An Improvement in the Construction of Cellular Double Bottoms in Iron and Steel Ships.
Year: 1896

page_text: Date of Application, 21st Apr., 1896
Complete Specification Left, 18th Jan., 1897-Accepted, 27th Mar., 1897
PROVISIONAL SPECIFICATION.
An Improvement in the Construction of Cellular Double Bottoms
in Iron and Steel Ships.
1, GRORGE GALLILEE 57 Jalland Street Holderness Road Hull Ship Draughtsman
do hereby declare the nature of this invention to be as follows:-
Excepting in small ships, cellular double bottoms are usually constructed on one
or the other of the two following methods.
1st method, generally termed the longitudinal system. By this method the inner
bottom or tank top is supported by a continuous longitudinal girder at the centre
line, and by a continuous longitudinal girder at each side of the double bottom,
and also by continuous longitudinal girders between the centre line girder and the
tank side girders, and spaced on an average about four feet apart.
The inner bottom is further supported by transverse floors, fitted intercostally
between the longitudinal girders. The transverse floors are usually fitted on alternate
frames, excepting under the engines and boilers, where they are usually fitted on
every frame.
2nd method, generally termed the continuous floor system.
By this method, the inner bottom or tank top is supported by a continuous
longitudinal girder at the centro line, and by a continuous longitudinal girder at
each sido of the double bottom. The inner bottom is also supported by transverse
floors fitted continuous from the centre line girder to the tank side girders. These
transverse floors are nsnally fitted on every frame.
The inner bottom is further supported by longitudinal girders fitted intercostally
between the trausverse floors, and placed between the centre line girder and the
tank side girders.
In both the foregoing methods, the centre line girder is usually termed the centre
keelson, and the girders at the sides of the double bottom are usually termed the
tank side plates or tank margin plates.
And in both the foregoing methods of construction, the transverse floors are
formed of plate with an angle bar rivetted on to upper and lower edges.
The inner bottom is attached to the angles on the upper edges, and the outer
bottom to the angles on the lower edges.
The angles to which the outer bottom is attached are termed the frames or frame
bars.
The frames are usually spaced from 20 inches to 30 inches apart, according to the
size of the ship.
Manholes are made in the transverse floors, for access to the various parts of the
doublo bottom, by cutting or punching pieces out of the floorplates. The pieces of
plate cut or punched out for this purpose, are of an oval shape, and average in sizo
about 24 inches long and 16 inches wide.
These pieces of plate are of little use for shipbuilding purposes, and become, to
a great extent, waste material. The cost of the material thus wasted, added to tho
cost of the labour and machinery involved in cutting or punching out the manholes,
is considerable.
The object of my invention is, to construct cellular double bottoms in iron and
steel ships, in such a manner that open spaces or manholes-for access to the various
:

page_text: parts of the double bottom-will be formed by the structural arrangement; and not,
as in the prevailing methods of construction, by being cut or punched out of solid
plutes.
My invention can be applied to ships of any size, great or small, and to ships
with banging keels, or with fint plato keels.
The accompanying drawing, which is a cross section of part of a ships bottom,
shews my invention applied to a ship with a hanging koel, formed by the centre
girder plate and side bars.
I will now describe my invention, making reference to the said drawing, by
letters.
A centre line longitudinal girder A is to be fitted as usual, of suitable soantlings,
according to the size of the ship.
Strong transverse frames B are to be fitted and spaced from 18 inches to 36 inches
apart, according to the size of the ship. These frames, to which the outer bottom
plating C is to be attached, will henceforth in this specification, be termed the bottom
frames. The inner bottom or tank top plating D is to be attached to strong transverse
beams E, fitted at every frame or at alternate frames. Henceforth, in this
specification, these beams will be termed the tank top beams.
The bottom fruines and tho tank top beams may be made of any of the under-
mentioned sections in iron or steel, namely,
Angle.
Double angles fitted back to back, or reverse.
Bulb angle.
Balb angle, with an angle attached.
Tee.
Bulb tee.
Bulb bar or bulb plate, with an angle, or with two angles, or with a teo bar
attached.
Flat bar or plate, with an angle, or with two angles, or with a tee bar attached.
Zed.
Zed with an angle, or with two angles attached.
Channel.
Channel with an angle, or with two angles attached.
