An Improved Apparatus for Ascertaining the Draught of Ships and the like.
Year: 1893

page_text: Date of Application, 17th Oct., 1893
Complete Specification Left, 16th July, 1894-Accepted, 29th Sept., 1894
PROVISIONAL SPECIFICATION.
An Improved Apparatus for Ascertaining the Draught of Ships and
the like.
I CHARLES SMITH HALL, of Barrow upon Humber in the County of Lincoln-
shire, Marine Engineer, do hereby declare the nature of this invention, to be
as follows:-
:-
The object of my invention is to construct an apparatus for taking the draught
of ships without the necessity of any person having to go round the ship in a boat,
or at nights to have to take a lamp for the purpose of examining the ship to
ascertain her draught.
I construct my apparatus as follows:-
I employ a spirit level, such level being pivotted near one end, and being
adjusted in the centre underneath by means of a screw or the like, and also having
a weight fixed or attached to it for the purpose of bringing it back to its original
position after the draught has been obtained.
To this spirit level at its moveable end I employ a pointer for the purpose of
indicating the trim of the vessel which is obtained by the employment of a
graduated arc which is marked off in feet and inches to a suitable scale; and in
connection with this arc I employ an indicator finger working on a long screw
fixed in a bracket or the like. This finger is set on the graduated arc, and the
pointer or finger in connection with the spirit level working up or down this arc
stops at the point which represents the depth of the ship at the stern.
I employ a mercurial U shaped barometer fixed in a frame, this barometer is
connected to a metal or other pipe which passes down through the bottom of the
ship near the keelson where it is bent over or forked, an end passing through the
ships bottom at each side of the keelson at equal distances from the centre of
the keel, the water from the sea passing up these pipes compresses the air and acts
upon the barometer, the barometer scale being set off in suitable distances, the
height of the mercury, showing the centre draught of the ship.
Suitable cocks are employed in connection with the aforesaid pipe for the
purpose of shutting off the water for cleaning and other purposes.
The spirit level and most of the apparatus can be arranged in a case for
the purpose of being fixed up in the chart room or in any suitable part of the
ship as found most convenient.
With this improved apparatus for ascertaining the draught of ships the necessity
of having to go in boats round the ship is entirely dispensed with and the quantity
of cargo put in or taken out is easily ascertained.
Dated this Fourteenth day of October 1893.
JOHN E. WALSH,
Savile Street, Hull, and Crossley Street, Halifax,
Agent for the Applicant.

page_text: COMPLETE SPECIFICATION.
An Improved Apparatus for Ascertaining the Draught of Ships and
the like.
I, CHARLES SMITH HALL of Barrow-upon-Humber, in the County of Lincoln-
shire, Marine Engineer, do hereby declare the nature of this invention, and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The object of my invention is to construct an apparatus for taking the draught
of ships, without the necessity of any person having to go around the ship in a boat,
or at night to have to take a lamp for the purpose of examining the outside of the
ship to ascertain her draught.
Hitherto when wanting to know the draught of a vessel it has been for the
person whose duty it is to obtain these particulars, to examine the vessel from
outside, this is almost impossible in many instances, as for example, when many
yessels are lying one alongside the other in tiers as is frequently the case; or at
night when it is dark and a lamp has to be employed, and in rivers or harbours
where there are danger-currents, under these conditions the information thus
obtained is far from correct.
By the employment of my improved apparatus all the above difficulties are
obviated and the correct draught of the ship is obtained aboard the vessel, also
the quantity of cargo taken aboard or unshipped is easily and correctly
ascertained.
DESCRIPTION OF DRAWINGS.
Fig. 1. is a front view of my improved apparatus for ascertaining the draught
of ships and the like.
Fig. 2. is a plan of Fig. 1.
I construct my invention as follows:-
I employ a spirit level A, such level being pivotted near one end B, and being
adjusted in the centre underneath by means of a screw or the like C, a weight or
its equivalent D is fixed or attached to it, for the purpose of bringing it back to
its original position, after the draught has been ascertained.
To the moveable end of the spirit level I employ a pointer or finger E, for the
purpose of indicating the trim of the vessel, this pointer is connected to the
movable end of the level by a link For the like, and has its point at the opposite
end to the point G on the level, and moves up and down on a graduated arc H,
marked off in feet and inches to a suitable scale; in connection with this arc H,
1 employ an indicator J working on a long screw or threaded spindle K, fixed in a
bracket or the like. The finger E is set on the graduated arc H, and being
connected to the pointed end G of the spirit level A, and working up or down this
arc H, stops at the point which represents the difference of draught between the
head and stern.
The pointed end G of the spirit level A, (being the opposite end to where the
level is pivotted at B.) if provided with a plate L marked off to scale, will show
by itself the trim of the vessel fore and aft on such plate, the longer the combined
level and pointer, the larger the scale will be. The object of my employing a
separate finger or pointer E, which shows the trim on the graduated arc H at the
pivotted end of the level is to enlarge the scale, thus making it more easily seen,
and by multiplying the number of fingers, each finger above the other, the scale is
enlarged each time, and has the same effect in a small space as employing one very
long pointer.
employ a mercurial U shaped barometer M fixed in a frame N, on which is
marked off to scale a certain depth of water; this barometer M is connected to a

