## Medium Girder Bridge November 2010 Distribution Restriction: **Approved For Public Release; Distribution Is Unlimited.** Headquarters, Department Of The Army

         This publication is available at
Army Knowledge Online (www.us.army.mil) and
General Dennis J. Reimer Training and Doctrine
    Digital Library at (www.train.army.mil).

## Medium Girder Bridge Contents

Page

PREFACE........ v
Chapter 1
MEDIUM GIRDER BRIDGE COMPONENTS ........ 1-1
Advantages of the MGB/LRS ........ 1-2 Disadvantages of the MGB/LRS ........ 1-2 Major Parts ........ 1-2 Allocation/Capabilities ........ 1-3 Component List ........ 1-3 MGB Design ........ 1-4
Chapter 2
MGB 4-12 BAY SS DESIGN ........ 2-1
Chapter 3
MGB 1-12 BAY DS DESIGN........ 3-1
Chapter 4
MGB 13-22 BAYS WITHOUT LRS (Where Water Level or Any

Obstructions Are At Least 2.7m Below Bank Heights) ........ 4-1
Chapter 5
MGB 13-22 BAYS WITH LRS (Where Water Level or Any Obstructions

Are At Least 3.7m Below Bank Heights) ........ 5-1
Chapter 6
MGB DESIGN PRO FORMAT(All Measurements Are in Meters) ........ 6-1
SS 4 Through 12 Bays ........ 6-1
DS 2E + 1 Through 2E + 12 Bays ........ 6-4
DSS 2E + 13 Through 2E + 22 Bays Without LRS (Where Water Level or
Any Obstructions Are At Least 2.7m Below Bank Heights) ........ 6-8
DS 2E + 13 Through 2E + 22 Bays With LRS (Where Water Level or Any
Obstructions Are At Least 3.7m Below Bank Heights) ........ 6-11
Appendix A
SAFETY RULES (FOR ALL MGBs) ........ A-1
Appendix B
MGB BUILDING, BOOM, AND DELAUNCH TABLES ........ B-1
Appendix C
COUNTERWEIGHTS FOR MGBs ........ C-1

GLOSSARY ........ Glossary-1

REFERENCES ........ References-1


DISTRIBUTION RESTRICTION: Approved for public release; distribution is unlimited.

## Figures

Figure 1-1. Launching nose configuration........ 1-1
Figure 1-2. Location of components in bridge configurations ........ 1-2
Figure 2-1. Key construction points ........ 2-4 Figure 2-2. SS MGB site layout ........ 2-5 Figure 3-1. Key construction points for DS MGB 1 through 12 bays ........ 3-1 Figure 3-2. Key construction points ........ 3-4 Figure 4-1. Key construction points for DS MGB 13 through 22 bays without LRS ........ 4-3 Figure 4-2. Key construction points ........ 4-4 Figure 5-1. Key construction points for DS MGB 13 through 22 bays with LRS ........ 5-1 Figure 5-2.Key construction points ........ 5-3
Figure C-1. Counterweights for 6 through 8 bays single-story ........ C-1 Figure C-2. Counterweights for 9 through 12 bays single-story (on restricted sites) ..... C-1
Figure C-3. Counterweights for 2E + 13 through 2E + 22 bays double-story without
LRS (on restricted sites) ........ C-2
Figure C-4.Counterweights for 2E + 13 through 2E + 22 bays double-story with LRS
(on normal sites) ........ C-3

## Tables

Table 2-1. Bridges 4 through 8 bays SS ........ 2-1 Table 2-2. Bridges 9 through 12 bays SS ........ 2-1 Table 2-3. Bearings ........ 2-3 Table 2-4. MGB pallets SS ........ 2-6 Table 2-5. Work parties and building times on good sites (firm dry ground) ........ 2-6
Table 3-1. DS MGB design 2E + 1 through 2E + 12 bays  (all measurements are in
meters) ........ 3-2
Table 3-2. Bearings ........ 3-3 Table 3-3. MGB pallets DS ........ 3-6 Table 3-4. Work parties and building times on good sites (firm dry ground) ........ 3-7
Table 4-1. DS MGB 2E + 13 through 2E + 22 bays without LRS (where water or any
obstructions are at least 2.7m below bank heights) ........ 4-2
Table 4-2. Bearings ........ 4-3 Table 4-3. MGB pallets without LRS ........ 4-6 Table 4-4. Work parties and building times on good sites  (firm dry ground) ........ 4-6
Table 5-1. DS MGB 2E + 13 through 2E + 22 bays with LRS (where water or any
obstructions are at least 3.7m below bank heights) ........ 5-2
Table 5-2. Bearing ........ 5-2 Table 5-3. MGB DS with LRS ........ 5-4 Table 5-4. Work parties and building times on good sites  (firm dry ground) ........ 5-5 Table 6-1. Bridges 4 through 8 bays SS ........ 6-1
Table 6-2. Bridges 9 through 12 bays SS ........ 6-2 Table 6-3. MGB pallets SS ........ 6-4 Table 6-4. Work parties and building times on good sites (firm dry ground) ........ 6-4
Table 6-5. DS MGB design 2E + 1 through 2E + 12 bays (all measurements are in
meters) ........ 6-6
Table 6-6. MGB pallets DS ........ 6-7 Table 6-7. Work parties and building times on good sites  (firm dry ground) ........ 6-7
Table 6-8 DS MGB 2E + 13 through 2E + 22 bays without LRS (where water or any
obstructions are at least 2.7m below bank heights) ........ 6-8
Table 6-9. MGB pallets without LRS ........ 6-10 Table 6-10. Work parties and building times on good sites (firm dry ground) ........ 6-10
Table 6-11. DS MGB 2E + 13 Through 2E + 22 Bays With LRS (where water level or
any obstructions are at least 3.7m below bank heights) ........ 6-11
Table 6-12. MGB DS with LRS ........ 6-12 Table 6-13. Work parties and building times on good sites  (firm dry ground) ........ 6-13 Table 6-14. V distance for all double-story bridges ........ 6-14 Table 6-15. Disposition of work parties ........ 6-15 Table B-1. Building and boom table 4 through 8 bay single-story - normal site ........ B-3 Table B-2. Delaunch table 4 through 8 bay single-story - normal site ........ B-4 Table B-3. Building and boom table 9 through 12 bay single-story - normal site ........ B-5 Table B-4. Delaunch table 9 through 12 bay single-story - normal site ........ B-6 Table B-5. Building and boom table 9 through 12 bay single-story - restricted site ....... B-7 Table B-6. Delaunch table 9 through 12 bay single-story - restricted site ........ B-8
Table B-7. Building and boom table 2E + 1 through 2E + 12 bay double-story -
normal site ........ B-9
Table B-8. Delaunch table 2E + 1 through 2E + 12 bay double-story - normal site -
near bank ........ B-10
Table B-9. Delaunch table 2E + 1 through 2E + 12 bay double-story - normal site -
original far bank........ B-11
Table B-10. Building and boom table 2E + 1 through 2E + 12 bay double-story -
restricted site ........ B-12
Table B-11. Delaunch table 2E + 1 through 2E + 12 bay double-story - restricted site
- near bank ........ B-15
Table B-12. Delaunch table 2E + 1 through 2E + 12 bay double-story - restricted site
- original far bank........ B-17
Table B-13. Building and boom table 2E + 13 through 2E + 22 bay double-story
(wo/LRS) - normal site ........ B-20
Table B-14. Delaunch table 2E + 13 through 2E + 22 bay double-story (wo/LRS) -
normal site - near bank ........ B-22
Table B-15. Delaunch table 2E + 13 through 2E + 22 bay double-story (wo/LRS) -
normal site - original far bank ........ B-23
Table B-16. Building and boom table 2E + 13 through 2E + 22 bay double-story
(wo/LRS) - restricted site ........ B-24
Table B-17. Delaunch table 2E + 13 through 2E + 22 bay double-story (wo/LRS) -
restricted site - near bank ........ B-25

## Contents

Table B-18. Delaunch table 2E + 13 through 2E + 22 bay double-story (wo/LRS) -
restricted site - original far bank ........ B-26
Table B-19. Building and boom table 2E + 13 through 2E + 22 bay double-story
(w/LRS) - normal site ........ B-28
Table B-20. Delaunch table 2E + 13 through 2E + 22 bay double-story (w/LRS) -
normal site - near bank ........ B-30

## Preface

This publication contains amendments to Technical Manuals (TMs) 5-5420-212-72, Operator and Organizational Maintenance manual for Medium Girder Bridge (MGB) and 5-5420-212-12-7, Operator and Organizational Maintenance Manual Link Reinforcement Set for the Medium Girder Bridge (MGB). These TMs are being updated to correspond with information contained in this general subject technical manual. This publication describes design, recon reports, safety rules, and building, boom and delaunch tables for the MGB. The Bridging Branch, Department of Military Engineering, US Army Engineer School, has developed this design package with significant input from Fairey Engineering, Ltd., The Royal School of Military Engineering
(United Kingdom) and countless Engineer Officer Basic/Advanced Noncommissioned Officer Course students resident instruction at Fort Belvoir. The purpose of this publication is to standardize procedures and make the design process easy to understand. (Abbreviations for MGB design are included in the glossary.) No longer will engineers have to count boxes and squares on scaled paper to employ the MGB. This publication applies to the Active Army, the Army National Guard/Army National Guard of the United States, and the United States Army Reserve unless otherwise stated. The proponent of this publication is the US Army Training and Doctrine Command. The preparing agency is the US Army Engineer School. Submit changes for improving this publication on DA Form 2028 (Recommended Changes to Publications and Blank Forms), and forward it to Commandant, US Army Engineer School, ATTN: ATSE-Z-BTD-P, Fort Belvoir, VA 22060-5291.

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## Chapter 1 Medium Girder Bridge Components

1-1. The medium girder bridge (MGB) is lightweight, hand-built, bridging equipment. It can be built in various configurations to provide a full range of bridging capability for use both in the forward battle area and in the communications zone. Speed of erection by few Soldiers is its major characteristic.

1-2. The MGB parts are fabricated from a specially developed zinc, magnesium, and aluminum alloy
(DGFVE 232A). This enables a lightweight, high strength bridge to be built. All except three parts weigh under 200 kg. Most parts can be handled easily by four Soldiers. The three heavier parts, used in limited quantities, are six-man loads.

