Improvements in Floating Caissons suitable for Repairing Ships or Vessels.
Year: 1890

page_text: Date of Application, 26th Nov., 1890
Complete Specification Left, 25th Aug., 1891-Accepted, 26th Sept., 1891
PROVISIONAL SPECIFICATION.
Improvements in Floating Caissons suitable for Repairing Ships or
Vessels.
I, MATTHEW WHELDON AISBITT, of 47 Mount Stuart Square, Cardiff,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to that class of caisson which is floated into position under
the portion of the ship to be repaired, a tight joint being made between its open
end or ends against the ship's side. In such caissons it has been usual to make this
joint by means of lock gates which when the caisson is in position are shut against
the side of the ship.
According to this invention I dispense with such gates and close the end of the
caisson by building up temporary walls which roughly fit against the outside
of the skin of the ship, the joint being completed, if necessary by packing or
caulking.
I also dispense with the usual hollow sides obtaining all the necessary flotation
from the hollow bottom. I also make the sides sloping the inside of the caissoni
being narrower at the bottom than at the top; by this means I obtain greater
stability and strength. I make the sides of plate iron supported by vertical and
horizontal web frames being open on the outside to the water but being closed on
the inside by the skin of the caisson.
I make the caisson with a bottom and two fixed sides and when necessary, close
one end by means of a moveable side, which is attached to the fixed sides and to
the bottom. By this means any part of the ship and not the ends only may be
repaired.
Dated thin orth of Nawamba 1900
COMPLETE SPECIFICATION.
Improvements in Floating Caissons suitable for Repairing Ships or
Vessels.
I, MATTHEW WHELDON AISBITT, of 47 Mount Stuart Square, Cardiff,
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 :-
This invention relates to that class of caisson which is floated into position under
the portion of the ship to be repaired, a tight joint being made between its open
end or ends against the ship's side. In such caissons it has been usual to make
this joint by means of lock gates which when the caisson is in position are shut
against the sides of the ship and afterwards pump out the water contained
between the vessel's sides and the caisson by means of a pump not placed on the
caisson.
According to this invention I dispense with such gates and close the end of the
caisson by building up temporary walls which fit against the outside of the skin of
the ship, the joint being completed by means of a canvas pillow having oakum or
other yielding substance, the necessary boiler and machinery for pumping out the
caisson, or any individual tank, being placed on board the caisson, valves being
provided so that any compartment may be pumped out as desired for the purpose
of floating and stability.
I also dispense with the usual hollow sides obtaining all the necessary floatation

page_text: from the (hollow) bottom. I also make the sides sloping the inside of the caisson
being narrower at the bottom than at the top; by this means I obtain greater
stability and strength. I make the sides of plate iron or steel supported by vertical
and horizontal web frames being open on the outside to the water but being closed
on the inside by the skin of the caisson.
I make the caisson with a bottom and two fixed sides and when necessary
close one end by means of a moveable side which is attached to the fixed sides and
to the bottom. By this means any part of the ship and not the ends only may be
repaired.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is an outside elevation and Figure 2 a half plan of a caisson constructed
according to my invention.
Figure 3 is a transverse section on the lines X X of Figures 1 and 2.
The double bottom A A is divided into 8 or more or less water tight compart-
ments B as may be desired running from end to end into which water can be
admitted or pumped out individually or collectively for trimming or floating
purposes; upon this double bottom is erected two sides of plating CC which are
supported by vertical and horizontal plate brackets D angle iron stiffeners E with
small brackets at top and bottom being fitted in order to support the plates and on
the top of these vertical stiffeners and brackets, a plate F is fitted as a gangway
for convenience of working the caisson.
The movable end G is constructed in a similar way to the sides and rests
on either of the tables H H as may be desired and is attached to the sides C C.
A pocket tank I I is constructed in one corner of the caisson in which are placed
the necessary boiler and steam pump for pumping out the caisson or any compart-
ment or compartments of the double bottom.
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 :-
1.
1. A floating caisson consisting of a bottom and inclined sides and without fixed
ends substantially as described.
2. A floating caisson consisting of a buoyant bottom and non-buoyant sides,
substantially as described.
3. A floating caisson consisting of a buoyant bottom and non-buoyant inclined
sides substantially as described.
4. A floating caisson substantially as described and shewn in the drawings.
Dated this 18th day of August 1891.
M. W. AISBITT.