A Ship Elevator.
Year: 1891

page_text: Date of Application, 22nd May, 1891
Complete Specification Left, 22nd Feb., 1892-Accepted, 26th Mar., 1892
TROVISIONAL SPECIFICATION.
A Ship Elevator.
CHARLES GUILFOYLE DORAN Dunworth House Queenstown County Cork
Ireland Architect and THOMAS NEVILLE STACK, Crosby Buildings Crosby
Square, London E.C. Newspaper Proprietor do hereby declare the nature of this
invention to be as follows :-
:-
Near navigable water, and near or upon the incline hereinafter described, to
construct a pontoon-the longitudinal elevation of which will be that of a truncated
right angled triangle-of steel, iron, wood or any other material-or any com-
bination of materials that may be found suitable to the locality in which it is to be
used.
The pontoon to be properly built and strengthened with longitudinal and
transverse girder framing securely connected together, and braced and stayed, and
provided with ribs and supports where necessary-and to be sheeted on the outer
sides, top, bottom, and ends, with sheeting of steel, iron, wood, or other material of
sufficient strength-securely fixed and made thoroughly watertight.
The dimentions of the pontoon in each case to be proportioned to the dimentions
of the largest vessel proposed to be raised upon it, and of cubic vacuum in excess of
the water displacement of such vessel when fully laden and afloat, and where
considered necessary provision to be also made for vacuum or water displacement
equivalent to the weight of the whole, or part, of the carriage hereinafter described
and the pontoon itself.
The pontoon to be strengthened with, among other girders, one longitudinal
girder, properly framed and braced, and fitted in its longitudinal section throughout
its entire length, and in the middle of its width, said girder to he firmly secured to
sustain the rail or rails to be provided for the carriage which is to travel upon it
directly supporting the keel of the vessel being elevated.
This pontoon to be mounted upon as many ranges of wheels, provided with axles
playing in proper bearings securely fixed to its bottom, as may be necessary to
support the superincumbent weight-one range or two ranges as may be required
to be fixed, immediately under the central girder, or as near thereto as desirable-
at least one range under each of the outer girders, and as many intermediate ranges
as may be found requisite for the proper distribution of the weight of the pontoon,
carriage, and vessel, over a sufficient number of bearing points on the rails on which
the pontoon is to travel-which rails are to be fixed on the incline-hereinafter
described to be prepared for its reception.
A sufficient number of ranges of rails of proper material, strength, and pattern to
be fixed on the top of the pontoon, throughout its length, on which the wheels of
the carriage to convey the vessels are to travel-one range or two ranges to be
fixed directly over the beforementioned longitudinal strengthening girder, and the
outer and intermediate rails to be fixed as nearly as possible in lines vertical over
the lines of wheels fixed underneath the pontoon. The ends of these rails over the
leep end of the pontoon to be turned up sufficiently to form a check against the
back wheels of the carriage and thereby maintain the carriage in its proper
position.
The vertical height of the pontoon at its deepest end and the vertical height of
ts truncated end may bear any desirable proportion to its top or horizontal length,
nd may be determined by the designers or constructors when calculating the
buoyancy required in each individual case.
A sufficient number of sluice valves or other valves equally effective in their

page_text: working to be fixed within apertures to be formed in the deepest end near the
lowest angle of the pontoon, to admit water, allow it to pass out, or altogether
exclude it, when necessary.
These valves to be opened and closed by suitable appliances from the quay or
ground adjoining.
A few man-holes with strengthening rings and properly secured covers to be
provided in the sheeting where most convenient for cleaning and repairing the
interior of the pontoon when necessary.
In the horizontal or top surface of the pontoon near the vertical angles of its
deepest end, or other convenient places, provision is to be made for pumping out the
water by the insertion of suitable pipes to reach to the lowest angle internally, and
of sufficient bore to allow the water admitted into the pontoon to be discharged in a
stipulated time-these pipes to form tail pipes for the pumps, and to be provided
with proper connections at the surface of the pontoon to which force pumps of
sufficient power to throw out-in the stipulated time-the quantity of water
necessary to be removed at each operation, or to empty the pontoon altogether
when it may be desirable to do so-can be readily and securely attached.
