Improvements in Boat Davits.
Year: 1892

page_text: Date of Application, 1st July, 1892
Comolete Specification Left, 23rd Feb., 1893-Accepted, 8th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in Boat Davits.
I, ANDREW ANDERSON, of No. 17, Erskine Road, South Shields, in the County
of Durham, Master Mariner, do hereby declare the nature of this invention to be
as follows:-
My invention relates to improvements in boat davits, and consists in mechanism
by which the weight of the boat is the operative factor in carrying the latter out
clear of the ship's side ready for being lowered or dropped.
In carrying it into effect, provide a pair of horizontal guides which are
supported in any suitable way at a convenient height above the deck. These
guides stand out in the direction of the ship's side. I prefer to support them both
by a pair of posts standing close to the ship's side. Each guide consists preferably
of a pair of bars. 1 provide a travelling arm for each guide. The length of the
arm is proportioned to the distance the boat has to be carried out to clear the
ship's side. Each arm is connected by its rear end to its guide, and a bracket or
rest is provided near the front end thereof for the arm to travel over. A horizontal
bar connects the front ends of the two arms, and is provided with blocks through
which the falls are rove. The falls are led through blocks on the inner ends of
the arms, bent on cleats on the posts and then taken to cleats fixed in any suitable
position.
A second horizontal bar is releasably supported on the two posts, and slings are
led from between it and the horizontal bar which connects the front ends of the
two arms.
The operation of my invention is as follows. When the boat is home, it hangs
inside the posts and second horizontal bar and is supported on the slings, the arms
being also back upon the guides as far as they will travel. When the second
horizontal bar is released, it drops and frees the boat. The weight of the latter
pulling on the blocks on the immer ends of the armis, projects the latter along the
guides for the length of their travel. As the inner end of each arm reaches the
end of its travel, it passes an automatic detent which locks it up against the bracket
or rest above mentioned. The boat is then clear of the ship's side and ready for
lowering, which may be effected in any suitable or well known way.
Dated this 1st day of July 1892.
PHILLIPS & LEIGH,
Agents for the Applicant."
COMPLETE SPECIFICATION.
Improvements in Boat Davits.
I, ANDREW ANDERSON, of No. 17 Erskine Road, South Shields, in the County
of Durham, Master Mariner, 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 :-
My invention relates to improvements in boat davits and consists in mechanism
by which the weight of the boat is the operative factor in carrying the latter out
clear of the ship's side, and lowering it ready for being lowered further or dropped.
In order that the invention and the means by which it is to be carried into
practical effect, may be thoroughly understood, I will describe it and them in detail,
referring in so doing to the accompanying drawings which are to be taken as part
of this Specification and read therewith.

page_text: Fig. 1 is a front elevation shewing the boat hanging inboards from the davits
and supported by the boat slings.
Fig. 2 is an end elevation corresponding as to its full lines with Fig. 1.
The dotted lines shew the boat after it has been carried out clear of the ship's
side and lowered by its own weight before the tackles are let go.
Fig. 3 is a plan omitting the boat and the tackles.
a a are a pair of duplex columns. They stand up, from the deck upon which
they are aligned near to the side rail b, being separated by a distance greater than
the length of the boat, because, with my invention, the boat moves out between
them beam on. I do not confine myself to using duplex columns, inasmuch, as
they may be single, and, in either case, of any convenient construction provided
that they will support the davit guides.
e, c are the davit guides. Each is shewn as consisting of a pair of parallel inverted
T bars standing inwards of the respective column, to which they are held by
brackets d. The two bars of a guide are at a suitable distance apart to receive the
respective davit between them. e is a duplex plummer block standing upon the
top of each column. It may be made fast to the front end of the davit guide. Its
function is to carry an antifriction roller g over which the davit rides. The guides
are held by the brackets with their front ends on a level with their respective
antifriction roller and may be horizontal or inclined upwards towards the centre
line of the ship. The latter position favours the action of the invention. In point
of length, a guide is longer than a davit. h, h are the davit stops. They are fixed
to the inner ends of the davit guides to prevent the heels of the latter being pulled
off them.
i, i are the davits. They must be long enough to carry the boat away from the
ship's side as far as is necessary for her to keep clear of it. Their connection with
the davit guides must be of such a nature that they can project after the manner of
a cantilever from the front end of them and still be held safely to them, and also
that while they do so project, they shall be held by the guides in the plane of the
latter without sagging. The devices illustrated for effecting the connection above
specified are as follows:-j, are rollers mounted upon stud axles which project
symmetrically from the sides of the foot of the davit. The two rollers on a side
are set at a proper distance from each other for the top one to ride on the top edge
of the bar while the other rides on the bottom side thereof., are a second pair
of rollers carried in the same way by the head of each davit. The bottom front
corner of the latter is rounded off in order to provide for the davit moving on to
the roller g without jumping.
Any other device for effecting the connection between davit and guide may be
adopted provided that it will fulfil the conditions specified.
Both davits and davit guides are horizontal or nearly so. They may be inclined
a little towards the water, as illustrated, but this little is included in the term
horizontal.
m is a horizontal bar which is made fast to the heads of the two davits so that
the latter must more together. nn are a pair of standing blocks and o, o, a pair of
travelling blocks together constituting a pair of double purchases or double whips.
p, p are the eyes of the bars of the releasing gear. 9, q are a pair of standing
blocks or single purchases or single whips held to the davits near their feet.
, are the respective tackles which are made fast to their respective standing
blocks n, rove through the blocks o and q, and led from the latter over antifriction
rollers, and through eyes s to cleats t on the outer columns.
It is to be noted that, for the purpose of this invention, the tackles must be led
from the blocks q, q, to fixed points in a vertical plane to the front of the positions
which the pulleys q, q occupy after the davits have been traversed out.
m² are the boat slings. They form a sort of cradle or support for the boat, by
being led under it, for the purpose of keeping its weight off the tackles. Each
one is therefore made fast by one end to the bar m, and by its opposite end to a
baru described further on. The distance along either bar between the points at

