. 12. 124.90

a • 1 . 137.20 1 0 . 12. 1 3 0 . 8 0

i. 1 . 1 39 . 9

0

'J 12. 1 23 . 3

0

12. C a 1 39. 60 6. 12. 123.20

1 0. 2 . 140. 00 4. 12. 121.20

8. 2. 138.20 C f8 . 125.30

6. 2 •. 1 35 . 3

0

1. 12. 1 23 . 9 0

4. 2 . 132. 3 0 1 0. 13. 134. 3 0

C. 2 . 137. 1 0 • 13. 1 32 . 2

0

1 . 134.1 0 6. 1

3

. 1 3 0 . 9 0

'i 2 .

1

0

. 3. 137.20

14 0. 3 0

4.

C

13.

13.

129.50

125.80

jlj •j • 1 35 . 6

0

1 . 13. 125. 30

6. Z‘ m 129. 80 12. 15. 1 8 i . i U

4. 128.40 1 0. 15. 124. 4IJ

2 .

1

.

131 . 90

133. 1

0

6.

15.

15.

1 3 0 . 8 0

1 33 . 6 0

12.

1 0.

5.

5.

5.

124.60

133. 30

127.20

4.

C a 1.

15.

15.

15.

125.90

121.90

121. 8 0

6.

4.

2 .

1

.

5.

5.

CJ5.

12 0. 9 0

119.60

127.20

131 . 70

12.

1 0.

6.

17.

17.

17.

17.

124. 9

U

1 2 0 . 9 0

124.90

132.30

1 0. r 129.1

0

4. 17. 186. 8

0

O ^ r 122.90 c! 17. 124.7 U

6.

4.

7 . 119.30

119. 30

i

.

1 0.

17.

19.

123. 00

118. 0

0

c

1 . 12.

1 0.

8.

“j

r

r9.

9.

9.

124.90

1 3 0 . 3 0

124.90

129.40

121.90

O • 6.

4.c . 1.

19.

19.

19.

19.

19.

182.8 U 127.90

124.90

125.30

126.20

6.

4.

2.

1 . 12.

9.

9.

9.

9.

11.

119. 10

118.40

122.90

129.90

126.30

1 0.

• 6 . 4.c .

21 . 21.

21.

21.

21.

117.60

127.50

132. 00

129.20

128.70

1 . 8

.

1

1

. 11.

127.20

120.30

1 . 10.

C 1 u

IsT'Cb i U

114.90

RMS deviation from flatness 6.2 mm

X Y Z (mm)

127. 00

134.70

135. 00

135. 70

118.70

184.50

135.60

135.30

131.30

118.4 0

122. 00

1 88 • 6 0

129. 90

1

3

0 . 2 0

1

3

0 .

9

0

138. 30

F15
Table 13

El Paso Columbia

Plane 5

Flatness

Y/X

map without

1 2

water.

3 4 5 6 7 8 9 10 11 12

1 7. 5. -0. -5. “c! • 1. 5. 9. 1 0. 11. 12. 13

2 2 . 5. 2. 0. £• 4. 5. 7. 8. 9. 9. 9

3 1. -0. -2. -3. —c! • “C . 1. 5. l‘‘ • 1 0. o r’ 4 0. -8. -5. -7. — r* • -6. TM -I' a 1. 4. 6. 4. i 5 0. -4. -8. -12. “ii. -10. ”7

.

—J-! 0. p -1. -5

6 -0. -5. -8. -11. “U. “1 0. -8. -5. -2. 1

.

1. 1 7 -1. -6. -9. -11. -ii. “11. -9. -7. -4. -0. 6

8 -1. -7. -9. “11. -ii. “11. -9. — r • -4. 0. 1. i 9 -1. -7. -9. -12. -ii. “1 0. -9. -7. -3. 1. “2 -4

10 -4. -8. -9. “11. -10. -1 0. -9. —p a -5. “8

.

— *! 11 * 1 a -8. -9. -10. -9. -9. -9. —7 . -5. -3. “C

12 -6. -4. -6. -O•J • “ r* • -5. -5. -5. -I. 3. 0. -3

13 -4. -3. -1. 1. c! • pJ • a 4. 5. 1** 8. 9

14 -5. -5. " a “1. 2. 4. 4. 4. 2. 4. 5

15 -7. -7. -4. —2

.

2. 6. 5. o • 0. -3. -I. 1 16 -6. -5. ~3. -1. la • 5. 3. 1. -2. -4. “C . -0

17 _CTJ -2. -1. £• 5. 2 . -2. -4. -6. -3. -1

18 ** • -2. -I. i. ' a 0. -5. “l‘ — f . r' 19 -1. “£• —2 “ C • -0. 1. “1. —' t -6. —8. -10. -12

20 2. 0. 0. 0. c • 4. 1. -I. -4. -8. -11. -15

21 6. 2. c • • 4. 6. 4. 2 -8. -12. -17

22 8. 4. 5. 6. 7 • 8. 5. 2. -3. -9. -14. -19

23 9. 6. 8. 9. 9. 9. 6. 2. -4. -10. -16. —82

24 7. t • 8. 1 0. 1 0. 11. 5. -0. -6. —8. -11

25 13. 5. 5. 5. 5. 5. 2. -2. -2. —2. -4. -5

F16
Table 14

El Paso Columbia

Plane 5

Flatness data with water - Z is normal to the plane.

X Y Z (mm) X Y Z (mm) X i_ Z (mm)

12. 1

.

143.70 8. 11. 137.90 C 2 1

.

160. 0

L

1 0. 1. 146.1

0

6. 11. 135.20 1. C. 1

.

161. 0

C

8 • 1

.

1 33 . 5 0 4. 11. 129. 30 12. 2

3* 145. 2

C

6. 1 . 125. 00 C • 11. 1 32 . 0 0 1 0. 2 3. 156. 8 C 4. 1 . 123. 00 1 . 11. 1 3 0 . 8 0 8 . c!

3* 169. 2

L

C 1 . 131 . 1

0

12. 12. 147. 00 6. c

3' 175. or

1. 1 . 133. 30 1 0. 12. 1 5 0 . 9 0 4. 2

3* 172.1

0

12. 2 . 139.80 c* 12. 144.1

0

c C 3* 169. or

1 0. 2

.

144. 00 6. 12. 141 . 30 1. c 3« 171.10

8. C • 136. 0 0 4. 12. 136.80 12. 2 4. 145. 90

6

.

2

.

1 33 . 3 0 C 12. 138. 1

0

1 0. d 4. 161.10

4. C • 1 29 . 3 0 1. 12. 134. 00 © 24. 168. OH

C L_ • 134. 3 0 1 0. 13. 155.1

0

6. cl 4. 179. 30

1. 2. 129.50 o • 13. 1 52 . 3 0 4. c! 4. 176. 7 r 12. 8. 135.30 6. 13. 150. 3 0 CL m c! 4. 174.10

1 0. 3

.

142. 00 4. 13. 148. 10 1 . c' 4. 172.5 0 8

.

3. 132. 1

0

C. m 13. 142.30 12. •-i c 5. 169. 70

6. *i B 129. 70 1. 13. 140. 1 0 1 0. ©4— 5. 173. 0l

4. •J 125. 1 0 12. 15. 157.40 o “i lL 5. 166. 0C

2. 1 3 0 . 9 0 1 0. 15. 153.20 6. •“i CL 5. 168. 0l

1 . 127. 30 © • 15. 156.50 4. ~iC 5. 169. 20

12. 5. 131 . 1

0

6. 15. 159.50 c • c 5. 164. or

1 0. 5. 139. 00 4. 15. 149.50 1. d 5. 178. 0C

8

.

5. 129. 00 c • 15. 143. 00

6. 5. 123. 20 1. 15. 139. 70

4. 5. 119.20 12. 17. 158.80

2. 5. 127. 10 1 0. 17. 152.40

1

.

5. 129. 30 8. 17. 157.30

1 2

.

7. 119.90 6. 17. 159.50

1 0. l"" 141 . 30 4. 17. 153.60

8. 7. 134. 00 C • 17. 151.50

8. 7. 1 26 8 0 1. 17. 147.30

4. r” 125. 00 12. 19. 141 . 00

2

.

{ a 129.30 10. 19. 151.50

1. \ a 131.40 o 19. 156. 80

12. 8. 141. 10 6. 19. 165. 60

1 0. 9. 141.90 4. 19. 156. 3 0

8. 9. 135.20 2

.

19. 155. 00

6. 9. 129.70 1. 19. 155.60

4. 9. 126.80 12. 21. 149. 00

2. 9. 127. 0 0 10. 21

.

154.20

1. 9. 1 32 . 3 0 8. 21

.

161.20

12. 11. 142.80 6. 21

.

166.80

10. 11. 146. 70 4. 21. 163.10

RMS Deviation from flatness 7*9 mm

FI 7
Table 15

El Paso Columbia

Plane 5

Flatness map with water.

Y/X 1 2 3 4 5 6 7 8 9 10 11

1 6. 4. -0. -5. -4. -3. 1. 6. 13. IS. 17

2 1. 5. “i 0. c . 4. 5. 6. 1 0 . 14. 13

3 -3. 0. -3. -6. -3. -1. -0. 1. 6. 11. “7

4 -4. -3. — f . -1 0. -8. —6 . -4. —3 .

*• a 6 . 4

5 -4. — r* • -11. -15. -13. -11. -8. -5. -0. 4. 0

6 -5. i*‘ • -10. -13. -13. -1

1

. -8. -4. - 0 . 4. -3

7 -5. “ft. -10. -13. -11. -1

1

. -7. -4. 0. 4. “ »** 8 “ r* -1 0. -13. -13. -13. -1

1

. —

S

. -5. -1 . iZ. a -3

9 -8. -13. -13. -13. -13. -1

1

. -8. -6. “iZ- a 1 . 0

10 -10. — 13. -13. -14. -13. -10. -8. -6. “C a lL a 0

11 - 1 3. -11. -13. -14. -1

1

. -9. — i

-’

.

-6. “C! a.*i a 0

12 -11. “ I*‘ a _,C; -8. -6. -4. -3. -1. C. a 5.

13 -6. -4. -l. 1. C a • a 4. 5. 6 a 8. Q

14 —C; -5. -3 . 1. *•' a 6. 6. 6. 5. 5. f 15 -10. 1** -3. -0. 5. 9. 8

.

6. 4. O a 5

16 -8. -4. -£

.

0. 4. 8. 6. cr

-J a 1. 2* 17 -5. -1. -0. 1. *i a 6. 5 . 4. 1. -1 . C. 18 -3. -1. -0. 0. 4. 8. 5. C a -1. -3. -4

19 - 0 . -1. -0. 0. 5. 9. 5. 0. -3. -5. -11

20 1 . 0. 1. C a 5. 8. 4. 1 . “C a -6. -1 0

21 C! a 1. C a 4. 5. i

-

’

.

4. 1 . C a -6. —9

22 5. 4. 5. r* a

jZj 1 0. \ a 4. -1. -6. -10

23 9. I*‘ a 8. 1 0. 1

1

. 13. 9. 6. -0. -6. -13

24 9. 1 0. 11. 13. 14. 15. 9. 3 . -0. -4. -11

25 13. “C a 1. 3. C. a 1. -0. .*• a I*‘ a 5

12

15

1 Ci 4

0

-4

-1

1

-18

-9

0

-1

—

c

1 10

6

5

-16

-14

-1

1

-15

-18

-19

1

F18
Table 16

El Paso Columbia

Plane 5

Difference between "with water" and "without water" - Z heights in mm.

Y/X 1 2 3 4 5 6 7 8 9 10 ii 12

1 -1

.

-1 . 0. 1 . -1 . _3 —1 a a £ .

1* a 4. C. a 2 -1

.

1

.

0. -0. 0. 0. 0. -0. C a 5. •”i 1 . 3 -4. 1

.

-1 . —

£

. -1. 0. -£' . -4. -1 . 1

.

-1 . -3.

4 -4. -1

.

c • •J • C -0. -3. -1 . 1

.

0. -1

.

5 -4. “’ C • -3. j a ""C a -1 . -£

.

-0. 1 . 1 . 1 . 6 -4. c. ”"c' “lL a -1. -0. 0. 1. £ .

“i -4. -11

.

7 -5. —C* • -1

.

-1. -0. 0. £'

.

"• 4. 4. -10. -£4.

8 -6. -4. -3. -1

.

-1. 0. 1. 2' a ll! a lL -4. -10.

9 “ \

‘ a -6. -4. —cl . -1. -0. 1. C* a 1. 0. £

.

4.

10 -6. -4. -4. ' a a 0. 1. C a

•Z1 a 4. a C a 11 -5. -3. -4. -4. a 1. 1. C a 5. 8. 4. 0.

12 -5. ~3

.

— £

.

-0. 1. 1. 'J a 4. O a £

.

a 4.

13 — £

.

-1

.

- 0

.

1

.

1. 1. 1. 1 . 1. 1 . 1. 1 . 14 — w a -0. 0. 1

.

C a £

.

£

.

£

.

a a a -• a 15 _ 0. 1. C a

’i 4. —' a Z* a 4. 5. 6. t* a 16 1

.

1. C a a £. j a 4. 5. 5. C"

. . 17 -0. £

.

3

.

1. 1 . 1 . a 6. 5. 4. cr

-• a a 18 0. 1 . C £

.

~i 4. 5. 5. 4. -• C a 1 . 19 1

.

1

.

c! • C S. 6. -• a a C a -1 . -4.

20 -£ . -0. i. 1. 3. 4. a 1. C a C. a C a 1 . 21 -4. -1. -0. 1. 1. 1

.

0. -1. 1 . C a 4. 8 a 22 C. u -0. 0. 1. 1. C a £ . C a £ . 4. cr

23 -1

.

0. o. 0. d. a 4. 4. 4. 3 a 3 . 24 1

.

5. 4. J a Z* s 4. 4. 4. 3

.

C a “8a

25 -0. “ \ a -4. —

£

. “C* a -3. -1. C a Cj 9. 8 a 8 a

RMS deviation from flatness 3.5 mm

FI 9
Table 17

El Paso Columbia

Plane 6

Flatness data without water - Z is normal to the plane.

X Y Z (mm)

5. 1 . 142.10

•»* 1 . 165. SO

e*

•J c 132. 00

•—1 c 1 38. 1

0

5. 131.1

139. 80

CT 5. 1 3 0 . 1 0

' CTJ a 1 38 . 3 0

1. 5. 1 36 . 2 0

5

.

r' 134. 30

' r m 132. 90

1. r 147.90

c

J 9. 137. 3 0

•J 9. 131. 3

0

1

.

9. 137. 90

5. 11. 137. 30

•—1 11. 1 36 . 2 0

1. 11. 142. 3 0

5. 12. 133.50

3

.

12. 1 3 0 . 3 0

1

.

12. 141. 0 0

5. 13. 145.80

• 13. 142.1

0

5. 15. 149.1

'• • 15. 148.60

1

.

15. 147.1

0

5. 17. 154. 10

17. 149. 60

1

.

17. 145.20

5. 19. 161. 3

0

. 19. 150.30

1

.

19. 144.7 0

5. 21. 1 68 . 9 0

3 m 21. 152. 00

1 . 21. 133. 1

0

5. C •-» 175. 10

-• m C J* 156.20

1 . 23

.

137. 80

5. jCC -• . 181. 3

0

J m c- C-J • 175.70

1. ocC -« • 164. 90

RMS deviation from flatness 10.3 mm

F20
Table 18

El Paso Columbia

Plane 6

Flatness map without water.

y/x 1 2 3 4 5

l 56. 43. 31. 18. 6

.

2 9. 6. C • -£. -5.

3 13. 8. • —£

.

-7.

4 6. •J* e 1. -4. —9 m 5 -1. -1. -1. -5. -10.

6 w • -0. -4. -7. —9

.

7 8. 0. -8. —8. -8.

8 £. -4. -1 0. —8. -7.

9 -4. -8. -11. -9.

10 -£. -6. -10. -9.

11 -1. —5. -8. -9. —C|.

12 ~3. -9. -15. -14. -13.

13 — 7 • -6. -4. —0 • — £ • 14 -4. -3. -£. —£

.

-1.

15 -0. 0. 0. -0. -1.

16 —c! -1. - 0

.

0. 1.

17 -4. —£ • -1. 1. £.

18 -5. -3. -1

.

£

.

5.

19 -6. -4. •' • 8.

20 -13. -8. 4. 11.

21 —£0. -11. -£• 6. 13.

22 -13. -10. -i. © 16.

23 -17. -9. 0. 9. 1 8.

24 -5. £. 9. 14. £0.

25 8. 13. 18. £ 0

.

££

F21
Table 19

El Paso Columbia

Plane 6

Flatness data with water - Z is normal to the plane.

X Y Z (mm)

—1 • 1 . £61 8

0

1. 1. £34 . 6

0

• c £31 . UU

.•» Z' m £ £6 . i' U

5. 5. £39.50

•”i Cj £16. 00

1. Cj 1 98 . £

0

5. 1 ££9.40

1 a £00. 00

1. I*’ £ 03 . 3

0

5. 9. ££8. 00

•J* 9. 193.90

1. 9. 187. 1

0

5. 11. ££3. 1

0

j s 11. 196. 0

0

1. 11. 1 86 . 0

0

5. 1£. £17. 0

12. 194.1

0

Cj 13. ££ r' • 4 U

*• m 13. 198. 00

1 . 13. 1 r* £ • 6 U

5. 15. £££ . 5 0

3. 15. 196. 70

1

.

15. 178.30

5. 17. £££ • 4 U

”i 17. 1 9 0 . 3 0

1. 17. 173.70

CJ 19. ££ 1 . 1 0

”i 19. 1 8£ . 6 0

1

.

19. 159.60

5. £1. ££6. 50

•Z* • 31. 181.4 0

1

.

£1. 147.1

0

C Z> m 183. 1

0

•1* 35

.

£03. 1

0

1. 35. 16c'. 8 u

RMS Deviation from flatness 11.9 mm
Table 20

El Paso Columbia

Plane 6

Flatness map with water.

Y/X 1 2 3 4 5

1 lC 86. 3 0

.

r‘ 2 15. 18. 1

.

84. 87

3 9

.

1 0. -1

.

14. 17

4 c

.

c

.

C • 5. r* 5

_cr -6. r* -5. —3

6 0. -6. -18. -9. -A

7

cr

. — 18. -13. -y

8 -1. -10. -19. -13. -7

9 -13. -19. — 1 8. -5

10 _Cj -10. -16. -10. -5

11 -3. -8. -18. -9. -5

12 -15. -14. -18. -10. —9

13 -13. -9. -6. -1. 4

14 -6. -5. -4. 0. 4

15 -1. —8

.