These pumps to be provided and fixed before the pontoon is submerged,
and to be worked by suitable machinery from the quay or ground adjoining.
The number and diameter of the pipes to be proportioned to the capacity of the
pontoon in each case.
One stand pipe of sufficient diameter, or more than one where necessary to be
inserted and firmly secured in the pontoon for the ingress, and egress, of air-said
pipes to be of sufficient height to reach above the surface of the water when the
pontoon is submerged to its lowest position.
The pontoon to be perfectly watertight-Pulleys with sheaves, suitable for chains
or cables to work in, to be fixed to the bottoms of the side girder framing, and
intermediate girder framing where necessary for the reception of the chains or
cables--as the case may be-by which the pontoon is to be brought up or let down
the incline.
These pulleys to be fixed to the undersides of the longitudinal girders of the
pontoon a few feet from the truncated end.
All the wheels to be of suitable material and sufficient strength, and to be plain,
single-flanged, or double-flanged, as may best suit the requirements of each case.
Where the bank or shore dips at an angle coinciding with the bottom of the
pontoon when its top surface is horizontal, and affords sufficient depth of water for
draught of vessel over the carriage and pontoon when submerged, the surface
required for the incline to be carefully smoothed, and to be overlaid with a bed of
the best Portland cement concrete, of sufficient thickness to resist the action of the
water and substantially support the greatest weight proposed to be carried upon it.
Where the dip is at a greater angle than that required for the pontoon the
difference is to be made up with rubble stone or concrete to the proper incline and
then to be overlaid with a bed of concrete as stated above.
Where the dip is less than the angle required for the pontoon, or where the incline
is to be formed in a bank the difference is to be excavated or dredged out for the
required distance and the bed is to be made even and concreted as before
mentioned.
The bed of concrete in every case to be somewhat wider than the breadth of the
pontoon, and to extend from the surface of the quay or ground into the water-a
distance to be regulated by the position the pontoon is to occupy upon it when a
vessel of the greatest draught of water calculated for could be floated into the
carriage for elevation.
In every case when preparing the ground for the bed of concrete trenches-each
of about three feet in width and one foot in depth-are to be excavated across the
incline the full width of the bed and about twenty feet apart and the concrete is to
be filled into these trenches at the same time that the concrete bed is being made on
the incline so that it will be built up from the bottom of the excavation to the

page_text: finished surface of the incline in one operation—the whole when completed forming
a compact mass without any joinings whatever.
When the concrete bed is laid on the incline and sufficiently set the requisite
ranges of rails are to be fixed in their proper positions upon it.
These rails are to be secured to the incline by bolts of mild steel, wrought iron,
or other suitable material. One end of each bolt to be screwed and provided with
a washer and proper close-fitting nut, and the other end to be swelled to twice the
diameter of the bolt so as to form a dovetail-the bolts to be each about two feet in
length and to be properly fixed and maintained in the required positions while the
concrete bed of the incline is being made and carefully packed about them.
A wall of concrete or masonry of sufficient strength to be built up from the
deepest end and sides of the incline to at least a height coinciding with the level
of the top surface of the carriage on the pontoon when submerged to the lowest
depth to form a chamber for the pontoon, and where requisite one or both of the
side walls to be built up to the surface of the ground, or quay level.
Proper freedom for the working of the pontoon to be allowed in the chamber and
between the said walls.
In tidal waters where there is considerable rise and fall the foregoing works can
be readily carried out, and where this advantage does not exist cofferdams may be
availed of and they may be constructed in the manner usual for carrying out
subaqueous operations.
In the highest end of the incline to properly and securely fix pulleys corresponding
in size, number, and direction with the pulleys attached to the pontoon and in line
with them, for sustaining the passing of the chains or cables to or from the machinery
when the pontoon is being worked.
In the highest end also proper eyes, hooks, or other fastenings of sufficient
strength to be provided and deeply and securely fixed in masonry or concrete-their
number and position to be deterinined by the number and position of the chains or
cables in every case one fastening to be provided for one end of a chain or
cable.