1-3. The MGB is a two-girder, deck bridge. The two longitudinal girders, with deck units between, provide a 4.0m wide roadway. Girders of top panels can form a shallow, single-story configuration. This type of bridge is used for short spans that will carry light loads. A heavier double-story configuration using top panels and triangular bottom panels is used for heavy loads or longer spans. Single-story bridges can be constructed by 9 to 17 Soldiers. The normal building party for double-story bridges is 25 Soldiers.

1-4. The bridge can be supported on unprepared and uneven ground without grillages. It is constructed on one roller beam for single-story construction; two roller beams, 4.6m apart, for double-story construction; and on three roller beams when constructing a double-story bridge over 12 bays long. The ends of the roller beams are supported on base plates and each can be adjusted in height. No leveling or other preparation of the ground is required. Single-span bridges are launched using a centrally mounted launching nose (figure 1-1).

1-5. A third configuration using the link reinforcement set (LRS) is constructed when a long, high class type of bridge is required. The LRS deepens the girder and transfers the load throughout the length of the bridge. This type of construction requires a building party of 34 Soldiers, and is built on three roller beams.

## Advantages Of The Mgb/Lrs


Lightweight - no component requires more than six Soldiers to lift or carry.

Easy to assemble - components have special alignment aids built into them.

Minimal maintenance - very little lubrication required.

Air transportable - in either standard pallet loads or in partially assembled bridge
configurations.

Compatibility - all US components will fit MGBs in use by allies, except for launching nose
cross girder (LNCG) posts.

## Disadvantages Of The Mgb/Lrs


Length - Maximum length is 49.7m.

Military Load Class (MLC) - MLC is 60, not 70.

## Major Parts

1-6. See figure 1-2.

## Allocation/Capabilities

1-7. An MGB company (corps level) is issued four bridge sets, two erection sets, and two link reinforcement sets. These are divided between two platoons.

COMPONENT LIST
Bridge Set

Girder, push bar - 2
Item description and quantity

Handle, carrying - 46
Bag, equipment - 8

Jack, bridge, 15-ton - 7
Basket, equipment - 14

MGB pallet, truck mounted - 13
Beam assembly, bankseat - 7

Rear bumper assembly - 13
Brace, sway - 19

Lug, tie-down, steel - 104
Clip, retainer - 94

Stray assembly, 5,000-pound capacity - 52
Curb assembly - 42

Strap assembly, 10,000-pound capacity - 117
Deck - 74

Tie-down, cargo, 10,000-pound  - 26
Guide assembly, marker - 24

MGB pallet, trailer mounted - 12
Panel assembly, end taper - 5

Adapter, pallet - 12
Panel assembly, bottom - 26

Bracket adapter, with hardware - 48
Panel assembly, junction - 5

Rear bumper assembly - 12
Panel assembly, top - 34

Strap assembly, 5,000-pound capacity - 28
Pin, bracing - 68

Strap assembly, 10,000-pound capacity - 108
Pin, panel - 92

Tie-down, cargo, 10,000-pound - 48
Pin, panel, headless - 5

Nose assembly, launching - 8
Ramp assembly, short - 29

Nose, light, front - 5
Ramp assembly, long - 15

Nose, light, rear - 5
Bridge Erection Set

Panel erection aid - 3
Item description and quantity

Pedestal assembly, adjustable, MKI - 2
Adapter, push bar - 2

Pedestal, building - 7
Bag, equipment - 2

Pin, anchorage** - 10
Bar, carrying - 46

Pin, bracing - 8
Bar assembly, launching - 2

Pin, launching nose - 23
Basket, equipment - 61

Pin, panel - 20
Beam assembly, roller - 4

Plate, base, DS - 6
Cable, extractor - 1

Plate, base, SS - 7
Clip, retainer - 56

Post assembly, jacking - 4
Girder assembly, launching - 2

Bracket, lifting - 4
Girder, cross frame - 3

Post, launching nose - 2
Girder, longitudinal* - 3

Roller assembly, landing - 4
    Roller assembly, launching - 2

    Rear bumper assembly - 1
    Seat, building frame, jack - 5                             Strap assembly, 5,000-pound capacity - 4
    Support assembly, adjustable - 6                      Strap assembly, 10,000-pound capacity - 9 Support assembly, fixed - 7                               Tie-down, cargo. 10,000-pound - 4

Support, jacking - 5

Nose assembly, launching - 6
Sling, steel, wire - 1

Pedestal assembly, adjustable, MKII - 2
Link Reinforcement

Pin, anchorage** - 10
Item description and quantity

Pin, bracing - 22
Anchor assembly - 4

Pin, capsill - 3
Antiflutter tackle - 5

Pin, launching - 40
Bag, equipment - 2

Post, footwalk - 10
Bar assembly, launching - 2

Post-tensioning assembly - 4
Basket, equipment - 4

Puller assembly, tirfor, T-35 - 2
Bearer, footwalk - 10

Roller assembly, rocking - 2
Bracket, jacking - 2

Rope, guard - 4
Capsill, bridging - 1

Seat, building frame, jack - 2
Clip, retainer - 150

Tackle, light - 20
Davit post assembly - 2

Wrench, ratchet, 34-inch - 2
Footwalk, bridge - 4

Expendable Supplies and Materials
Hammer, hand, nylon - 4

(per bridge set)
Jack, bridge, 20-ton - 2

Item description and unit of issue
Link, launching, two-tier - 3

Grease, automotive - lb can
Link, reinforcing, long - 20

Oil, lubricating, GP, MIL-L-7870A - gal can
Link, reinforcing, short - 4

Coating compound, metal retreatment - gal can
MGB pallet, truck mounted - 1

Primer coating, phenolic resin - gal can
Rear bumper assembly - 1

Enamel, alkyd, camouflage forest green - gal can
Lug, tie-down, steel - 8

Enamel, lusterless, white - gal can
Strap assembly, 5,000-pound capacity - 4

Walkway compound, OD - gal can
Strap assembly, 10,000-pound capacity - 9
Cleaning solvent - gal can
Tie-down, cargo, 10,000-pound - 2

Lumber, softwood, 3" x 8" x 14' - 40 each
required.
MGB pallet, trailer mounted - 1

Cut into lengths to obtain:
Adapter, pallet - 1

144 pieces 3" x 8" x 36"
Bracket, adapter, with hardware - 1

4 pieces 3" x 8" x 84"


*Issued in some sets, though not required. **Transfer to bridge erection set or reinforcement set. [Items with separate national stock numbers (NSNs) that together with other item(s) in brackets comprise an assembly.

## Mgb Design

Step 1. Measure the angle of repose (AR) gap. This step is common to all lengths and configurations.

## Select A Bridge Centerline

1-8. The centerline should extend from a point approximately 15.2m on the far bank to a point approximately 45.7m on the near bank. This will ensure that there is space on the far bank for vehicle egress and space on the near bank for the R distance of any bridge length. There should be sufficient clear area extending out 3.0m on both sides of the centerline for its full length to allow for bridge construction.


1-9. Determine the location of firm ground on the near and far banks.

For the field method of determining firm ground, assume the AR of the soil to be 45 degrees.

At the edge of firm ground on the near bank, place the A' peg. At the edge of firm ground on the
far bank, place the A peg. The distance between the two pegs is known as the AR gap. Keep in
mind that the MGB must not bear on the ground at either end for more than 2.1 m (SS) or 2.3m (DS), regardless of its length.
1-10. If actual slope of bank **does not** exceed 45 degrees horizontal, place A and A' pegs as shown in a or b below.

1-11. If actual slope of bank **does** exceed 45 degrees from the horizontal, place A and A' pegs a distance H
from the toe of slope which is equal to the height of the bank measured from the toe of slope to the top of the gap, as shown in c above.

Note. Gaps in illustration are shown with one prepared and one unprepared abutment. Actual sites may be any combination of examples shown.

##

1-12. Measure the distance from the edge of firm ground on the near bank (A' peg location) to the edge of firm ground on the far bank (A peg location) using one of the methods described below. This distance is known as the AR gap.


Triangulation method.

A string line with a weight attached thrown across the gap and measured while being retrieved.

If in a relatively secure area and site conditions allow, a tape measure should be used.
1-13. Select the type of bridge to be built, based on resources available, the MLC desired, and the AR gap.
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## Chapter 2 Mgb 4-12 Bay Ss Design

Step 1. Measure the AR gap (see MGB DESIGN, Step 1, page 1-5).

Step 2. Select a bridge. Using column (a) of table 2-1 or table 2-2, choose a bridge length whose AR gap range brackets the AR gap measured. Always select the smallest range possible to avoid wasting assets. For example, if the AR gap measured 9.5m, choose the AR gap range of 7.4m to 9.8m, even though the range of 9.2m to 11.6m also meets the criteria. Read the bay configuration column (c), and check the MLC of the bridge column (d) to ensure that it meets what is specified by the tasking authority.

Site Dimensions
Launch Design
RB
RB
N
N
AR Gap
(a)
L
(b)
Bays
(c)
MCL
(d)
Nose
(e)
R
Dist
(f)
BP
Only
(g)
BP + DU
Only
(h)
BP
Only
(i)
BP + DU
Only
(j)
5.8
1.30
1.75
3-7-6.1
7.9
4
60
5.6-8.0
9.8
5
6.7
1.14
1.68
0.43
0.60
7.4-9.8
11.6
6
40
7.6
1.07
1.60
LLN
Only
9.2-11.6
13.4
7
30
9.5
0.76
0.91
11.0-13.4
15.2
8
11.3
0.38
0.84



Dimension N Above Line Through Ground at RB
& O When Rear BSB Is on Ground. The RB Is on
BP or BP & DU, & LNCG Is on 4, 2, or 1
Site Dimensions
LNCG Settings
4
2
1
AR GAP
(a)
L
(b)
Bays
(c)
MLC
(d)
Nose
(e)
BP +
DU
(l)
BP
Only
(k)
BP +
DU
(j)
BP
Only
(i)
BP +
DU
(h)
BP
Only
(g)
R
Dist
(f)
12.9-15.3
17.1
9
24
5N1
10.4
-0.76
-0.08
0.61
1.14
1.83
2.36
14.7-17.1
18.9
10
20
12.2
-0.99
-0.61
0.38
0.76
1.60
1.98
16.5-18.9
20.7
11
6N1
-1.37
-1.07
0.15
0.48
1.83
2.44
18.4-20.8
22.6
12
16
14.0
-2.13
-1.60
-0.46
0.08
1.07
1.60



Step 3. Read the bridge length column (b).
Step 4. Read and note the R distance column (f). Step 5. Read and note the nose configuration column (e). Step 6. Identify key construction points as follows:

F peg - Designates the approximate location of the far bank bankseat beam. Initially placed 0.9m from A peg on far bank.

