IMPROVEMENTS IN TURNTABLES OR SWITCHES FOR SHIP RAILWAYS AND IN MEANS FOR WORKING THE SAME
Year: 1884

page_text: I JAMES BUCHANAN EADS, temporarily of the First Avenue Hotel, High
Holborn in the County of Middlesex, Civil Engineer, do hereby declare the nature
of my invention for IMPROVEMENTS IN TURNTABLES OR SWITCHES FOR SHIP
RAILWAYS AND IN MEANS FOR WORKING THE SAME to be as follows:-
The object of the present invention is to provide a turntable or switch for
deflecting ship or other heavy trains and engines onto other lines or sidings, or on
to portions of the same line at an angle to their previous line of travel, and which
shall be capable of supporting very heavy loads and of being nevertheless operated
with a minimum amount of labour.
To these ends I propose to construct the turntable or switch after the manner of
a pontoon and of the dimensions necessary to receive the ship train or engine to be
deflected and of such displacement as will carry the same afloat.
This pontoon I pivot so that when afloat it can be freely swung through a circle
or an arc of a circle and its course be correctly guided, and I arrange it within a
basin of proper form and construction which permits it to swing through the desired
angle but fits closely against it in its extreme positions and I provide the basin with
circular ways or guides upon which the pontoon can be grounded by filling it with
water when a ship train is running on or off, and on which it can slide or move
and against which it can guide itself when the pontoon is afloat just above them.
These circular ways I make of such height as to leave the necessary room between
the basin and the pontoon for the free exchange of the water from one side or part
of the basin to the other.
I construct the pontoons with longitudinal and transverse girders carrying the
lines of rails and providing the necessary stiffness, and I divide it into a number
of watertight compartments which communicate with each other and with the
centre compartment, and which can be connected or separated from each other at
will by means of valves or sluice gates.
In order to fill the pontoon with water and ground it when in its proper position,
other sluice gates or valves are arranged through which the various compartiments
can be filled with water from the basin, and for the purpose of emptying or
draining the pontoon the various compartments are connected by conduits and
sluices with pumps on the pontoon or on shore which eject the water from the

page_text: pontoon into the basin. Thus in grounding the pontoon the water level sinks in
the basin, while the water rises in the pontoon and only a fraction of the whole
floatation of the pontoon needs to be destroyed to hold it secure on its ways while
a ship train is being moved on or off. In floating it again with a train on it, this
fractional amount of water only has to be pumped out and discharged into the
basin, lowering the water level in the pontoon and raising it in the basin. The
saving in time and power necessary for operation thus effected is in the inverse
proportion of the area of the space between the basin and the pontoon to the
area of the pontoon, and amounts to over 50 per cent for a turntable having an
angular motion of 90°, and the saving increases with the smallness of the angle of
deflection through which the pontoon is adapted to move. Where the water
supply is sufficient and continuous, pumping machinery is superfluous and the basin
may be merely a water reservoir in which the pontoon is pivotted.
In this case it is only necessary to maintain the water in the basin at its high
level from the natural supply, and fill and ground the pontoon from the water in
the basin through sluice gates or valves at its sides, and to drain the water from
the pontoon into a low level conduit in order to float it; and for this purpose I
construct the centre pivot of the pontoon hollow, in the shape of a large tube
working through a stuffing box at the bottom of the basin and discharging into a
canal walled up below the bottom of the basin and draining into a low level. Into
this hollow centre pivot the various compartments of the pontoon open with conduits
and sluices, through which it can be wholly or partially emptied at pleasure.