The carriage to be about the same length and breadth as the top surface of the
pontoon and only of such height as will ensure sufficient strength and rigidity in its
construction to sustain the heaviest weight proposed to be borne upon it-and to be
of the same description of materials as those used in the construction of the
pontoon and to be similarly sheeted.
Indents to be formed in the back end of the carriage to accommodate the pumps
provided to discharge the water from the pontoon.
The carriage to be provided with a number of ranges of wheels corresponding to
the number of ranges of rails provided on the pontoon-those wheels to be fitted
with axles, and suitable bearings which are to be fixed to the bottom of the carriage
in such positions as will accurately coincide with the lines of rails fixed on the
pontoon upon which they are to travel.
The carriage to have a central longitudinal girder well framed and braced, the
cross section of which will be of the same height as the carriage, and its width the
same as the width of the central longitudinal girder of the pontoon, and the ranges
of wheels are to be fixed in the same manner under this girder as they are fixed
under the girder of the pontoon.
The wheels in every case, both of the pontoon and the carriage to be of the
smallest diameter consistent with the requisite strength.
Upon the top of the central girder of the carriage a line of proper keel-blocks to
be fixed to support the keel of any vessel to be elevated, and at each side of this
line of blocks a sufficient number of suitably-shaped standards to be erected and
braced, stayed, and secured to the carriage to sustain the bilges and sides of each
vessel when resting on the keel-blocks-these supports to be so arranged as to be
readily adjusted to vessels of any width or beam.
When the foregoing works are completed and the number of chains or cables
decided upon, one end of each chain or cable is to be connected to one of the

page_text: fastenings in the high end of the incline corresponding with the pulley attached to
the pontoon through which the chain or cable is to work, the other end to be brought
through the said pulley and returned to the top of the incline and passed over the
corresponding pulley fixed there, and on to the drum, of the winding machinery, or
where hydraulic power is to be used to the head of the piston rod to which it is to
be securely attached.
The length of each chain or cable to be at least such as that when the pontoon
is at the lowest end of the incline the chain or cable fastened at the highest end and
brought through the pulley fixed to the pontoon will reach back and coil on the
barrel of the winding machinery, or connect with the piston of the hydraulic
apparatus, which may be provided in any suitable place above, or under, ground as
may best meet the requirements of cach case.
Separate lines of suitable rollers properly spaced to be fixed on the incline to
sustain the lines of chains or cables working the pontoon.
The pontoon, being in its proper position upon the rails on the incline, and its top
surface being on a level with the top of the quay or ground to which it is prepared
to work, the triangular space formed by the truncated end of the pontoon, the slope
of the incline, and the horizontal line of the top surface of the pontoon produced to
meet the top of the incline, to be built up to sustain the continuation of the lines of
rails fixed on the pontoon. This may be best done with wood or iron, or a
combination of both, which would facilitate removal at any time that it would be
necessary to draw up the pontoon altogether out of the water for overhauling or
repairs, but concrete or masonry might be used for the purpose if preferred-in
either case proper working space to be left about each chain, or cable, pulley and
fastening.
Lines of rails corresponding in strength, number, and position, to the rails on the
pontoon to be continued on proper sleepers along the surface of the quay or ground
for any distance to enable the carriage to travel with the vessel when elevated, to
the stores, or workshops, or, to any desirable position for overhauling, shelter, or
defence.
The mode of operation-as follows.
The pontoon being at the highest position on the incline-the carriage in its
proper place upon it, and the water admitted through the open valves into the
interior just sufficient to neutralise its buoyancy-the valves then closed-the
machinery by which the chains or cables are to be worked is to be reversed, and
the pontoon thereby allowed to descend the incline until the level of the
keel-blocks on the carriage will suit the draught of the vessel to be elevated.
The vessel is theu to be floated in-its keel in line with, and over, the line of
keel-blocks on the carriage.
The machinery is then to be set in motion and the pontoon advanced to take the
weight of the vessel.
The hauling machinery is then to be stopped-the pumps set to work-and a
quantity of water equal to the displacement of the vessel, and as much in excess of
it as may be decided upon-having due regard to the steadiness of the pontoon
upon the rails of the incline-pumped out.