“C.' 1. 4

16 -1. C -3. c . y

17 -1. “C • -4. 8. 9

18 -6. -5. -5. 8. 1 0

19 -10. -9. ““ r* • 18

20 -14. -10. -5. 6. 17

21 — 18. -11. -3. 9. 88

22 -10. -3. 4. 16. c r’ 23 lL 5. “i c'8 32

24 5. 13. 80. 89. j i*’ 25 13. 81. 88. 35. 43

F23
Table 21

El Paso Columbia

Plane 6

Difference between "with water" and "without water" - Z heights in mm.

Y/X 1 2 3 4 5

1 -34. -17. -1. 15. 31

.

2 8. 1 £. -1. £5. 3£

.

3 -4. £. -4. 18. £4.

4 -4. -1. 1. 8. 18.

5 * 9 -5. -8. 0. 1 • 6 — J a -6. -8. —£. 3 a 7 “ ' a —7 • -10. -5. -0.

8 -3. -6. -9. -4. 1.

9 — Z' . -5. -8. * o' a £.

10 —

£

. -4. —6. -£. a 11 —£. -3. -4. -0. 4.

12 — 1£. -4. —' a 4. 5.

13 -5. " a -1. £. t a 14 "* a C a — c. • C a 5.

15 -1. —£. —£. 1. 5.

16 1. -1. -3. 1. 5.

17 J1 a 0. —3. 1. 8.

18 -0. —£

.

-4. 1. 5.

19 -4. -4. -5. -0. 4.

20 -1. —£

.

" •' a £. 8.

21 £. 0. -1. 4. 9.

22 8. 7 8. 9. 1£.

23 15. 14. a 13. 15.

24 1 0. 11. 11. 14. 18.

25 5. 8. 1 0. 15. £1 .

RMS deviation from flatness 9.0 mm

F24
Table 22

El Paso Columbia

Plane 7

Flatness data without water - Z is normal to the plane.

X Y Z (mm) X Y Z (mm) X Y Z (mm)

15. £5. £17. 1 0 15. 15. £15. 30 7. 6. £35. 80

13. £5. £47. 30 13. 15. £45.30 5. 6. £45. 30

1

1

. ocL. J a £41

.

5 0 11. 15. £45. 10 «' a 6. £55. 0 0

9. £5 . £39. £0 9. 15. £3y , 9 u 1. 6. £6 0

.

00

\ a £5. £36

.

0 0 r’ a 15. £44. 1

0

15. 4. 195. £0

5. £5. £31

.

1 0 5. 15. £49. 1

0

13. 4. £1£. 30

15. £4 . £13. 5 0 w* • 15. £60. 00 11. 4. ££0. 0 0

13. £4 . £*4 ? a £0 1. 15. £74.30 9. 4. ££7 . 00

1

1

. £4. I* c; L'.'L a 70 13. 13. £34. 1

0

7. 4. £31 . 80

9. C'4 , £44. 3 0 11. 13. £38. 70 5. 4. £4£. 3 0

1 a £4. £4£. 70 9. 1 3. £4£. 00 3. 4. £48. 90

5. £4. COC a 5 0

•' a 13. £45. 30 15. £. 183. 80

15. CO a £06. 3 0 5. 13. £55.50 13. £. £10. 00

13. £3. £44. 3 0 •J a 13. £66. £0 11. £ . ££1 . 70

11 . C a £47 . 30 1. 13. £7 0 . 8 0 9. £. £3£. 50

9. C a £41 . 1 0 15. 1 £ . £13. 30 7. £ . £39. 1 0

\ a £3 . £39. 0 0

1

3

. 1 £. ££9. 00 5. £. £44. 80

e-J a C a £ 3 3

.

0 0 11. 1 £. £35.30 15. 1. 173. 80

•' a C - a £35. 60 9. 1£. £36. 30 13. 1. 195. 10

15. £ 1

.

£04. 8 0

1* a 1£. £43. 50 11. 1. £ 06

.

80

13. £ 1

.

£4£. 0 0 5. 1 £. £51.30 9. 1. £13. 30

11. £ 1

.

£47. 40 j a 1£. £69. 30 7. 1. £££. 50

9

.

£1

.

£45. 90 1. 1£. £78. 30 5. 1. £ 3 1

.

30

\ a £1

.

£4£

.

8 0 15. 1 0. £10.90

tr

a £1

.

£38

.

0 0 13. 1 0. £££.40

•' a £ 1

.

£44. 50 11. 1 0. ££ (' . 8 0

1 . £ 1

.

£59. 0 0 9. 1 0. £3£. 50

15. 19. 199. 0 0

i

r a 1 0. £40. £0

13. 19. £4 0. 5 0 5. 1 0. £50. 1

0

11. 19. £48. £0 3. 10. £64. 80

9. 19. £44. 6 0 1. 1 0. £68. 80

r’ a 19. £4£

.

30 15. 8. £01 . 00

5. 19. £44. 9 0 13. 8. £11.40

•J a 19. £5£. 1 0 11. 8. ££9. 1

0

1. 19. £67. 1 0 9. O a £31 . 0U

15. 17. £07. 30 1*’ a O a £38. 70

13. 17. £4 0. 50 5. 8. £48. 70

11. 17. £43. 3 0 O a 8. £61 . 90

9. 17. £43. 0 0 1. 8. £64 . £ 0

r’ a cr

•J a 17.

17.

£48.

£49.

10

3 0

15.

13.

6.

6.

£10. 00

£12.30

•J a 17. £37. 30 11. 6. ££5.40

1. 17. £ 7 0

.

£ 0 9. 6. £31 . 00

RHS deviation from flatness 11,1 mm

F25
Flatness

map

without

water

i-t CO f-_ CO U~* CO *3" iji 't • in f'-- iji t~t rf- CO 1*0 oil Ml* CO CO CO f'-

, CO CO ft I III I I ft ft ft ft ft ft I I till I I I I I I

H- co

.= r- fH N CO CO UO uo H* CO iJ-. UO CO rH * * CO CO co r - co H CO

1 i iH1

I ' 1 1 1 1 rH rH rH l

f'O CO CO co co CO H* U0 X* rH H* r-- cr. H

- *Jn *3" »-• CC* f'- Ml* * ji« n r- 01* a* H 1

1 1 1 1 1 1 1 1 rH ft CO CO rH rH rH rH rH rH rH CO rH

CH

rH uo

rH

1

’-I CO CO

1 1 1 fH1 fH

1 fH

l rH

1 rH CO •X* *j. CO

rH

\£i —' CO IT* rH CU rH rH

•>0 rH

X*

rH rH

'•JJ rHuo uo

rH rH

J.

rH COrH

CO vs CO CO CO 111* CO CO UO CO rH H

- Mil U0 CO uo r-- •X* uo CO co •X* rH

1 T 1 rH rH rH rH rH rH rH rH rH rH rH rH o H- CO CO 1=, rH CO CO rH rH co uo o. a. ctn a. •J. O rH rH 01* •X* rH

r*

1

1 T rH rH rH rH rH

ON h- h* '-i co iTi rH rH rH rH CO r- UO CO H

- UO UO •X* •X* •X* CO C*J r*

1

1 i T 1 I I T 1

00 CO ^ H* CO fH rH rH rH rH CO UO CO N-* CO H" CO rH rH CO uo CO J.

1

1 i 1 1 1 l 1 1 i 1 1

r>. CO Tt fH If• H* CO rH rH rH rH CO CO «-• o co co rH uo UO r- r-- rH

1

1 1 i 1 1 1 I T l 1 i 1 i rH

1

i rH

1

vO CO CO CO CO fH rH rH rH rH CO i’tj rH rH Cm f- •J. rH rt r-- •x* fH

1 T 1 i 1 T 1 1 T i 1 i rH

I rH

i rH

1 rH

1 CO1 m tH CO o co fH rH CO CO CO CO CO •X* CO CO CO CO •X* cr. CO f- CO uo r1

1 1 T 1 1 1 1 1 rH

i rH1 CO CO CO

1 1 1 CO1

>3 fH rH CO ^4 fH CO If* llO MI* •x* r- N co o r - CO rH •J. CO CC* CO ‘X* CO CO

1

1 1 1 i i rH

I rH

l

1 rH

1 rH

l CO1 CO1 coi CO

1

r> o o CO © co if* co or. *j. rH CO a. U0 ft ft CO •x* •J. 01* CO •10 CO iJ.

1

1 1 1 rH rH rH

I CO1 rH1

1 rH

1 rH1 CO1 CO

1

’fr

1 CO

1

CM J. rH CU 0*1 fH rH CO If* X* CO CO f-- •Jl* uo CO •X* uo o CM rH rH U'l

1 1 1 1 1 rH rH 1 rH

l

1 i rH

I 1 CO1 co

1 UO

1 *1

•H CO >*0 CO CO CO rH CO H

- Ml* O H- •X* fN. CC* *Jl* CO rH CO •X* rH CO CO rH

1 1 1 1 1 I rH 1 I rH

1 CO1 Cm

1

*x*

1

U'*

1 X

;*-* *H CM m <r m vO r^- 00 ON O rH CM CO m no r*. oo ON o rH CM CO <r i •H •H iH rH H H rl *H rH rH CM CM CM CM CM iCM
Table 24

El Paso Columbia

Plane 7

Flatness data with water - Z is normal to the plane.

X Y Z (mm) X Y Z (mm) X Y Z (mm)

13. 35. 393. 50 •2• • 15. 36 0 . 6 0 6. £54. 50

11. “i C

l_ J • c! 33 . 3 U 1. 15. 363. 00 1. 6. £47.50

C|

m

CT

L- 337. 50 13. 13. 387. 00 13. 4. £67. 50

f‘ • CT

L_ J • 355.80 11. 13. 379. 90 11. 4. £65. 50

5. 35. 339. 00 9. 13. c! f c • c' U 9. 4. £63.80

13. 34. 3 0 0 . 7 0 r* 13. £66. 00 1*’ • 4. £56. 00

1 1

.

£4

.

3 9 3 . 3 0 5. 13. 364 . 8 0 5. 4. £53.90

Q _ c'4

.

3 7 4 . if ij 2* m 13. 365. 30 .*• a 4. £5 1.60

r’ 34. 36 0 . 5 0 1 . 13. 363. 1

0

13. c £66 . 4 0

5. 34. 340. 00 13. 13. 384. 1

0

11. £

.

£66. 30

o c'4. 337. 90 1 1

.

13. c! r r" . 4 1.1 9. £

.

£67. 50

1 1

.

S3

.

388. 70 9. 13. 369. 00' r* • cl m 361. 0 0

Q B C d r cl • cl U

r 13. 363. 00 5. £

.

356. 1

0

r’ • C OC7 e* |"i C J i* • IJ 5. 13. 360. 00 -• • £

.

£47.80

BT C • 339 . 9 0 • 13. 367. 50 13. 1. £53. 00

C a 335.30 1. 1 3

.

£63 . 8

0

11. 1. £ 5 £ . 8 0

1 . 23 343.80 13. 1 0. £79. 00 9. 1. £5 1 . 3 0

13. 31

.

395.30 11. 1 0. c! r c .

j' 0 l’ a 1. £47. 00

1

1

. 31 . 388. 1

0

9. 1 0 . 365. 30 5. 1

.

344.40

Q _ 31 . £7 c=; cr j-| r • 1 0. £60. 90

r’ 31 . 359. 50 5. 1 0. 358. 00

Cj 31 . 343.50 1 0. £64. 00

31 . 341.50 1 . 1 0 . 357. 10

l

.

31 . 345. 00 13. 8 . 374. 1

0

13. 19. 394. 00 1

1

. 373. 80

1

1

. 19. 390. 30 9. 'J 365. 10

9. 19. cl r 4 . r’ U

r* • 8 . 359. 50

r • 19. c' 6 3 • 1 0 5. 8 . 355. 90

5. 19. 349. 3 0 2* m 361 . 0 iJ 19. 349. 90 1. 8. £55.50

1 . 19. 355.90 13. 6. 373. 1

0

13. 17. 396 . 9 0 11. 6. 373. 60

1

1

. 17. 396. 90 9. 6. £66. 0

Q _ 17. £73. 00 I** 6. 356 . 6 0

r 17. £64. 7 0 5. 6. 355. 60

5. 17. 353. 90

.j m 17. 356. 00

1 . 17. £56. 70

13. 15. £99 . 8

0

11. 15. £86. 1 9. 15. 37 0. 4 0

r 15. £63. 1

0

c;J 15. cl 5 r • c* l.l

RMS Deviation from flatness 10.2 mm

F27
Table 25

El Paso Columbia

Plane 7 Flatness map with water.

Y/X 1 2 3 4 5 6 7 8 9 10 11 12 13

1 -5. -6. -8. -9. -11. — 13. -14. -14. -15. -17. -19. -31. — 34 . 2 -5. *© • -1. 1. 0. 0. 1. 1. “~C a -6. -3. -11.

3 0. -0. * U • -1. -1

.

” c J • -3. —3 . -4. -6. -8. -11.

4 5. —' • i. -1. •J • -4. -5. -5. -4. -6. “ f* a -9. -1 0.

5 4. a d • 0. “C. • -4. -5. -4. © a -3. -3. -6. -8.

6 3 . 3. 3. 1. -1. —5. -3. -1. -0. 1. -3. -6.

7 6. 6. 6. 3. -1. -4. -3. —3

.

-1 . 0. -3. -6.

8 9. 9. 9. 4. -1. —3 . «' • -3. •' a -1 . 0. “”C a -5.

9 10. 1 0. 11. 5. -0. —C a •—1 a -3. © a ~"C.' a -1 . C a ~ ; 1 10 1 0. 11. 13. 6. 0. -1. —3 . -3. -4. -3. a -1 . ~ 1 1 11 13. 13. 13. 7. 1. -1. —C. m —3 . “C, a -i

.

0. 1. 1. : 12 15. 15. 15. 8. 3. 0. —3. -1. -0. i. 3. 3. 4. : l 13 14. 13. 13. 9. 6. 4. 3. © a 4. 5. 6. 6. l 14 14. 13. 9. 6. C • 1. 0. 1. C a 5. 8. 1 0. 13. : i 15 14. 1 0. ? a •1° a -1. “c • —3 -1. 0. 5. 1 0. 14. 19. I! IS 16 11. 8. 4. 0. -4. ““dm -1. 0. 1. 8. 15. 16. 17. , ;? 17 8. 5. c. —3. -6. -1. 1. 3. 11. 31. 18. 15. ; IS 18 7. z< —3. -5. -9. -5. — c

.

0. © a 1 0. 17. 15. 13. [ IS 19 6. 1. -5. —8

.

-11. © a -4. -0. © a 8. 13. 13. 1 3 • i 10 20 1. -4. -10. -IS. -14. -1 0. -5. -1. © a L' a 13. 13. 13. S i 21 -5. -10. -14. -16. -18. — IS. — 7

.

—3

.

3 a 1* a 11. 1 1

.

13. it :i 22 -6. — 1c’. -17. -19. -30. -14. -8. —3

.

C'a 6. 11. 14. 17. Is i 23 ““ §** • -14. -31

.

-31. —33

.

-16. -10. —5

.

-0. 5. 11. 16. 33. !( 24 -35. -33. -39. -35. —33

.

-14. -7. -3. d a 8. 15. 1 6

.

17. IS 25 -46. -40. -35. -39. — 18. -13. -9. -6. -1

.

© a 9. 14.

1

Sis

F28
Table 26

El Paso Columbia

Plane 7

Difference between "with water" and "without water" - Z heights in wl

Y/X 1 2 3 4 5 6 7 8 9 10 11 12 13

1 3. 3. £. 1. 0. -0. -1. -1. -1. -3. -6. -6. “ 1 2 ~3e -3. -£. “c. -1. —

£

. a * • -5. “ r* • f‘ a -ft

3 3. £ 1. -0. -1. -£. -£. -£ . — *-! •J • -4. -6. l‘* a —

y

4 9. 6. 4. i. -1. -1. -0. -1. -£. —. “j -5. “ 1** a —ft 5 6. 4. 3. i. -1. -1. -£. —

£

. -£ . —£ • -3. -4. —6

6 £ m £. 1. 0. -1. -£ . ~3. -£. -1. -i . -£ . -£ . -3

7 4. 3. 1. -0. -£. -£. -3. “C • —£

.

~c' e -3. -£ -1

8 { a 4. £. -1. -3. _ J • -3. C. e -£

.

-3. -4. £. a 1 9 6. 4. £. -0. -3. -£. -£

.

-£

.

— c -3. -4. -I' a -£

10 4. 3. £. 0. -£• -£. -£

.

-£

.

J • -3. -4. -4. -5

11 w 3. £. 1. -1. -£. j e V . -£

.

-4. -5. -5. -5

12 1. £

.

£. 1. -0. -£. * • — -2* m —£

.

-4. -6. -6. —ft

13 8. 6. 3. £. 1. -0. -1. ~£. -4. -5. -6. “ f a r

- 14 7. 6. 4. 3. 1. -0. -1. -£

.

•' -4. -6. -6. — ft 15 6. 6. 6. 3. 1. -1. -£. —£

.

-4. -6. -5. -5

16 e;J • 10. 15. 7. -1. “C . 2'

m

' • -1. 1. -1

.

-4

17 crw • 15. £4. 11. -3. ~3. -4. •—* • J a C a 8

.

—1 a -3

18 7. 1 0. 14. 6. -£. -£. “"c! • -£

.

- 0

.

£. -1 . -4

19 o 6. 4. 1. -£. -1. 0. -1 . -3. -3. -4. -5

20 r’ 6. 4. 1. -1. -1. -1. -£

.

“ C. a -3. -4. -4. -5

21 6. 5. 4. £. -0. -1. -£. -3. -4. -4. -4

22 16. 11. 6. 3. 1. -0. -1. -1. -1. ~c. • -3. “ C. a - o 23 £6 e 17. 7. 5. £. 1. 0. 0. 0. -1. -3. 1 . 4

24 £5. 19. 14. 8. 3. 1. U • -0. -0. -3. ~3 . 25 c;W • 5. 4. 4. £• 0. —£

.

-£

.

—3 e -4. -5

RMS deviation from flatness 5.0 mm

F29
Table 27

El Paso Columbia

Plane 8

Flatness data without water - Z is normal to the plane.

X Y Z (mm) X Y Z (mm) X Y Z (mm)

15. 1. £98 . 9 0 11. 11. £83 . 3 0 13. CC a £74. 3C

13. 1. 311. 3

0

9. 11. £75. 50 1 1

.

LLa £56 . 8

0

11. 1. 313. £0 I*‘ a 11. £76 . 4 U 9. C C a d 4c • 6 L 9. 1. 313.50 5. 11. c' i

-

’ i’’ . f U

1? ^ CC a £34. 30

r‘ • 1. 307. 70 •»' a 11. iz.' 8£ . 5 U 5. CC a £41. 3

0

5. 1

.

£95. 80 1. 11. £90.90 Z* a CC a £67. 30

15. £

.

