Improvements in the Transport of Ships on Inland Waters and Over Bars or Shallows, and in Structures therefor.
Year: 1890

page_text: Date of Application, 12th Nov., 1890-Accepted, 27th Dec., 1890
COMPLETE SPECIFICATION.
Improvements in the Transport of Ships on Inland Waters and Over
Bars or Shallows, and in Structures therefor.
I, PETER JENSEN of 77 Chancery Lane in the County of London, Fellow of the
Institute of Patent Agents do hereby declare the nature of this invention a com-
munication to me from abroad by Christian Anker of Fredrikshald, Merchant, Thorleif
Bache of Drammen Merchant, Mathias Morterud of Christiana Factory Manager and
Stian Sartz Backer of Christiana, Engineer, all in Norway, 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 this invention is to overcome the difficulty of putting inland towns
and centres of trade and commerce in complete communication with the sea by canals,
inasmuch as the latter have heretofore had to he very deep in order to enable seagoing
ships to pass them, thus entailing very great expense.
By the present invention it becomes possible to establish intercommunication by
means of large seagoing ships between the sea and inland towns and places on canals
and other waterways which in themselves cannot be navigated by such deep going
ships. For this purpose we lift the ships by means of specially constructed floating
docks of shallow depth and transport them therein on the water. Hereby we attain
that the largest ships can pass along very shallow canals and waters. Obviously the
building of canals is thus greatly cheapened, and lakes and rivers made navigable
without costly dredging.
These floating docks are of special importance in places where the harbours are
only accessible over bars by high water and where thus the ships sometimes have to
wait several hours for the tide, which is very inconvenient especially for sailing ships
as it not infrequently happens that the wind meanwhile has shifted so that the ship
cannot get through.
It has heretofore been proposed for the aforesaid purpose to employ floating docks
and pontoons for supporting ships thereon by suitable chocks, but this method has not
been found suitable because the ships suffer thereby being strained in a different
manner than when water borne. We on the contrary construct our floating dock
in such manner that it contains a tank or basin wherein the ship floats during
transport.
Such a tank-ship or tank-dock is shewn as an example upon the accompanying
drawing,
Figure 1 being a length section,
Figure 2 cross section and
Figure 3 plan.
Figures 4 and 5 are details.
The floating dock A contains a basin or tank B which is closed by walls on three
sides, while the rear end when the dock is lowered can communicate with the water
outside by means of a sluice door C. This door is by preference hollow and turns on
lower horizontal axis and rests in a recess in the bottom of the tank when a ship is
o enter the dock so that the ship can pass freely over it. The gudgeons D of the
loor are arranged one on each side as shewn more clearly in Figures 4 and 5 and
vork in bearings E which are adjustable in the length direction of the dock to enable
he door to make a tight joint against the end of the dock by means of interven.ing
acking of canvas matting on wood or other suitable packing. The hollow of the coor
by means of the hollow gudgeons D the hose pipe and the pipes G in communi-
ation with a pump whereby water can be forced into the door.
When the tank dock or ship is to be used the sluice door is clapped down
orizontally into its recess and water pumped into the hollow spaces of the deck until

page_text: it has become lowered far enough to take the ship which is to be transported. The
ship having been run in, the door is loosened and will thereby rise into the upright
position shewn. Water is now pumped out of the hollow sides of the dock, so that
the dock with the ship in its tank will rise into the position shewn and is transported.
When the dock with the ship has come back into deep water again some water is pumped
into the hollow sides of the lock until the latter has been lowered so far that the level
of the water in the tank of the dock is the same as the water outside whereupon the
door C of itself will swing down because as shewn the joint surface of the same is
somewhat inclined to the inside.
During the transport the ship floats in the tank being braced to the side walls of
the same by ropes. There will consequently be no more or other strain on the ship
than when it lies in harbour, thus fulfilling the main condition viz. transporting large
ships without weakening them.
Instead of one sluice door of the construction shewn there may be two one behind
the other, so as to get better joint, but sluice doors of other suitable constructions may
of course be employed if desired.
The floating dock may be propelled by means of a screw propeller on each quarter,
or in any other suitable way.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me,
by my foreign correspondent I declare that what I claim is:-
First. The method of transporting a ship consisting of floating the same into a
floating dock with end door capable of being closed so as to form a tank in the dock
while the dock is in deep water, then closing such tank and raising the dock by pumping
water out of its hollow walls then floating the dock in shallow water to the desired
place and after return into deep water lowering the dock again by pumping water
into its hollow walls until the water level in the tank is the same as that outside, and
then floating the contained ship out.
Second. The construction of floating dock with inner tank and with one or more
end doors for entry and exit of ships substantially as and for the purpose set forth.
Third. In a floating dock the construction of hollow sluice door with lower hollow
gudgeons communicating with the hollow walls of the dock substantially as described
and shewn.
Dated this 12th day of November 1870.
LCHAU
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.