The machinery is then to be started, and the pontoon aided by its buoyancy
brought up until the rails on its surface correspond in level with the lines of rails
meeting them at-the head of the incline when it is to be stopped.
The valves are then to be opened to admit just as much water as will neutralise
the buoyancy of the pontoon-before the carriage bearing the vessel is drawn off—
and then to be closed.
Traction engines or other hauling power to be then attached to fastenings,
provided on the front of the carriage, and set in motion, and the carriage bearing
the vessel brought away to wherever required.
Any number of carriages may be provided.
Another carriage being in readiness can be run in upon the pontoon, and the same
operations performed with the next vessel to be elevated as those just described, and

page_text: so on, any number of vessels that there are carriages, turn-tables, and sidings, to
accommodate can be elevated by one pontoon, without waiting the release of
carriages already occupied.
When a vessel is ready for return to the water, the carriage bearing it is to be
moved in upon the pontoon which is held in readiness at the head of the incline-
the machinery is then to be reversed and the pontoon allowed to descend to a
depth greater than the vessel's draught-when the vessel will immediately float and
pass out of the carriage.
The machinery can be worked by steam, gas, hydraulic, electric, or other engines,.
and as the pontoon by its buoyancy, supplemented by the advantages of the incline,
can be made to supply the elevating power, the engine power required for hauling
will be proportionately small.
Dated 15th dor of May 1901
CHARLES GUILFOYLE DORAN.
THOMAS NEVILLE STACK.
COMPLETE
SPECIFICATION.
A Ship Elevator.
CHARLES GUILFOYLE DORAN Dunworth House Queenstown County of Cork,.
Ireland, Architect, and THOMAS NEVILLE STACK Crosby Buildings Crosby
Square London E.C. Newspaper Proprietor do hereby declare the nature of our
invention for A SHIP ELEVATOR and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement :—
Near navigable water and near or upon the incline hereinafter described to.
construct a pontoon-the longitudinal elevation of which will be that of a
truncated right angled triangle A. B. C. D. Figure 1. Sheet 1.-of steel, iron,.
wood, or any other materials that may be found suitable to the locality in which it.
is to be used.
The pontoon to be properly built and strengthened with longitudinal and.
transverse girder framing securely connected together, and braced and stayed and
provided with ribs and supports where necessary-and to be sheeted on the outer
sides, top, bottom and ends, with sheeting of steel, iron, wood or other material of
sufficient strength-securely fixed and made thoroughly watertight.
The dimentions of the pontoon in each case to be proportioned to the dimentions
of the largest vessel proposed to be raised upon it, and of cubic vacuum in excess of
the water displacement of such vessel when fully laden and afloat, and when
considered necessary provision to be also made for vacuum or water displacement.
equivalent to the weight of the whole, or part, of the carriage hereinafter described,.
and the pontoon itself.
The pontoon to be strengthened with, among other girders one longitudinal.
girder properly framed and braced and fitted in its longitudinal section throughout
its entire length; and in the middle of its width, said girder to be firmly secured to.
sustain the rail or rails to be provided for the carriage B. E. F. C. Figure 1..
Sheet 1. which is to travel upon it directly supporting the keel of the vessel being..
elevated.
This pontoon to be mounted upon as many ranges of wheels A. C. Figure 1.
Sheet 1.-provided with axles playing in proper bearings securely fixed to its.
bottom as may be necessary to support the superincumbent weight-one range, or
two ranges as may be required to be fixed immediately under the central girder, or
as near thereto as desirable-at least one range under each of the outer girders,.
and as many intermediate ranges as may be found requisite for the proper
distribution of the weight of the pontoon, carriage, and vessel, over a sufficient
number of bearing points on the rails on which the pontoon is to travel which
rails are to be fixed on the incline hereinafter described-to be prepared for its
reception.

page_text: A sufficient number of ranges of rails G. G. G. G. Figure 2 Sheet 1. of proper
material strength and pattern to be fixed on the top of the pontoon throughout its
length, on which the wheels of the carriage to convey the vessels are to travel-
one range, or two ranges, to be fixed directly over the before mentioned longitudinal
strengthening girder, and the outer and intermediate rails to be fixed as nearly as
possible in lines vertical over the lines of wheels fixed underneath the pontoon.