£90.40 13. 13. dd5 • d 0 15. £4. £75. £0

13. C a 305.90 11. 13. £ 8 5 . 6 0 13. £4

.

C »' 4 a z' U 11. £'

.

309. 80 9. 13. iz! r' 4 * f U 11. £4. £53. 30

9. £'

.

309. 30 •* a 13. £73. 50 9. £4. iz! 4>! . 6 0

1** a £. 3 0 9 . 8 0 5. 13. d (' 5.1 U 1 a £4. £39. 30

5 £'. £89. 30 •»' a 13. dyd • d U 5. £4. £47. 00

15. Z* a £87.40 1. 13. £81 . 90 15. £5. £59. 30

13. J'' a 304. 00 13. 14. 303. 1

0

13. £5. c' 5 1 • cl U 11. a 3 0 0 . 5 0 11. 14. d (' f . -Z* U 11

.

er

L_ -• a £5 0 . 9 0

9. -• £98. 70 9. 14. £64.90 9. £5. £45.30

r‘ • 3. £99. 1

0

1*’ a 14. £57. 80 l‘‘ a £5. £44.40

5. • £83. 50 cr

-• a 14. £59. 30 5. £5. £51.50

• o • £78.30 3

.

14. £79. 50

15. 5. £71 . 30 1 . 14. £96. 00

13. 5. £9£. 30 15. 16. 307. £0

11. 5. £94. 50 13. 16. £93. 1

0

9. 5. £91.50 11. 16. £67.90

•’* • 5. £89. 80 9. 16. £55 . 3

0

CTJ • 5. £80. 30 1 a 16. £49. 1

0

•J a 5. £81 . 1

0

5. 16. £ 5 iz! . 4 U

1. 5. £88 . 8

0

3. 16. £76. 00

15. I'* a £71 . 7 0 1. 16. £91 . 30

13. 7

.

£88. 90 15. 18. £89. 00

11. 1*’ a £94.30 13. 18. £81.50

9. f* a £85. 1

0

11. 18. £70. 1 0

r a

1** a £84. 00 9. 18. £48. 1

0

5. 7. £79. 80 •'* a 18. £4 1 . £ 0

J a

1*’ a £83. 90 5. 18. £50. 00

1. l‘‘ a £90. 00 a 18. £74. 00

15. 9. £70. 00 1. 18. £97. 1

0

13. 9. £86.40 15. £0. £86. 70

11. 9. •I* OC "7 f

i

C O a 1 U 13. £ 0

.

£79. 70

9. 9. £ r 8 . 5 0 11. £0. £64 . 1

0

l’ a 9. £81.50 9. £ 0

.

£46. 50

5. 9. £78. 00 l' a £ 0

.

£38. 50

a 9. £85 . 4 0 5. £ U

.

£48.80

1. 9. £90. 30 3

.

£ 0

.

£70. 00

15. 11. £77. 50 1. £0. £93. £0

13. 11. £87. 30 15. ££. £8 0 . 4 0

RMS deviation from flatness 12.9 mm

F30
Flatness

map

without

water.

Ipj

• in rH CU CO OJ • • co r- rH •XI o •X' CU I'Ll r- rH OJ rH ij. cr. U'l rH i rH

1 rH1 rH1 CU

1 CU

1 CU

1 rH1 rH

1 rH

1

l U'i ’t 1.0 cu cu CU 0J CU cu rH rH

<• CU co CO CO CO CU rH cr. U'l CO •xi a. ijj ajj cu (- ajj cr, ijj r-- ijj cr, ’t

i 1 1 rH

1 rH

i rH1 rH

1

i 1 1 ijj CO cu cu rH rH rH rH rH rH rH

CO CO UO in rH CO CU CU rH ,r, CU U'i xi r - r - ’t rH r-- ajj H- •xi U'l H- X' ijj ajj

1 1 1 1 1 cu cu OJ rH rH rH rH rH rH rH rH

CN

rH

cr. r- t rH rH rH Q rH CO U'i r -- o- rH ijj ajj ajj ajj ajj f- •X' r-- ijj

i 1 i rH rH

rHrH

rH

rH

cr-. CU rH CU CU rH

fl rH 't 9jj rH rH

1 1 rH

1 OJ rH rH

1

1*0

1

1*0

1 CU

1 ro

1 o rH cr. rH rH rH ,r, CU H- ro co CU U'l r-- cr. CO CO CO cr. ijj r. U'l rH 1 1 I I I i I l i rH

1

1 i 1 1 I rH

1

1 i 1

ct\ rH iTi rH rH CU U'i 'X' r- r-- •XI U'i .V. rH CO •X' ajj cr. CO r-- r- r- H- rH CO

rH 1 l 1 1 1 8 ! 1 l 1

i rH1 rH1 rH1 rH1 rH

1 rH1 i rH1 rH1 rH1

1

00 cr. rH rH ro in U'i ••ill U'i U'l co •XI a. rH CU rH rH —

,

r. ijj ijj rH 1 i l i 1 1 1 1 1 11 rH

8 rH1 rH1 cu1 cu

1 CU1 CU1 cui OJ1

rH

1 rH1

1

MO rH rH H- in U'i U'l 't 9

• 9g «

a

11 9

0 ’t f - CU •x> U'l "t H" H- U'i CO

rH 1 1 i i I 1 1 i 1 I rH

1 CU1 cu1 cu1 cu1 0J

1 OJ

1 Cu

1 OJ

1 CU1 rH

1

1

vO —# \0 r- CO CO r-- •xi u'i CO 1*0 CO 'XI CO rH rH cr, rH •X'

1 i 1 i i 1 1 1 1 i I ~

1 rH1 CU

1 CU cu1 OJ1 rH

1 CU

1 cu

1 rH

1 rH

1

1

m in t CO CO rH cr. co [- U'i co CU CU U'l r-- ijj r- •XI U'l H" U'i r- CU f'- rH

i rH

1 1 rH

1 rH1 rH

1

i 1 1 1 i 1 8 rH

1 rH1 rH

l rH

1 rH

1 1 rH

1 rH

1

rH

1 rH1

1 1

'd- rH o CU r- U'l CO 0J rH CU U'l •X' •X' U'l -fr ro ijj CO •<t CO ajj 01

rH

1 CU1 rH1 rH

1 rH1 rH

1

i 1 1 I i 1 1 1 1 1 1 1 1 1 1 i

CO r-- co in CU CO U'i CU rH CU CU ’t •xi u'i •X' •X' f-- CO CO CO J. U'l rH N

rH

1 ro

1 i rH1 rH

1

l i 1 rH

CN i‘0 t «= rH rt r- rH rH •t U'i f'- •XI •XI ’t fM- o rH 01t U'i j CU ’T

1 1 CU

1 rH

1

i 1 1 rH rH rH rH cu cu cu CU CU rH

rH

• ijj CO ro fO rH CU H \0 cr. rH cr. •XI cu CU CU r-- cu OJ cu •X' 01 .7, U'l CU U'* CU rH i 1 rH cu cu 0J cu CO CO i*l CO 01 cu rH

I I I l

x

>* oo on o

rH r-M i—I CN H CM M

CM CM CM <r in

CN CN

F31
Table 29

El Paso Columbia

Plane 8

Flatness data with water - Z is normal to the plane.

X Y Z (mm) X Y Z (mm) X Y Z (mm

)

13. 1. 303. 00 13. 13. c! r" 8 . 8 l.l 5. El cl a 315. 30

9. 1 . £95. £0 1 1

.

13. 366 . 1

0

•“i 33. 337. 00

f' 1 . 8 3 4.6 0 9. 13. 356. 80 1

.

lIC a 349. 30

5. 1 . 369. 90 7 13. 349. 30 15. 84

.

363. 00

15. c 336 . 5 0

cr 13. d 4 r' . c! LI 13. £4. 36 0 . 9 0

13. L. a 397.30 a 13. 353. 1 0 11. 34. cl Z' b' a cl l.l

1 1

.

C a 397.30 1 . 13. 35 1.6 Li 9. 34. 334. 00

9. C a 393. 50 15. 14. 393.30 f* a 34. 314.9 0

I c 337. 90 13. 14. 390. 00 5. 34. 317. 1

0

5. 8 . 8 6 3 . 3 U 1 1

.

14. 363. 00 •”i 34. £35.70

15. 331 . 30 9

.

14. 344. 30 15. 35. 354. 30

13. Z> m 39 0 . 3

0

1* a 14. 334 . £ 0 13. cr

CL a £49.50

11. J • 334. 70 5. 14. 330. 80 1 1

.

cr CL J a 335.30

9. a C 8CL a 3 0 Z> a 14. 343. 30 9. O cr C _« a £36 . 3 0

r 363. 3

0

1 . 14. 361 . 00 I*‘ a cr

CL a 33 0. 1 0

5. 3. 343. 70 15. 1 6

.

399. 1

0

cr

a cr C .> a 334. 00

15. cr 364 . 3

0

13. 1 6

.

383. 1

0

13. cr

-» • 333. 50 1 1

.

1 6

.

353 . £ 0

11

.

er

•_« . 383. 1

0

9 „ 16. 333. 90

9 B cr

•_» . 8 (' 8 • 4 l.l l‘ a 16. 333. 50

5. cr 351 . 70 5. 16. c! cl cl m cl LI 3. 5. 351.1

0

3

.

1 6

.

344. 90

15. r 364. 1

0

1 . 1 6

.

353. 50

13. r 379.70 15. IS. 379. 30

1 1

.

“7 379. 90 13. IS. 371 . 30

9 . r 355. 30 1 1

.

IS. 354.30

r* r 360. 1

0

9 . IS. £37. 00

r 353. 00 7 13. 3 1 3 . 0 0

15. 9. 364. 00 5. IS. 316. 3

0

13. 9. 376. 90 Z' a 18. 848 • 8 l.l 11. 9. d \ d m d 0 1 . IS. 363. 70

9. 9. 358. 90 15. 3 0

.

379. 6

0

»'* 9 . 354.30 13. 3 0

.

cl 6 r a cl LI 5. 9 . 354. 50 1 1

.

£ 0

.

343. 80

O 9 . 351 .70 9 . 3 0

.

336. 00

15. 1 1

.

d r' 1 • 3 0 I** a 3 0

.

3 1 0 . 6 0

13. 1 1

.

cl r y a r’ u 5. £ 0

.

315. 1

0

11

.

1 1

.

369. 70 z' a 3 0

.

cl y r‘ • cl l.l 9. H. 357. 00 1 . £ 0

.

363. 1

0

r a 1 1

.

353 . 5 0 15. 33. £71 . 00

CT 1 1

.

346.90 13. £3. 364. 90

Z' m 1 1

.

351. 0

0

1 1

.

£3. 343.70

1 . 1 1

.

353.30 9. 33. 333. 70

15. 13. £85. 1

0

f a £3. 309. 30

RMS Deviation from flatness 14.5 mm

F32
El

Paso

Columbia

oCO

0)

i“H«H

CO

4*a

«

iH

Pi

• M

0)

4-1 (03

J5

4J •H3

I

to

CO

0)e

4-1 CO iH

f*4

m o- CO Oj ij'l •'u

» i ijj •£' •“• if* CO CO Clj -t- •£' cr, rH CO CO cr, CO

r-i 1 1

1 1

•'•J

1 OJ •"•j

i

rH

1 rH

1

rH

1

l rH 0J cu CO 0J ’*' cu C'J OJ rH rH '•J

I? .v, rH U*' (J. CO rH iT. Clj CO rH 111 •j. rt *•£' f

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F34
Appendix G

Deadwood Survey Data

El Paso Columbia, Hull 2266, Tank 3

By

W. C. Haight, R. G. Hartsock, and R. J. Hocken

Deadwood Survey Data

i El Paso Columbia, Hull 2266, Tank 3

The first 26 tables presented in this appendix contain the results of a detailed dimensional survey of all deadwood members on Tank 3 of the El Paso Columbia,

including the thickness of the eight exterior tank walls. In the context of

this appendix, deadwood is defined to be any solid tank member whose volume

reduces the internal liquid capacity of the tank. The deadwood members measured

in this survey include all tank exterior walls, interior bulkheads, interior

beams and interior stiffness.

Each table presents the actual measured data for a given deadwood component

in millimeters, and the nominal component size in inches and millimeters as taken from Conch Methane Services, Ltd. drawing number 6043-125-3/0G-5 , Alt. no.

12. These measured and nominal dimensions can be used in each case to determine

the actual oversize or undersize of deadwood from the specified values. Each

data point is referenced by an index number which, in conjunction with the

diagrams provided, locates the measurement point physically on the tank. Exterior

wall thickness measurements were made near every photogrammetric survey target,

and the average values for a given plate are reported.

All thickness readings reported in these tables were taken with an ultrasonic thickness gage utilizing the pulse-echo technique. The instrument operates

as follows. For each measurement, a small amount of liquid couplant is applied

to the surface of the tank member to be measured, and a probe is held firmly on

the tank at that point. The couplant eliminates any air gap between the probe

and the material to be measured, insuring a good accoustic bond. A pulse of

ultrasound is then emitted by the instrument through the probe. An echo occurs

at the back wall of the member at the solid/air interface and the instrument

times the interval for this pulse round trip. The thickness of the test piece

is proportional to this time interval and the proportionality constant is a

function of the velocity of sound in the test piece.

The instrument /probe assembly was field calibrated to determine the material

sound velocity. For this purpose, a reference block was manufactured by NBB

from a sample of Aluminum Alloy 5083-0 Temper obtained from the tank construction

site in Mobile, Alabama. This block had steps of 25.40 mm, 19.05 mm, 12. /0 mm

and 6.35 mm and the instrument calibration was re-checked every hour during the

G-l
survey. The resolution of the instrument is 0.01 mm and the total uncertainty

of all thickness measurements is estimated to be +0.05 mm. All remaining dimensional measurements reported herein were made with a steel surveying tape, graduated in 1 mm increments and calibrated at NBS

.

This survey was conducted while the tank was in storage at a construction

yard in Mobile, Alabama and while the tank had an average exterior temperature

of 13.5°C. All data reported herein is for the tank at these conditions.

The final two tables in this Appendix, Tables 27 and 28 report the results

of the computation of the volume occupied by the surveyed deadwood. The computations were performed by representing deadwood elements by simple geometric

figures. Except in the case of the balconies, these computations were straight

forward and can easily be reproduced by quick examination of the drawings of the

structural members shown in Tables 4 through 10.

For the balconies the following model was used. The web thickness was assumed to be constant at the average value. The web length was assumed to

have one value along two walls and another along the other two. The rounded

corners were approximated by triangles. The flange was assumed to have a constant

length and thickness except in the four corners of the tank, (borders of the triangle

sections) where different flange lengths and thicknesses were allowed. Implementation of this model required (11) eleven parameters. The model was altered

slightly by the subtraction of some sections for balconies of the type in tank

quadrants two (2) and four (4). Since only the balconies in quadrants one (1)

and four (4) were measured. Quadrant three was assumed equal to one (1) and

two (2) equal to four (4) when reporting the results. The results are reported

by levels (balconies) with the deadwood volume of balcony one (1) being reported

in level one, etc.

In Table 28 the percentage deviation of the deadwood from nominal is given.

The exterior walls are not included since their deviations from nominal thickness

are reported in Tables 1 through 3 by plate.

:

I,

I

1

G-2
Table 1

Exterior Plate Thickness

Aft and Stbd Walls

Plate Nominal Measured

Number inch mm mm

1.1 0.84 21.3 22.4

1.2 0.81 20.6 21.7

1.3 0.81 20.6 21.6

1.4 0.75 19.1 19.3

1.5 0.63 16.0 15.6

1.6 0. 56 14.2 14.7

2.1 0.84 21.3 none

2.2 0.81 20.6 none

2.3 0.81 20.6 none

2.4 0.75 19.1 none

2.5 0.63 16.0 none

2.6 0.56 14.2 none

3.1 0.84 21.3 21.5

3.2 0.84 21.3 21.7

3.3 0.81 20.6 20.8

3.4 0.75 19.1 18.9

3.5 0.69 17.5 18.3

3.6 0.63 16.0 16.3

3.7 0.50 12.7 13.1

4.1 0.84 21.3 21.2

4.2 0.84 21.3 21.3

4.3 0.81 20.6 20.6

4.4 0.75 19.1 19.3

4.5 0.69 17.5 17.7

4.6 0.63 16.0 16.1

4.7 0.50 12.7 14.1

Location Diagram:

G-3
Table 2

Exterior Plate Thickness

Fwd and Port Walls

Plate Nominal Measured

Number inch mm mm

5.1 0.84 21.3 21.6

5.2 0.81 20.6 21.3

5.3 0.81 20.6 22.0

5.4 0.75 19.1 19.3

5.5 0.63 16.0 16.9

5.6 0.56 14.2 13.8

6.1 0.84 21.3 22.3

6.2 0.81 20.6 22.3

6.3 0.81 20.6 21.2

6.4 0.75 19.1 18.4

6.5 0.63 16.0 16.1

6.6 0.56 14.2 14.9

7.1 0.84 21.3 21.2

7.2 0.84 21.3 21.3

7.3 0.81 20.6 20.5

7.4 0.75 19.1 19.9

7.5 0.69 17.5 18.9

7.6 0.63 16.0 16.0

7.7 0.50 12.7 13.4

8.1 0.84 21.3 21.5

8.2 0.84 21.3 21.7

8.3 0.81 20.6 20.6

8.4 0.75 19.1 18.9

8.5 0.69 17.5 17.3

8.6 0.63 16.0 17.0

8.7 0.50 12.7 13.7

Location Diagram:

G-4
Table 3

Exterior Plate Thickness

Top and Bottom Surfaces

Plate Nominal Measured

Number Location inch mm mm

9.1 1 0.50 12.7 13.7

9.1 3 0.50 12.7 13.7

9.2 5 0.50 12.7 13.3

9.3 7 0.56 14.2 14 .

6

9.4 9 0.56 14.2 14.7

9.5 11 0.56 14.2 14.5

9.6 15 0.56 14.2 14.9

9.7 17 0.56 14.2 15.2

9.8 19 0.56 14.2 14.8

9.9 21 0.50 12.7 12.9

9.10 23 0.50 12.7 13.3

9.10 25 0.50 12.7 13.3

10.1 1 0.81 20.6 22.0

10.2 5 0.81 20.6 20.6

10.3 7 0.81 20.6 none

10.4 9 0.81 20.6 21.7

10.5 13 0.81 20.6 21.4

10.6 15 0.81 20.6 none

10.7 17 0.81 20.6 21.9

10.8 19 0.81 20.6 21.8

Location Diagram:

Fwd

9.1 93 93 9.4 35 9.6 9.7 9.8 39 310

91 32 9.3 9.4 35 9.6 9.7 9.8 9.9 91 0

x > X X X x > X X X X ? *

1 5

i 7 9 11

i: 15 17 19 21 23

25

Aft

Port

Fwd

1 01 c\i 103 1 0.4 10.5 1 0.6 p 1 Q8

l(U

X X

102

<

1 0.3.

