IMPROVEMENTS IN THE CONSTRUCTION AND ARRANGEMENTS OF FLOATING PONTOON DOCKS, AND IN THE LONGITUDINAL WAYS AND CRADLES FOR HEAVING-UP SLIPS TO BE USED PART IN CONNECTION THEREWITH
Year: 1878

page_text: LETTERS PATENT to Robert Turnbull, of Derby Terrace, South Shields, in the
County of Durham, Naval Architect, for the Invention of "IMPROVEMENTS IN
THE CONSTRUCTION AND ARRANGEMENTS OF FLOATING PONTOON DOCKS, AND IN
THE LONGITUDINAL WAYS AND CRADLES FOR HEAVING-UP SLIPS TO BE USED
PART IN CONNECTION THEREWITH."
"
Scaled the 11th March 1879, and dated the 14th September 1878.
PROVISIONAL SPECIFICATION left by the said Robert Turnbull at the Office
of the Commissioners of Patents on the 14th September 1878.
ROBERT TURNBULL, of Derby Terrace, South Shields, in the County of Durham,
Naval Architect. "IMPROVEMENTS IN THE CONSTRUCTION AND ARRANGEMENTS OF
FLOATING PONTOON DOCKS, AND IN THE LONGITUDINAL WAYS AND CRADLES FOR
HEAVING UP SLIPS TO BE USED PART IN CONNECTION THEREWITH."
The object of my Invention is to construct or arrange floating docks or pontoons
that they may when desirable be fitted to rise and fall in a "berth" and be swung or
rotated round at one end upon a centre post or cylinder projecting from the ground
at a slight distance from the berth. The post or cylinder is in deep water, and
when the dock or pontoon is swung a quarter of a circle and sunk to the desired
depth by letting in the amount of water a vessel can be floated in and then secured,
the pontoon with the vessel on it being then raised by the ordinary means (pumping)
until she is a little above the level of the berth; the whole is then swung round
over the berth, the vessel then being high and dry to enable repairs or other opera-
tions to be conducted.
For the purpose of this part of my Invention I form a cavity or opening say at
the tail or after end of a pontoon to fit over or around a "dolphin" pillar or cylinder
standing vertically from the ground in deep water that the pontoon may be held to
it as a fulcrum, and about which the pontoon can be swung. The pontoon I prefer
to employ is of an improved construction with air chambers at or about the centre
Pine 871

page_text: at the sides to balance it, and these and also the end chambers may be partitioned
off horizontally in order that the submerging within a berth or in shallow water
can be conducted without risk, the upper chambers being afterwards supplied with
water to sink the pontoon to the full depth before a vessel is hauled in.
The pontoon with the vessel is then lifted above the level of the berth in which
it has to be placed, and then swung round into the berth. In some cases the pon-
toon is provided with a cradle so that when in the berth the vessel on the cradle can
be hauled up a slip whose rails are arranged as a continuation of the cradle rails of
the pontoon, which can be furnished with another cradle and the foregoing opera-
tion repeated for lifting another vessel.
In this case I purpose arranging my fulcrum post or cylinder that the pontoon
may deliver a vessel on to the rails or slips provided radially, taking the post or
cylinder as a centre. There may be any number of slips so arranged, and one pon-
toon may be made available for several posts or cylinders at the deep water parts of
neighbouring repairing or building yards, in which case the recessed portion of the
pontoon when arranged around or over the post or cylinder can have stays or
retaining bars fitted to prevent it leaving the post when the swinging is taking
place, such as might happen in a tideway.
A pontoon attached to a fulcrum post or cylinder may be fitted within an ordinary
wet dock according to my Invention, and then the pontoon before or after the vessel
is upon it can be slewed round to suit the slips up which the vessel has to be
moved, supposing there are several slips arranged radially therefrom; in this case
the pivot end of the pontoon would be a fixture so to speak to the fulcrum post or
cylinder.
My fulcrumed pontoon may be made available for lifting heavy weights from
other vessels by fitting sheer legs or a crane jib or other apparatus at one end, the
lifting power being in the pontoon itself.
I have referred to providing a recess in the end of a poutoon or floating dock, but
I do not limit myself thereto as other modes of accomodating a poutoon or floating
dock to a fulcrum or pivot for the purposes of my Invention can be adopted.