The ends of these rails over the deep end of the pontoon to be turned up sufficiently
to form a check against the back wheels of the carriage and thereby maintain the
carriage in its proper position.
The vertical height of the pontoon at its deepest end A. B. and the vertical
height of the truncated end D. C may bear any desirable proportion to its top or
horizontal length, and may be determined by the designers or constructors when
calculating the buoyancy required in each individual case.
A sufficient number of sluice valves or other valves equally effective in their
working to be fixed within apertures to be formed in the deepest end near the
lowest angle of the pontoon, to admit water, allow it to pass out, or altogether
exclude it when necessary.
These valves to be opened and closed by suitable appliances from the quay or
ground H. H. Figure 2 Sheet 1-adjoining.
A few manholes with strengthening rings and properly secured covers to be
provided in the sheeting where most convenient for cleaning and repairing the
interior of the pontoon when necessary.
In the horizontal or top surface of the pontoon near the vertical angles of its
deepest end or other convenient places provision is to be made for pumping out
the water, by the insertion of suitable pipes I. I. Figure 2. Sheet 1. to reach the
lowest angle internally and of sufficient bore to allow the water admitted into the
pontoon to be discharged in a stipulated time-these pipes to form tail pipes for
the pumps and to be provided with proper connections at the surface of the pontoon
to which force pumps of sufficient power to throw out in the stipulated time-the
quantity of water necessary to be removed at each operation, or to empty the
pontoon altogether when it may be desirable to do so-can be readily and securely
attached.
These pumps to be provided and fixed before the pontoon is submerged, and
to be worked by suitable machinery from the quay or ground H. H. adjoining.
The number and diameter of the pipes to be proportioned to the capacity of the
pontoon in each case.
One stand pipe of sufficient diameter, or more than one where necessary to be
inserted and firmly secured in the pontoon for the ingress and egress of air-said
pipes to be of sufficient height to reach above the surface of the water when the
pontoon is submerged to its lowest position.
The pontoon to be perfectly watertight.
Pulleys with sheaves suitable for chains or cables to work in, to be fixed to the
bottoms of the side-girder framing, and intermediate girder framing where necessary
for the reception of the chains or cables-J. J. J. J. as the case may be by which
the pontoon is to be brought up or let down the incline.
These pulleys to be fixed to the undersides of the longitudinal girders of the
pontoon a few feet from the truncated end C. D.
All the wheels to be of suitable material and sufficient strength, and to be
plain, single-flanged, or double-flanged, as may best suit the requirements of each
case.
Where the bank or shore dips at an angle coinciding with the bottom of the
pontoon when its top surface is horizontal, and affords sufficient depth of water for
draught of vessel over the carriage and pontoon when submerged, the surface K. K
required for the incline to be carefully smoothed and to be over laid with a bed of
best Portland cement concrete L. L.-of sufficient thickness to resist the action
of the water, and substantially support the greatest weight proposed to be carried
upon it.

page_text: Where the dip is at a greater angle than that required for the pontoon the
difference is to be made up with rubble stone or concrete to the proper incline, and
then to be overlaid with a bed of concrete as stated above.
Where the dip is less than the angle required for the pontoon or where the
incline is to be formed in a bank the difference is to be excavated or dredged
out for the requisite distance and the bed is to be made even and concreted as
before mentioned.
The bed of concrete in every case to be somewhat wider than the breadth of the
pontoon, and to extend from the surface of the quay or ground into the water--a
distance to be regulated by the position the pontoon is to occupy upon it when
a vessel of the greatest draught of water calculated for could be floated into the
carriage for elevation.
In every case when preparing the ground for the bed of concrete trenches M. M.
M. M. &c. each of about three feet in width and one foot in depth are to be
excavated across the incline the full width of the bed and about twenty feet apart,
and the concrete is to be filled into these trenches at the same time that the
concrete bed is being made on the incline so that the whole will be built up
from the bottom of the excavation to the finished surface of the incline in one
operation--the whole when completed forming a compact mass without any joining
whatever.
When the concrete bed is laid on the incline and sufficiently set the requisite
ranges of rails G. G. G. G. are to be fixed in their proper positions upon it.
