Improvements in Boat Lowering and Disengaging Gear.
Year: 1893

page_text: Date of Application, 14th Sept., 1893
Complete Specification Left, 14th Jun, 1894-Accepted, 14th Sept., 1894
PROVISIONAL SPECIFICATION.
Improvements in Boat Lowering and Disengaging Gear.
I ALEXANDER MCKINLAY, Commander, British India Steam Navigation
Company, of 13 European Asylum Lane, Calcutta, East India do hereby declare
the nature of this invention to be as follows:-
This invention relates to improvements in boat lowering and disengaging gear
and has for its object to disconnect the boat lashings and chocks simultaneously, the
davits being adapted to act automatically by the weight of the boat and a breast
provided to steady the boat when swinging out and being lowered, and boat falls
so arranged as to disconnect simultaneously by moving a lever as hereinafter
described.
The davits which are made of iron and placed sufficiently far apart for the boat
to swing out between them, have two sockets like the ordinary davits, one for the
keel to ship in and another as a band or journal higher up to support the davit.
The lower sockets are placed slightly nearer each other than the upper one to
From above the
assist the davits to swing out from the inclination of the davits.
upper socket or band the davit curves inboard until it is almost above the centre
of the boat on the skids, then it curves fore and aft which forms the jib to the end
of which the tackle for the boat is attached. When swinging a boat out, the
davits only turn half round, through their being in a position with the jib fore
and aft.
A stay is clamped on to the davits at the top of the first curve and above the top
socket or clamped at the top of the curve and fitted with a bracket above the upper
socket. The bracket clamped on the davit above the upper socket has a tie from
the outer end to a position 3 feet above the socket, and two arms projecting out
It will
from the davit on each side with stay to the outside end to strengthen it.
be of the required length to bring the stay that supports the davit perpendicular
for the breast to travel in.
The breast is made of iron, one end of which is fitted with rollers to travel up
and down the stay. The other end has holes for the fall to pass through, well
rounded with flanges and, through this end being weighted, it rests on the top of
the lower fall-block. The boat falls pass through the holes, and as the boat is
lowered, it keeps its position on the top of the block, the other travelling down on
the stay until it reaches the bracket when it stops, and, by a tie that leads from the
portion of the breast attached to the stay, the breast will keep horizontal, acting
always as a support to steady the boat while being swung out and lowered.
The chock can be made double or single with exactly the same gear attached and
made of iron with flanges of wood or iron on the top, and can be either made solid
or simply outline supports, the design in each case being the same, except the clamp
on the skid which only requires to be of sufficient size for the support to pass up
and down through it. The pin for the chock to revolve on is fitted to the skid.
The skid has a clamp on the side at the position of the chock with an opening for
the chock to pass up and down between the clamp and the skid revolving on the
pin. The pin is fitted through the clamp chock and skid in a position at the inside
of boat's keel for the chock to turn on. The inboard side of chock is resting on the
skid in the ordinary way, outside chock or a little inside the centre of the double
chock, the pin is fitted which supports that portion and on which the chock turns
over when the bar is relieved. The bar is fitted to the skid by an eye-bolt or two
eye-bolts with a pin with sufficient play to drop perpendicularly when relieved, and
fits in a groove in lower part of the chock and skid supporting chock and rest: on

page_text: the lever. The lever is fitted with a pin to the side of the skid across, in the same
direction as the skid, to take the end of the bar slightly inside of the pin, and the
other end fits over a tumbler. The tumbler is fitted to two eye-bolts with a pin
to the side of the skid sufficiently slack to turn over when relieved by the clutch.
The clutch is fitted to the skid by two brackets working on a pin, one end being
attached to the tumbler, the other end, when the gear is connected, fitted to the
lock. The lock constitutes two small brackets fitted to the platform with holes to
fix a pin in, to lock the clutch. The chock can be either entirely working or the
inside and support for the keel stationary and only the outside chock working.
The boat can be fitted with two chocks as described or only one and fitted with
rests for the keel at each end.
The two end rests are made of iron, and can be made solid or merely outline
supports. The skid has a clamp on the side at the position of the rest with an
opening for the rest to turn round on the pin. The pin is fitted through the clamp
rest and skid in a position at the inboard side of the keel. Inside end of the rest
rests on the skid with a chock, the top of which has a flange, and against the boat
which keeps the rest steady while the boat is in an upright position, but when it
heels from the chock the rests will tumble over.