My improved slip for lifting vessels off the cradle has the usual centre and side
longitudinal rail, but the double centre rails are placed further apart the full length
of the slip so as to allow another double line of rails to be laid from the top of the
slip down for the length of the vessel, which may be termed a compound slip, and
form a series of levels and rise in an opposite direction from the main slip or rails.
The cradles are also compound, the main cradle running on the outside centre rails
and the compound cradle running on the centre rails, which are laid at a series of
levels.
The upper part of the main cradle must be parallel from the wheels or rollers, and
the upper part of the compound cradle must be parallel from the upper side of the
main cradle but a little below, say 1/2 or 2 inches to have a clearance, so that in
heaving the main cradle up the slip with a vessel on it the lower part of the keel
blocks shall in all cases be clear of the upper side of the compound cradle.
The vessel now being hove up, the compound sideways must be blocked up to
the shape of the vessel's bilge, but the 1/2 or 2 inches clear; the main and com-
pound cradles are then connected together and the engine power walked back, both
cradles going down the slip; when about 2 feet has gone, the compound cradle
begins to take the weight of the vessel off the main cradle, and a further distance
of four feet the compound cradle has got the full weight of the vessel and lifted her
about inches clear of the main cradle; the main cradle is then disconnected
one keel block at each length, two at the fore end, and the bilge coads clear of the
vessel's bottom; the main cradle is then lowered down the slip as usual and pre-
pared for another vessel; the vessel is then hove along the rails to the top of the
slip and repairs commenced.
When a vessel has to be launched the compound cradle with the vessel on it must
be hove out again, the main cradle hove up and connected to the compound cradle,
then the blocks on the main cradle at the sides must be fitted and 1, or 2

page_text: inches clear, then both cradles are hove to the top of the slip, the main cradle taking
the weight of the vessel, the compound cradle being clear the 11/2 or 2 inches is
disconnected, and the main cradle with the vessel on it is lowered down the slips in
the usual way on to the pontoon the reverse of the lifting proceedings.
The engine and machinery for heaving up the vessel and cradle is fixed upon
wheels running on rails across the upper ends of the ways, and will do for all the
slips.
The compound cradle I fit in the centre for slips now constructed, and I place the
compound cradles and rails outside the present longitudinal ways without any
alteration. The rails forming a series of levels would be bolted to the present
longitudinal ways, a new set of keel blocks only being required.
In heaving the vessel and cradle out on to the compound rail if the lift is not
sufficient on account of the small elevation or angle, the two cradles can be made to
act together, the weight of the vessel being then borne by one cradle while the other
gets into position again for the next lift, and so on until the vessel is lifted the
desired height.
In some cases to lengthen the pontoon I add 25 or 50 feet lengths at the fore
end, and when not required they form a short pontoon suitable for small vessels.
I also make a swinging twin dock capable of lifting two vessels, and by having
a joint at one side of the centre it can be opened out to make a long pontoon.
Greased ways may be used for the compound cradle.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Robert Turnbull in the Great Seal Patent Office on the 14th March
1879.
ROBERT TURNBULL, of Derby Terrace, South Shields, in the County of Durham,
Naval Architect. "IMPROVEMENTS IN THE CONSTRUCTION AND ARRANGEMENTS OF
FLOATING PONTOON DOCKS, AND IN THE LONGITUDINAL WAYS AND CRADLES FOR
HEAVING-UP SLIPS TO BE USED PART IN CONNECTION THEREWITH."
The object of my Invention is to construct or arrange floating docks or pontoons
that they may when desirable be fitted to rise and fall in a "berth" and be swung
or rotated round from one end upon a centre post (dolphin) or cylinder projecting
vertically above from the ground at a slight distance from the berth. The post or
cylinder is in deep water, and when the dock or pontoon is swung about a quarter
of a circle it can be sunk to the desired depth by letting in the amount of water; a
vessel can then be floated in and there secured, the pontoon with the vessel on it
being then raised by ordinary means (pumping) until she is a little above the level
of the berth; the whole is then swung round over the berth, the vessel being then
high and dry for repairs or otherwise.