Aitch or joist.
:
On the drawing, the bottom frames and the tank top beams are shown of bulb
angle, that being the section, which I consider the most suitable. The bottom
frames and the tank top beams need not necessarily be of the same section.
The bottom framos and the tank top beams may extend in one length from the
centre line girder to the tank side F, as shown on the drawing, or they may extend
in one length across the double bottom, from side to side, the centre girder being cut
out to receive them.
The bottom frames and the tank top beams are to be connected to each other by
transverse vertical plates G fitted at the centre line girder and at the tank sides, and also
(except in small ships) at intervals between the centre line girder and the tank sides.
The transverse vertical plates are to be connected to the centre line girder, and
to the tank side plates, and to the intermediate longitudinal girders (in vessels where
the latter are fitted) by angles H of suitable size.
Or, instead of the bottom frames and tank top beams being connected and tied
together at intervals by transverse vertical plutes, they may be connected and tied
together at intervals by angles, or bulb angles, or by any other suitable section in
iron or steel, fitted transversely, and either vertically or diagonally.
And, as usual, in all excepting small ships, intermediate longitudinal girders I are
to be fitted betwcon the centre line girder and the tank sides, formed of plates with
an angle on the upper and lower edges.
In large ships, tho number of these intermediate girders will be increased' beyond
what is shown on the drawing. These intermediate girders may be fitted intercostally
between the transverse vertical plates as shewn on the drawing, or the girder plutes

page_text: may be fitted continuous, scored out in way of the frames and the beams, and the
angles on the upper and lower edges of the girder plates, fitted intercostally between
the beams and frames respectively. If the girder plates are fitted continuous, the
transverse vertical plates will be fitted in two pieces, one on each side of the girder,
and connected to the girder by angles.
The tank sidos F may be formed, as usual, by a longitudinal girder as shown on
the drawing, or the tank top may be continued out to the ship's side. In the latter
case, the tank top beams will also extend to the ship's sides, and the bottom frames
will extend up to the tank top, the said beams and frames being connected at their
junction by bracket plates.
The tank top may be level ncross from side to side, as shewn on the drawing,
may be inclined upwards or downwards from the contre line.
Briefly expressed, my invention consists in dispensing with the solid floorplates
which are usually fitted in cellular double bottoms, and substituting therefor, strong
bottom frames and strong tank top beams, made of any of the sections in iron or
steel, described in the foregoing specification. The bottom frames and the tank top
beams are to be sufficiently strong, thuat, being efficiently tied together and con-
nected at intervals by transverse vertical plates or other ties, the solid floorplates
usually fitted, may with safety be dispensed with.
The spaces which are left between the bottom frames and the tank top beams, and
between the transverse vertical plates or other ties, will form open spaces. or
manholes for access to the various parts of the double bottom.
Under the engines and boilers, and in any other places where great rigidity is
required, the solid floorplates usually fitted, may be retained, if deemed desirable.
The construction of the parts which are not new, such as the centre girder, the
tank side girders, and the intermediate girders, also the number of the intermediate
girders, may be modified and altered from that which is described in the foregoing
specification, or shown upon the drawing, without prejudice to this patent.
Also the number of the transverse vertical plates, and their shape and construc-
tion, may be modified and altered from that which is described in the foregoing
specification, or shewn upon the drawing, without prejudice to this patent.
Dated this 18th day of Anril 1896
GEORGE GALLILEE.
An Improvement in the Construotion of Cellular Double Bottoms
in Iron and Steel Ships.
I, GEORGE GALLILBE, 57 Jalland Street Holderness Road Hull, Ship Draughts
man 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 :-
Excepting in small ships, cellular double bottoms are usually constructed on one
or the other of the two following methods.
1st method, generally termed the longitudinal system. By this method, the
inner bottom or tank top is supported by a continuous longitudinal girder at the
centre line, and by a continuous longitudinal girder at each side of the
double bottom, and also by continuous longitudinal girders between the centre
lino girder and the tank side girders, and spaced on an average about four feet apart.
The inner bottom is further supported by transverse floors fitted intercostally
between the longitudina! girders.

page_text: The transverse floors are usually fitted on alternate frames, excepting under the
engines, where they are usually fitted on every frame.