The tumblers for boat lashings are made of iron and fitted to brackets on the
lower side of the skid. A lanyard of wire-rope is attached to the lower end of the
tumbler, the upper end hooks on to the boat lashings, the tumbler is well balanced
that, when the lanyard is let go, it will fall back, and disconnect itself from the
boat lashings. The lanyards are fitted with screws or lashings to adjust the exact
tightness required, to have equal weight on the two lanyards at each respective end
when joined together and led to a lever with a cross piece at the end of the lever
working in a socket or two sockets fitted with two arms, one in the same direction
as the lever and the other in the opposite. These arms have a hole in each end for
the lanyard to be attached and a half round on each one underneath and the other
on the top for the lanyards to fit over when connected. The arms and lanyards
are of such length that with the lever in one direction will give sufficient length to
the tumblers to disconnect and in reversing its position they will be sufficiently
tight to be connected. By pushing the lever forward or aft connects or disconnects
the tumblers.
The lower boat-fall block fitted with guards on each side over the sheave to
prevent the fall getting off the sheave when the vessel is rolling with heavy weight
on the breast.
•
The falls will be either wire or rope with wires, the fall from the upper block
is led through a block at the curve on the davits, and thence across inboard through
another block to two small hand winches, one for each fall, close together, beside the
boat at the midship chock. The winches fitted with hand-brakes, the hand lever
for brakes sufficiently weighted to suspend the boat full of people.
The tumblers for disconnecting boat falls are the same as those for boat-lashings
with the exception that the brackets for the tumblers are in one. The lever for
the lanyards is fitted in the centre of the boat attached to a thwart or fixed to the
bottom, and is of the same description as the lever for boat lashings.
A tumbler is fitted the same as the others inboard of the centre chock and the
lanyard from it leading to the boat-lashing lever. On the span that is stretched
between the two davits a slip rope is led, one end set up with the lashing, the other
over the tumbler which acts against the boat falls and steadies the davits and
becomes disconnected simultaneously with the boat-lashings.
To get a boat into the water with boat-falls, in ordinary way, hand tight. With
the chock and rests higher than the skid all that is necessary to swing the boat out
and lower it over the side, is to let go the clutch when the tumbler drops over and
disconnects the lever, the lever the bar, and the bar the chock, the chock and the
rests will tumble over bringing the weight of the boat on the davits and, as they
act automatically, by the weight will swing outwards. When the boat is outside
of the vessel's side ease the brakes on the winches which lowers away, another man

page_text: in the boat can disengage the tackles whenever he chooses by letting go the lever
in the centre of the boat. All the tumblers will be so nicely balanced that very
little weight will be on to the lever. With these appliances nothing should prevent
one man at each boat, to have all the boats on board of a vessel swung out and
lowered into the water, in any ordinary weather, in less than a minute and a half.
The boats will swing bodily out, and the breasts will maintain them in position and
prevent them from being stove in against the vessel's side however much she is
rolling.
Dated this 14th day of Contember 1902
A. MCKINLAY,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Boat Lowering and Disengaging Gear.
I, ALEXANDER MCKINLAY, Commander British India Steam Navigation
Company, of 13 European Asylum Lane Calcutta, East India, 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 boat lowering gear, and has for its principal object to
enable the boat to be swung outboard automatically by the effect of its own weight,
and the invention comprises davits swinging on outwardly inclined axes and having
jibs so formed and directed as to cause the boat to be carried outboard at both ends
simultaneously and with a slight continuous falling movement of the boat in passing
from the position of rest on the chocks to the outboard position ready to be
lowered away so that the swinging of the boat outboard is performed automatically
by virtue of the weight of the boat itself.
The invention also comprises mechanism whereby the boat lashings may be
readily released, a special construction of chocks adapted to support the boat when
stowed and capable of yielding so as to allow the boat to swing outboard from its
position of rest on the chocks without first being raised therefrom, mechanism for
controlling the action of the chocks and mechanism for automatically detaching the
boat from both of the lowering tackles simultaneously after the boat has been
lowered into the water.
Reference is to be had to the accompanying drawings, forming part of this
Specification, in which
Figure 1 is an elevation of the boat lashed upon the chocks, looking outboard.
Figure 2 is a plan of the same, aud Figure 3 is an end elevation, looking fore
and aft.