These rails are to be secured to the incline by bolts, of mild steel, wrought, iron;
or other suitable material. One end of each bolt to be screwed and provided with
a washer and proper close fitting nut, and the other end to be swelled to twice the
diameter of the bolt so as to form a dovetail-the bolts to be each about two feet
in length, and to be properly fixed and maintained in the required positions
while the concrete bed of the incline is being made and carefully packed
about them.
A wall of concrete or masonry N. N. of sufficient strength to be built up from
the deepest end and sides of the incline to at least a height coinciding with the
level of the top surface of the carriage on the pontoon when submerged to the
lowest depth to form a chamber for the pontoon, and where requisite one or both
of the side walls to be built up to the surface of the ground or quay level.
Proper freedom O. O. at the sides of the pontoon to be allowed in the chamber,
and between the said walls, for the working of the pontoon.
In tidal waters where there is considerable rise and fall the foregoing works can
be readily carried out, and where this advantage does not exist cofferdams may be
availed of and they may be constructed in the manner usual for carrying out
sub-aqueous operations.
In the highest end of the incline to properly and securely fix pulleys P. P. P. P.
Figures 3 and 4 Sheet 2, corresponding in size number and direction with the
pulleys attached to the pontoon, and in line with them, for sustaining the
passing of the chains or cables to or from the machinery when the pontoon is
being worked.
In the highest end also, proper eyes, hooks, or other fastenings of sufficient
strength to be provided, and deeply and securely fixed in masonry or concrete-
their number and position to be determined by the number and position of the
chains or cables-in every case one fastening to be provided for one end of a chain
or cable.
The carriage B. C. E. F. to be about the same length and breadth as the top
surface of the pontoon, and only of such height as will ensure sufficient strength
and rigidity in its construction to sustain the heaviest weight proposed to be borne.
upon it and to be of the same description of materials as those used in the
construction of the pontoon-and to be similarly sheeted.
Indents to be formed in the back end of the carriage to accommodate the pumps
at I. 1. provided to discharge the water from the pontoon.

page_text: The carriage to be provided with a number of ranges of wheels B. C. corre-
sponding to the number of ranges of rails provided on the pontoon-those wheels to
be fitted with axles, and suitable bearings which are to be fixed to the bottom of in
such positions as will accurately coincide with the lines of rails, fixed on the
pontoon, upon which they are to travel.
The carriage to have a central longitudinal girder, well framed and braced, the
cross section of which will be of the same height as the carriage, and its width
the same as the width of the central longitudinal girder of the pontoon, and the
ranges of wheels are to be fixed in the same manner under this girder as they are
fixed under the girder of the pontoon.
The wheels in every case both of the pontoon and the carriage to be of the
smallest diameter consistent with the requisite strength.
Upon the top of the central girder of the carriage a line of proper keel-
blocks Q. Q. to be fixed to support the keel of any vessel to be elevated, and at
each side of this line of blocks a sufficient number of suitably shaped standards R. R.
to be erected and braced, stayed, and secured to the carriage to sustain the bilges,
and sides of each vessel when resting on the keel blocks-these supports to be so
arranged as to be readily adjusted to vessels of any width or beam.
When the foregoing works are completed and the number of chains or cables
decided upon one end of each chain or cable is to be connected to one of the
fastenings in the high end of the incline-corresponding with the pulley attached
to the pontoon through which the chain or cable is to work, the other end to be
brought through the same pulley and returned to the top of the incline and passed
over the corresponding pulley fixed there and on to the drum of the winding
machinery, or where hydraulic power is to be used, to the head of the piston rod to
which it is to be securely attached.
The length of each chain or cable to be at least such as that when the pontoon
is at the lowest end of the incline the chain or cable fastened at the highest end and
brought through the pulley fixed to the pontoon will reach back and coil on the
barrel of the winding machinery, or connect with the piston of the hydraulic
apparatus which may be provided in any suitable place above or under ground, as
may best suit the requirements of each case.
Separate lines of suitable rollers S. S. properly spaced to be fixed on the incline
to sustain uniformly the lines of chains or cables working the pontoon.