In some cases the pontoon is provided with a cradle so that when in the berth
the pontoon is allowed to sink by opening the valves; the vessel on the cradle
can be hauled up a slip whose rails are arranged as a continuation of the cradle
rails.
The pontoon can then be furnished with another cradle and the foregoing opera-
tion repeated for lifting another vessel.
In this case I purpose arranging my fulcrum post or cylinder that the pontoon
may deliver a vessel on to the rails or slips provided radially, taking the post or
cylinder as a centre. There may be any number of slips so arranged, and one pon-
toon may be made available for several posts or cylinders at the deep water parts of
neighbouring repairing or building yards, in which case the recessed portion of the
pontoon when arranged around or over the post or cylinder can have stays or
retaining bars fitted to prevent it leaving the post when the swinging is taking
place, such as might happen in a tideway.
A pontoon attached to a fulcrum post or cylinder may be fitted within an ordinary
wet dock according to my Invention, and then the pontoon before or after the vessel
is upon it can be slewed round to suit the slips up which the vessel has to be
moved, supposing there are several slips arranged radially therefrom; in this case
the pivot end of the pontoon would be a fixture so to speak to the fulcrum post or
cylinder.
My fulcrumed pontoon may be made available for lifting heavy weights from
other vessels by fitting sheer legs or a crane jib or other apparatus at one end, the
lifting power being in the pontoon itself.
I have referred to providing a recess in the end of a pontoon or floating dock,
but I do not limit myself thereto as other modes of accomodating a pontoon
floating dock to a fulcrum or pivot for the purposes of my Invention can be
adopted.
My improved slip for lifting vessels off the cradle has the usual centre and side
longitudinal rails, but the double centre rails are placed further apart the full length
of the slip so as to allow another double line of rails to be laid from the top of the
slip down for the length of the vessel, which may be termed a compound slip, and
form a series of levels and rise in an opposite direction from the main slip or rails.
The cradles are also compound, the main cradle running on the outside centre rails
and the compound cradle running on the centre rails, which are laid at a series of
levels.
My Invention is clearly represented in the annexed Drawings, in which Figure 1,

page_text: Sheet 1, is a side elevation of a pontoon A fulcrumed to a dolphin or cylinder post
B, and with a vessel upon it within a berth C; Figure 2 is a plan of the same with
the pontoon cut short on one side.
'
The after part D of the pontoon is formed with an opening, but it may be full
ended and provided with keys or stays to fit over the dolphin if desired.
E is the ordinary high-water line, and when the pontoon is not engaged it can be
swung round a quarter circle or a half circle as to be clear of the berthi C; it can
then be sunk to the desired depth by pumping into it a sufficient quantity of water,
say to the dotted line F, for a vessel which has to be repaired or otherwise operated
upon to be drawn over it and lashed in position. The water is then pumped out of
the pontoon and made buoyant to lift the vessel above the water level E, the pontoon
being then swung round into the position shown.
The deck of the pontoon may be provided with rails, on which a cradle G can be
arranged so that the vessel can be hauled up a slipway H to enable the pontoon to
be used in a similar manner for the reception of another vessel.
There may be several slipways arranged radii from the dolphin B, as at I, J,
which are shown in Figure 2 with vessels upon them. By this means several vessels
can be brought into a ship-repairing yard and the pontoon be available as a floating
dock, or it may be swung round to be clear of the berth C, when by removing the
keys K it can be hauled away to be used at another repairing yard for a similar
operation if desired, whether the other yard be provided with a dolphin at the
entrance or not.
I purpose making my pontoon with air chambers L, M, N, at the bow, centre, and
stern only, the latter being the larger of the three, that the pontoon can be utilized
for lifting heavy weights, such as boilers, big guns, etc., from barges or other vessels
placed near the dolphin for that purpose. This will be understood by Figures 3
and 4, Sheet 2 of the Drawings, where the pontoon has secured upon its fore part a
small vessel P carrying the inner end of a lever Q. This lever Q is supported at its
outer end on the head of the dolphin as upon a turntable R that it may turn upon
it when the pontoon is swung; the outer end Q¹ projects as a crane jib by which
the weight or weights can be held suspended. The other lever S is double, the inner
ends being attached or pivotted to the former by gudgeons T. The two legs of the
double lever are braced, and the forked ends U extend beyond the stern of the
pontoon, where they form a jib for lifting the weight or weights at each lift of
the pontoon end by the expulsion of the water from the after chambers N, the other
lever then having the links V adjusted for holding the weight suspended while the
pontoon end is again sunk for the jib to take a fresh hold of the weight for another
lift, if such be necessary. The outer end of the main lever Q is preferably slotted
to enable the links V as they are disconnected from the lift chain to be slid
along it.