RB peg - Designates the position of the roller beam (RB). It may be located in one of two
different positions depending upon launch method used, push launch (4 through 8 bays) or jack launch (4 through 12 bays).
Note. Push launches are to be performed only in an actual wartime bridge operation. Push launches are no longer performed for training or demonstration purposes.

Push launch - The distance to the RB peg is calculated by using the position of the A' peg on the near bank, the bridge length (L), AR gap, minimum bearing requirement (0.9m), and the approximate distance the bridge falls in front of the roller beam (0.23m). This distance is X.

Note. To adhere to minimum/maximum bearing rules without having to dig out or pack up under the end of bridge, you must ensure that the RB peg is placed between 1.113m and 2.33m from the A' peg.

Jack launch - The distance to the RB peg is calculated by using the position of A' peg on the near bank, the bridge length, AR gap, minimum bearing requirement (0.9m), and the approximate distance required behind the roller beam to attach the jacks (0.23m). This distance is X.
  (    0.23)  (    0.9)

Note. To adhere to minimum/maximum bearing rules without having to dig out or pack up under the end of bridge, you must ensure that the RB peg is placed between 0.67m and 1.87m from the A' peg.


O peg - Marks the clear distance behind the roller beam required to construct the bridge. It is positioned by measuring the R distance, tables 2-1 or 2-2, page 2-1, column (f), behind the RB
peg.
Adjust the position of the F peg, if required, and determine the final position of the bridge on the near bank (F' peg).

Notes. (These notes apply to both table 2-1 and table 2-2.)
1. An extra 0.075m of clearance can be obtained by lifting on the nose to remove the pin sag. Where levels are estimated, this should not be taken into account during design but left to compensate for any errors in calculating the value of H (for SS 4 through 8 bays). 2. An extra 0.6m of clearance can be obtained by lifting on the nose to remove the pin sag (for SS 9 through 12 bays). 3. Any additional packing under the RB will increase the vertical interval N by three times the thickness of the packing. For example, if the packing is 0.075m thick, N will be increased by
0.225m. 4. The table incorporates an allowance to ensure that the nose clears the landing roller (LR) when it is positioned 0.230m in front of point F.


Bearing Check. The minimum/maximum bearings for any SS bridge up to and including 12
bays are shown in table 2-3.

| Bearing    | Near Bank    | Far Bank    |
|------------|--------------|-------------|
| Minimum    | 0.9m         | 0.9m        |
| Maximum    | 2.1m         | 2.1m        |

To calculate the actual locations of the F and F' pegs, the following procedure is used:
Near bank bearing = bridge length - (AR gap + 0.9m)

 *where*
Bridge length is obtained from column (b) of table 2-1 or 2-2. The AR gap was measured by you in the first step of this design procedure. An assumption of 0.9m is made at this point in the calculation sequence because we know that this is the minimum acceptable bearing allowable on the far bank.

If the near bank bearing is within acceptable limits, you do not have to adjust the position of the F peg.

Its final position will be the initial value that you assumed of 0.9m from the A peg. The F' peg will be located at a distance equal to the near bank bearing measured from the A' peg on near bank. If the near bank bearing is greater than the maximum allowable (2.1m), you must do one of the following:
Move the F peg further away from its present assumed location to a point where the amount of bearing on the near bank is less than or equal to 2.1m, and greater than or equal to 0.9m. This will allow the F' peg to be placed at a suitable distance from the A' peg. The RB peg must be moved toward the gap the same distance the F peg is moved away from the gap. This will also move the O peg towards the gap.

Dig out the soil from the near bank until the maximum allowable bearing is not exceeded. Crib up under the end of bridge upon completion. Physically locate the key construction points on the ground and take elevations relative to the RB peg. Locate O, RB, F, F', A, and A' pegs. Estimate elevations of F and O pegs relative to the RB peg. A positive value indicates a point higher than the RB peg and a negative value indicates a value lower than the RB peg. The RB peg will always be 0.0 elevation. Place the elevations on the baseline as shown in figure 2-1.

  (   0.23)  (    0.9)
  (   0.23)  (    0.9)

Truck and trailer loads__________________ Manpower required____________________ Time to construct______________________


|          |    |    |    |    |    |     |   Pallet Type  |   Number of Bays  |
|----------|----|----|----|----|----|-----|----------------|-------------------|
| 4        | 5  | 6  | 7  | 8  | 9  | 10  |            11  |               12  |
| Erection | 1  | 1  | 1  | 1  | 1  |  1  |             1  |                1  |
| Bridge   | 2  | 2  | 3  | 3  | 4  |  4  |             5  |                5  |
| Total    | 3  | 3  | 4  | 4  | 5  |  5  |             6  |                6  |

Note. More vehicles are required to transport personnel. Erections pallets may only be partial depending on bridge being constructed.



| (a)                   | Single-Story    |
|-----------------------|-----------------|
| 5 Bays 9.8m           |                 |
| MLC 60                |                 |
| (b)                   |                 |
| 8 Bays 15.2m          |                 |
| MLC 60                |                 |
| (c)                   |                 |
| 12 Bays 22.6m         |                 |
| MLC 60                |                 |
| (d)                   |                 |
| Work party            | 1 + 8           |
| Time by day (hours)   | 12               |
| Time by night (hours) | 34               |

 Note. For disposition of work parties, see table 6-15, page 6-15.



## Chapter 3 Mgb 1-12 Bay Ds Design

Step 1. Measure the AR gap (see MGB DESIGN, Step 1, page 1-4). Step 2. Select a bridge. Using column (a) of table 3-1, page 3-2, choose a bridge length whose AR gap range brackets the AR gap measured. Always select the smallest range possible to avoid wasting assets. For example, if the AR gap measured 16.2m, choose the AR gap range of 14.0m to 16.3m, even though the range of 15.8m to 18.1m also meets the criteria. Read the bay configuration column (c), and check the MLC of the bridge column (d) to ensure that it meets what is specified by the tasking authority. Step 3. Read the bridge length column (b).

Step 4. Read and note the R distance column (f). Step 5. Read and note the nose construction column (e). Step 6. Identify key construction points. These points are constant for any DS bridge construction up to and including 2E + 12 bays (figure 3-1).

## Figure 3-1. Key Construction Points For Ds Mgb 1 Through 12 Bays


F peg - Designates the approximate location of the far bank bankseat beam. Initially placed
0.9m from A peg on far bank.

FRB peg - Designates the position of the r roller beam (FRB). It is placed 0.9m from the A  peg
on the near bank as measured to the centerline() of the roller beam.

RRB peg - designates the position of the rear roller beam (RRB). It is place 4.6 m from the FRB
(measured  to ).

O peg - Marks the clear distance behind the front roller beam required to construct the bridge.
It is positioned by measuring the R distance, table 3-1, page 3-2, column (f), behind the FRB
peg.



Bearing Check. The minimum/maximum bearings for any DS bridge up to and including 2E +
12 bays are shown in table 3-2.

| Bearing    | Near Bank    | Far Bank    |
|------------|--------------|-------------|
| Minimum    | 1/4m         | 0.9m        |
| Maximum    | 2.3m         | 2.3m        |

To calculate the actual locations of the F and F' pegs, the following procedure is used:
Near bank bearing = bridge length - (AR gap + 0.9m)

where Bridge length is obtained from column (b) of table 3-1. The AR gap was measured by you in the first step of this design procedure. An assumption of 0.9m is made at this point in the calculation sequence because we know that this is the minimum acceptable bearing allowed on the far bank. If the near bank bearing is within acceptable limits, you do not have to adjust the position of the F peg.

Its final position will be the initial value that you assumed of 0.9m from the A peg. The F' peg will be located at a distance equal to the near bank bearing measured from the A' peg on the near bank.

If the near bank bearing **is greater than** the maximum allowable (2.3m), you must do one of the following:


Move the F peg further away from its present location to a point where the amount of bearing on the near bank is less than or **equal to** 2.3m, and greater than or equal to 1.4m.
This will allow the F' peg to be placed at a suitable distance from the A' peg.

Crib up the near bank end of bridge to where the maximum allowable bearing is not exceeded.

Dig out the soil from the near bank until the maximum allowable bearing is not exceeded.

Physically locate the key construction points (figure 3-2, page 3-4) on the ground and take elevations relative to the FRB.

Locate O, RRB, F', FRB, A', A, and F pegs on the ground along the centerline of the bridge.

Estimate elevations of F, RRB, and O pegs relative to the FRB peg. Positive value indicates that a point is above the FRB peg and a negative value indicates that a point is below the
FRB peg. The FRB peg will always be 0.0 elevation.

Place the key construction point elevations and distances on the baseline below (figure 3-2).
Step 7. Slope check. Ensure that the difference in elevation between the F and F' pegs does not exceed one-tenth of the total bridge length. If it does, you are either going to have to crib up, undertake a major construction project, or choose another centerline. Note that the elevation of the F' peg cannot be lower than the elevation of the FRB or the bridge will not receive full bearing. In these cases, the normal procedure is to crib up or fill in until the elevation of the F' peg is at least as high as the FRB. Otherwise, you would have to remove the soil next to the bank to the level of the F' peg. This also applies to the F peg. Step 8. Calculate the far bank height (H), near bank tail clearance (G) relative to the baseline, and the distance of water below a line joining FRB and F (C) using these formulas:

      (  0.5)
46

46

Step 9. *RULE 1*
If both bank heights **are greater than** 0.6m above the waterline, go to RULE 2. See table 3-1, page
3-2. If either or both bank heights **are less than** 0.6m from the waterline, choose an LNCG setting from column (h), (i), or (j) so that C **is greater than** D to avoid immersion in water, and go to RULE 2.

If C **is greater than** D, go to RULE 2.