2nd method, generally termed the continuous floor system. By this method the
inner bottom or tank top is supported by a continuous longitudinal girder at the
centre line, and by a continuous longitudinal girder at each side of the double
bottom. The inner bottom is also supported by transverse floors fitted continuous
from the centre line girder to the tank side girder. The transverse floors are usually
fitted on every frame. The inner bottom is further supported by longitudinal girders
fitted intercostally between the transverse floors, and placed between the centre line
girdor and the tank side girders.
In both the foregoing methods, the contre line girder is usually termed the centre
keelson, and the girders at the sides of the double bottom are usually termed the
tank side plates or tank margin plates.
And in both the foregoing methods of construction, the transverse floors are
formed of plates averaging in thickness about 6 of an inch, with an angle bar
averaging in size about 34 in. x 3 in. x 16 in. riveted on to the upper and
lower edges.
The inner bottom or tank top is attached to the angles on the upper edges, and
the outer bottom to the angles on the lower edges.
.The angles to which the outer bottom is attached are termed the frames or
frame bars.
The frames are usually spaced from 18 inches to 30 inches apart, according to
the size of the ship.
Manholes are made in the transverse floorplates, for access to the various parts of
the double bottom, by cutting or punching pieces out of the floorplates.
The pieces of plate cut or punched out for this purpose are usually of an oval
shape, and average in size about 24 inches long and 16 inches wide. These pieces
of plate are of little use for shipbuilding purposes, and become to a great extent,
waste material.
The cost of the material thus wasted, added to the cost of the labour and
machinery involved in cutting or punching out the manholes is considerablo.
The object of my invention is, to construct cellular double bottoms in iron and
steel ships, in such a manner, that open spaces or manholes-for access to the various
parts of the double bottom-will be formed by the structural arrangement, and not,
as in the prevailing methods of construction, by being cut or punched out of solid
plates.
My invention can be applied to ships of any size, great or small, and to ships
with hanging keels, or with flat plate keels.
The accompanying drawings shew my invention applied to a, ship with a hanging
keel formed by the centre girder plate and side bars.
Figure 1 is a cross section of part of the bottom of a ship, with a double bottom
constructed in accordance with my invention.
Figures 2 and 3 are longitudinal sections of part of the double bottom, at the lines
marked respectively Y Y and Z Z on the cross section.
I will now describe my invention, making reference to the said drawings by
letters, the corresponding parts in the various figures being indicated by the same
letter. A centre line longitudinal girder A is to be fitted as usual, of suitable
Scantlings, according to the size of the ship.
Strong transverse frames B are to be fitted and spaced from 18 inches to
36 inches apart, regulated by the size of the ship
These frames, to which the outer bottom is attached, will henceforth in this
specification, be termed the bottom frames.
The inner bottom or tank top plating D is attached to strong transverse frumes E
spaced the same distance apart as, and corresponding in position with, the bottom
frames.
Henceforth in this specification, these frames to which the inner bottom or tank top
plating is attached, will be termed the tank top frames.

page_text: The bottom frames and the tank top frames may be formed of angle iron or angle-
sieel, of about the size given for main frames in the building rules and tables of
Lloyds Registry or the building rules and tables of the British Corporation of
Shipping. Or they may be formed of angle iron or angle steel of any other size, that
is sufficiently strong.
Or, the bottom frames and the tank top frames may be formed of any of the
undermentioned sections in iron or steel, namely,
Two angles fitted back to back, or fitted reverse, or fitted to forin a channel.
section.
Bulb angle
Or, the bottom frames and the tank top frames may be formed of any of the
undermentioned sections in iron or steel,—namely,
.
Two angles fitted back to back, or fitted reverse, or fitted to forin a channel.
section.
Bulb angle
Bulb angle with an angle attached.
Tee.
Bulb Teo.
Bulb bar or bulb plate with an angle attached, or with two angles attached, or with:
a tee bar attached.
Zed.
Zed, with an angle attached, or with two angles attached.
Channel.
Channel with an angle attached, or with two angles attached.
When the bottom frames or the tank top frames are formed of a single section..
such as angle, bulb angle, tee, or any other single section, they may be strengthened
in way of the manholes by attaching thereto, short pieces of angle bar, fitted either as
reverse bars to the frames, or as doubling bars to the frames, or fitted so as to forin
with the frame bar, a channel section. Or the strengthening pieces may be formed of
bulb plate, or bulb angle, or any other suitable section in iron or steel. These
strengthening pieces need not be fitted in cases where they are deemed unnecessary.