The pontoon being in its proper position upon the rails on the incline, and its top
surface being on a level with the quay or ground H. H. to which it is prepared to
work, the triangular space D. C. P. Figure 3 Sheet 2, formed by the truncated end
of the pontoon, the slope of the incline, and the horizontal line of the top surface
of the pontoon produced to meet the top of the incline, to be built up to sustain the
continuation of the lines of rails fixed on the pontoon.
This may best be done with wood or iron or a combination of both which would
facilitate removal at any time that it would be necessary to draw up the pontoon
altogether out of the water for overhauling or repairs, but concrete or masonry
might be used for the purpose if preferred-in either case proper working space to
be left about each chain or cable, pulley and fastening.
Lines of rails corresponding in strength number and position to the rails on the
pontoon to be continued on proper sleepers along the surface of the quay or ground
for any distance to enable the carriage to travel with the vessel when elevated to
the stores or workshops, or to any desirable position for overhauling, shelter, or
defence.
The mode of operation, as follows.
The pontoon being at its highest position on the incline-the carriage in its
proper place upon it and the water admitted through the open valves into
the interior--just sufficient to neutralize its buoyancy-the valves then closed-
the machinery by which the chains or cables are to be worked is to be reversed,
and the pontoon thereby allowed to descend the incline until the level of the keel
blocks on the carriage will suit the draught of the vessel to be elevated.

page_text: The vessel is then to be floated in its keel in line with, and over, the line of
keel blocks on the carriage. The machinery is then to be set in motion and the
pontoon advanced to take the weight of the vessel. The hauling machinery is then
to be stopped the pumps set to work and a quantity of water equal to the
displacement of the vessel, and as much in excess of it as may be decided upon―
having due regard to the steadiness of the pontoon upon the rails of the incline-
pumped out. A gauge should be attached to the air pipe to indicate the quantity
of water to be ejected or admitted at each operation. The machinery is then to be
started and the pontoon aided by its buoyancy brought up until the rails on its
surface correspond in level with the lines of rails meeting them at the head of the
incline when it is to be stopped.
The valves are then to be opened to admit just as much water as will neutralize
the buoyancy of the pontoon before the carriage bearing the vessel is drawn off,.
and then to be closed.
Traction engines or other hauling power to be then attached to the fastenings
provided on the front of the carriage and set in motion, and the carriage bearing
the vessel brought away to wherever required. Any number of carriages may be
provided.
Another carriage being in readiness can be run in upon the pontoon and the
same operations performed with the next vessel to be elevated as those just
described, and so on, any number of vessels that there are carriages. Turn-tables,
and sidings to accommodate can be elevated by one pontoon without waiting the
release of carriages already occupied.
When is ready for return to the water the carriage bearing it is to be moved in:
upon the pontoon which is held in readiness at the head of the incline-the
machinery is then to be reversed and the pontoon allowed to descend to a depth
greater than the vessel's draught-when the vessel will immediately float and pass
out of the carriage.
The machinery can be worked by steam, gas, hydraulic, electric, or other engine.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is
1. That the pontoon being formed as a counterpart of the incline upon which it
travels insures its top surface and the carriage and vessel borne upon it maintaining
a horizontal position, which in the case of steam vessels will admit of the fires in:
their furnaces, the water in their boilers, and their cargoes, remaining undisturbed.
as if the vessel was afloat in calm water.
2. That the pontoon by its buoyancy-which can be increased or diminished in
proportion as more or less water is pumped out, will furnish lifting power which
can be accommodated to the weight of any vessel with or without cargo, ordnance,.
or stores, being elevated upon it.
3. That the cubic vacuum in the pontoon being in excess of the cubic water
lisplacement of the vessel being elevated, reduces the power required from the
nachinery to a minimum.
4. That the elevating power of the inclined plane upon which the pontoon
ravels, combined with the power of the pulleys attached to the pontoon itself-in
conjunction with the advantage obtained by the buoyancy of the pontoon-will
vork constructed as herein described-with a power under fifteen per cent. of the
otal weight calculated to be elevated-a ship elevator.
Dated this 20th day of February 1892.
CHARLES GUILFOYLE DORAN.
THOMAS NEVILLE STACK.