If C **is not greater than** D and the water is not flowing, go to RULE 2.

If C **is not greater than** D and immersion in water **is less than** 0.3m and the current speed is less than
5 meters per second (reps), it is not essential to adjust the LNCG setting. Therefore, go to RULE 2.

If C **is not greater than** D and the current speed **is greater than** 5 mps, another site must be chosen.

## Step 10. *Rule 2*

Using the LNCG settings from RULE 1, choose a setting from column (l), (m), or (n) (whichever is allowable from RULE 1) which gives an N greater than H. If none of the choices meet the criterion, choose the highest value available. Check to see if the T value from column (k) **is greater than** G. If N **is not greater than** H, or if T is not greater than G, proceed to RULE 3. If N **is greater than** H and T is greater than G, the LNCG setting chosen has adequate nose lift and the bridge selected has adequate tail clearance.

## Step 11. *Rule 3*

Raise both the FRB and RRB by 0.69m to increase nose clearance (N) and tail clearance (T).

  3     2   0.69

| (a)                   | Double-Story    |
|-----------------------|-----------------|
| 4 Bays 16.8m          |                 |
| MLC 60                |                 |
| (b)                   |                 |
| 8 Bays 24.1m          |                 |
| MLC 60                |                 |
| (c)                   |                 |
| 12 Bays 31.4m         |                 |
| MLC 60                |                 |
| (d)                   |                 |
| Work party            | 1 + 24          |
| Time by day (hours)   | 34               |
| Time by night (hours) | 114              |

Notes. 1. All timings exclusive to work on approaches. 2. Add 20 percent for untrained personnel. 3. Add 30 percent for adverse site conditions. 4. For disposition of work parties, see table 6-15, page 6-15.


This page intentionally left blank.


## Chapter 4 Mgb 13-22 Bays Without Lrs (Where Water Level Or Any Obstructions Are At Least 2.7M Below Bank Heights)

Step 1. Measure the AR gap (see MGB Design, Step 1).

Step 2. Select a bridge. Using column (a) of table 4-1, page 4-2, choose a bridge whose AR gap range brackets the AR gap measured. Always select the smallest range possible to avoid wasting assets. For example, if the AR gap measured 34.2m, choose the AR gap range of 32.3m to 34.6m, even though the range of 34.1m to 36.4m also meets the criteria. Read the bay configuration column (c). Check the MLC of the bridge column (d) to ensure that it meets what is specified by the tasking authority. Step 3. Read the bridge length column (b).

Step 4. Read the R distance column (f). Step 5. Read and note the nose construction column (e). Step 6. Identify key construction points. These are constant for any DS bridge construction 13 through 22 bays without LRS (figure 4-1, page 4-3).


F peg - Designates the approximate location of the far bank end of bridge. It is initially placed
0.9m from A peg on far bank.

CRB peg - Designates the location of the capsill roller beam. It is placed 0.9m from the A' peg
on near bank as measured to the centerline of the capsill roller beam.

FRB peg - Designates the location of the front roller beam. It is placed 9.1m from the CRB peg
to the centerline of the front roller beam.

RRB peg - Designates the location of the rear roller beam. It is placed 4.6m from the FRB peg (measured centerline to centerline).

O peg - Marks the clear distance behind the capsill roller beam required to construct the bridge.
It is positioned by measuring the R distance, table 4-1 column (f), behind the CRB peg.

Bearing Check. The minimum/maximum bearings for any DS bridge 2E + 13 through 2E + 22 bays are shown in table 4-2, page 4-3.
To calculate the actual locations of the F and F' pegs, the following procedure is used:
Near bank bearing = bridge length - (AR gap + 0.9m)

where Bridge length is obtained from column (b) of table 4-1. The AR gap was measured by you in the first step of this design procedure. An assumption of 0.9m is made at this point in the calculation sequence because we know that this is the minimum acceptable bearing allowed on the far bank. If the near bank bearing is within acceptable limits, you do not have to adjust the position of the F peg.

Its final position will be the initial value that you assumed of 0.9m from the A peg. The F' peg will be located at a distance equal to the near bank bearing measured from the A' peg on the near bank.

| Bearing    | Near Bank    | Far Bank    |
|------------|--------------|-------------|
| Minimum    | 1.4m         | 0.9m        |
| Maximum    | 2.3m         | 2.3m        |

If the near bank bearing **is greater than** the maximum allowable (2.3m), you must do one of the following:


Move the F peg further away from its present assumed location to a point where the amount of bearing on near bank is less than or **equal to** 2.3m, and greater than or **equal to** 1.4m.
This will allow the F' peg to be placed at a suitable distance from the A' peg.

Crib up the near bank end of bridge until the maximum allowable bearing is not exceeded.

Dig out the soil from the near bank until the maximum allowable bearing **is not** exceeded.

Physically locate the key construction points (figure 4-2, page 4-4) on the ground and take elevations relative to the CRB peg.

Locate the O, RRB, FRB, CRB, F', A , A, and F pegs on the ground along the centerline of the bridge.

Estimate elevations of F, RRB, and O pegs relative to the CRB. A positive value indicates that a point is above the CRB and a negative value indicates that it is below CRB. The CRB will the always be 0.0 elevation.

Place the key construction point elevations on the baseline (figure 4-2).
Time to construct ________________

|          |     |     |     |     |     |     |     |   Pallet Type  |   Bays  |
|----------|-----|-----|-----|-----|-----|-----|-----|----------------|---------|
| 13       | 14  | 15  | 16  | 17  | 18  | 19  | 20  |            21  |     22  |
| Erection |  1  |  1  |  1  |  1  |  1  |  1  |  1  |             1  |      1  |
| Bridge   |  9  |  9  |  9  | 10  | 10  | 10  | 11  |            11  |     11  |
| Total    | 10  | 10  | 10  | 11  | 11  | 11  | 12  |            12  |     12  |

Note. More vehicles are required to transport personnel.



|                        | Double-Story Single-Span    |
|------------------------|-----------------------------|
| 13-22 Bays Without LRS |                             |
|                        | 13 Bays 33.2m               |
| MLC 50                 |                             |
| 18 Bays 42.4m          |                             |
| MLC 30                 |                             |
| 22 Bays 49.7m          |                             |
| MLC 16                 |                             |
| (a)                    | (b)                         |
| Work party             | 1 + 24                      |
| Time by day (hours)    | 112                          |
| Time by night (hours)  | 3                           |

 Notes. 1. All timings exclusive of work on approaches. 2. Add 20 percent for untrained personnel. 3. Add 30 percent for adverse site conditions. 4. For disposition of work parties, see table 6-15, page 6-15.

## Chapter 5 Mgb 13-22 Bays With Lrs (Where Water Level Or Any Obstructions Are At Least 3.7M Below Bank Heights)

Step 1. Measure the AR gap (see MGB DESIGN, Step 1, page 1-4). Step 2. Select a bridge. Using column (a) of table 5-1, page 5-2, choose a bridge whose AR gap range brackets the AR gap measured. Always select the smallest range possible to avoid wasting assets. For example, if the AR gap measured 40.2m, choose the AR gap range of 37.8m to 40.5m even though the range of 39.8m to 42.4m also meets the criteria. Read the bay configuration column (c). Check the MLC of the bridge column (d) to ensure that it meets what is specified by the tasking authority. Step 3. Read the bridge length column (b).

Step 4. Read the R distance column (f). Step 5. Read the nose construction column (e). Step 6. Identify key construction points. These are constant for any DS bridge construction 13 through 22 bays with LRS (figure 5-1).


F peg - Designates the approximate location of the far bank end of bridge. It is initially placed
the distance shown under far bank minimum column, table 5-2, from the AR peg on the far bank.

CRB peg - Designates the location of the CRB. It is placed 2.7m from the A' peg on the near bank as measured to the centerline of the CRB.

FRB peg - Designates the location of the FRB. It is placed 9.1 m from the CRB peg to the centerline of the FRB.

RRB peg - Designates the location of the RRB. It is placed 4.6m from the FRB peg (measured
centerline to centerline).

O peg - Marks the clear distance behind the CRB required to construct the bridge. It is
positioned by measuring the R distance, table 5-1, column (f), behind the CRB peg.

|                             | Launch Design    |
|-----------------------------|------------------|
|                             |                  |
| Site Dimensions             |                  |
| Rule 1                      |                  |
| Nose Lift N With Nose Cross |                  |
| Girder at -                 |                  |
| Rule 2                      |                  |
| Lower                       |                  |
| RRB to                      |                  |
| Increase N                  |                  |
| N                           |                  |
| R                           |                  |
| Dist                        |                  |
| AR Gap                      |                  |
| Brg                         |                  |
| Lgth                        |                  |
| Tail                        |                  |
| Lift                        |                  |
| T                           |                  |
| Hole                        |                  |
| #6                          |                  |
| **                          |                  |
| Hole                        |                  |
| #4                          |                  |
| **                          |                  |
| Hole                        |                  |
| #2                          |                  |
| **                          |                  |
| 2E +                        |                  |
| # of                        |                  |
| Bays                        |                  |
| MLC                         |                  |
| Nose                        |                  |
| Const                       |                  |
| *                           |                  |
|                             |                  |
| (a)                         | (b)              |
| 28.6 - 31.4                 | 33.2             |
| 30.5 - 33.3                 | 35.1             |
|                             |                  |
| 28.7                        |                  |
| 0.37                        | 0.31             |
|                             | 0.34             |
| 29.6                        | 0.30             |
|                             |                  |
| 8N1                         |                  |
| 32.3 - 34.7                 | 36.9             |
| All                         |                  |
| MLC                         |                  |
| 60                          |                  |
| 35.9 - 38.7                 | 40.6             |
|                             |                  |
| 29.3                        |                  |
|                             |                  |
| 0.27                        |                  |
| -0.77                       | 1.12             |
| 37.8 - 10.6                 | 42.4             |
| 39.8 - 42.4                 | 44.2             |
|                             |                  |
| 0.21                        |                  |
| -1.46                       | 0.40             |
| 41.4 - 44.2                 | 46.0             |
| 38.4                        |                  |
| -1.75                       | 0.11             |
| 1.9 (0.63-G)                |                  |
| 43.3 - 45.6                 | 47.9             |
| 45.1 - 46.5                 | 49.7             |

* Each nose includes a complete light nose. ** Nose cross girder setting 6, 4, and 2 is the position of the girder resting on the 6th, 4th, and 2nd hole from the bottom of the post.