Figure 4 is an elevation of the middle chock.
Figure 5 is a horizontal section, on line 1-1, Figure 4.
Figure 6 is an elevation of the trigger mechanism for releasing the middle
chock.
Figures 7 and 8 are face and edge views of the end chocks, and
Figures 9 and 10 shew the tumblers for releasing the boat lashings.
The same letters of reference indicate the same parts in all the figures.
A, A, are the davits made of iron and placed at a greater distance apart than
the length of the boat so as to allow the latter to swing bodily between them at
both ends simultaneously, the davits swinging in opposite directions simultaneously
through an arc of about 90 degrees or 95 degrees. The lower portions a of the
davits are pivoted in suitable bearings, the upper and lower bearings being so
arranged relatively to each other that the axes on which the davits turn are inclined
outboard at an angle of, say, from about five to ten degrees to the vertical, the

page_text: inclination being less the greater the weight of the boat. The upper part or jib
of each davit is so curved and proportioned that the jib-head is directly over the
centre line of the boat as it rests on the chocks and the two jib-heads are directed
towards each other and are at a slightly lesser distance apart than the points of
attachment of the boat lowering tackle to the boat.
The preferred form of the jib is first an inboard curvature and then a fore and
aft curvature assuming the davits to be in the position shewn in Figures 1 to 3, and
in order to strengthen the davit at the first bend it may be strutted, as at A'.
The boat lowering tackles C are attached to the jib heads in the usual way, the
falls c. being led from the standing blocks at the jib heads through guide blocks c¹
on the davits and through guide blocks cl attached to any suitable fixed points to
the barrels c of winches upon which they are wound, the winches being close
together opposite the middle of the boat and provided with brakes adequate to
control the lowering of the boat when fully loaded. Or the falls may be handled
or controlled by tackle in any suitable manner.
The chocks upon which the boat rests comprise a middle chock D and end
chocks E, E, all supported and pivoted on the skids F in such manner as to admit
of the oscillation of the chocks, as hereafter described. The middle chock D is
pivoted upon a horizontal axis d situated at the underside and at the inboard side
of the centre line of the boat and the chock is free to oscillate thereon only in the
outboard direction, as indicated by the arrow 1 through an arc 2 of sufficient
amplitude to bring the outer arm d' of the chock wholly below the level of the
keel of the boat so as to allow the latter to swing clear of the chock.
To admit of the boat remaining upright during this outboard motion the out-
board arm d¹ of the chock is shaped as at d" so as not to cause the boat to heel
over by opposing the movement of the keel directly the arm d¹ ceases to support
the outboard side of the boat by the chock beginning to swing on its pivot.
Instead, however, of the whole chock swinging on its pivot the inner arm d
may be fixed, the outer arm d' being made separate as indicated by the dotted
line at d
In either case the chock is retained in the upright position by a series of
successively engaging latch levers G, H, I, J. The outboard projecting part of
the base of the chock rests on the cross lever G which is the first of the series, and
is pivoted at one end g to a fixed support on the skid F the free end of the lever G
being supported by the lever H which is at right angles to the lever G and is
pivoted ath to the skid the part on which the lever G rests being at a short
distance from the pivotal axis h.
The free end of the lever H is supported in turn upon the hooked end of the
lever I also pivoted at i to the skid, the tail end of this lever being notched and
engaged by the short arm of lever J pivoted at j, whose tail end is locked by a
cross pin or other trigger which is released by the pull of a lanyard whereupon
the whole series of levers successively release each other and fall or swing as
indicated by the arrows thus leaving the chock free to oscillate on its pivot to allow
the boat to swing outboard. The end chocks E are each pivoted to oscillate on a
centre e in the same way as the middle chock. Their motion is limited in the
inboard direction by a shoulder e¹ and they support the boat on the inboard side
only so that they do not oppose the outboard swinging of the boat and no latch
lever mechanism is required for them.
The davit heads are connected by a span chain or rope K which limits the
distance that the davits can swing apart when the boat is swung outboard. To
the middle of this span chain is attached a block or eye through which is rove a
slip rope L, one end of which is made fast to a fixed point I, whilst the other end
is detachably connected to the hooked end of a latch lever or tumbler M, pivoted
to a fixed point at a distance inboard from the boat and opposite to the middle
chock. The object of this slip rope L is to tighten the span K and put sufficient
strain on the boat suspension tackle as to prevent the davits swinging with the roll
of the vessel. The tumbler M is so balanced that it tends to release the slip rope

page_text: with which it is held in operative engagement by a lanyard m attached to the tail
end of the tumbler and so connected with the mechanism for releasing the boat
lashings that the lashings and slip rope will be released simultaneously.