X

1 Q.4 1 0,5

X

i as

_s_

107

X

1 0.8

1 3 5 7 9 U

13 15 17

ig

21

Aft

Stbd

Bottom
Table 4

Interior Bulkhead Thickness

Swash Bulkhead, Quadrants 1 and 4

Quadrant 1 Quadrant 4 Nominal measured measured

Location inch mm mm mm

7.9 0.50 12.7 X 13.0

7.7 0.50 12.7 none X

7.1 0.50 12.7 13.4 X

6.9 0.50 12.7 X 13.7

6.7 0.50 12.7 13.6 X

6.1 0.50 12.7 12.3 X

5.9 0.50 12.7 X 13.2

5.7 0.50 12.7 13.2 X

5.1 0.50 12.7 13.4 X

4.9 0.50 12.7 X 12.5

4.7 0.50 12.7 13.6 X

4.1 0.50 12.7 16.1 X

3.9 0.50 12.7 X 13.5

3.7 0.50 12.7 13.8 X

3.1 0.50 12.7 13.3 X

2.9 0.50 12.7 X 12.7

2.7 0.50 12.7 13.3 X

2.1 0.50 12.7 13.4 X

1.9 0.56 14.2 X 15.5

1.7 0.50 12.7 13.2 X

1.1 0.50 12.7 13.9 X

0.9 0.56 14.2 X 15.5

0.7 0.56 14.2 14.6 X

0.1 0.56 14.2 14.

X

Location Diagrams (Location = i.j; where i = level, j = location)

Port

1

0

Bottom

G-6

Aft
Table 5

Interior Bulkhead Thickness

Liquid Tight Bulkhead, Quadrants 1 and 4

Nominal Measured

Location inch mm mm

7.3 0.50 12.7 13.0

7.1 0.50 12.7 13.0

6.3 0.50 12.7 12.7

6.1 0.50 12.7 13.5

3.3 0.50 12.7 13.0

5.1 0.50 12.7 12.8

4.3 0.50 12.7 13.4

4.1 0.50 12.7 13.3

3.3 0.50 12.7 13.2

3.1 0.50 12.7 13.0

2.3 0.50 12.7 13.9

2.1 0.50 12.7 14.0

1.3 0.50 12.7 13.9

1.1 0.50 12.7 13.9

0.3 0.56 14.2 15.0

0.1 0.56 14.2 15.1

Location Diagrams (Location = i. j

where i = level, ;j = location)

Fwd

Port

G-7
Table 6

Balcony Beam Locations, Vertical Positions

Quadrants 1 and 4

Measured Vertical Separation

Nominal Vertical Separation Quadrant 1 Quadrant

Location ft, inch mm mm mm

8-7 11' 4" 3454.4 none none

7-6 11' 4" 3454.4 3415.0 3407.0

6-5 10' 6" 3200.4 3186.7 3242.0

5-4 9 ' 11" 3022.6 3033.5 2984.7

4-3 9’ 0" 2743.2 2728.8 2739.4

3-2 8’ 7" 2616.2 2642.4 2612.4

2-1 7' 10" 2387.6 2365.6 2398.0

1-0 6' 10" 2082.8 2106.0 2090.5

Location Diagrams: [Location = Level (i) - Level ( j )

]

G-8
Table 7

Large Floor Beam Dimensions

Quadrants 1 and 4

Quadrant 1 Quadrant 4

Nominal measured measured

Dimension Location inch mm mm mm

A Beam 1 54 1371.6 1368 1373

Beam 2 54 1371.6 1367 1370

Beam 3 54 1371.6 1382 1377

Beam 4 54 1371.6 1364 1370

B Beam 1 16 406.4 412 413

Beam 2 16 406.4 412 413

Beam 3 16 406.4 411 410

Beam 4 16 406.4 409 414

C Beam 1 0.63 16.0 17.0 16.8

Beam 2 0.63 16.0 17.1 16.5

Beam 3 0.63 16.0 16.9 16.2

Beam 4 0.63 16.0 16 .

16.2

D Beam 1 1.38 35.1 35.4 35.3

Beam 2 1.38 35.1 35.5 35.4

Beam 3 1.38 35.1 36.2 35.9

Beam 4 1.38 35.1 36.2 35.8

Location Diagram: Dimension Diagram:

Fwd

Stbd

Floor

G-9
Table 8

Small Floor Beam Dimensions

Quadrants 1 and 4

Quadrant 1 Quadrant 4

Nominal measured measured

Dimension Location inch mm mm mm

A Beam 1 16 406.4 406 409

Beam 2 16 406.4 408 405

B Beam 1 4.5 114.3 112 114

Beam 2 4.5 114.3 114 114

C Beam 1 0.56 14.2 14.5 14.6

Beam 2 0.56 14.2 14.6 14 .

6

D Beam 1 1.05 26.7 27.1 27.1

Beam 2 1.05 26.7 27.0 27.0

Location Diagram: Dimension Diagram:

Port

Fwd

Q4 Q1

Aft

Floor

G-10
Table 9

(Sheet 1 of 2)

Vertical Stlffner Dimensions

Quadrant 1

Dimension

A

B

Level 7 Level 1

Nominal Measured Measured

Location inch mm mm mm

1 9 228.6 228 228

2 9 228.6 226 226

3 13 330.2 330 327

4 13 330.2 329 329

5 13 330.2 328 331

6 13 330.2 329 406

7 9 228.6 225 227

8 9 228.6 228 224

1 2.5 63.5 63.5 63.0

2 2.5 63.5 63.2 64.0

3 2.5 63.5 63.3 63.0

4 2.5 63.5 63.2 63.0

5 2.5 63.5 64.0 63.0

6 2.5 63.5 63.1 64.0

7 2.5 63.5 64.0 64.0

8 2.5 63.5 65.0 64.0

G-ll
Table 9

(Sheet 2 of 2)

Vertical Stiffner Dimensions

Quadrant 1

Dimension

C

D

Level 7 Level 1

Nominal Measured Measured

Location inch mm mm mm

1 0.406 10.3 10.8 10.7

2 0.406 10.3 10.7 10.7

3 0.4375 11.1 11.9 10.7

4 0.4375 11.1 11.6 11.2

5 0.4375 11.1 11.5 11.0

6 0.4375 11.1 11.3 11.5

7 0.406 10.3 10.9 10.7

8 0.406 10.3 10.9 10.7

1 0.875 22.2 22.4 22.4

2 0.875 22.2 22.5 22.3

3 0.875 22.2 22.4 22.4

4 0.875 22.2 22.4 22.3

5 0.875 22.2 22.8 22.4

6 0.875 22.2 22.5 23.1

7 0.406 10.3 11.5 11.0

8 0.406 10.3 11.5 11.1

Location Diagram:

Fwd

Port

\ 18 7

2 Q1 6

i 4 5l

Aft

Stbd

Dimension Diagram:

G-12
Table 10

Vertical Stiffner Dimensions

Quadrant 4

Level 7 Level 2 Nominal Measured Measured

Dimension Location inch mm mm mm

A 2 13 330.2 327 328

3 13 330.2 328 330

4 13 330.2 329 328

5 13 330.2 330 329

6 13 330.2 329 331

B 2 2.5 63.5 62.0 63.0

3 2.5 63.5 63.0 63.0

4 2.5 63.5 63.0 64.0

5 2.5 63.5 63.0 63.0

6 2.5 63.5 63.0 63.0

C 2 0.4375 11.1 11.3 11.3

3 0.4375 11.1 11.7 11.6

4 0.4375 11.1 11.7 11.5

5 0.4375 11.1 11.4 11.2

6 0.4375 11.1 11.6 11.3

D 2 0.875 22.2 22.3 22.5

3 0.875 22.2 22.2 22.5

4 0.875 22.2 22.6 22.5

5 0.875 22.2 22.5 22.4

6 0.875 22.2 23.2 22.5

Location Diagram:

Fwd

Port

2 X

3 04

4 5 6

Aft

Stbd

Dimension Diagram:

Wall

G-13
Table 11

Balcony Beam Dimensions

Quadrant 1, Level 1

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

1.1 18 457.2 461 1.19 30.2 31.4

1.2 18 457.2 463 1.00 25.4 25.4

1.3 18 457.2 476 1.00 25.4 25.8

1.4 18 457.2 463 1.00 25.4 25.8

1.5 21 533.4 538 1.50 38.1 38.9

1.6 18 457.2 463 1.00 25.4 25.9

1.7 18 457.2 461 1.19 30.2 31.6

1.8 18 457.2 466 1.00 25.4 26.3

Web Length, WL Web Thickness, WT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

1.1 2708 0.63 16.0 16.7

1.2 60 1524 1526 0.63 16.0 16.6

1.3 4517 0.63 16.0 16.9

1.4 78 1981 1981 0.63 16.0 16.7

1.5 5026 0.63 16.0 16.7

1.6 78 1981 1981 0.63 16.0 16.4

1.7 4459 0.63 16.0 16.6

1.8 60 1524 1523 0.63 16.0 16.9

Location Diagram: Dimension Diagram:

G-14
Table 12

Balcony Beam Dimensions

Quadrant 1, Level 2

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

2.1 18 457.2 462 1.19 30.2 30.4

2.2 18 457.2 462 1.00 25.4 25.5

2.3 18 457.2 463 1.00 25.4 25.9

2.

A

18 457.2 465 1.00 25.4 25.9

2.5 27 685.8 687 1.50 38.1 38.0

2.6 18 457.2 462 1.00 25.4 26.7

2.7 18 457.2 459 1.19 30.2 30.4

2.8 18 457.2 463 1.00 25.4 26.7

Web Length, WL Web Thickness

,

WT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

2.1 2711 0.63 16.0 15.4

2.2 60 1524 1522 0.63 16.0 15.4

2.3 4495 0.63 16.0 16.0

2.4 78 1981 1981 0.63 16.0 16.0

2.5 5231 0.63 16.0 16.5

2.6 78 1981 1998 0.63 16.0 16.6

2.7 4789 0.63 16.0 16.5

2.8 60 1524 1528 0.63 16.0 16.4

Location Diagram: Dimension Diagram:

Aft

Stbd

G-15
Table 13

Balcony Beam Dimensions

Quadrant 1, Level 3

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

3.1 18 457.2 465 1.19 30.2 30.7

3.2 18 457.2 465 1.00 25.4 26.7

3.3 18 457.2 466 1.00 25.4 26.0

3.4 18 457.2 466 1.00 25.4 26.0

3.5 27 685.8 692 1.50 38.1 38.9

3.6 18 457.2 462 1.00 25.4 26.1

3.7 18 457.2 458 1.19 30.2 30.9

3.8 18 457.2 465 1.00 25.4 25.9

Web Length, WL Web Thickness, WT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

3.1 2710 0.63 16.0 16.4

3.2 60 1524.0 1526 0.63 16.0 16.6

3.3 4478 0.63 16.0 16.2

3.4 78 1981.2 1983 0.63 16.0 16.2

3.5 4936 0.63 16.0 16.6

3.6 78 1981.2 1981 0.63 16.0 16.5

3.7 4485 0.63 16.0 16.2

3.8 60 1524.0 1524 0.63 16.0 16.2

Location Diagram: Dimension Diagram:

Port

Aft

Stbd

G-16
Table 14

Balcony Beam Dimensions

Quadrant 1, Level 4

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

4.1 18 457.2 468 1.19 30.2 30.5

4.2 18 457.2 463 1.00 25.4 25.6

4.3 18 457.2 463 1.00 25.4 26.1

4.4 18 457.2 466 0.75 19.1 19.1

4.5 24 609.6 615 1.50 38.1 38.3

4.6 18 457.2 464 0.75 19.1 19.0

4.7 18 457.2 462 1.19 30.2 30.7

4.8 18 457.2 465 1.00 25.4 26.1

Web Length, WL Web Thickness, WT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

4.1 2711 0.63 16.0 16.1

4.2 60 1524.0 1527 0.63 16.0 15.9

4.3 4486 0.63 16.0 16 .

4

4.4 78 1981.2 1983 0.63 16.0 16.5

4.5 4937 0.63 16.0 15.2

4.6 78 1981.2 1980 0.63 16.0 15.4

4.7 4505 0.63 16.0 16.2

4.8 60 1524.0 1581 0.63 16.0 16.2

Location Diagram: Dimension Diagram:

Aft

G-17
Table 15

Balcony Beam Dimensions

Quadrant 1, Level 5

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

5.1 18 457.2 461 1.19 30.2 30.4

5.2 18 457.2 465 1.00 25.4 25.3

5.3 18 457.2 460 1.00 25.4 26.1

5.4 18 457.2 460 0.75 19.1 19.3

5.5 24 609.6 615 1.50 38.1 38.5

5.6 18 457.2 464 0.75 19.1 19.0

5.7 18 457.2 465 1.19 30.2 30.8

5.8 18 457.2 478 1.00 25.4 25.9

Web Length, WL Web Thickness

,

WT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

5.1 2710 0.63 16.0 15.2

5.2 60 1524.0 1523 0.63 16.0 15.3

5.3 4490 0.63 16.0 15.6

5.4 78 1981.2 1981 0.63 16.0 16.4

5.5 4939 0.63 16.0 16.5

5.6 78 1981.2 1976 0.63 16.0 13.7

5.7 4486 0.63 16.0 16.5

5.8 60 1524.0 1522 0.63 16.0 16.4

Location Diagram: Dimension Diagram:

Port

Aft

Stbd

G-18
Table 16

Balcony Beam Dimensions

Quadrant 1, Level 6

Flange Length,

Nominal

FL

Measured

Flange Thickness, FT

Nominal Measured

Location inch mm mm inch mm mm

6.1 16 406.4 411 1.00 25.4 25.2

6.2 16 406.4 411 0.75 19.1 19.7

6.3 16 406.4 411 1.00 25.4 26.3

6.4 16 406.4 409 0.75 19.1 19.6

6.5 20 508.0 511 1.50 38.1 40.0

6.6 16 406.4 410 0.75 19.1 19.7

6.7 16 406.4 410 1.00 25.4 26.0

6.8 16 406.4 409 0.75 19.1 19.6

Web Length, WL Web Thickness

,

WT

Nominal Measured Nominal Measuri

Location inch mm mm inch mm mm

6.1 2724 0.63 16.0 16.4

6.2 60 1524.0 1526 0.63 16.0 16.0

6.3 4503 0.63 16.0 16.8

6.4 78 1981.2 1982 0.63 16.0 16.6

6.5 4968 0.63 16.0 16.8

6.6 78 1981.2 1972 0.63 16.0 16.6

6.7 4496 0.63 16.0 16.6

6.8 60 1524.0 1522 0.63 16.0 16.6

Location Diagram: Dimension Diagram:

Port

Aft

Stbd

G-19
Table 17

Balcony Beam Dimensions

Quadrant 1, Level 7

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

7.1 14 355.6 357 0.75 19.1 20.0

7.2 14 355.6 363 0.75 19.1 20.0

7.3 14 355.6 358 0.75 19.1 19.2

7.4 14 355.6 363 0.75 19.1 19.6

7.5 18 457.2 460 1.00 25.4 26.4

7.6 14 355.6 362 0.75 19.1 19.3

7.7 14 355.6 364 0.75 19.1 19.7

7.8 14 355.6 365 0.75 19.1 20.1

Web Length, WL Web Thickness

,

WT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

7.1 2714 0.63 16.0 16.6

7.2 60 1524.0 1529 0.63 16.0 16.3

7.3 4521 0.63 16.0 16.1

7.4 78 1981.2 1978 0.63 16.0 16.1

7.5 4948 0.63 16.0 16.3

7.6 78 1981.2 1980 0.63 16.0 17.1

7.7 4487 0.63 16.0 25.5

7.8 60 1524.0 1520 0.63 16.0 25.5

Location Diagram: Dimension Diagram:

Port

Aft

Stbd

G-20
Table 18

Balcony Beam Dimensions

Quadrant 4, Level 1

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

1.2 18 457.2 456 1.19 30.2 30.1

1.3 18 457.2 464 1.00 25.4 26.2

1.4 21 533.4 539 1.50 38.1 39.1

1.5 18 457.2 460 1.00 25.4 25.5

1.6 18 457.2 459 1.00 25.4 25.9

Web Length, WL Web Thickness

,

WT

Nominal Measured Nominal Measuri

Location inch mm mm inch mm mm

1.2 3787 0.63 16.0 16.4

1.3 78 1981.2 1977 0.63 16.0 16.1

1.4 4904 0.63 16.0 16.3

1.5 78 1981.2 1980 0.63 16.0 16.2

1.6 3741 0.63 16.0 16.7

Location Diagram: Dimension Diagram:

Fwd

Port

1.2 1.1

1.3 Q4

1.4 1.5 1.6

Aft

Stbd

G-21
Table 19

Balcony Beam Dimensions

Quadrant 4, Level 2

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

2.2 18 457.2 459 1.19 30.2 30.9

2.3 18 457.2 464 1.00 25.4 26.2

2.4 27 685.8 688 1.50 38.1 39.5

2.5 18 457.2 464 1.00 25.4 25.4

2.6 18 457.2 463 1.00 25.4 26.0

Web Length, WL Web Thickness, WT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

2.2 3753 0.63 16.0 16.1

2.3 78 1981.2 1990 0.63 16.0 17.6

2.4 4948 0.63 16.0 16.5

2.5 78 1981.2 1980 0.63 16.0 16.8

2.6 3794 0.63 16.0 16.4

Location Diagram: Dimension Diagram:

Port

Fwd

2.2 2.1

2.3 Q4

2.4 2.5 2.6

Aft

Stbd

G-22
Table 20

Balcony Beam Dimensions

Quadrant 4, Level 3

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

3.2 18 A57.2 463 1.19 30.2 30.1

3.3 18 457.2 463 1.00 25.4 26.2

3.