Bearing Check. The minimum/maximum bearings for any DS bridge 2E + 13 through 2E + 22
bays are shown in table 5-2.

Bridge Length
2E +
Near Bank Minimum
Far Bank Minimum
13, 14, 16 through 20 bays
0.9m
0.9m
15 bays
1.1m
1.1m
21 bays
1.14m
1.14m
22 bays
1.6m
1.16m
Maximum bearing for all DS MGB with LRS.

To calculate the actual locations of the F and F' pegs, the following procedure is used:
Near bank bearing = bridge length - (AR gap + far bank bearing)

where - Bridge length is obtained from column (b) of table 5-1. The AR gap was measured by you in the first step of this design procedure. Far bank bearing is obtained from the appropriate column in table 5-2. If the near bank bearing is within acceptable limits, you do not have to adjust the position of the F peg. Its final position will be the initial value obtained from table 5-2 as measured from the A peg. The F' peg will be located at a distance equal to the near bank bearing measured from the A' peg on the near bank.

## Mgb 13-22 Bays With Lrs (Where Water Level Or Any Obstructions Are At Least 3.7M Below Bank Heights)

If the near bank bearing **is greater than** the maximum allowable (2.3m), you must do one of the following:
Move the F peg further away from its present location to a point where the amount of bearing on near bank is less than or **equal to** 2.3m and greater than or equal to the value given in table 5-2 for minimum bearing. Crib up the near bank end of bridge to where the maximum allowable bearing is not exceeded. Dig out the soil from the near bank until the maximum allowable bearing is not exceeded. Physically locate the key construction points (figure 5-2) on the ground and take elevations relative to the CRB peg. Locate the O, RRB, FRB, F', A', A, and F pegs on the ground along the bridge centerline. Estimate elevations of F, RRB, and O pegs relative to the CRB peg. A positive value indicates a point is above the CRB peg and a negative value indicates it is below the CRB peg. The CRB peg will always be 0.0 elevation. Place key construction point elevations on the baseline (figure
5-2). Step 7. Slope check. Ensure that the difference in elevation between the F' and F peg does not exceed one-twentieth of the total bridge length. If it does, you will have to crib up, undertake a major construction project, or choose another site. Note that the elevation of the F' peg cannot be lower than the elevation of the CRB peg or the bridge will not receive full bearing. In these cases, the normal procedure is to crib up or fill in until the elevation of the F' peg is at least as high as the CRB peg.

Otherwise, you would have to remove soil next to the bank, level with the F' peg. This same rule applies to the F peg.

|                       | Double-Story Single-Span     |
|-----------------------|------------------------------|
| 13-22 Bays With LRS   |                              |
| (a)                   | 13 Bays 33.2m                |
| MLC 60                |                              |
| 18 Bays 42.4m         |                              |
| MLC 60                |                              |
| 22 Bays 49.7m         |                              |
| MLC 60                |                              |
| (b)                   | (c)                          |
| Work party            | 2 + 32                       |
| Time by day (hours)   | 2                            |
| Time by night (hours) | 3                            |

 Notes.

1. All timings exclusive of work on approaches.

2. Add 20 percent for untrained personnel. 3. Add 30 percent for adverse site conditions. 4. For disposition of work parties, see table 6-15, page 6-15.

| Step 13                                        |
|------------------------------------------------|
| 2E + _______________________________ bays      |
| LNCG setting ____________________________      |
| CRB setting ______________________________     |
| RRB setting ______________________________     |
| Bearing: NB _______________FB____________      |
| Truck and trailer loads ______________________ |
| Manpower required ________________________     |
| Time to construct __________________________   |

This page intentionally left blank.



Site Dimensions
Dimension N Above Line Through Ground at
RB & O When Rear BSB Is on Ground. The RB
Is on BP or BP & DU, & LNCG Is on 4, 2, or 1.
LNCG Settings
4
2
1
AR Gap
(a)
L
(b)
Bays
(c)
MLC
(d)
Nose
(e)

R
Dist
(f)

BP
Only
(g)

BP +
DU
(h)

BP
Only
(i)
BP +
DU
Only
(j)

BP
Only
(k)
BP +
DU
Only
(l)
12.9 - 15.3
17.1
9
24
5N1
10.4
-0.76
-0.08
0.61
1.14
1.83
2.36
14.7 - 17.1
18.9
10
20
12.2
-0.99
-0.61
0.38
0.76
1.60
1.98
16.5 - 18.9
20.7
11
16
6N1
-1.37
-1.07
0.15
0.48
1.83
2.44
18.4 - 20.8
22.6
12
14.0
-2.13
-1.60
-0.46
0.08
1.07
1.60

Notes. 1. An extra 0.07 of clearance can be obtained by lifting on the nose to remove the pin sag. Where levels are estimated, this should not be taken into account during design but left to compensate for any errors in calculating the value of H (for SS 4 through 8 bays). 2. An extra 0.6m of clearance can be obtained by lifting on the nose to remove the pin sag (for SS 9 through 12 bays). 3. Any additional packing under the RB will increase the vertical Interval N by three times the thickness of the packing, for example if the packing is 0.075m thick, N will be Increased by 0.225m. 4. The table incorporates an allowance to ensure that the nose clears the LR when it is positioned 0.230m in front of point F.

6-22. Choose an LNCG setting that ensures depth of C > depth of D.
6-23. LNCG settings permitted _____ _____ _____
6-24. *RULE 2*. LNCG setting to give N > H and T > G.
Choose an LNCG setting so that N > H. LNCG setting chosen ____________________

Note: The setting chosen cannot be lower than that chosen in RULE 1.

if N > H and/or T >G, go to RULE 3.

6-25. *RULE 3*. Raise the FRB and RRB by 0.69m.
N RULE 3 = N RULE 2 + 0.69m N = **____**
Check N Rule 3 > H - Yes/No Check T > G Yes/No - column (p) T = ____ If Yes, design is OK.

if N Rule 3> H, go to RULE 4a if T Rule 3> G, go to RULE 4b

6-26. *RULE 4a*. Lower RRB.

N RULE 4a = N RULE 3 + answer to column (q). Check N > H
6-27. *RULE 4b*. Lower FRB.

T RULE 4b = T RULE 3 + answer to column (r). Check T > G
6-28. Loads required. From table 6-6, determine the truck and trailer loads required for the bridge.

6-29. From table 6-7, extract the following information:

Construction time _______________________ Manpower requirements __________________

6-30. Final design:

2E + ______________________________bays LNCG setting _______________________ FRB setting _________________________ RRB setting _________________________ Bearing: NB __________FB ____________ Truck and trailer loads _________________ Manpower required ___________________ Time to construct _____________________
Pallet Type
Bays
1
2
3
4
5
6
7
8
9
10
11
12
Erection
1
1
1
1
1
1
1
1
1
1
1
1
Bridge
5
5
5
6
6
6
7
7
7
8
8
8
Total
6
6
6
7
7
7
8
8
8
9
9
9

Note. More vehicles are required to transport personnel.



|                       | Double-Story     |
|-----------------------|------------------|
| 4 Bays 16.8m          |                  |
| MLC 60                |                  |
| 8 Bays 24.1m          |                  |
| MLC 60                |                  |
| 12 Bays 31.4m         |                  |
| MLC 60                |                  |
| (b)                   | (c)              |
|                       |                  |
|                       |                  |
| (a)                   |                  |
| Work party            | 1 + 24           |
| Time by day (hours)   | 34                |
| Time by night (hours) | 114               |

Notes.

1. All timings exclusive of work on approaches. 2. Add 20 percent for untrained personnel. 3. Add 30 percent for adverse site conditions. 4. For disposition of work parties, see table 6-15, page 6-15.

DSS 2E + 13 THROUGH 2E + 22 BAYS WITHOUT LRS (WHERE WATER LEVEL OR ANY OBSTRUCTIONS ARE AT LEAST 2.7M BELOW BANK HEIGHTS)

Grid _________________________________________ Recon Officer _________________________________ Map Ref **_____________________________________**
Unit _________________________________________ MLC **_______________**_________________________
6-31. Measure AR Gap A to A' ________________

Note. Use table 6-8 to obtain the answers to the following:

6-32. Select bridge. 2E + ______________________bays
6-33. Bridge length ______________________________
6-34. R distance ________________________________
6-35. Nose construction __________________________



| Site Dimensions                  | Launch Design    |
|----------------------------------|------------------|
| Other methods of adjusting N & T |                  |
| Rule 1                           |                  |
| Nose lift N with nose cross      |                  |
| girder at -                      |                  |
| Rule 2                           |                  |
| Raise RRB                        |                  |
| & CRB by                         |                  |
| 0.25                             |                  |
| Rule 3a                          |                  |
| Lower                            |                  |
| RRB to                           |                  |
| increase N                       |                  |
| Rule 3b                          |                  |
| Lower CRB                        |                  |
| to increase                      |                  |
| T                                |                  |
| 2E                               |                  |
| +# of                            |                  |
| Bays                             |                  |
| MLC                              |                  |
| Nose                             |                  |
| Const                            |                  |
| *                                |                  |
| R                                |                  |
| Dist                             |                  |
| Tail                             |                  |
| Lift                             |                  |
| T                                |                  |
| Hole                             |                  |
| #6                               |                  |
| **                               |                  |
| Hole                             |                  |
| #4                               |                  |
| **                               |                  |
| Hole                             |                  |
| #2                               |                  |
| **                               |                  |
| N                                | T                |
| Brg                              |                  |
| Lgth                             |                  |
| (a)                              | (b)              |
| 28.6-30.9                        | 33.2             |
| 50                               |                  |
| 6N1                              | 27.4             |
| 30.5-32.8                        | 35.1             |
| 7N1                              |                  |
| 32.3-34.6                        | 36.9             |
| 40                               |                  |
| 0.34                             | -0.49            |
| 34.1-36.4                        | 38.7             |
| 35.9-38.2                        | 40.1             |
| 30                               | 8N1              |
| 29.3                             | 0.27             |
| 37.8-40.1                        | 42.4             |
| 34.8                             | 0.21             |
| 0.46                             | 1.9 (0.63-G)     |
| 0.2 (1.97-H)                     |                  |
| 41.4-43.7                        | 46.0             |
| 43.3-45.6                        | 47.9             |
| 39.6-41.9                        | 44.2             |
| 24                               |                  |
| 6N1                              |                  |
| +                                |                  |
| 3N2                              |                  |
| 45.1-47-4 49.7                   | 22               |



* Each nose includes a complete light nose.