The boat lashings N N'are connected at both ends to similar tumblers or hooked
latch levers O O O O¹ pivoted to the skids, the tumblers being self disengaging
and held in operative engagement with the lashings by lanyards o o o¹ o¹ attached
to the tail ends of the tumblers, the lanyards o o being led through suitable guides
and connected together, and the lanyards o' of being also connected together and
each continued as one to segments of a drum P or other suitable device operated.
by a lever handle p which is locked by a pin pl and whereby the lanyards.
connected to both lashings N N' may be simultaneously tautened and released. On
releasing lever the lanyards are slacked, the tumblers O O' become disengaged
from the boat lashings at the same time that the lanyard m controlling the slip rope,
tumbler M and which may be spliced as shown to one of the lanyards o o' or
otherwise controlled by the same device P, is also set free.
Thus to lower the boat into the water in the ordinary way with the boat falls.
hand tight, the chocks being higher than the skids all that is necessary to swing the
boat out and lower it over the side is to release the lashings and slip rope, and then
to release the series of chock retaining levers whereupon the weight of the boat.
will come upon the davits which being pivoted on an outwardly inclined axis will
cause the boat to swing outboard bodily as shown in dotted lines in Figure 2.
Then by easing the brakes of the winches controlling the lowering gear the boat
can be lowered away.
The mechanism for disconnecting the boat from the lowering tackles C consists
of oppositely directed hooked tumbler levers R pivoted in a fore and aft direction
in brackets fixed to the bow and stern parts of the boat.
The loop attached to the lower blocks of the tackles engages with the hooked
ends of the tumbler levers which are retained in engagement with the tackles by
the long arms of the tumblers being connected by lanyards to oppositely directed
drum segments s carried by an axis mounted at the middle of the boat and operated
by a lever handle t which is locked by a pin u. The parts are made of sufficient
strength to maintain the connection of the tackles with the tumblers under the
strain due to the weight of the boat and its load and the tail ends of the tumblers
preponderate so that on releasing the levert the tumblers unhook themselves
automatically from the tackles.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is :-
1. In boat lowering gear, mounting the davits to swing upon axes inclined
outboard at such a distance apart, the davit jibs being of such form and so directed
towards one another as to carry the boat between them at both ends simultaneously,
the inclination of the axes producing a slightly descending motion of the boat in
swinging outboard so as to render the action in this direction automatic by the
weight of the boat, substantially as specified.
2. In combination with davits mounted on outwardly inclined axes and adapted
to effect the automatic outboard swinging of the boat, as specified, chocks or
cradles adapted to yield to the outboard descending motion of the boat and
mechanism for locking the same in position to support the boat.
3. In combination with davits adapted to cause the boat to swing outboard
automatically, the chocks pivoted upon horizontal axes in such manner as to allow
them to yield to the outboard descending motion of the boat, and mechanism for
locking the chock or chocks in position to support the boat, substantially as
specified.
4. The combination, with a chock mounted to turn upon a horizontal axis so as
to yield to the outboard motion of the boat, of a series of consecutively interlocked
latch levers adapted to retain the chock rigidly in position to support the boat, the

page_text: levers so supporting each other as to multiply the effect of the leverage and enable
them to be released by a very slight effort to set free the chock whilst under the
strain due to the weight of the boat, substantially as specified.
5. The combination, with the boat lashings, of a connected system of tumbler or
latch lever mechanisms and lanyards or equivalent connections, substantially as
described, for simultaneously releasing the lashings at both sides and ends of the
boat, as described.
6. The combination, with the davits mounted on inclined axes and adapted to
swing the boat outboard automatically, as described, of a span connecting the davit
heads and limiting their outward swing and of a slip rope or tackle for hauling
taut the span and boat lowering tackles so as to prevent the davits swinging with
the rolling of the vessel, as described.
7. The combination of the connected system of lashing releasing mechanism and
of the span tightening slip rope or tackle with a single tumbler lever or equivalent
releasing device for.freeing simultaneously the lashings and davits, as described.
of June 1901.
Dated
A. MCKINLAY,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.