A

27 685.8 683 1.50 38.1 39.3

3.5 18 457.2 465 1.00 25.4 25.2

3.6 18 457.2 462 1.00 25.4 26.2

Web Length, WL Web Thickness

,

WT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

3.2 3436 0.63 16.0 15.9

3.3 78 1981.2 1982 0.63 16.0 16.8

3.4 4935 0.63 16.0 16.7

3.5 78 1981.2 1982 0.63 16.0 16.5

3.6 3772 0.63 16.0 17.1

Location Diagram: Dimension Diagram:

G-23
Table 21

Balcony Beam Dimensions

Quadrant 4, Level 4

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

4.2 18 457.2 466 1.19 30.2 30.1

4.3 18 457.2 461 0.75 19.1 19.6

4.4 24 609.6 614 1.50 38.1 38.6

4.5 18 457.2 460 0.75 19.1 19.5

4.6 18 457.2 461 1.00 25.4 26.0

Web Length, WL Web Thickness, WT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

4.2 3755 0.63 16.0 15.9

4.3 78 1981.2 1984 0.63 16.0 16.8

4.4 4931 0.63 16.0 16.1

4.5 78 1981.2 1982 0.63 16.0 16.0

4.6 3760 0.63 16.0 16.4

Location Diagram: Dimension Diagram:

Fwd

Port

4.2 4.1

4.3 Q4

4.4 4.5 4.6

Aft

Stbd

G-24
Table 22

Balcony Beam Dimensions

Quadrant 4, Level 5

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

5.2 18 457.2 458 1.19 30.2 30.1

5.3 18 457.2 461 0.75 19.1 19.6

5.4 24 609.6 614 1.50 38.1 38.5

5.5 18 457.2 463 0.75 19.1 19.5

5.6 18 457.2 462 1.00 25.4 25.9

Web Length, WL Web Thickness

,

WT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

5.2 3795 0.63 16.0 16.3

5.3 78 1981.2 1986 0.63 16.0 16.4

5.4 4953 0.63 16.0 16.7

5.5 78 1981.2 1989 0.63 16.0 16.7

5.6 3777 0.63 16.0 16.3

Location Diagram: Dimension Diagram:

Fwd

, —. —

5.2 5.1

5.3 Q4

5.4 5.5 5.6

FT

WT

Top

kT

FL

±

WL

Port Stbd
Table 23

Balcony Beam Dimensions

Quadrant 4, Level 6

Flange Length,

Nominal

FL

Measured

Flange Thickness, FT

Nominal Measured

Location inch mm mm inch mm mm

6.2 16 406.4 412 1.00 25.4 26.5

6.3 16 406.4 414 0.75 19.1 19.5

6.4 20 508.0 508 1.50 38.1 38.8

6.5 16 406.4 411 0.75 19.1 19.3

6.6 16 406.4 412 1.00 25.4 26.5

Web Length, WL Web Thickness

,

WT

Nominal Measured Nominal Measure

Location inch mm mm inch mm mm

6.2 3771 0.63 16.0 16.3

6.3 78 1981.2 1982 0.63 16.0 16.8

6.4 4945 0.63 16.0 16.4

6.5 78 1981.2 1982 0.63 16.0 16.

6

6.6 3786 0.63 16.0 16.4

Location Diagram: Dimension Diagram:

Port

Fwd

6.2 6.1

6.3 Q4

6.4 6.5 6.6

Aft

Stbd

G-26
Table 24

Balcony Beam Dimensions

Quadrant 4, Level 7

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

7.2 14 355.6 352 0.75 19.1 19.6

7.3 14 355.6 365 0.75 19.1 20.0

7.4 18 457.2 462 1.00 25.4 26.3

7.5 14 355.6 363 0.75 19.1 19.4

7.6 14 355.6 368 0.75 19.1 20.0

Web Length, WL Web Thickness

,

WT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

7.2 3383 0.63 16.0 16.3

7.3 78 1981.2 1983 0.63 16.0 16.8

7.4 4950 0.63 16.0 16.4

7.5 78 1981.2 1988 0.63 16.0 16.6

7.6 3781 0.63 16.0 16.0

Location Diagram: Dimension Diagram:

Port

G-27
Table 25

Balcony Beam Dimensions

Quadrant 2, Level 1-7

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

1.5 18 457.2 460 1.00 25.4 25.7

2.5 18 457.2 464 1.00 25.4 25.2

3.5 18 457.2 463 1.00 25.4 25.2

4.5 18 457.2 458 0.75 19.1 18.1

5.5 18 457.2 461 0.75 19.1 19.6

6.5 16 406.4 412 0.75 19.1 19.7

7.5 14 355.6 361 0.75 19.1 19.6

Web Length, WL Web Thickness, WT

Nominal Measured Nominal Measured

Location inch mm mm inch mm mm

1.5 78 1981.2 1982 0.63 16.0 16.5

2.5 78 1981.2 1975 0.63 16.0 16.6

3.5 78 1981.2 1981 0.63 16.0 16.5

4.5 78 1981.2 1980 0.63 16.0 16.5

5.5 78 1981.2 1983 0.63 16.0 16.9

6.5 78 1981.2 1978 0.63 16.0 16.1

7.5 78 1981.2 1975 0.63 16.0 16.2

Location Diagram:

(Location = i.j; where i = level, j = location)

Dimension Diagram:

Port

Fwd

Measurements

made here*——

6 5 4

T ' 3

1 2

Stbd

Aft

G-28
Table 26

Balcony Beam Dimensions

Quadrant 3, Level 1-6

Flange Length, FL Flange Thickness, FT

Nominal Measured Nominal Measured

Location inch mm mm inch mm ran

1.8 18 457.2 467 1.00 25.4 26.3

2.8 18 457.2 464 1.00 25.4 26.3

3.8 18 457.2 462 1.00 25.4 26.6

4.8 18 457.2 463 1.00 25.4 26.0

5.8 18 457.2 463 1.00 25.4 26.7

6.8 16 406.4 409 0.75 19.1 19.4

7.8 Not accessable

Web Length, WL Web Thickness, WT

Nominal Measured Nominal Measured

Location inch mm mm inch mm ran

1.8 60 1524 1524 0.63 16.0 16.7

2.8 60 1524 1527 0.63 16.0 16.0

3.8 60 1524 1526 0.63 16.0 16.7

4.8 60 1524 1514 0.63 16.0 16.0

5.8 60 1524 1526 0.63 16.0 16.8

6.8 60 1524 1519 0.63 16.0 16.2

7.8 Not accessable

•Location Diagram: Dimension Diagram:

(Location * i.j; where i = level, j * location)

Port Stbd

Aft

G-29
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ti >0 a o

.-1 o 2 * B -o a 9

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00

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r-* rH

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in

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G-30
Table

28-

Deviation

of

Interior

Deadwood

from

Nominal

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pH

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m • • • • © • • • ro CN CN pH CN 00 CN

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CN CN CN CN CN CN CN CN

CN i i 11 0 i i 8 CN

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G-31

Appendix H

Bottom Surveys of Freestanding

LNG Cargo Tanks

By

W. C. Haight, F. Scire, R. G. Hartsock,

C. Johnson, and R. J. Hocken
Table of Contents

Page

Abstract HI

1. Introduction HI

2. The Measurement Method H2

3. Data Analysis H9

4. Error Analysis H10

5. Results and Conclusions Hll

6. Tables of Survey Data H16

7. References H58

List of Figures

Figure 1 - LNG Tank Schematic H3

Figure 2 - Laser Level Schematic H4

Figure 3 - LNG Tank Bottom Plan H6

List of Tables

Table 1 - Random Error Sources H10

Table 2 - El Paso Savannah, Bottom Flatness Summary H12

Table 3 - El Paso Cove Point, Bottom Flatness Summary H12

Table 4 - El Paso Savannah, Capacitance Gage Survey H13

Table 5 - El Paso Cove Point, Capacitance Gage Survey H15

Tables A1-A40 - Tables of Survey Data ..... H16

i
Bottom Surveys of Free-Standing

LNG Cargo Tanks

W. C. Haight, F. Scire, R. G. Hartsock,

C. Johnson, and R. J. Hocken

Abstract

Large Liquid Natural Gas (LNG) cargo tanks in a variety of configurations are presently under construction worldwide. Metrologists are being

called upon to measure their (a) capacity, (b) deformation under load, and (c

)

mechanical deformation due to handling after calibration. The results of a

series of measurements made on free standing aluminum tanks to determine the

extent of the permanent distortion caused by loading them into a ship with a

large crane were presented in a previous paper (1). In this paper, we

present the results of the mapping surveys performed on the bottom (i.e. bottom

survey) of ten (10) such tanks that were placed on the two ships, the El Paso

Savannah and the El Paso Cove Point.

1 . Introduction

Measurement of LNG cargo volume determines one of three essential quantities upon which the dollar value of LNG shipments is based, the other two

being LNG composition and density. The volume of a shipboard cargo is typically

determined from a measurement of the liquid-gas interface level relative to

the tank bottom in each tank. This measurement, in conjunction with a prior

determination of the tank size and shape, can be used to compute a liquid

volume at the time of gaging. Techniques for calibration of tanks and computation of total volume have been reported elsewhere.

HI
The area of concern for this paper is the flatness of the bottoms of

freestanding prismatic tanks. Tank construction is conducted independently

of ship construction. When the tanks are completed, the ship deck plates are

removed and the tanks are lifted into the ship's hull by means of a large

crane. Primary tank calibrations were done photogrammetrically , prior to

loading into the ship, while the tanks were still in the storage yard. The

tank bottoms were surveyed by the tank construction firm from beneath. It

is the desire of the sponsor to know if these measurements remain valid after

the tanks have been loaded into the ship and are resting on a base other than

the one on which they were calibrated. To meet this end, the bottom profiles

of every quadrant of each tank in the El Paso Savannah and the El Paso Cove

Point were measured by NBS after the tanks were installed in the ships. A

typical tank is shown in Figure 1.

2. The Measurement Method

"Flatness" mapping surveys were conducted for each tank on the tank interior

bottom, after the tank was loaded into the ship's hull. The characterization

of the bottom flatness involved the following technique:

A rotating laser, schematized in Figure 2, was used to define a plane

flat to +10 sec of arc and approximately parallel to the tank surface. This

laser has a self leveling feature that permits the plane to be established

perpendicular to the earth's gravitational field. For the surveys reported

herein, the laser was always allowed to self-level after initial setup, and

was then locked to insure that the reference plane remained fixed throughout

the survey. Offsets from this swept-plane were measured to the actual tank

surface, which was marked with a nearly uniform grid of points, using a beam

seeking laser rod. These commercially available rods had been refitted with

higher accuracy scales, kinematic base plates, and a circular bubble level to

H2
25m

Figure 1 - A typical LNG tank of the freestanding prismatic type. The

8

tank is internally divided into quadrants as shown and is

uniformly supported on the bottom while in the ship The

coordinate system used to report the measurement data is

shown here. (View from Aft)

H3
Rotation Axis

Figure 2 - Schematic of laser level with beam seeking "laser

rod. The rotating pentaprism causes the beam to be

swept in a plane. Manufacturer’s specifications are +10 seconds of arc flatness. Resolution of rod is

0.1 mm.

H4
insure that the rod was perpendicular to the survey plane. The laser rod

contained an active detector that searched for the laser beam, averaged a

large number of readings, and then locked so a reading could be taken. These

offset measurements were made at a large number of points, to fully characterize

the contours of the surface being surveyed.

The survey was complicated by the fact that the tank is divided into quadrants with a longitudinal liquid-tight bulkhead and a transverse swash bulkhead.

A schematic of the tank bottom is shown in Figure 3. It was further complicated

by the fact that floor beams up to 1372 mm high, are present. Consequently, four

separate flatness surveys are conducted, one in each tank quadrant, using a

nominal 2 m x 2 m grid spacing. The laser was mounted on the top flange of a

floor beam and the intersection of the laser plane with the wall beam flanges

was marked at the four water tube tie-in points shown in Figure 3 for each

quadrant. Offsets from the laser plane to the tank floor were measured with

the beam seeking level rod in the usual manner. Extreme care was taken to

insure that the rod was perpendicular to the laser plane since the offset

measurements are approximately 1.9 m in length and the chance of a significant

cosine error is substantial. A circular bubble level on the rod was used for

this purpose.

Upon completion of the four quadrant surveys, a hydrostatic differential

level (water tube) was used to attempt to define a level plane throughout the

tank. Short offset measurements from the laser plane intersection marks in

each quadrant shown in Figure 3 were to be used to reference the four quadrant

surveys to a single surface. The water tube technique involved using one

mark in one quadrant as a reference and measuring the 13 additional points

with the other end of the tube in the appropriate quadrants. Access to the

various quadrants was through a valve in the liquid-tight bulkhead and through

H5
FORWARD

1 58 13 16 18 20 3 5 8 13 16 20 24

Figure 3 - Bottom plan of a typical LNG tank showing grid

point definitions. Points marked O are water

tube tie-in points. Grid numbers are based on small floor and wall beam locations.

3

6

9

12

15

18

21

24

27

29

3

6

9

12

15

18

21

23

26

H6
manways in the swash bulkheads. The water tubes used for this survey were

made from tygon and had aluminum scales attached to each end as a means of

clamping to the tank beams. This technique, necessitated by the lack of optical

access between the quadrants, was the principal source of error in the measurements.

Hydrostatic differential leveling is one of the oldest measurement

techniques known for establishing elevation differences between two points.

The water tube apparatus used by NBS for this technique was thoroughly tested

in the laboratory under controlled conditions and found to have random errors

on the order of +0.2 mm. The apparatus was also used in the field under controlled conditions and found to produce similar results. Unfortunately, it

was not possible to make all measurements under carefully controlled conditions

for reasons that will be discussed below. The most significant conditions

that systematically affect water tube accuracy were found to be:

a) Stability of the tank or ship

b) Constrictions in the tygon tubing

c) Thermal gradients in the apparatus

Each error source will be commented on.

a) Stability of the tank or ship - When the flatness surveys were made on

the El Paso Savannah, the ships was berthed in the Mississippi River at Avondale

Shipyard. Despite assurances to the contrary, the ship’s balast tanks were

being loaded and unloaded while the NBS survey was underway. This leads to

changes in ship trim on the order of 300 mm. Furthermore, a second El Paso

ship was tied up along side the Savannah while our survey was being conducted.

This completely disrupted the water tube survey by introducing a list in the

ship of approximately 60 mm. Because of the difficult working conditions, a

decision was made to not resurvey the entire ship, but to try and analyze the

H7
data at NBS. This analysis was unsuccessful because of the random variation

of the water survey tie-in points. In many cases, the four tie-in points in

each quadrant did not form a plane to within 50 mm.

The El Paso Cove Point was surveyed in a floating dry dock, also in the

Mississippi River. While the platform was more stable than the Savannah case,

passing ship traffic still caused water tube elevation differences of 10-20 mm.

In our opinion, this hydrostatic leveling technique is only practical on

land or in rivers with very light ship traffic, and then only when no changes

in ship list/trim occur.

b) Constrictions in the tubing - This is a significant error source, often

causing leveling errors of 20-30 mm or more. In tanks of the type reported

on here, the tubing must be strung over many large I-beams on the tank floor.

It must also be threaded through butterfly valve openings with sharp edges

on the valve. Care must be taken to insure that the tubing does not constrict

under its own weight when strung over a beam edge or through a valve. For

these surveys, a tube approximately 30 meters long was used, and the operators

wre instructed to inspect the entire tube for constrictions before taking any

data. Because there was no lighting in the tanks, this task was difficult

at best, and some constrictions inevitably remained in the tubing.

c) Thermal gradients in the apparatus - A long tube of this type has an

extreme sensitivity to changes in temperature of the water. Interior tank

temperatures during these surveys was as high as 35°C and quite non-uniform.

While this error source is difficult to quantify, it is felt to far exceed

the +1.6 mm random survey error.

H8
Because of these large errors, the quadrant surveys could not be tied

together and referenced to a single water-level defined plane. Therefore,

the data is reported by quadrants only.

During the course of the bottom surveys, the capacitance gage orientation

with respect to the level plane was also established. This was done by using

the laser level in the right angle mode, (with the reference plane parallel

to gravity), in two orthogonal orientations with respect to the ship and

measuring offsets from these planes to the capacitance gage at the bottom and

near the top of each tank.

3. Data Analysis

The raw data from a complete bottom survey for each tank quadrant consisted

of five sets of X, Y, Z coordinates. Data points on the X and Y directions

are were approximate and expressed as index numbers, the data points in the Z

direction, which were measured with the beam seeking laser rod, have a resolution of 0.1 mm. The intent was to determine the best-fit plane from the differences between these five data sets and then, by using those plane coefficients, bring the second set of Z's into coincidence with the first.

For practical purposes, we really have five planes — one for each quadrant,

generated by the rotating laser, and the fifth (which overlaps each of the

other four) generated by the water tube measurements. In principle, all that

is needed is to generate a value for the best fit "water tube" plane at each

point in the other four planes, calculate the differences, and then transform

the laser planes into the water tube plane, which is taken to be absolute and

uniform. The final step planned was to fit a plane to the whole surface,

storing deviations from that plane and the rms value of those deviations.

However, since the water tube data did not form a plane within even one quadrant

H9
(with four points the fit is slightly over-constrained) this data could not be

used to determine the "whole-surface" planes. Instead the rms deviations from

flatness are reported on a quadrant by quadrant basis.

4. Error Analysis

Several types of errors are associated with the individual flatness surveys.

We will discuss three types in this paper: random, systematic, and model errors.

The random errors currently identified in tank flatness surveys are shown

in Table 1.

Table 1 - Random Errors in Free-Standing Tank Measurements

Physical Source Error Value Error Source

Laser planed) +1.5 mm Manufacturer

Spec (1)

Laser rods(2)

Reading Error +0. 3 mm Estimated (2)

Cosine Error(^) +0.6 mm Computed (3)

Total Random Error +1 . 6 mm Sum of errors

in quadrature

(1 ) Specifications on the laser plane include wobble, lack of flatness, and

deviation from level when a self-leveling feature is used. The manufacturer

specifies that the sum of these errors will not exceed +10 arc sec. For

the maximum length of a tank, L«30 m, this error is +1.5 mm.

(2) Scales on the laser rods are blank lines in mm increments on a light

background. The random error for this type of scale is based on years of

laboratory experience.

H10
(3) For an absolute displacement measurement, a rod cosine error is systematic

For relative measurements, this becomes random. For a discussion of the

calculation method used to predict this error, see Reference 1.

It must be noted that the absolute laser rod calibration cannot contribute an

error in this survey since only relative displacement from flatness of two

planes are being computed.

5. Results and Conclusions

The results of the bottom surveys on the two ships, the El Paso Savannah

and the El Paso Cove Point are summarized in Tables 2 and 3 by tank quadrant.

These tables show the rms deviation of each of the surfaces from the best fit

plane. The maximum deviation of 11.76 mm was observed in quadrant 2 of Tank 1

of the El Paso Savannah. The complete data sets are given in Section 6.

The results of the capacitance gage surveys are reported in Tables A and 5

These data are based on dimensional measurements made from within the tanks

after the tanks were installed in the ships and all tank construction and

fitting out was complete.