** Nose cross girder setting 6, 4, and 2 is the position of the cross girder resting on the 6
th, 4
th, and 2d hole from the bottom of the LNCG post.



6-36. Key construction points, dimensions, and elevations.


Pallet Type
Bays
13
14
15
16
17
18
19
20
21
22
Erection
1
1
1
1
1
1
1
1
1
1
Bridge
9
9
9
10
10
10
11
11
11
12
Total
10
10
10
11
11
11
12
12
12
13

Note. More vehicles are required to transport personnel.

6-44. From table 6-10, extract the following information:

Construction time ________________________ Manpower requirements __________________

6-45. Final design:

2E + ______________________________ bays LNCG setting ___________________________ CRB setting _____________________________ RRB setting _____________________________ Bearing: NB _____________FB _____________ Truck and trailer loads _____________________ Manpower required _______________________ Time to construct _________________________
|                        | Double-Story Single-Span    |
|------------------------|-----------------------------|
| 13-22 Bays Without LRS |                             |
| 22 Bays                |                             |
| 49.7m                  |                             |
| MLC 60                 |                             |
| 18 Bays                |                             |
| 42.4m                  |                             |
| MLC 60                 |                             |
|                        | 13 Bays                     |
| 33.2m                  |                             |
| MLC 60                 |                             |
| (a)                    | (b)                         |
|                        |                             |
| (c)                    |                             |
|                        |                             |
| (d)                    |                             |
|                        |                             |
| Work party             | 1 + 24                      |
| Time by day (hours)    | 1 12                         |
| Time by night (hours)  | 3                           |

Notes.

1. All timings exclusive of work on approaches. 2. Add 20 percent for untrained personnel. 3. Add 30 percent for adverse site conditions. 4. For disposition of work parties, see table 6-15, page 6-15.

DS 2E + 13 THROUGH 2E + 22 BAYS WITH LRS (WHERE WATER LEVEL OR ANY OBSTRUCTIONS ARE AT LEAST 3.7M BELOW BANK HEIGHTS)

Grid _________________________________________ Recon Officer _________________________________ Map Ref **_____________________________________**
Unit _________________________________________ MLC **_______________**_________________________
6-46. Measure AR gap A to A' _________________

Note. Use table 6-11 to obtain the answers to the following:

6-47. Select a bridge _________________________
6-48. Bridge length __________________________
6-49. R distance ____________________________
6-50. Nose construction ______________________
|                             | Launch Design    |
|-----------------------------|------------------|
| Site Dimensions             |                  |
| Rule 1                      |                  |
| Nose Lift N With Nose Cross |                  |
| Girder at                  |                  |
|                             |                  |
| Rule 2                      |                  |
| Lower RRB                   |                  |
| to Increase                 |                  |
| N                           |                  |
| N                           |                  |
| Hole                        |                  |
| #2                          |                  |
| **                          |                  |
| Hole                        |                  |
| #4                          |                  |
| **                          |                  |
| Hole                        |                  |
| #6                          |                  |
| **                          |                  |
| R                           |                  |
| Dist                        |                  |
| Tail                        |                  |
| Lift                        |                  |
| T                           |                  |
| MLC                         | Nose             |
| Const                       |                  |
| *                           |                  |
| AR Gap                      | Brg              |
| Lgth                        |                  |
| 2E +                        |                  |
| # of                        |                  |
| Bays                        |                  |
| (a)                         | (b)              |
| 28.6 - 31.4                 | 33.2             |
|                             |                  |
| 27.4                        | 0.40             |
| 0.37                        | 0.31             |
|                             |                  |
| 7N1                         |                  |
|                             |                  |
| 28.7                        |                  |
| 32.3 - 34.7                 | 36.9             |
|                             |                  |
| 0.34                        | 0.25             |
| 29.6                        | 0.30             |
|                             |                  |
| 8N1                         |                  |
| -0.77                       | 1.12             |
|                             |                  |
| 29.3                        |                  |
|                             |                  |
| .027                        |                  |
| 37.8 - 40.6                 | 42.4             |
| 1.9 (0.66-G)                |                  |
| -1.46                       | 0.40             |
|                             |                  |
| 6N1                         | 34.8             |
|                             |                  |
| .021                        |                  |
| 41.4 - 44.2                 | 46.0             |
|                             |                  |
| +                           |                  |
| 38.4                        |                  |
| -1.75                       | 0.11             |
| 1.9 (0.63-G)                |                  |
| 43.3 - 45.6                 | 47.9             |
|                             |                  |
| 3N2                         | 0.18             |
| 45.1 - 46.5                 | 49.7             |
|                             |                  |
| 40.1                        | 0.15             |

* Each nose includes a complete light nose. **Nose cross girder setting 6, 4, and 2 is the position of the girder resting on the 6th, 4th, and 2nd hole from the bottom of the post.

6-51. Key construction points, dimensions, and elevations.

6-52. Slope check. Ensure that the difference in elevation between the F' and F peg does not exceed
one-twentieth of the total bridge length. If it does, you will have to crib up, undertake a major construction project, or find another centerline.

6-53. Calculate H and G

6-54. *RULE 1*. LNCG setting to give N > H and T > G. Choose an LNCG setting to give N > H.
If N > H, go to RULE 2. If T > G, choose another site, or prepare to dig out under NB end of bridge prior to launch.

6-55. *RULE 2*. Lower RRB.
N Rule 2 = N RULE 1 + answer to column (k). Check N > H
6-56. Loads required. From table 6-12, determine the truck and trailer loads required for the bridge.


Type
Bays
13
14
15
16
17
18
19
20
21
22
Erection
1
1
1
1
1
1
1
1
1
1
Bridge
9
9
9
10
10
10
11
11
11
12
Link
2
2
2
2
2
2
2
2
2
2
Total
12
12
12
13
13
13
14
14
14
15

6-57. From table 6-13, extract the following information:

Construction time ______________________________ Manpower requirements _________________________
|                       | Double-Story Single-Span    |
|-----------------------|-----------------------------|
| 13-22 Bays With LRS   |                             |
|                       | 13 Bays                     |
| 33.2m                 |                             |
| MLC 60                |                             |
| 18 Bays               |                             |
| 42.4m                 |                             |
| MLC 60                |                             |
| 22 Bays               |                             |
| 49.7m                 |                             |
| MLC 60                |                             |
| (a)                   | (b)                         |
|                       |                             |
| (c)                   |                             |
|                       |                             |
| (d)                   |                             |
|                       |                             |
| Work party            | 2 + 32                      |
| Time by day (hours)   | 2                           |
| Time by night (hours) | 3                           |

 Notes. 1. All timings exclusive of work on approaches.

2. Add 20 percent for untrained personnel. 3. Add 30 percent for adverse site conditions. 4. For disposition of work parties, see table 6-15, page 6-15.

6-58. Final design: 2E + _______________________bays
LNCG setting _________________________________ CRB setting __________________________________ RRB setting __________________________________ Bearing: NB ___________________FB ____________ Truck and trailer loads __________________________ Manpower required ____________________________ Time to construct ______________________________

6-59. **V Distance**. The V distance, for delaunching purposes, is the distance from the FRB/CRB to the LRP
for DS bridges requiring a launching nose. The V distance must never exceed the distance given in table 6-14, page 6-14. Exceeding the V distance may result in failure of the launching nose.


|                 |            |            |      |      |      |      |      |      |      |      |      |   Length of Bridge 2E + Number of Bays  |
|-----------------|------------|------------|------|------|------|------|------|------|------|------|------|-----------------------------------------|
|                 | 1          | 2          | 3    | 4    | 5    |  6   |  7   |  8   |  9   | 10   | 11   |                                      12 |
| Brg Lgth        |            |            |      |      |      |      |      |      |      |      |      |                                         |
| (m)             |            |            |      |      |      |      |      |      |      |      |      |                                         |
| 11.3            | 13.1       | 14.9       | 16.8 | 18.6 | 20.4 | 22.3 | 24.1 | 25.9 | 27.7 | 29.6 | 31.4 |                                         |
| Normal Site     |            |            |      |      |      |      |      |      |      |      |      |                                         |
| Nose Conf       | 2N1        | 3N1        | 4N1  | 5N1  | 6N1  |      |      |      |      |      |      |                                         |
| V Distance      | 11.6       | 13.7       | 15.5 | 17.0 | 19.2 | 21   | 22.6 | 24.7 | 26.5 | 28   | 30.2 |                                      32 |
| Restricted Site |            |            |      |      |      |      |      |      |      |      |      |                                         |
| Nose Conf       |            |            |      |      |      |      |      |      |      |      |      |                                         |
| 3N1             | 4N1        |            |      |      |      |      |      |      |      |      |      |                                         |
| 4N1/            |            |            |      |      |      |      |      |      |      |      |      |                                         |
| 5N1             |            |            |      |      |      |      |      |      |      |      |      |                                         |
| 5N1 or 6N1      | 6N1 or 7N1 | 7N1 or 8N1 |      |      |      |      |      |      |      |      |      |                                         |
| V Distance      | 11.9       | 13.7       | 15.5 | 17.4 | 19.2 | 21   | 22.9 | 24.7 | 26.5 | 28.3 | 30.2 |                                      32 |
|                 |      |           |      |            |      |      |      |      |      |   Length of Bridge 2E + Number of Bays without LRS  |
|-----------------|------|-----------|------|------------|------|------|------|------|------|-----------------------------------------------------|
|                 | 13   | 14        | 15   | 16         | 17   | 18   | 19   | 20   | 21   |                                                22   |
| Brg Lgth (m)    | 33.2 | 35.1      | 36.9 | 38.7       | 40.5 | 42.4 | 44.2 | 46   | 47.9 |                                                49.7 |
| Normal Site     |      |           |      |            |      |      |      |      |      |                                                     |
| Nose Conf       | 6N1  | 7N1       | 8N1  | 6N1 +  3N2 |      |      |      |      |      |                                                     |
| V Distance      | 33.5 | 35.7      | 37.5 | 39.0       | 41.1 | 43   | 48.3 | 49.1 | 49.7 |                                                50.3 |
| Restricted Site |      |           |      |            |      |      |      |      |      |                                                     |
| Nose Conf       | 8N1  | 6N1 + 3N2 |      |            |      |      |      |      |      |                                                     |
| V Distance      | 33.4 | 35.2      | 37.0 | 38.9       | 40.7 | 42.5 | 44.3 | 46.2 | 48   |                                                49.8 |
Length of Bridge 2E + Number of Bays with LRS