In the drawings, the bottom frames and the tank top frames are shewn of angle-
section, that being the section which I consider most suitable.
And strengthening pieces K of angle har are shown attached to the bottom frames as
reverse bars, in way of the manholes. Strengthening pieces may also be fitted to the
tank top frames in way of the manholes, if they are deemed necessary or desirable.
The bottom frames need not necessarily be of the same section or size as the tank.
top frames.
The bottom frames and the tank top frames may extend in one length from the-
centro line girder to the tank side; or they may extend in one length across the
double bottom from tank side to tank side, the centre liue girder being scored out to.
receive them.
Transverse vertical plates G connecting the bottom frames to the tank top frames
are to be fitted at the centre line girder, and at the tank sides, and also (excepting in
small ships) at intervals between the centre line girder and the tank sides.
The transverse vertical plates may he on an average about 7 of an inch in thickness,.
and are to be connected to the centre line girder, and to the tank side girders, and to
the intermediate longitudinal girders (in vessels where the latter are fitted) by angles H
of suitable size.
Or, instead of transverse vertical plates, angle bars, bulb angle bars, tee bars or any
other suitable section in iron or steel may be used to connect the bottom frames to
the tank top frames, being fitted transversely and either vertically or diagonally.
And, excepting in small ships, an intermediate longitudinal girder I is to be fitted
between the centre line girder and the tank sides, formed as usual, of plates with an
angle on the upper and lower edges. In large ships the number of these intermediate
girders will be increased.
These intermediate girder plates may be fitted intercostally between the transverse
vertical plates as shewn in the drawing, or the girder plates inay be fitted continuous,
being scored out in way of the bottom frames and the tank top frames. In the latter
case, the transverse vertical plates in way of the intermediate girder will be fitted in
two pieces, one on each side of the girder, and connected to the girder plate by
anglos.

page_text: The tank side F may be formed as usual by a longitudinal girder as shewn in the
drawing or the tank top may be continued out to the ship's side. In the latter case
the tank top frames will extend to the ship's side, and the bottom frames will extend
up to the tank top, and be connected to the tank top frames by transverse vertical
plates of a bracket shape.
The tank top may be level across, from side to side, as shewn in the drawing, or it
may be inclined upwards or downwards from the centre line.
The construction of the parts which are not now, such as the keel, the contre line
girder, the tank side girders, and the intermediate girders, also the number of the
intermediate girders, may be modified from that which is described herein, or shewn
in the accompanying drawing.
Likewise, as regards some of the new features. For instance, the transverse vertical
plates which, in the drawing are shewn fitted on each side of the centre line girder,
may be in one plate instead of two, and the centre line girder plates bo fitted
intercostally between the transverse vertical plates.
And the number, position and shape of all the transverse vertical plates, also
the construction of, and the mothol of fitting, the strengthening pieces in way of the
manholes, may be modified from that which is described herein, or shewn in the
accompanying drawings.
.
And the tank top frames which in the drawings are shewn looking in the same
direction as the bottom frames, may be reversed. And other modifications of an
unimportant character may be made.
Briofly expressed, my invention consists in dispensing with the solid floor plates
with manholes in them, which are usually fitted in cellular double bottoms, and
substituting therefor, strong bottom frames and strong tank top frames, made of angle
iron or angle steel, or of other sections in iron or steel, as described in this specification.
The bottom frames and the tank top frames are to be sufficiently strong, that being
efficiently connected and tied together by transverse vertical plates or other ties, the
solid floorplates with manholes in them, which are usually fitted, may with safety be
dispensed with.
The spaces which are left vertically between the bottom frames and the tank top
framos, and transversely between the transverse vertical plates or other ties, will form
open spaces or manholes for access to the various parts of the double bottom.
Under the engines and boilers, and in other places where great rigidity is required,
or at the ends of the ship where the double bottom becomes narrow, the usual solid
floorplates with manholes in them, may be fitted, if deemed desirable..
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
An improvement in the construction of cellular double bottoms in iron and steel
ships, substantially as berein described.