Hll
Table 2 - El Paso Savannah, Bottom Flatness Summary

Tank Quadrant

RMS Deviation

from Flatness (mm)

1 1 6.03

1 2 11.76

1 3 5.50

1 4 6.17

2 1 6.61

2 2 8.02

2 3 6.47

2 4 8.54

3 1 7.18

3 2 8.29

3 3 7.04

3 4 7.48

4 1 6.42

4 2 5.38

4 3 6.61

4 4 7.19

5 1 4.85

5 2 5.06

5 3 6.87

5 4 6.26

H12
1

1

1

1

2

2

2

2

3

3

3

3

4

4

4

4

5

5

5

5

Table 3 - El Paso Cove Point, Bottom Flatness Summary

Quadrant

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

RMS Deviation

from Flatness (mm)

4.42

4.77

4.26

5.33

2.90

2.43

4.21

4.05

6.27

7.45

9.15

10.43

6.10

9.31

6.98

7.28

7.72

7.22

4.01

4.50

HI 3
Table 4 - El Paso Savannah, Capacitance Gage Survey

Tank

Measurement

Location

Z, mm

X-liq. tight

Bulkhead, mm

X-Port

seam, mm

Y-Swash

Bulkhead, mm

Y-Aft

Wall, i

1 0 (Tank floor) 631 9215 2873 12399

20500 628 N/A 2890 N/A

2 0 (Tank floor) 1783 12673 2873 15637

20500 1771 N/A 2895 N/A

3 0 (Tank floor) 2992 11887 2228 16278

20500 3000 N/A 2230 N/A

4 0 (Tank floor) 3004 11886 2234 16289

20500 2989 N/A 2248 N/A

5 0 (Tank floor) 2054 12078 3487 8515

20500 2057 N/A 3510 8532

Gage Height from

Tank Floor, mm

39.0

41.2

39.5

40.0

40.0

NOTES :

a) All gages are located in the aft-port quandrant of the respective

tank.

b) N/A means either not applicable or not available because of lack of

access to that point.

c) X-Portseam refers to the weld seam between the floor and the port

chine base plate.

Tank

1

2

3

4

5

H14
Table 5 - El Paso Cove Point, Capacitance Gage Survey

Measurement

Location X-liq. tight X-Port Y-Aft

Tank Z , mm Bulkhead, mm seam, mm Wall , mm

1 0 (Tank floor) 562 9283 12373

2 0 (Tank floor) 1811 12635 15652

3 0 (Tank floor) 2995 11876 16274

4 0 ( Tank floor) 2996 11878 16261

5 0 (Tank floor) 2060 12087 8511

Gage Height from

Tank Tank Floor,, mm

1 40.3

2 38.3

3 39.1

4 40.5

5 41.0

Gage Orientation

X-Offset, mm Y-iOffset

,

mm

Tank Z=500 mm Z=20500 mm Z=500 mm Z= 20500 mm

1 50.2 69.0 46.0 70.0

2 110.3 108.0 49.9 47.0

3 75.0 68.0 54.0 61.0

4 48.4 64.0 75.0 97.0

5 43.8 96.0 63.0 89.0

NOTES :

a) For X-Offset measurements, the laser plane was on the port side of the

gage (viewed from above).

b) For Y-Offset measurements, the laser plane was aft of the gage (viewed

from above).

H15
6. Tables of Survey Data

For completeness, tables have been added to present the actual deviations

of each data point from the "best fit" plane applicable to that surface. The

composition of each table is as follows:

Table Contents

Al Savannah Tank 1, Quadrant 1 A2 Savannah Tank 1, Quadrant 2

A3 Savannah Tank 1, Quadrant 3 A4 Savannah Tank 1, Quadrant 4 A3 Savannah Tank 2, Quadrant 1 A6 Savannah Tank 2, Quadrant 2 A7 Savannah Tank 2, Quadrant 3

A8 Savannah Tank 2, Quadrant 4

A9 Savannah Tank 3, Quadrant 1

A10 Savannah Tank 3, Quadrant 2

All Savannah Tank 3, Quadrant 3

A12 Savannah Tank 3, Quadrant 4

A13 Savannah Tank A, Quadrant 1 A14 Savannah Tank A, Quadrant 2

A15 Savannah Tank A, Quadrant 3

A16 Savannah Tank A, Quadrant 4

A17 Savannah Tank 3, Quadrant 1 A18 Savannah Tank 3, Quadrant 2 A19 Savannah Tank 5, Quadrant 3

A20 Savannah Tank 5, Quadrant 4

A21 Cove Point Tank 1, Quadrant 1 A22 Cove Point Tank 1, Quadrant 2

A23 Cove Point Tank 1, Quadrant 3

A24 Cove Point Tank 1, Quadrant 4

A25 Cove Point Tank 2, Quadrant 1 A26 Cove Point Tank 2, Quadrant 2 A27 Cove Point Tank 2, Quadrant 3

A28 Cove Point Tank 2, Quadrant 4

A29 Cove Point Tank 3, Quadrant 1

A30 Cove Point Tank 3, Quadrant 2

A31 Cove Point Tank 3, Quadrant 3

A32 Cove Point Tank 3, Quadrant 4 A3 3 Cove Point Tank A, Quadrant 1 A34 Cove Point Tank A, Quadrant 2

A3 5 Cove Point Tank A, Quadrant 3

A36 Cove Point Tank A> Quadrant 4

A3 7 Cove Point Tank 3, Quadrant 1 A38 Cove Point Tank 5, Quadrant 2

A3 9 Cove Point Tank 3, Quadrant 3

A40 Cove Point Tank 5, Quadrant 4

H16
Table A1

EL F'fiSa SRVRNNRHjTRNK -1

BOTTOM S- U RVE

V

> TflM K I M S HIP* Q UR D R

h

h T :: 1

X Y DEV

5. 3. 10. 18

5. 6. -3. 04

5. 9. 1.10

5. 18. 1.65

5. 15. 4. 39

5. 18. 6. 33

8 . 3. -11.71

C;

o 8. -4.77

8. 9. — 10.83

8. 18. -3. 99

8. 15. 3.85

8. 18. -.41

8. 81. -1.37

13. 6 . 9.61

13. 9

.

8. 75

13. 18. 4.59

13. 15. 4. 83

13. 18. -1.93

13. 81. -8. 39

IRTIOM FROM R PLRME

H17
Table A2

BOTTOM

EL PR SO SAVANNAH-. TANK “1

SURVEY 5 TANK I N SHI P , QUADRANT

X Y DEV

w° • 6. . -6.35

w' • 9. 6. 45

o 12. S. 15

•• • 15. 8. 55

IS. . 75

6. 6. -11. 00

6. 9. -. 70

6. 12. 1 2.20

6. 15. 6. 41

6. IS. -32. 29

9. 6

.

-10. 24

9. 9. 6.76

9. 12. 16. 36

9. 15. 3. S6

9. IS. -6.34

RMS DEVI RT I ON FROM R PLANE 1

1
Table A3

BOTTOM

EL PRSO SAVANNAH.* TANK ul

SURVEY.* TANK I N SH I P , QUADRANT

X Y DEV

ow* • 6. 4. 16

3. 3. 8.43

3. 13. 6. 30

w* 15. 1. 12

3. 18. —

7

6. 6. -8. 13

6. 3. -1 . 07

6

.

12. -1.16

6. 15. -2. 74

6. 18. -7. 32

9.

*

• -4.84

9, 3. — . 83

9. 12. 2. 13

3. 15. 4.31

3. 18. 8.13

RMS DEV I ATI OH FROM R PLANE
Table A4

EL PR 2D SRVRNNRHjTRNK ^1

DOTTDM SURVEY? TANK IN SHI P? QURDRRHT -4

X Y DEV

1. 6. 9.40

1. 9. 8.81

1. 12. 11.42

1. 15. 3.93

1. 18. — . 48

1. 21. -7 • Or* 5. 3. -9. 22

5. 6. -9. 21

5. 9. -8. 30

5. 15. -3. 33

5. 18. -4. 47

5. 21. -8.56

o o W* • •m* • -4. 03

8. 6. -4.52

8. 9. -1.81

8. 12. 5. 30

8. 15. 5.41

8. 18. 6 . 42

8. 21. -1.57

12. 6

.

w* •

•'* 6

12. 9. 6. 77

12. 12. 1 . 78

12. 15. 3.69

12. IS. -4.50

DEV I RT I DM FROM R PLRNE

H20
Table A5

BDTTDM

RMS

EL PR'D SAVANNAH? TANK :*£

SURVEY? TANK IN SHIP? QUADRANT?*!

X Y LEV

1. Cl

•• • 1 1 . £7

1. 1 £. 9. 63

1

.

15. 7.89

1. 18. 1 0. 05

1

.

£1. 7.01

5. 6

.

1.93

5. 9. £. 03

5. 1 £. £. £9

5. 15. -1 . 05

5. 13. .71

5. £1. -. 93

5

.

£4. -3. 67

8. 3. — 4 . 64

8 • 6. ~3. 9

3*

8. 9. -6. 0£

8. 1 £. — 6 . 06

o m 15. -4.4 0

8. 13.. — 3 • £4

8. £1. -1.03

oL* • £4. -5. 4£

13. w* • 1.44

_ - 1 w* • t*. J m !• U

13. 9. — 6 . 74

13. 1 £. -7. £8

13. 15. -6. 9£

13. 18. -5. 06

13. £1. -5.60

13. £4. -15.34

16. 6. -4.65

16. 9. -1 .89

16. 1 £. -.54

16. 15. 1 . 4£

16. 13. .53

16. £1. -5. 06

£0. 6. .71

£ 0. 6. 17

£0. 1 £. © • • £0. 15. 16. 09

£0. 18. 9. 45

£0. £1. 1 1 . 30

: AT I E3N FROM A PLANE

H21
Table A6

BOTTOM

EL PASO SAVANNAH? TANK «£

SURVEY? TflHK IN SHIP? QUADRANT “£

X Y DEV

1. 9. 14.73

1. 12. 15. 15

1. 15. 10.77

1. IS. 10.69

1. 21. 12.71

1. £4. 10. 9£

5. 6. -. 53

5. 9. -1.91

5. 1£. 1.81

5. 18. £.95

£1 1.57

5. £4. -£.11

5. £7. -5.49

8. 6. -11.56

8. 9. -7. 04

8. 1 £. -5.82

s. 15. -4. 30

8. 18. -8. 18

8. £1. —6. £6

«**. U o £4. -12.94

8. £7. -11.72

8. £9. -£.84

13. 6. -11.20

13. 9. -8. 48

13. 1 £. -4.36

13. 15. -4.34

13. 18. -6. 9£

13. £1. -6.91

13. £4t -7. £9

13. £7. -5. 67

13. £9. £.31

16. 6. 1.37

16. 9. -5. 01

16. 1 £. -1.39

16. 15. 1 . 33

16. 18. -.85

16. £ 1 . -£.83

16. £4. 1.39

16. £7. -1.49

16. £9. —

£

. 61

£0. 9. 3. 35

20. 1 £. 8. 37

£0. 15. 1 4 . 89

£0. 18. 14.51

£0. £1 . 1 0. 63

£0. £4. 11.45

RMS DEVIATION FROM ft PLANE S. 0
Table A7

EL PhSD SmVhMNHH* TRMk ::£• BOT TDM SURVEY, ThNK IN SHIP, PURI- PnN'

X Y DEV

1.

1.1.

1,

1.

1

.

5.

5.

5.

5.

5.

5.

5.

S.

8 . 8 . 8 . o I C;< 8 . OV < O

13.

13.

13.

13.

13.

13.

13.

13.

13.

1 6.

16.

16.

16.

16.

16.

16.

1 6.

18.

18.

18.

13.

18.

18.

9.

IE.

15.

13.

£ 1

,

£4.

6 . Cl, 12 . 15.

18.

£1

.

£4.

£9.

6.

9.

1 £.

15.

IS.

£ 1 . £4.

*.

13. 1 £.

15.

18.

£ 1 . £4.

£7.

1 £.

15.

18.

£ 1 . £4.

£7

.

9.

1 £.

15.

IS.

£ 1 . £4.

£.34

8. 39

C; ;.c W • u. .* 12. 00

13. 35

8.61

-9. £3

- 11.88

-.62

. 13

1.49

4.34

-1.51

-5. 85

-£. 75

-. 9£

- 10.66

-5. £1

-4. 35

-4.50

-3. £5

-6. 19

-7.74

10. 17

-3. 06

-1. 06

-3. 70

.45

-. 1 0

-3.54

-13. 39

-6. 13

-4.48

• ^ QC; J • w*«.» 3. 06

.5!

4.76

3. ££

4.57

-.07

-3.12

-7.77

3.75

11.31

9.76

9.22

5.87

£.

RMS I'v ’v'IH f I DM FPHM ft

H23
Table A8

EL F'fiSQ Z hVhNMRH * TH'iK “8

EDI TDfl SURVEY 5 TRN< IN SHI P« Q'JnDrflNT«4

X Y DEV

3. 6. 6.53

Cj

w' • Q•• • 13.43

3. 13. 13. 04

3. 15. 13.30

3. 13. 13. 37

3. 31. 5.33

5. 6. -6.49

5. 9. — . 33

5. 13. 1.13

5. 15. 3. 39

5. IS. 5. 15

5. 31. -. 09

5. 34. -4. 93

8. 6. -11.96

8 . 9. -3. 00

O 1 o • Ji <= ® -5. 34

8. 15. -7.57

S . IS. -3. 31

8. 31. -6.45

8. 34. -3. 39

S. 36. -13. 03

13. 6. -11.14

13. 9. " l'‘ • 4 » 13. 13. -5.51

13. 15. -4.45

13. IS. —3. 09

13. 31. -.43

13. 34. —4. 67

13. 36. — 1 8 .76

16. 6. -6. 30

16. 9. — 3. 34

16. 13. -1.33

16. 15. 1.43

16. 13. 3.54

16. 31. 3. 50

16. 34. 1 . 36

13. 9. 7.55

13. 13. 1 0. 71

13. 15. 13.67

13. 13. 9. 13

13. 31. 16.7?

DEVIftTICN cC'DM 8 PLftHE

H24
Table A9

LOT TQM

EL PftSO T hM;

. «3

SURVEY- T ftfik! 1 H SHIP- QUhL phHT

l

X Y ui t—i

o. e*. 1 8. 03

3. 9. 1 0. 16

3. 13. 9. 00

3. 15. 1 0. 14

3 «. 13. 1 1 . 33

3. 31. 9. 33

5. 3. 1 0. 91

5. 6. ~d . 7' 5. 9. . 79

5. 1£. 1.73

5. 15. 8 . cl C 5. 13. 1 . 01

5. £1. 3. 05

5. 34. -1 . 31

8. 3. -8.70

8 . 6

.

—7 . 75

3. 9. — i • i 1 8 . 13. -5*. 67

3. 15. — 8 . 6 3

8. 13. -4.39

8. 31. . 05

8. 34. — 10.61

3:. 36. -11. 33

13. 3. — •

' • 4- »’ 13. 6. -10. 43

13. 9. -9. 59

13. 13. -7. 75

13. 15. -6.51

13. 18. -9. 17

13. 31. -. 03

13. 33. -1 . 80

13. 36. -3. 56

16. 3

.

4.53

16. 5. — ‘-,C

i 16. 8. -6.41

16. 11. — ^7

16. 14. -.53

16. 17. -4. 18

16. 3 0

.

-. 14

16. 33. -. 30

16. 35. o r. 30. 8. 18.76

30. 11. 1 0. 30

30. 14. 18. 84

30. 17. 8.48

30. 30. 7. 73

30. 33. 4.76

E V I }- T ] ON = -0*1 H

:

i- fns 7.18

H25
Table AIO

DOT TO:

EL PHSO SflVRNNRH* TRfik ::3

•1 SURVEY-. TR*^: IN SHIP? QURDPRN T

s

X DEV

1. 9. 1 0.40

1. IE. 18. £5

1. IS-. 1 0. 50

1. 18. 1 0.84

1. £1. 1 £. £9

5. 6. -1.87

5. 9. -. 5E

5. IE. 3 . ££

5. 15. 1.57

5. 18. 3.5E

5. El. • c* r 5. £4. 3.71

5. £7. -8.84

8 . 8 . -3. 18

8. 9. -3. 9E

8. IE. -5. 97

8. 15. -8. 7E

8. 18. — 4 . 77

8. El. w" • u S' 8 . £4 . -3. £8

8. £7.

8 . £ 9 . - . 7 0

13. 8. -8. 8E

13. 9.

13. IE.

13. 15.

-11.37

-10.4 8

13. 13. -11.03

13. £1.

13. £4. - 3 ! 93

1 3 . E i‘ • — 3 . 99

13. £9. -1.35

18. 8 . 1. 19

18. 9. -3. 78

18. IE. -7. 0£

18. 15. - 8 . £7

18. 18. — 4 . 9 E

18. £ 1 . -1 . 37

18. £4. -1 . 93

18. £7. - . 33

18. £9. -9. 55

£0. 9. 3. El

c U . 1 IE. 33

£0. 15. 1 3.41

£ 0 . 13. 14.75

£ 0 . El. 19. 30

£0. E4. 17.85

DEVI RT I ON h c

’i_ *

!

H26
Table All

EL PftSO SAVANNAH? TftNK «3

.BOTTOM SURVEY? TANK IM SH

I

=* ? QUADRANT“

X Y DEV

1.

1.

1.

1.

1.

5.

5.

5.

5.

Qm~ a 12 . 15.

18.

21 . 6 . 9.

12 . 15.

18.

2 1

.

c!4

.

11.55

1 1 . 05

11.75

1 0. 15

13.45

5. 19

.79

-1.61

-I

-1

01

41

11

0 0

4 0

13.

13.

13.

13.

13.

13.

13.

16.

16.

16.

16.

15.

16.

16.

IS.

13.

IS.

18.

18.

18.

12.

15.

13.

21 . 24.

ll! f a 6.

9 . 12 . 15.

IS.

21 .

1

12 . 15.

IS.

21 . 24.

9.

12 . 15.

18.

21 . 24.

10 . 95

- 9.55

- 13.65

- 11.15

- 10 . 75

- 4 . 45

- 4.45

Z* « o'

- «*’ — A C Z* -t • *-> - 5 . 03

-4.32

“2 . dd

5.43

-4.27

-1.47

.33

-. 17

1.53

2 . 30

7 . 00

1 0 . 1 0

5 . 00

9 . 30

1

1

. 00

RM3 DEVI ft II OM PROM M r'LH.•Mr IIJ

H27
Table A12

EL P8SD Sriv’A^'iPH? T3HK «3

BOTTOn SURVEVi' TANK Ir- : HI P? QU-DRtiHTn4

Y LEV

T-M

1. 3. 7.19

i. 6. 11.42

1. 9. 1 0.24

1. 12. 1 C • 2* i

1. 15. 7. 90

1. 13. 7. 1 3

1. £0. 16. 31

5. 1. p Z[ Z* 5. 3. -6. 80

5 . 6

.

5. 9. -4.94

5. 12. -3. 92

5. 15. -4. 79

5. 17. 3.4 0

5. 20. 1 . 52

5. 23. -1. 35

8. 1. 2.18

8. 3. -3. 84

8. 6. -6: 01

8. 9. -1 0.23

8 . 12. -11. 36

8. 15. -11.13

8. 17. -1.74

8. 20. -3. 92

8. 23. - . 79

8. 25. -2. 1 0

13. 1. 2. 14

13. 3

.