13
14
15
16
17
18
19
20
21
22
Brg Lgth (m)
33.2
35.1
36.9
38.7
40.5
42.4
44.2
46.0
47.9
49.7
Normal Site
Nose Conf
7N1
8N1
6N1 + 3N2
V Distance
34.6
36.4
37.6
39.9
42.4
43.7
45.5
47.5
48.6
49.5
| Bridge Length                                                      | Work Party                                   | Main Tasks       | Performed by    |
|--------------------------------------------------------------------|----------------------------------------------|------------------|-----------------|
| Numbers                                                            |                                              |                  |                 |
| 1 + 8                                                              | Supervisor                                   | NCO              |                 |
| 4 and 5                                                            |                                              |                  |                 |
| Bays                                                               |                                              |                  |                 |
| SS                                                                 |                                              |                  |                 |
|                                                                    | Left hand side panels and launching nose     | 1*, 2, 3, and 4  |                 |
| 5*, 6, 7, and 8                                                    |                                              |                  |                 |
|                                                                    | Right hand side panels and roller beam.      |                  |                 |
| 1 + 16                                                             | Supervisor                                   | NCO              |                 |
| 6 - 8                                                              |                                              |                  |                 |
| Bays                                                               |                                              |                  |                 |
| SS                                                                 |                                              |                  |                 |
|                                                                    | Right hand side panels and roller beam.      |                  |                 |
|                                                                    | Left hand side panels.                       |                  |                 |
|                                                                    | Left hand side panels and launching nose     | 1*, 2, 3, and 4  |                 |
| 5*, 6, 7, and 8                                                    |                                              |                  |                 |
| 9*, 10, 11, and 12                                                 |                                              |                  |                 |
| 13*, 14, 15, and 16                                                |                                              |                  |                 |
|                                                                    | Right hand side panels.                      |                  |                 |
| 1 + 16                                                             | Supervisor                                   | NCO              | 9 - 12          |
| Bays                                                               |                                              |                  |                 |
| SS                                                                 |                                              |                  |                 |
|                                                                    | Right hand side panels                       |                  |                 |
|                                                                    | Near and far bank bankseat beam and          |                  |                 |
| launching nose.                                                    |                                              |                  |                 |
|                                                                    | Left hand side panels                        | 1*, 2, 3, and 4  |                 |
| 5*, 6, 7, and 8                                                    |                                              |                  |                 |
| 9*, 10, 11, and 12                                                 |                                              |                  |                 |
| 13, and 14                                                         |                                              |                  |                 |
| 15 and 16                                                          |                                              |                  |                 |
|                                                                    | Miscellaneous tasks.                         |                  |                 |
| *Party Leader, responsible for inserting pins and locking rollers. |                                              |                  |                 |
| 1 + 24                                                             | Supervisor                                   | NCO              |                 |
|                                                                    | Left hand side party leader, responsible for |                  |                 |
| all pins and left side jacks.                                      |                                              |                  |                 |
| 15                                                                 |                                              |                  |                 |
|                                                                    | Left hand side girder and building frame     |                  |                 |
| (FRB).                                                             |                                              |                  |                 |
| 1*, 2, 3, 4, 5*,                                                   |                                              |                  |                 |
|                                                                    |                                              |                  |                 |
| All                                                                |                                              |                  |                 |
| Double-Story                                                       |                                              |                  |                 |
| 2E + 1                                                             |                                              |                  |                 |
| through                                                            |                                              |                  |                 |
| 2E + 22                                                            |                                              |                  |                 |
| Bays, with or                                                      |                                              |                  |                 |
| without LRS                                                        |                                              |                  |                 |
|                                                                    | Numbers 1 through 4-top panels, 5 through    |                  |                 |
| 0-bottom panels.                                                   |                                              |                  |                 |
| 6, 7, and 8                                                        |                                              |                  |                 |
|                                                                    | Near and far bank bankseat beam and          |                  |                 |
| launching nose.                                                    |                                              |                  |                 |
| 9*, 10, 11, 12                                                     |                                              |                  |                 |
| 13, and 14                                                         |                                              |                  |                 |
|                                                                    | Right hand side party leader, responsible    |                  |                 |
| for all pins and right side jacks.                                 |                                              |                  |                 |
| 16                                                                 |                                              |                  |                 |
| 17*, 18, 19, 20,                                                   |                                              |                  |                 |
| 21*, 22, 23, and 24                                                |                                              |                  |                 |
|                                                                    | Right hand side girder and building frame    |                  |                 |
| (RRB). Numbers 17 through 20-top panels,                           |                                              |                  |                 |
| 21 through 24-bottom panels.                                       |                                              |                  |                 |
| *Party Leader, responsible for inserting all pins.                 |                                              |                  |                 |
| 1 + 8                                                              | Supervisor                                   | NCO              | Link            |
| Reinforcement                                                      |                                              |                  |                 |
| Party                                                              |                                              |                  |                 |
|                                                                    | Left hand side reinforcement                 | 25*, 26, 27, and |                 |
| 28**                                                               |                                              |                  |                 |
|                                                                    | Right hand side reinforcement                | 29*, 30, 31, and |                 |
| 32**                                                               |                                              |                  |                 |

* Responsible for all pins, his side. ** Responsible for opening jacks and locking CRB rollers. LRS party under supervision of NCO will download, unstrap, unload, and position all LRS components on site in preparation for use.


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## Appendix A Safety Rules (For All Mgbs)


Rule
Reason
1.
Do not throw tie-down straps across loads or
vehicles when strapping or unstrapping loads.
To prevent injury to personnel and damage to equipment.
2.
Do not drop, throw, or shove components off
loads or vehicles.
To prevent injury to personnel and damage to equipment.
3.
Always check all tie-down straps prior to cranelifting pallets onto vehicles.
To prevent injury to personnel and damage to equipment.
4.
Check tightness of tie-down straps during convoy
rest stops.
To prevent injury to personnel and damage to equipment.
5.
Do not drop pallets without rubber bumpers.
To prevent damage to equipment.
6.
Do not put fingers or hands into pin holes or
between components being moved.
To prevent injury to personnel. To prevent injury to personnel and damage to equipment.
7.
Ensure that all members of work party are fully aware of action to take place prior to start of action.
To prevent damage to equipment.
8.
Do not use any type of metal object to drive pins or shoot bolts. If a pin or shoot bolt has to be driven, use a rubber/nylon-faced hammer or a block of wood.
To prevent injury to personnel and damage to personnel.
9.
Do not use carrying bars on bridge during
booming procedures. USE HANDS ONLY ON
BRIDGE.
To prevent injury to personnel.
10.
Do not position yourself between girders during
booming of bridge. STAY OUTSIDE OF GIRDERS.
11.
Do not release roller locks until bridge is being
held by manpower or vehicle.
To prevent injury to personnel and damage to equipment. To prevent injury to personnel and damage to equipment.
12.
Do not try to boom a bridge larger than 2E + 8
bays by manpower. Always use a 5-ton truck (loaded). If any doubt exists as to the ability of work party to boom by hand, **USE A TRUCK.**
13.
Do not engage roller locks while bridge is moving
over rollers.
Roller locks will break, or bridge will skew over rollers.



Rule
Reason
14.
Ensure that all roller locks are engaged before
disconnecting vehicle from bridge.
To prevent injury to personnel and damage to equipment.
To prevent injury to personnel and damage to equipment.

15.
Ensure that jack seat is always positioned on
support pins or capsill pins in holes 1, 2, or 3 from bottom of adjustable support. NEVER USE HOLES 4, 5, OR 6 FOR JACK SEAT.

To prevent injury to personnel and damage to equipment.

16.
Monitor the jack-up of roller beams and/or capsill
to ensure that they are not jacked too high. The fixed pins must never get within 2.5cm (1 inch) of the top of the adjustable support vertical posts.
17.
Ensure that all personnel are clear of the bridge
during booming/launching/ delaunching.
To prevent injury to personnel.

To prevent damage to equipment. Bridge will skew over rollers.

18.
Ensure that the push vehicle is centered over
bridge centerline and is in line with the bridge throughout the boom/launch/delaunch.
19.
Always use a loaded vehicle (LRD load) to
boom/launch/delaunch all DS bridges.
To increase vehicle traction.

To prevent serious injury to personnel.

20.
Always use the access holes in the side of the LRP
to operate the jack. Keep hands and feet clear of the LRP base when operating the jack.
21.
Ensure that the jack heads are properly seated in
jack hoods prior to applying load to the jack.
To prevent damage to equipment.
22.
Ensure that the jacks are properly placed for the
bridge that is being raised/lowered.
To prevent injury to personnel and damage to equipment.
23.
Monitor jacking operation to ensure that the
bridge is lowered/raised as evenly as possible.
To prevent injury to personnel and damage equipment.

| 24.                                            |
|------------------------------------------------|
| all times.                                     |
| Improperly placed markers can result in bridge |
| tipping down at the heavy end.                 |

25.
Never jack the near end of bridge if the far end is
up on the LR or LRP.
LR and LRP are not equipped with a lock; bridge is free to roll.

Pins can vibrate out at certain stages of construction or as traffic crosses.

26.
Put lock pins in panel, bracing, and nose pins as
identified below:
a. Bracing pins - ALL

b. Nose pins - ALL

c. Panel pins - ALL, except where bottom
panel connects to top panel. Shoot bolt jaw traps ridge on pin against panel.

d. Headless panel pins - ALL, both ends of
pin. Be especially watchful with the pins in the LNCG and posts.
27.
Ensure that support pins are fully seated in the
adjustable supports.
Jack seat bears on pin taper and pushes pin out.