page_text: I JAMES BUCHANAN EADS temporarily of the First Avenue Hotel, High Holborn,
in the County of Middlesex, Civil Engineer, do hereby declare the nature of my
invention for "IMPROVEMENTS IN TURNTABLES OR SWITCHES FOR SHIP RAILWAYS
AND IN MEANS FOR WORKING THE SAME," 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 the present invention is to provide a turntable or switch for
deflecting ship or other heavy trains and engines onto other lines or sidings or onto
portions of the same line at an angle to their previous line of travel, and which
shall be capable of supporting very heavy loads and of being nevertheless operated
with a minimum amount of labour.
To these ends I propose to construct the turntable or switch after the manner of
a pontoon and of the dimensions necessary to receive the ship train or engine to be
deflected, and of such displacement as will carry the same afloat.
This pontoon I pivot so that when afloat it can be freely swung through a circle,
or an arc of a circle, and its course be correctly guided; and I arrange it within a
basin of proper form and construction which permits it to swing through the
desired angle, but fits closely against it in its extreme positions, and I provide the
basin with circular ways or guides upon which the pontoon can be grounded by
filling it with water when a ship train is running on or off, and on which it can
slide or move, and against which it can guide itself when the pontoon is afloat just
above them. These circular ways I make of such height as to leave the necessary
room between the basin and the pontoon for the free exchange of the water from
one side or part of the basin to the other.
I construct the pontoon with longitudinal and transverse girders carrying the
lines of rails and providing the necessary stiffness, and I divide it into a number of
water-tight compartments, preferably arranged in groups, which communicate with
cach other and with a central compartment, and which can be connected or
separated from each other at will by means of valves or sluice gates operated from
the platform or deck above.
In order to fill the pontoon with water and ground it when in its proper position,
other sluice gates or valves, also operated from above, are arranged, through which
the various compartments or groups of compartments can be filled with water from
the basin, and for the purpose of emptying or draining the pontoon, the various
compartments are connected by conduits and sluices with pumps on the pontoon
or on shore, which eject the water from the pontoon into the basin.
Where the water supply is sufficient and continuous, pumping machinery is
superfluous and the basin may be merely a water reservoir in which the pontoon is
pivotted. In this case it is only necessary to maintain the water in the basin at
its high level from the natural supply, and fill and ground the pontoon from the
water in the basin through sluice gates or valves in its bottom or sides, and to drain
the water from the pontoon into a low level conduit in order to float it; and for
this purpose
I construct the centre pivot of the pontoon, hollow, in the shape of
a large tube working through a stuffing box at the bottom of the basin, and
discharging into a canal or conduit walled up below the bottom of the basin, and
draining into a low level. Into this hollow centre pivot the various compartments
of the pontoon open by means of suitably arranged conduits and sluices, and thus
all or any of them can be wholly or partially emptied at pleasure.

page_text: The invention will be more fully understood on reference to the accompanying
drawing in which
Fig: 1 is a plan of a pontoon turntable or switch constructed according to my
invention; and
Fig 2 is a sectional elevation on the line xx of Fig: 1 with a vessel mounted
upon a ship carriage, in position upon the pontoon turn table.
A is the pontoon constructed of cellular compartments arranged in groups each
of which can be put into communication with a central compartment or basin at
pleasure.
B is the pivot or centre on which the pontoon turns, and this pivot preferably
consists of a large tube which works through a stuffing box at the bottom of the
basin C, and is directly connected with a central compartment, or compartments
within the pontoon, communicating by suitable valves or sluices with the several
other compartments or cells thereof and which may be used to discharge water
from the pontoon into a canal or conduit such as D', built or walled up below the
bottom of the basin and draining into a low level, or may be connected through a
pipe e with a centrifugal or other pump, E, situate on the shore or margin of the
basin C, as shown, or it might bo connected, through a pipe or pipes within the
pontoon, with a pump carried by the pontoon itself.
The arrangement shown is however that which is preferred, as it leaves the
platform or deck of the turntable clearer.
The pontoon A is constructed of plates and angle irons rivetted together and
suitably braced and stiffened by longitudinal and transverse girders to impart the
necessary strongth, and upon the platform or top of the pontoon are fixed the lines
of rails constituting a portion or short section of the ship railway track, other
portions of which track f¹ƒ extending from the margin of the basin are shown
in the plan view Fig: 1.
Grepresents a ship carriage constructed according to the invention for which
Letters Patent were granted to the present Applicant bearing date 24th November
1883, Nº 5512, and H represents a vessel mounted thereon.
cc are semi-circular or segmental ways laid around the bottom of the basin C,
and extending to a suitable height therefrom, to allow the water to pass freely
from one side to the other of the basin when the turntable is swung round.
A simple and convenient arrangement of the several compartments of the
pontoon for the purposes of my invention is illustrated in the drawings as shown
in Fig 1. The pontoon in this arrangement is divided into four principal
compartments or groups of compartments, a¹ a¹, a² a², a³ a³ a¹ a. These com-
partments communicate by openings and sluices with a central chamber a³ and by
means of separately operated valves or sluice gates numbered from 1 to 8 in the
plan view, it is possible to fill or empty the several compartments in one or more
of the corners or quarters of the pontoon at a time, as may be desirable to suit the
distribution of the load on the platform. For example, if the preponderance of
weight is towards the end of the platform over the compartments a¹ and a³ and
that end of the pontoon requires to be upheld by the force of flotation to a greater
extent than the other end, in order to relieve the drag upon the ways c c below the
said compartments, then the valves connecting the compartments a' a' and a³ a²
with the central compartment a, would be opened, and also the valves 5 and 6 and
water would be ejected or drawn off from the said compartments by the steain
pump E, or would be allowed to escape through the hollow pivot B, or else the
valves 3 and 4 would be opened and water would be admitted to the compartments
a, a, at the other end, to maintain the horizontality of the platform. I do not
however limit myself to- this precise arrangement of the cellular compartments, as
is is obvious that other arrangements for effecting a substantially similar result
might be devised.
The object in giving to the basin C the form indicated in the plan view Fig: 1,
is to effect a saving of time in floating or grounding the pontoon during the opera-
tion of deflecting a ship train, or the carriage or carriages composing the train, by