-2.57

13. 6

.

-1 . 35

13. 9. -1.22

13. 12. -3.49

13. 15. -7. 86

13. 17. “ m . Z* 13. 20. ~Cl m 13. 23. ~ . 7 Z‘ 13. 25. -1 0. 14

16. 3. -. 32

16. 6

.

-6. 89

16. 9. —4 . 86

16. 12. —3. 3:3 16. 15. -3.91

16. 17. .4 *. *T • *• w 16. 20. -3. 7?

1 & . tL •• • -1.37

16. 25. _ c 2, Z* 20. 9. 16. 55

20. 12. 15. 1 2

20. 15. 12. 31

20. 17. 15. 29

20. 20. 1 0. 62

tiEVJfiTTCn 9 -L
Table A13

EL PASO SAVANNAH, TANK #4

BOTTOM SURVEY, TANK IN SHIP, QUADRANT#!

X Y hi

w° a

•7» a 6.

9.

-6. 39

-9. 50

o*»* a 1 £. -9. 1 0

oW a 15. -18.71

Ow* a IS. -9.71

5. n» £. 63

5. 6. . 13

5. 9. -2.53

5. 1 £. -3.89

5

.

15. -5.29

5. 18. -5. 30

5. £ 1

.

-3. 30

5. £ 3. — a 4 o°' 8 . 8 . 8 . 8 . 8 . 8 . Ou • 8 . 8 . 13.

13.

13.

13.

13.

13.

13.

13.

13.

18.

16.

16.

16.

16.

16.

16.

16.

16.

19.

£ 0 . £ 0 . £ 0 . £ 0 . £ 0 . 19.

b.

9.

12 . 15.

18,

£ 1 .

6 . 9.

12 . 15.

18.

21 . £ 8 . £6 .

a 6 . 9.

1 £.

15.

17.

£ 1 . £3.

£5.

6 . 9.

12 . 15.

IS.

21 . c’3.

7. 15

6.55

3. 04

3.24

. C. Zf £ . 1 3

£. 6£

7. 65

2 . 93

7.59

C £ o

C‘ *7 -# a -• • cr "7 Ca

1 1 . 83

1 . 82

2 . £1

1.51

-1.30

-.£0

.92

£.78

6. 01

8.54

-5.76

-11.17

-1 0. 07

- 8 . £8

“ •' a • C* - 1 1 a £6

RMS DEV 1 9T in* 1 c 8QM 8 CM- H29
Table A14

EL PASO SAVANNAH, TANK #4

BOTTOM SURVEY, TANK IN SHIP, QUADRANT#

2

r-rr

X Y DEV

1. 9. -10.54

1 . lc. -9. 11

1. 15. -11.48

1. 18. -6. 34

1. 81. -9.11

1. £3. -11.09

5. 6. - . £6

5. 9. -1.73

5. 18. -1.00

5. 15. -. 66

5. 18. 3.67

5. 81. 3.5 0

5. 84. 4.63

5. 87. 5.56

8. 5. 1.64

8. 8. 1 . 37

8. 9. 4. 03

8. 18. 3.71

8. 14. 6.34

8. 17. «*’ • 4 r 8. 80. 7. 1 0

8. 83. 3.53

8. 86. 8 . 76

8. 89. 6. 30

13. 6. w* • -• t 13. 10. .71

13. 18. 1 13. 15. . 56

13. 18. . 79

13. 81. 3. 03

13. 84. 2.96

13. 87. 1.89

13. £9. 2. 71

16. 6. £.47

16. 9. 3.51

16. 12. 8. 04

16. 15. -1.83

16. 18. . 70

16. £1. . 04

16. £4. -.13

16. 27. -.30

16. 89. . 6*2

18. 6. “PC* ^ • • -• £0. 9. . 52

£0. 12. -4.35

£0. 15. -? r, 80. 1 3

.

•6. 73

80. 21. -3. 35

18. 24. -5. 83

18. 27. — tjf1 H30

T.'VTftTTriN rc^riM ft PI ftwr
Table A15

EL PASO SAVANNAH, TANK//

4

BOTTOM Sl’RVEY, TANK IN SHIP, QUADRANT03

X Y LEV

3. 6. -.40

1. 9. -1 0. 17

1. 1 £. —7.8Si 1. 15. -9. £9

1.‘ 18. -10. 5 0

1 . £ 1

.

- 3 .81

1 . £4 . - 1 3. 4£

5. 6. 3.75

5. 9. 4 . 64

5. 13. . 03

5. 15. -£. 18

5. IS. — 3 m ji y

5. £1. -.89

5. £4. 1 . 6 0

5. £7. 5.59

8. 4. £. 15

8 . 6 . 3. 64

8. 9. 6-. £3

8. 1 £. 3. 6£

8. 15. 1.51

8. 18. 3 . 6 0

8. £1. 4. 79

8. £4. 1 0. 93

8. £7. 1 -> . £ 7

13. 4. 3 . £ 8

1 3 . 8

.

i • c o 13. 9. (' . C i 13. 1 £. £.16

13. 15. £.15

13. 18. £.94

13. £1. 5.53

13. £4. 8 . 1 £

1 8 • d >' •

•’ • Z’C. 16. 6. -1.73

16. 9. -1.14

16. IS. -1.35

16. 15. -3. 06

16. 18. -3. 17

16. £ 1

.

-1.68

16. £ 4 . £.61

16. £7

.

3. 30

18. 9. -5.13

IS. 1 £. -9. 09

18. 15. — 1 £. 1

0

18. 13. -9. 31

13. £1. -9. 3£

18. £4. -6.53

P.1;: r'£VI^TIDr '* -SDTM h r.6 1

H31
Table A16

EL PASO SAVANNAH, TANK//4

BOTTOM SURVEY, TANK IN SHIP, QUADRANT#4

v V DEV

1 . .

— • j . -14.88

1 . Cl

b -14.88

1. 18. -11. 38

1 . 15. -11.87

1 . 18. -10. 57

1 . £0. -7.81

•Z* m C. Z' • -.81

C* 1 . 5.14

c_l • ”» . 8 0

5. £, o -1 . 80

5. 9 . — . 88

J . 18. . 1

1

C* 15. . 1

cr

_l . 17. . 38

5. 80. 3. 03

cr

Jl * CL j • c. • z* c» 5. -.cr

C. J - 4.35

s. 1. 4 . 38

8. 1 . 88

8

.

3 . 8 8

Q o 7 . 88

s. 18. 8 . 78

r. 15. 3 . 5 0

p 17. 5: 13

8 • 80. 3.83

C' . C • 3 . 5 7

8 • CD. 8 . 87

(Con’d)

H32
Table A16 (continued)

TANK// 4 , QUADRANT// 4, (Con'd)

13 . 13.

13.

1 3.

13 . 13.

13.

13.

13.

13.

It*. 16.

16.

16.

1 6

.

1 6 • 16.

16.

16.

IS.

E 0

.

£ 0 . £ 0

.

£0.

£ 0 . 13.

y.

1 £ . 15.

17.

£ 0 .

9.

IE.

15.

17.

£ 0

.

IE.

15.

17.

EG.

1 3 . 6 0

6. 97

8. 07

S • i i 6. 97

. £ »' 7. £4

7 . £4

7. 94

9.81

3. 15

— 3 . ill 4

-1.94

-£.04

-1.57

3.43

£. 00

-10. 35

-11.16

- 9 . 5 6

-14.86

-13. 09

-10. 83

RMS DEVI AT I ON FROM ft PLhME 7. 19

H33
Table A17

EL PASO SAVANNAH, TANK #5

BOTTOM SURVEY, TANK IN SHIP, QUADRANT#!

X Y LEV

3. 4. -18. 30

1. 7. -4.87

1. 9. -5. 17

ow* • 13. .52

5. 4. 1 . 89

5. 7. .99

5. 9. .59

5. 13. -.10

5. 15. -. 70

8. l: 1 . 06

8. 4. - 86

S. •* 9 1 • £6

o a Ci

• ' • a ‘Z* l 8. 13. -4. 03

9. 16. Z* a

1*’ •** 18. 1. 33

11. 4. 4.43

11. 1** ® 3. 04

11. Cl

-• a 5. 04

11. 13. 1.44

11. 16. -. 15

15. 1. 3.59

15. 4. 8. 80

15. 7. 8. 1 0

15. 9. 3. 70

15. 13. 3.91

14. 16. 5. 08

16. 1. 7.43

16. 4. 3. 09

16. •’* • 1.79

16. 9. 1 . 89

16. 13. 8. 80

18. 4. -14. 13

20. 7. -7. 74

20. 9. —6. 64

13. 12. -9. 43

RMS DEVI ATI DM FROM H -•[. AME

H34
Table A18

EL PASO SAVANNAH, TANK 05

BJTTOM SURVEY, TANK IN SHIP, QUADRANT#2

X Y DEV

3 . 6 . . L. O

8. 9. .55

1. 13. -5. 06

1. 15. -13.33

£. IS. -11.81

5. 5. -3.81

5. 6. 3. 85

5. 9. .83

5. 13. -.69

5. 15. -4. 31

5. 13. -3. 03

5. 31. 3.95

3. 4. 5* 60

8. 6. 4.33

3. 9. 5.51

3. 13. -• *4 ^ 8. 15. • l*‘ l*‘ 3. 13. 4.35

3. 31. 7.33

13. 4. -.64

13. 6. • U.W 13. 9. .57

13. 13. 3.85

13. 15. 4.13

13. IS. 4.11

13. 31. 9. 69

16. 6 . -.44

16. 9. - 1 . 36

16. 13. . 68

16. 15. .90

16. 13. 3. IS

16. 31. 1 . 86

19. 9. -5.78

19. 13. -6. 80

d U . 1 j. -9.43

19. 13. -5.64

IRTIDM ?SDM H FLh’HE

H35
Table A19

EL PASO SAVANNAH, TANK 05

BOTTOM SURVEY, TANK IN SHIP, OUADRANT#3

X. Y DEV

3. 7. —7 . 83

1. 10. -6.74

1. 13. -12. 06

1. 16. -12. 08

£. 19. -18. 00

5. 5. 3.54

5. 7. .36

5. 10. — . 96

5. 13. 2. 98

5. 16. 3.40

5. 19. . 78

5. 21. 4. 1 0

3. 4. 4 . £6

8. 7. 3.-14

S. 10. 4. 32

8. 13. 9. 30

8 . 16. 1 0.53

8. 19. 11.16

8 . del - 13. 14

13. 4. -.53

13. 7.

13. 10. -1 . 01

13. 13. 3.47

13. 16. 3.85

13. 19. 4.83

13. £2. 6.21

16. 7. -.21

16. 10. • w' l’’ 16. 13. .45

16. 16. “• •** 1 16. 19. -2.99

16. 22. -£*.£1

18. 10. -4.45

18. 13. —7 . 3?

18. 16. -7.69

18. 19. -11.50

IftTIOM FPDrl h PLrK'tE

H36
Table A20

EL PASO SAVANNAH, TANK 05

BOTTOM SURVEY, TANK IN SHIP, QUADRANT04

Y DEV

to® © 4 . .33

1 . • o -7.33

1 . 10 . -.98

2 . 13 . . 13

5 . 1 . “83!. 96

5. 4 . 3.74

5 . 7* 9 “.16

5 . 10 . .24

5. 13 . -.84

5. 15 . 1 . 88

C;J • 1 . 3.61

8 . 4 . 5 . 91

1 0 . —;» 1 m r • 8 . 10 . 1.61

ft . 13 . 1.11

o © 16 . . 01

13 . 1 . 5.43

13 . 4 . 6 . 73

13 . 7 . 3.59

13 . 1 0 . 3.38

13 . 13 . . 98

12 . 16 . 2 . 53

16 . 4 . - 1.35

16 . 7 . - 1.45

16 . 10 . -. 65

16 . 14 . —6. 49

13 . 1 0 . - 12.14

RMS DEV I FIT I DM FROM ft F'LftNE t'.CD

H37
Table A21

EL PflSD COVE POINT ? TANK -1

BOTTOM SURVEY? TANK IN SHIP? GlUftDRANTitl

X Y DEV

3. 5. 4. 02

o•' • 8. 4.75

m 11. 2 . 09

12. 2 . 94

Om 17. 6. 27

6. 8. -7.58

6. 11. -8. 34

6. 12. -7. 29

6. 15. -4.96

6. 18. —2. 52

9. 5. -2.55

9. 8. -4. 01

9. 11. -4 S37

9. 14. -1 . 03

9. 17. 1.10

9. £0. 1.64

11. *—• • 3. 03

11. 7. 5. 92

11. 10. 2.76

11. 13. 1 . 6 0

11. 16. 4.44

11. 19. 1.47

I AT ION FROM ft PLANE

H38
Table A22

BOTTOM

RMS

EL PfiSD COVE POINT? TRNK st 1 SURVEY ? TRNK I N SH I P ? OURDRRNT“2

X Y DEV

4. ~ I'* • l** J

i> • o' •

1 0. -.64

I; 13 . £'. £1

16 . 6-. 35

6 . 4 . - S . 04

1 © . 5 0

6 . 1 0. 3 . £5

6 • 13 . . 09

t.. 16 . - 3 . 16

9. 4 . -. 66

•it _ { m 6 .

6

3

9. 1 0 . 3 . 03

9 . 13 . - 3 . 13

9 . 16 . - 9 . £8

DEV I RT I ON FROM R PLRNf. 4.

H39
Table A23

EL PASO COVE PD I NT? TANK ::1 BOTTOM SURVEY? TANK IN SHIR? QUADRANT::?

X Y DEV

2* m 5. -1.E7

2* m 6. 4.4b

2° • 9. 8. 54

IE. • Ci

»* % 15. Cl

— 7 -! f1 6. 6. -1 . 3E

6. 9

.

-1 . 13

6. IE. -3. 34

6. 15. -5.73

f,

.

IS. — b . 9 7

9. -I; -E. 03

9. 1.11

9. Ci

w E . 69

9. IE. j *j O

Ci. 15. 5.17

9. IS. E. 75

RMS DEVIATION FROM A PLANE 4 . E6»

H40
Table A24

E'OTTOO

FT-1S n

EL F’fi I COVE ED I HI. TRNt

_ K VEY ? 1 H M K I M H I F‘ J L! • n P

DEV

1

1

1

1

1

1

r

12

12

12

12

12

12

4

f.

12

15

12

4

12

15

IS

21

12

15

12

21

-1 . 32

7.24

5. 53

Z> . 1 cl 3 . 06

5. . 1 0

-10.41

-6*. 75

-5.71

"4 B

»*’

a —' »’ -1 . 03

. 35

-7.21

-4.13

-1 . 23

-1 . 35

— y . 51

EVIRTION FED M H F'LRHE

«1

PfiNT -4

H41
Table A25

EL PftSO COVE POINTS TfiHK «8

BOTTOM SURVEY* TfiMK IN SHT => CLIRBR8MT:; 1

X Y DEV

1. H . 4. 04

1. 18. 4. 56

1. 15. 5. 43

1 . 18. 5. 60

1. 81. 8. 88

5. 6. — 3 . 78

5. 9. -8. 00

5. 18. -1.83

5. 15. . 14

5. 18. -.84

e*

.i

,

81. -3. 81

«r

-• • 84. -1 . 08

O 'Z* -5.. 30

8.

Q

D.

Ci ??

O m 8. 13. C. a Z* o . 15. -8. 51

8. 18. -8. 78

8. C*1 . -4. 57

13. 3. c o

13. 6. . 8 0

13. H«* O 1.38

13. 18. 3.54

13. 15. 8. 86

13. 18. 3. 88

13. 81. . 41

13. 84. -1.57

16. 6. . 15

16. Q•’ • -.53

16. 18. -. 11

16. 15. . 1

1

16. IS. -. 17

16. 81. -8.85

16. 84. -3. 88

30. C|a* • C • C. -• 80. 13. £‘. ?.*

80. 15. 1 . 87

80. 18. 1 . 88

8 Ci

.

81. 1 . 88

RMS DEVIhTIOM FROM fi PLPNE r' HI

H42
Table A26

EL PRS3 CD v'E PDI MT « ThMk £i TDM SURVEY » 1 RMK I M SHI P - QUR LRRHT

X Y DEV

1 o 1 . 0£

1. 1£. 1 . 9 0

1. 15. 1 . 97

1. 13. £. 75

1. £1. ft . £ 3

1. £4. 4. £0

5. 6. 4.51

5. 9. ® CO

5. lc. -4. 14

5. 15. —=• *• ^Ct 5. 18. -1.99

5. £1. -. 01

5. £4. -.£4

5 • c i' • 5. 04

C; 4 5.4ft

ft ft 'J • • ® . 13

Cj. Q a -£. 84

8. 1£. -ft. 57

8. 15. -9. £9

8. 18. -9. 7£

8. £1. — 7. 34

8. £4. -4 . 36

8 . £7

.

£.31

8. £9. ft. 03

13. 4. 3. 52

13. 6- £ . 8 3

13. 9. . 31

13. 12. -3.81

13. 15. -ft. 04

13. IS. -5.4ft

13. £1. -5.83

13. ft4

.

-£. £1

1 ** • C t > 1.67

13. £9. 1 . 89

16. ft. 7. £1

16. 9. .48

16. 1 £. -1.94

16. 15. - 1 . £ft

16. IS. — '!• £*Q

16. £1. -.51

1ft. £4. 1 . 3ft 1ft. £ > . 3.44

IS. 1 £• £.54

13. 15. O . -• c 13. IS- 3. 09

IS. £1. 5. £7

PM": IiEV I RT I DM CPDM R = '-RMi

H43
Table A27

EL PRSD CDVE RDTHTj ThRk:. «£

EG 1 TQM SURVEY t Th'-iK I N SHI P. QURL'RRNT

b\

13.

13.

13.

13.

13.

13.

13.

13.

13.

13.

16.

16.

16.

16.

16.

16.

16.

16.

18.

13.

13.

13.

Y

Q

13

15

13

31

34

6

9

13

15

13

31

34

9

13

15

13

31

34

3 7

3 3

4

6

9

13

15

13

31

34

13

15

13

31

34

u. • 13

15

13

31

DEV

1 . 03

1 . 9 0

1 . 97

3. 75

6. 33

4 .