Rule
Reason
28.
Put lock pins in support pins if bridge to be
constructed is 2E + 13 or larger.
To prevent pins from vibrating out.
Launching equipment will be overloaded.

29.
During launching, the LRP must be placed at the
given (or higher) LZ number when the published CG is over the roller, which is nearest the gap.

Launching equipment will be overloaded.

30.
When delaunching, check the V distance to ensure
that it does not exceed the V distance given in table 6-14, page 6-14.
31.
Jack on far bank only when near bank end is on
locked rollers and PUSH BAR is DISCONNECTED from BRIDGE.

Vertical movement is limited when vehicle is connected. a. Jacking up under nose as it crosses far bank may buckle light nose, overload nose cross girder, or over-compress push bar. b. Jacking down may over tension push bar. Launch equipment will be overloaded.

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## Appendix B Mgb Building, Boom, And Delaunch Tables

This appendix provides the MGB user with a complete set of building, boom, and delaunch tables required to construct/disassemble any length of MGB on the various types of sites that may be encountered. It is limited to the bridge lengths that can be constructed with US Army MGB sets. It does not provide instructions for MGBs constructed on piers or on floating supports. It is strongly advised that only experienced users attempt to use this appendix. Personnel new to the MGB must use TM 5-5420-212-12 for MGB and TM 5-5420- 212-23 for MGB with Link Reinforcement Set.

## List Of Tables Page

Table B-1. Building and boom table 4 through 8 bay single-story - normal site ........  B-3
Table B-2. Delaunch table 4 through 8 bay single-story - normal site ........  B-4
Table B-3. Building and boom table 9 through 12 bay single-story - normal site ........  B-5
Table B-4. Delaunch table 9 through 12 bay single-story - normal site ........  B-6
Table B-5. Building and boom table 9 through 12 bay single-story - restricted site ........  B-7
Table B-6. Delaunch table 9 through 12 bay single story - restricted site ........  B-8
Table B-7. Building and boom table 2E + 1 through 2E + 12 bay double-story - normal
site ........  B-9
Table B-8. Delaunch table 2E + 1 through 2E + 12 bay double-story - normal site - near
bank ........  B-10
Table B-9. Delaunch table 2E + 1 through 2E + 12 bay double-story - normal site -
original far bank ........  B-11
Table B-10. Building and boom table 2E + 1 through 2E + 12 bay double-story -
restricted site........  B-12
Table B-11. Delaunch table 2E + 1 through 2E + 12 bay double-story - restricted site -
near bank ........  B-15
Table B-12. Delaunch table 2E + 1 through 2E + 12 bay double-story - restricted site -
original far bank ........  B-17
Table B-13. Building and boom table 2E + 13 through 2E + 22 bay double-story
(wo/LRS) - normal site ........  B-20
Table B-14. Delaunch table 2E + 13 through 2E + 22 bay double-story (wo/LRS) -
normal site - near bank ........  B-22
Table B-15. Delaunch table 2E + 13 through 2E + 22 bay double-story (wo/LRS) -
normal site - original far bank ........  B-23
Table B-16. Building and boom table 2E + 13 through 2E + 22 bay double-story
(wo/LRS) - restricted site ........  B-24
Table B-17. Delaunch table 2E + 13 through 2E + 22 bay double-story (wo/LRS) -
restricted site - near bank ........  B-25
Table B-18. Delaunch table 2E + 13 through 2E + 22 bay double-story (wo/LRS) -
restricted site - original far bank ........  B-26

## Appendix B

Table B-19. Building and boom table 2E + 13 through 2E + 22 bay double-story (w/LRS)
- normal site ........  B-28
Table B-20. Delaunch table 2E + 13 through 2E + 22 bay double-story (w/LRS) - normal
site - near bank ........  B-30


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## Appendix C Counterweights For Mgbs


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## Glossary Abbreviations, Definitions, Acronyms, And Brevity Codes

Acronym/Term
Definition
A
Indicates edge of gap, far bank.
A'
Indicates edge of gap, near bank.
A
anchor assembly
AA(L)
long link of anchor assembly
AA(S)
short link of anchor assembly
AF
antiflutter tackle
AR
Angle of repose which is marked on site with A (far bank) and A' (near bank) pegs.
AR Gap
The distance from the edge of firm ground (A') on the near bank to the edge of firm ground (A) on the far bank.
BES
bridge erection set
Boom Marker
Carrying bar (painted orange) which marks the position of the next booming or launching point
BP
building pedestal (SS only), baseplate (SS and DS)
brg
bridge
BSB
bankseat beam.
C
Distance of water below line joining FRB and F at distance W from
FRB (negative). Fine for up to 2E + 12 bays. For 2E + 13 through 2E + 22 bays DS bridges, a CRB is required.
CG Marker
Carrying bar (painted blue) which marks the center of gravity of the bridge during construction.
cm
centimeter
cntr
counter
conf
configuration
const
construction
CRB
Capsill roller beam. This type of roller beam must be used for 2E + 13 through 2E + 22 bays DS bridges with or without LRS.

Centerline
D
Deflection of bridge during launch in relation to line joining FRB and F pegs.
del
Delaunch
dist
Distance
DS
double-story bridge construction
DU
deck unit
E
end of bridge

## Glossary

elev
elevation
F
Final position of the far end of bridge as marked with the F peg.
F'
Final position of the near end of bridge as marked with the F' peg.
FB
far bank
FRB
front roller beam
G
Distance between O peg and baseline.
gal
gallon
H
Far bank height at F peg, relative to the baseline.
Ht
height
kg
kilogram
L
length of bridge
LAU
launch
lb
pound
lgth
length
LLN
light launching nose
LNCG
launching nose cross girder
LNH
launching nose heavy
LR
Landing roller. Used by itself for 4 through 8 bays of SS. Used in LRP for all other bridge lengths.
LRD
Long ramp and deck pallet. This is last pallet to be off-loaded on a bridge site. Should be loaded onto push vehicle to maintain a proper counterweight.
LRP
Landing roller pedestal (MK I for 2E + 1 through 2E + 12 bays DS, MK II for 2E + 13 through 2E + 22 bays DS with or without LRS).
LRS
link reinforcement set
LT
light tackle
LZ
landing zone
m
meter
max
maximum
MGB
medium girder bridge
min
minimum
MLC
military load class.
mps
meters per second
N
nose tip height above baseline
N1
launching nose heavy, one story high
N2
launching nose heavy, two stories high
NB
near bank
NCO
noncommissioned officer
NSN
national stock number
O
Distance R from RB (single-story), FRB (double-story), and CRB
(double-story with or without LRS) as marked with the O peg.
PT
post-tensioning assembly
R
Maximum distance to the rear of the bridge during construction (excluding push bar and vehicle).
RB
roller beam
rcvr
recover
rem
remove
RRB
rear roller beam
spec
special
SS
single-story bridge construction
T
Height of near bank end of bridge in relation to baseline.
thru
through
TM
technical manual
V
For delaunching purposes, the maximum allowable distance between the FRB or CRB to the LRP for bridges requiring a launching nose.
W
Distance of end taper panel from FRB for maximum deflection.
WL
waterline
wt
weight
1LL
one long reinforcing link
1SL
one short reinforcing link
6N1, 7N1, and 8N1
Types of single-story nose construction. The first number shows the number of heavy nose sections used. The N1 means single-story nose.
6N1 + 3N2
Type of double-story nose construction. The 6N1 is explained above. The 3N2 means that three heavy nose sections are used in second story. The N2 means double-story nose.
2 + 3 + or 8 through 10
Describes number of bays to be added or removed. The 2 + 3 + means add second and third bays, or remove third and second bays if numbers reversed, 3 + 2 +. Similarly, the 8 through 10 means add bays 8 through 10, or remove bays 10 through 8, if reversed.
Boom to
Movement of bridge until panel point given is over RB (for SS) or RRB (for DS).
Launch to
Movement of bridge until panel point given is over RB, FRB, or CRB.
3D, 8D, 20D, 27D + 6C,
and 37D + 6C
Counterweight codes giving the number of deck units and curbs used.
(4p0), (2p4), and (Bp3)
Examples of the way that the center of gravity (CG) is shown.

## Symbols

| >    | is greater than             |     |
|------|-----------------------------|-----|
|     | is greater than or equal to |     |
|     | is less than or equal to    |     |
|      |                             |     |
| >    | is not greater than         |     |
|      |                             |     |
|      |                             |     |
|      |                             |     |
|      |                             |     |

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## References

REQUIRED PUBLICATIONS
Required publications are sources that users must read in order to understand or to comply with this publication.

TECHNICAL MANUALS (TMS)
  TM 5-5420-212-10-1.  Medium Girder Bridge Including Bridge Set (NSN 5420-00-172-3520) Bridge
  Erection Set (NSN 5420-00-172-3519) Link Reinforcement Set (NSN 5420-01-139-1503).
  16 February 1993.
  TM 5-5420-212-10-2.  Medium Girder Bridge Including Bridge Set (NSN 5420-00-172-3520) Bridge
  Erection Set (NSN 5420-00-172-3519) Link Reinforcement Set (NSN 5420-01-139-1503).
  29 January 1993.
  TM 5-5420-212-23, Unit and Direct Support Maintenance Manual for Medium Girder Bridge (MGB)
  Including Bridge set (NSN 5420-00-172-3520) Bridge Erection Set (5420-00-172-3519) Link
  Reinforcement Set (5420-01-139-1503). 26 August 1992

RELATED PUBLICATIONS
Related publications are sources of additional information. They are not required in order to understand this publication. Military Engineering Volume III, Part III, Medium Girder Bridge, Army Code No 71133, British Army.

This publication is available from the Publications Section, Headquarters, Royal School of Military Engineering, Brompton Barracks, Chatham, Kent, England, ME3 8NQ.

## Prescribed Forms None.

REFERENCED FORMS
 DA forms are available on the APD Web site (www.apd.army.mil).
 DA Form 2028. Recommended Changes to Publications and Blank Forms.


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By Order of the Secretary of the Army:
Official:


   JOYCE E. MORROW
Administrative Assistant to the Secretary of the Army 1029303 By Direction of the Commandant of the Marine Corps


## Distribution:

Active Army, Army National Guard, and United States Army Reserve. To be distributed in accordance with
initial distribution number 114386, requirements for TM 3-34.21.