page_text: preventing unnecessary pumping and the transfer of an unnecessary amount of
water during the operation of effecting the necessary alteration in the water level
in the pontoon and basin respectively. In grounding the pontoon the water
admitted to the several compartments or sets of compartments is taken from that
in the basin or reservoir C, and hence the water level in the basin sinks while tho
water in the pontoon rises, and only a fraction of the whole flotation of the pontoon
needs to be destroyed in order to allow it to settle down and hold it securely upon
the ways or guides co while a ship train is being run on or off. Similarly in
floating it again, or rather in giving it sufficient buoyancy to allow of its being
swung through the desired angle with a minimum of friction on the fixed ways,
only a fractional amount of water has to be removed from the pontoon and
discharged into the basin, thus lowering the water level in the former and raising
it in the latter.
The saving in time and power necessary for operating my pontoon turntable,
which is thereby effected is in the inverse proportion of the area of the space
between the basin and the pontoon to the area of the pontoon, and amounts to
over 50 per cent for a turntable having an angular motion of 90°, and this saving
increases with the smallness of the total angle of deflection through which the
pontoon is adapted to move.
In cases where there is an ample water supply, all pumping may be dispensed
with, and an arrangement of inlet and discharge conduits may be used similar to
that indicated in dotted lines in Fig: 2, in which D¹ as above described represents
a discharge conduit built or walled up below the said basin and communicating
with the interior of the pontoon by a hollow stem or pivot working watertight
through a stuffing box, and D is an inlet conduit for admitting water as required
to the basin C.
When the pontoon has been rendered sufficiently buoyant to admit of its being
freely swung through the desired angle upon its ways or guides cc and the ship
train is being moved from off the turntable onto the permanent track extending
from the margin of the basin, care must be taken to destroy the surplus buoyancy
of the pontoon during the transfer of the weight upon it from one end to the other,
and this can be readily done by opening one or more of the valves 1, 2, 3, 4, or
other valves suitably arranged, to admit water to the ends, or corners, of the
pontoon.
I would remark that if the centrifugal or other pump or pumps for emptying
the pontoon were carried by the pontoon itself, there would be no necessity for
having the pivot B hollow, and the central compartment a³ could be emptied by
a suitable arrangement of pipes connecting it with the pump or pumps on the
platform of the pontoon, and the water be discharged into the basin Cover the
side of the pontoon.
I would also remark that the turntable represented in Fig: 1 might be used to
deflect ship trains onto another line or track by swinging its upper end to the right
instead of to the left and that if such a double deflecting movement of the turn-
table were not required, it would be desirable to shape the basin according to the
principle of construction enunciated above, as indicated by the dotted lines enclosing
spaces marked L L¹ in the plan view; since any considerable decrease in the
difference between the area of the space between the basin and the pontoon, and
the area of the pontoon itself would, as above pointed out, greatly reduce the time
required for effecting the displacement or transfer of water within the pontoon and
basin respectively, which would be necessary to ground or float the said pontoon
for the purposes of my invention.
In some cases the basin or reservoir might take the form in plan view of a
sector of a circle, instead of two sectors of a circle connected at their inner or
central parts, and in that case the pontoon would be pivotted towards one end,
and the other end would be brought as required into coincidence with one or
other of the tracks radiating from the single segmental margin of the basin.

page_text: Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is:-
1. A pontoon turntable for ship railways constructed mounted and operating as
and for the purpose described with reference to the drawings.
2. The combination with a basin having a segmental margin or margins and a
track or tracks extending radially therefrom, of a section of the track or tracks
mounted upon. a pontoon turntable constructed with cellular compartments, and
provided with inlet valves, and a discharge pipe or pipes, as and for the purpose
described.
3. The combination with a basin such as C, having a segmental margin or
margins, a track or tracks radiating therefrom, and supply and discharge conduits
such as D D', of a pontoon turntable carrying a section of the track and provided
with a hollow pivot or discharge pipe B, fixed guides or ways c c for supporting
the pontoon clear of the bottom of the basin, and valves or sluices for varying the
level of the water in the pontoon and basin respectively, substantially as and for
the purpose set forth.
Dated thin 10th of Demba 1004