3

0

4.51

• iZ. O

-4. 14

ET £

-1 . 99

-.01

-. 34

5. 04

5. 46

. 13

—3 . 64

-7. 34

-4.36

3. 31

6 . 03

. 31

-3.31

-6. 04

-5.46

_CT Z* -3.31

1.67

1.89

7.31

.43

-1 . 94

-1 . 36

-3. 39

-. 31

1 . 36

i* • 4- 4

3.54

S' • S' c. 3. 09

cr -7

. w •

RMS DEVI RT I DM C RCM R PLRM3 4.31

H44
Table A28

EL PASO COVE POINT « TANK «3

BOTTOM SURVEY* TANK IN SHIP* QUAD*? ANT«4

X Y DEV

3. 1 9. 9.38

3. 13. 8.41

3. 15. 8.97

3. 18. 7.85

3. 31. 5. IS

5. 6. -3 .34

5. 9. -. 73

5. 13. -1.13

5. 15. -3. 77

5. 18. -3. 11

5. 31. -1.88

5. 34. -3. 00

C;

•’ O a —* «* -4.80

8 . 6 . -8*. 04

8. 9. -4. 93

S. 13. -4.53

8. 15.

8. 18. -3.55

8. 31. -3. 38

8. 34. -3. 80

13. 9.

13. 13. -1.47

13. 15. -3. 31

13. 18. -1.98

13. 31. -. 70

13. 34. -1 . 05

18. 3. 3.78

18. 6. -. 39

18. 9. -.13

18. 13. -1.87

18. 15. — . 8 -• 18. 18. • 74

18. 31. -.01

18. 8. 5. 13

IS. 9. 1.83

18. 13. m -J 18. 15. 4. 05

18. 13. 3. 30

18. 31. «!• • u 1*

DEVIATION PROM 9 PLANr 4 . (•

H45
Table A29

EL PR ID COVE PDINT-.TRML «3

FUTTOM SURVEY* TftHK IN SHI P .» G'UR DPRNT “ 1

X Y 1— Ml

1

3. 6. 9.45

*.® ® 9. 7. 96

3. IS. 5.77

r, 15. 6 . 89

3

.

18. 3. 10

3. SI. 4. 31

5. m>

° a 1.39

5. 6. -.SO

5- 9. 3.21

5. IS. . 02

5. 15. -. 46

5. 18. -3. 05

5. £1. 1 . 36

C* • V* • 1 . '07 8. 6. -2. 12

C;

^

Ci

•* o -.21

8. 12. -4.80

8. 15. —6. 49

8. 18. -4. 07

8. 21. •

»* 4- 13. mm1 9 -4. 1 1 13. i£. m -9. 79

13. 9. -10. 68

13. 12. -10. 77

13. 15. -10. 96

13. IS. -8. 65

13. 21. 2* • i •• 13. 24. • z.

c

16. *• -3. 42

16. 9. -.80

16. 12. -2. 79

16. 15. -2.43

16. 18. -1 . 97

16. El. -1.46

16. 24. -4.74

SO. Q•* » 1 0. 60

8 0

.

12. 1 3 . 0 1 SO. 15. 12. 62

SO. IS. 1 0. 33

SO. 21.

RTITi Fpr>’ h c, Li-i '8

HA6
Table A30

EL FRIO COVE F’DIMT > TRNK'

D3TT0M SURVEY, TANK IH SHIP* GMJRI.RRHT“£

X V DEV

1. 9. 8.22

1 . 12 . 12 . 01

1. 15. 14. 41

1. IS. 16. 60

1 . 21 . 1 3.89

5 . 6 . -2.9S

5. 9. -4.79

5. 12. -3. 50

5. 15. -1.71

5. 18. - 1 . 01

5. 21. -1.82

5. 24. -.43

5. 27. -. 14

S. 8 . - 6 . 49

8 . 9. - 8 . 50

8 . 12 . - 10.11

8 . 15. -9. 92

8 . IS. -9. 12

8 . 21 . -9.4 3

C; 04 — '2 . 24

T»

C° ® *_ i* ® -4.S5

8 . 29. 8 . 64

IS. 6 . -2.31

13. 9.

4 4 -3.42

1 . 1 Z. . 13. 15. -4.33

13. 13. '“i .4 — S' ® S* 13. 21. -4. 35

13. 24. - 6 . 7

6

13. 27. -7.47

13. 29. 1 . 23

16. 6 . —8 .42

16. 9. ““

• C. -• 16. 12 . — c» 16. 15. 1 . 06

16. 13. -.55

16. 21 . . 04

16. 24. -3.57

16. 27. -6 . 78

16. 29. j* •

•* r*

.

20. 9. ?• z*z* c 0 . 1 c • 8.25

20. 15. 1 0. 94

20. 13. 9. 14

20. 21. 14.26

20 . 24 . 1 0. 02

H47
Table A31

EL PASO COVE POINT < TANK «3

BOTTOM SURVEY > TANK I N SH I R , QUADRANT3

X V DEV

1. 9. 1 0. 17

1. 12. 12. 91

1. 15. 14.28

1 . 13. 17.41

1 . 21. 14. 95

5. 8. -1 . 18

5. 9. -3. 91

5. 12. -1 . 37

5. 15. -. 92

5. 13. “• w' 1 5. 21. •

4

5. 24. -. IS

8. 6. r r .'C 8. 9.

S. 12.

8. 15.

-8. 57

"• • W* -12.48

8. IS. -11.53

8. 21. -11. 29

8. 24. -1 1.84

o -• "? • c. • • -13. 89

13. 6. -4 . 7zl 13. 9. -4. 53

13. 12. —8. 33

13. 15. — S. 28

13. 18. -8.84

13. 21. -7.19

13. 24. -8. 34

13. 27. -7. 00

18. 9. -. 34

18. 12. -2. 29

18. 15. . 38

18. 18. - . 8 0

18. 21. z* tr C • I'J 18. 24. — • 3 0

18. 27. 3.84

18. 9. 8. 22

18. 12. l’ • -• « 18. 15. 1 0. 42

18. 18. 1 3: . 78

IS. 21. 15.51

13. 24. 2 «‘i . 1 3

RMS DEVIATION F P'OM A F LA*>E A. 15

H48
Table A32

DOT TOM

Rriii

EL PASO COVE POINT? TANK

SURVEY? TANK I N SH I P? QUADRft NT «4

D

X Y DEV

1. 6. £1.17

1. '9. 1 3.48

1. IE. 16.79

1. 15. 13. 40

1. 17. 7.64

5. 1. -3.53

5. 3. -3.79

5. 6. -1.08

5. 9.

5. 13.

1 . 03

_ • •' •' 5. 15. -. 14

5. 19. -1.23

5. 31

.

-4. 92

5. 34. -8.21

El l

.

1 1 59

S. 3. -12.77

9 . 9

.

-7. 86

S. 9. -4.95

S. 13. —7 . 4

S. 15. -4. 03

S. 19. -5.92

9. 31. -4.21

El 34. -5.4 0

13. 1. 3. 03

13. 3. -16. £9

13. 9. -14.37

13. 9. -12.46

13. 13. -14.25

13. 15. -13. £4

13. 17. -9.40

13. 31. -6.92

16. 3. -2. 67

16. 6

.

-1.46

16. 9. . 35

16. 1 2

.

-.83

16. 15. —3. 22

16. IS. -.51

16. £1. 3. 30

30. 9. 24.31

30. 13. 19.92

20. 15. 17. 23

20. 17. 17.57

I AT I ON RRCN H PLANE 10.4

H49
Table A33

BOTTOM

PMZ

EL PASO COVE POINT ? TANK «*4 SURVEY* TANK IN SHI -N QUADRANT**!

X Y . DEV

8 . 9.81

w* • <u-• • 7 . 75

w* • 12 . 7 . 09

w' • 15 . 3 . 94

w' • 18 . 8.88

ow* e 21 . 7.32

3 . 23 . 4 . 05

5 . C-. - 1.73

5 . 9 . - 1.09

5 . 12 . . 85

5. 15 . - 1.10

5 . 18 . . 74

5 . 21 . 1 . 38

8 . 3 . -4.84

8 . 8 . -7. ‘4 0

8 . 9 . - 4 . 85

£• • 12 . - 5 . 1 1 8 . 15 . — 8 . 98

8 . 18 . - 1.72

8 . £ 1 . -. IS

ou* • £ 3 . £ . 8 5

13 . w* - 9 . 3 * 13 . w* • - 9 . 50

13 .

Cl

. - 7 . 75

13. 12 . -5.71

13 . 15 . -5.77

13 . 1

8

. -3 . 32

13 . 21 . -5 . 18

13 . c! w' • -8.95

13 . c r . — 3 . 99

18 . 6. - 1.88

18 . 9 . -. 32

18 . 12 . C « i‘* -• 18 . 15 . 1.07

18 . IS. —2 . 89

1 8. £ 1 • -8.54

18 . iZ. J'

.

- 8.71

£ 0 .

j* . 9 . 28

£ 0 . 1 0 . 90

£ 0 . 12 . 13 . 35

£ 0 . 15 . 11.29

£ 0 . IS. 7.4 3

£ 0 . 21 . w • z' z* 20 . - 1.89

€VI AT I On cpDM A plane

H50
Table A34

EL PfiSD COVE PDIHT-ThHK “4

DOTTOM SURV E Y ? TRMK I H E HIP? Q'J N DP H N

T

X Y D

1. 9.

1. 1 8.

1. 15.

1 . 13.

1. El.

5. 6.

5. 9.

5. IE.

5. 15.

5. IS.

5. £1.

5. £4.

5 . £ 7

.

s . 3

.

13. IS.

13. £1-

13. £4.

1 -• • C° e" • 13. £9.

16.

6.

16. 9.

16. IE.

16. 15.

16. IS.

16. £1-

16. £4.

16. £7.

16. £9.

£0. 9.

£ 0 . 12 . 20. 15.

20. 13-

i'lj. w 1 - £ 0 . £4 .

1 1 . 12

IE. 39

1 1 . 36

1 0. 3E

11 . 39

3. 34

I . £ 0 -. 03

1.34

1.51

jS e *« Z* -.45

-3.6S

-£.19

—£. 63

-5.16

-5. 19

-7.4E

-6. 15

-5. S3

-6.41

-£. 04

-6.43

-S.56

-7. 39

-1 0. 7£

-11.85

—8 . 88

-£. 01

. 07

-3.35

-9.19

-12.42

-11.15

-1 0.28

-9. 01

-9. 84

-1.97

£.81

1 0. SO

1

“• • 3 r 17. 04

18 . 01

20. 57

£3. -'4

x srprjr* PLhhE

H51

DEV 1 91 1 OH
Table A35

POT TOM

EL PH SO COVE POIHT » TANK if 4

SURVEY* TANK I M SH 1 P* QUADRANT

X V DEV

1. 9. 7. 87

1. 1£. 7. 33

1. 15. 13.43

1. 18. 15.34

1. £1. 14.69

5. 6. 1. 17

5. 9. -6. 07

5. 1 £. -3.52

5. 15. • C -• 5. 18. -£. 1 1 5. £1. — 1 . 65

5. £4. -£. 40

E* • o • ~4 . “ 3 a. 9. -7.*53

8. 1£. -10. ££

8. 15. -11.6r

8. 18. -11.31

8 . £ 1

.

-10. 56

8. £4. -8. 80

&• c r • -3. 75

13. 6. -1.31

13. 9. -. 06

13. 1£. . 1 0

13. 15. — c.'Z* 13. 18. —6. 49

13. 21. —6. 64

13. £4. -5.98

13. £7.

16. 6. 1 . 93

16. 9. -. 06

16. 1£. -. 01

16. 15. .15

16. 18. -1 .£0

16. £1. -. 14

16. £4. -1.69

16. £7. 9. 67

18. 9. 5. 97

18. 1£. 8. 1£

18. 15. . —

i • j I' 18. 18. 6.13

18. £1. r • r

4 13. £4. 7. 64

EVInTTm =PDM A Z'L -* -

H52
Table A36

BUT TDM

C'M S

EL P.hSD CDVE P’DIMT * Tflh'K :t4 SURVEY? 79N* 1 M SHIP, QiJhLRhNT“4

X Y I«EV

1. S'. 1 3*73

1. 12. 15.49

1. 15. 9.84

1. 18. 10.49

1 . 21

.

3. 05

1. 24. 1.10

5. 3. 1.18

5. 6. .43

5. 9. -1.11

5. 12. 1.44

5. 15. -1.21

5. 18. -1.25

5. 21. -6.40

5. 24. -2. 94

8. 1

.

Z» m w 8 . . — . 93

8. 8. -5. 53

8. 9. — 4 .

{' (' S. 12. — 4 . e'e! 8. 15. -9. 37

8. 18. -6.41

8. 21. -4.46

v• • c.* 4

©

-5. 90

13. 1. 1 . 68

13. 3. -7.51

13. 6. —10. 36

13. 9. -6.21

13- 12. 5^ *• *1 13. 1 5. -9. 70

13. 18. -6.34

13. 21. -7.59

16. fi- -4.62

le* • 9

.

-1 .17

16. 12. -3.41

16. 15. -6.46

16. 18. -. 90

16. 21. 1 . 75

16. 24. .40

20. 9. 12.23

20. 12. 13. 04

20. 15. 11.30

20. 18. 13.45

20. £1. 11.20

H53
Table A37

EL PRSO COVE POINT? 7 RNk. :j 5

FDTTCri SURVEY? TRNK IN SHIR? QURDRRN7 “1

Y DEV

1. 6. 7. 36

1. T; 1.

cr 13. 3.59

J • 5. 6. 1.11

IT

-• . 9. 3. 13

cr

•-« • 13. 1.6-*

c*

_• • 15. -. 39

o 1. 5. 03

ft. !• m -.•94 o 6. -3. 03

c* • -.01

o 13. 3. 45

o 1 . -4. 43

13. 1. . 66

13. •“» — r 13. 6. -4. 09

13. 9 m -5. 63

13. 13. -3. 16

13. 15. -3. 49

16. 1. 43

16. Z* • -3. 45

16. 6. —37. 63

16. Q # 1 . 39

16. 13. — 3 . 3 5

16. 15. - 3 . 6 3

£0. 6

.

19. 37

£0. 9. 16.14

£0. 13. 4. 50

PUS DEV I RT I ON FRC'1 R F'LRNE

'

H5A
Table A38

EL PfiSD COVE POINT. T nr BOT TON SURVEY j TRN< IN SHIP-C".

X Y DEV

1. Q m . Se1

.

13. ll . 6 0

1. 15. 13.75

1. 13. 14. 69

5. 6. -.4 3

5. 9. -. 13

5. 13. . 06

5. 15. .40

5. 13.

5. 31. ..69

~y cr

C;

• 9 al’ • -• -5. 64

R. 13. -5. 90

8. 15. -7. 05

8. 13. -3. 51

8. 31. -6. 37

1 3.

1 3.

13.

6

.

-3. 71

13. -6. 03

1 3

.

15. — . X

13. 13. -9. I* 4

13. 31

.

— S. 79

16. 6. J* • Z* i

1 6. 9. -3. 03

16. 13. -1 . 88

16. 15. — 8 . 84

1 6. IS. -1.3 0

16. 31

.

-1 . 35

30. 9 # • S' 3

30. 13. 11.47

30. 15. 13.53

30. 1 8. 14. 06

DEVI rlT I ON FROM H

V< -5

:hDRhNT

H55
Table A39

BOTTOM

EL PASO COVE POINT, TANK

SURVEY, TANK IN CHI D « QUADRANT

DEV

PMC DEVIATION FROM R PLANE 4

H56
Table A40

BOTTOM

RMS

PH SO COVE POINT * T rlMK «5

RVEYj T RMk I H SHI P* CUhDRhNT

X Y DEV

1. 7 . 8 0

1. 6 . 7.47

1 . 9. 7. 03

5. 1. -1.6 0

5. •11 Uj • 1

5. 6. -3. 06

5. 9. -3.3?

5. 18. —4. 7

S. 1.

C; -8.-19

8. 6 . -3. 98

9. -1.76

8. 18. -1.9 0

0 _ 15. *""i C* 13. 1. -8. 74

13. •• -3. 06

13. 6. -4.60

13. Ci

m

.4 m i- -r 13. 18. -1 . ?7

16. 6. 3. 03

1

6

. 9. 8.60

IS. 18. 1 . 36

16. 15. 1. 18

18. 9. 18.68

ifiTior-i FROM H PLfiNE 4.

H57
7. References

1) Haight, W. C. , Borchardt, B. , Hartsock, R. G. , Veale, R. C. , and

Hocken, R. J., "Lifting Distortion of Free-Standing LNG Cargo Tanks".

2) Hocken, R. J. , and Haight, W. C. , "Multiple Redundancy in the Measurement

of Large Structures", Annals of the CIRP (1978).

3) Jelffs, P. A., "Calibration of Containers and Gages", J. Inst. Pet. ,

Vol. 58, No. 561, p 117-25 (May 1972).

A) Mann, D. B. , Editor, 1977, LNG Materials and Fluids . Thermophysical

Properties Division, National Bureau of Standards, Boulder, Colorado.

5) Haight, U. C., Borchardt, B. , Hartsock, R. G. , Johnson, C. J., and

Hocken, R. J. , "Hydrostatic Distortion in Free-Standing LNG Cargo

Tanks". Appendix F of this report.

H58
HBS-1UA

U.5- DEPT. OP COMM.

BIBLIOGRAPHIC DATA

SHEET (Sec nstructionsi

1. PUBLICATION or REPORT NO.

NBSIR 81-1655

2. Performing Organ. Report No . 3. Publ ication Date January 1982

4. TITLE AND SUBTITLE

Estimated Uncertainty of Calibrations of Freestanding Prismatn

Natural Gas Cargo Tanks

lc Liquefied

S. AUTHOR(S)

J. D. Siegwarth and J. F. LaBrecque

(. PERFORMING ORGANIZATION (If joint or other than NBS,

NATIONAL BUREAU OF STANDARDS

department OF COMMERCE

WASHINGTON. D.C. 20234

see in struction s) 7. Contract/Grant No.

8. Type of Report & Period Covered

J. s: :RGAS :ATION NAME AND COMPLETE ADDRESS (Street, City. State. ZIP)

LNG Custody Transfer Measurements Supervisory Committee, c/o El Paso Marine Co.

,

P.0. Box 1592, Houston, TX 77001; and the Maritime Administration, 14th and E Streets, Washington, DC 20235.

ll. supplementary notes

tesc-ibes a computer program; SF-185, FIPS Software Summary, is attached.

111. ABSTRACT -• ess factual summary of most significant information. If document includes a significant

bib iograph, or terature survey, mention it here)

The accuracy of the tank calibrated by the photogrammetric technique was examined during the calibration of fifteen freestanding prismatic LNG transport

tanks. This examination indicated that the calibration accuracy of the tanks

calibrated in the storage position was better than + 0.1%. Additional factors

influencing the accuracy of the calibration of the tanks, such as the effects of

installing the tanks into the ship and loading the ships with LNG, were examined

in the course of this work and the results are reported here. The various measurements used by various NBS personnel to analyze the calibration accuracy are detailed in the eight Appendices included in this report.

'-U.S. GOVERNMENT PRINTING OFFICE:1982—577-481 / 11£
I

'

,

» HMt • *>- .