In Figure 3 I have shown a big gun, say the 150 ton gun, suspended from the
lever Q, the gun having been lifted by the double lever S from the deck of the
vessel X. The outer end of the lever Q can be furnished with a crane jib suitable
for lifting light weights by the chain Y, and its tail end may be counterbalanced by
forcing water into it, the tail end being in tank form for that purpose.
Figure 5, Sheet 4, is a stern view of my pontoon with projecting cheeks Z, Z,
which with the keys K, K, embrace the dolphin B, the dotted line W, W, showing
the depth the pontoon can be lowered to outside the berth, where the dolphin is
fixed vertically in the ground.
When the weight lifting has been completed the pontoon end can be sunk suffi-
ciently to release the small vessel P after it is detached from the pontoon to enable
it, i.e., the small vessel, to be floated off along with the levers Q, S, one of which is
made lighter by the water being run out.
Figures 6, 7, 8, 9, 10, and 11 are views of my improved cradle and slipway
system.
Figure 6, Sheet 3, shows a vessel, a compound cradle, and a slipway in full length,

page_text: the slipway in stages, each stage being inclined to the fore end in a direction opposite
to that on which the main cradle slipway is made.
Figures 7, 8, 9, 10, and 11 are detail views of the slipway.
In practice a vessel is hauled over it to rest upon the main cradle G, which runs
upon rails b, b, b, b, arranged the full length of the slipway. The compound cradle
is composed of sections c, c, c, c, running upon rails d, d, d, d, arranged in stages
both inside and outside of the main cradle G, as seen in the cross sectional view
Figure 10.
The vessel is hove up to the top of the slip, the main and compound cradles are
connected together, blocks are fitted to the bilges, but with the same clearance as
the keel blocks, namely, about 2 inches, the two cradles with the vessel are then
lowered down the slip as far as they will go and hove the remainder of the distance,
the compound cradle gradually taking the weight of the vessel off the main cradle
and leaving her properly blocked ready for repairs, the main cradle being then about
4 inches clear, which cradle may be disconnected and lowered down the slipway, and
prepared for another vessel.
To launch the vessel the main cradle is hove up the slip and connected to the
compound cradle, bilge blocks are fitted as before, and the vessel hove to the top of
the slip; the cradles are then disconnected, and the vessel on the main cradle is
lowered down the slip and launched.
My pontoon may be arranged in pairs or as twin pontoons connected to a single
dolphin B, and in some cases two dolphins may be used for a single pontoon.
The dolphin B may be close to the berth or at a distance therefrom, according to
the arrangement of the berth or of the yard in which the repairing of the vessel has
to take place.
Having now described the nature of my said Invention and in what manner the
same is to be performed, I declare that I claim,-
First. The cylinder, post, or dolphin as a pivot on or from which a pontoon can
be swung and steadied, as and for the purpose described.
Secondly. The combination of a pontoon and cylinder, post, or dolphin arranged
as described in connection with a ship-repairing dock, said pontoon being capable
of a slewing motion from a shallow berth into deep water without leaving the
dolphin, to be there sunk for receiving a vessel and raised again with the vessel on
it, and be then slewed or swung into the berth again, as set forth.
Thirdly. I claim the arrangement of the cradles and their "ways," by which the
lift of a vessel can be effected, as set forth.
Fourthly. I claim the combination of apparatus by which heavy weights can be
lifted in stages by means of a pontoon, as set forth.
In witness whereof, I, the said Robert Turnbull, have hereunto set my hand
and seal, this Tenth day of March, in the year of our Lord One thousand
eight hundred and seventy-nine.
ROBERT TURNBULL. (L.S.)