page_text: metal or other pipe O, which passes down through the bottom of the ship, where it
is bent or forked, an end passing through the ships bottom at equal distances from
the centre of the keel, the water from the sea passing up the pipe compresses the
air and acts upon the barometer, the barometer scale being set off in suitable
distances the height of the mercury showing the centre draught of the ship, that
is, if the tube passes through the centre of the ship. Suitable cocks are connected
to the aforesaid pipes for the purpose of shutting off the water for cleaning and
other purposes.
In case of it not being convenient to pass the pipe direct through
or fix the apparatus in the centre of the ship, such pipe may be carried through,
and the apparatus fixed in any suitable part of the ship, say at the total length
from the stern or from the opposite end. In this case, suppose the pointer E
indicates 4 feet aft on the graduated arc H, and the mercury in the barometer M
shows 14 feet, take of the 4 feet shown by the pointer and add result to the
14 feet of the mercury, this will give total draft of the ship aft; then take ģ of
the 4 feet shown by the pointer E and subtract result from 14 feet of mercury, this
gives the forward draught, and by adding the forward draught and the aft draught,
thus obtained together, and dividing by the middle or mean draught is obtained.
When the apparatus is in the centre of the ship, the pointer E simply shows
what the draught of the vessel fore or aft is by working up and down the graduated
arc H, when she is deeper forward than aft, it is above the centre mark, when she
is deeper aft than forward, it is below the centre mark, the barometer showing by
the mercury what the mean or centre draught is.
The apparatus can be arranged, with the exception of the length of tube and sea
connections, in a case for the purpose of being fixed up in the chart room, or in
any suitable part of the ship as found convenient. In this case or box also, I may
fix the contrivance which has usually been employed for showing the list of
the ship.
This consists of a jib P to the end of which is pivotted a movable vertical
pointer with a split end, which swings backwards and forwards on a graduated
arc R marked in degrees. The jib and arc are attached to a vertical spindle S
working in brackets T and T' at the top and bottom. When in use the jib P and
arc R project from the box at right angles, thus the box being fitted lengthwise or
fore and aft the vessel, the jib and arc stand out athwart ship, so that when the
vessel has a list to either side, the pointer gives the degrees of list by showing it on
the graduated arc.
When not in use, the jib, arc and pointer lie flat in the box U as shown in dotted
lines Fig. 1.
The method of ascertaining the trim of the vessel is as follows:-
The spirit level A is set perfectly level, which sets the pointer on the level G and
the finger above E on the centre or even mark of their respective arcs or plates L
and H; the indicator finger J on the threaded spindle K is also set, by simply
turning the milled head K'; as the ship begins to settle or rise either forward or
astern, the bleb or bubble in the level A moves from the centre, and by setting the
level for the bleb or bubble to be in the centre again, if the pointed end G lowers
it draws the pointer E down at the end connected by the link F,
lifting up
its
opposite end, or if the pointed end G of the level A. rises, the pointed end of the
finger E falls, when the finger falls below the centre mark, it shows that the ship
is deeper at the stern than forward, and when the finger rises above the centre
mark it shows that she is deeper forward than astern.
When wanting to know how much the draught of the ship has changed, instead
of having to remember where the finger was when the party or parties left the
instrument, the indicator J is set opposite the finger E, and when the instrument
is next examined, the distance on the arc H, between the indicator J and finger E,
shows what difference in the set of the ship has taken place.
The centre draught of the ship is obtained by simply examining the mercury in
the barometer M which is compressed by the air forced up the pipe O, through the
ships bottom by the pressure of water as she sinks or rises in the water by the
difference in the weight within her.

page_text: Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. For ascertaining the draughts of ships, the combination of a pivotted spirit
level A, having a point G¹, working on a graduated plate L, marked off in feet
and inches to a suitable scale, a mercurial barometer M, connected to a pipe O,
running through the ships bottom to the sea, indicator J working on threaded
spindle K, weight D or its equivalent and adjusting screw C, substantially as
shown and described.
2. For ascertaining the draughts of ships or the like, the combination of a
pivotted spirit level A, working on a marked plate L, such level having a second
finger E (or as many as desirable) connected by a link or the like F, and moving
on a graduated arc or plate H, indicator J working on a threaded spindle K, weight
or its equivalent D, adjusting screw C, substantially as shown and described.
3. The whole of the apparatus described, arranged and operating within a case U,
in combination with jib P, pointer Q, and graduated are R, vertical spindle S, and
slate V, substantially as shown and described.
Dated
daw of Tul. 1901
JOHN E. WALSH,
Saville Street, Hull, and Crossley Street, Halifax,
Patent Agent for the Applicant.
JOHN E. WALSH,
Saville Street, Hull, and Crossley Street, Halifax,
Patent Agent for the Applicant.