page_text: which the slings are made fast to it is about the length of the boat, and such points
on one bar are respectively opposite to those on the other or nearly so. The
figures shew the slings as crossed under the boat and their opposite ends made fast
to the bar at the end of the latter opposite to that end of the bar m from which
the respective sling is led, but this crossing is not an essential feature of the
-invention so long as the weight of the boat is kept off the tackles.
The horizontal bar a is held in a pair of staples u', one on the front or outer face
of each column. 2 is the bottom bar of staple and is pivotted to the rest.
3 is a pin which rests in a hole bored through the column, such hole being bored
at a proper height for providing that when the bar 2 is supported by it, the
respective staple shall be closed. is a detaching line. It is bifurcatted or has
a second one spliced to it. The pair of ends are made fast to the pins ³, and the
opposite one to a cleat u³.
The slings m', m³ are connected to the bar in any convenient way. I have shewn
them as eyed and hooked to the bar m and eyed and passed over pins uª standing
up from the top of the bar u. u are chains holding the bar to the columns a so
far as to prevent it being lost.
is a shoulder on each davit, and ¹ is a fixed stop standing in its path.
wis a bar pivotted at w'. 2 is a stop standing in the path of the heel of each
davit: The stop is held in that position by any suitable device such as a counter-
poise w³.
w is a cord for pulling the stop w² out of the path of the davit heel.
The rear faces of the stops and the contacting faces of the davit heels are inclined
or convexed to expedite the depression of the stops by the advancing heels.
10 is
a rest pin for the bar w.
My invention acts, and a boat hung from davits constructed according to it, is
lowered, in the following way.
The line is pulled and the pins ³ pulled out of their holes. The bar u drops
and the slings m³ fall away from the boat so that the full weight of the latter
comes upon the tackles r. The latter are held tant, preferably by having their
ends made fast to their respective cleats t. Or if instead of being made fast to
the said cleats they are held releasably in some way or other, the points at
which or the devices by which they are so held, are always in a vertical plane
to the front of the outermost position of the pulleys on the davit heels;
or, failing this they are rove through eyes s or their equivalents fixed in such a
plane.
The weight of the boat consequently pulls on the davits through the blocks
and traverses them outwards along their guides until the shoulders v bear against
♥, 4,
the stops v. As the davits are being traversed down their guides, and before the
shoulders thereon reach their stops, the davit heels trip the stops w³ which are
pulled up again behind them, so locking the davits out. At the same time the
weight of the boat makes the davits carry it out from the ship's side and lower it
till it is stopped by the tackles r. The boat may then be lowered to the water by
freeing the said tackles or dropped by means of the ordinary releasing gear.
It will be noticed that with double purchases or double whips from which the
boat is suspended and single whips on the davits, the boat can be lowered for a
distance equal to twice the traverse of the davits.
When a boat has to be taken in, the davits are traversed out and locked out.
The tackles r,r are run out far enough to allow of the boat being made fast to
them. When this has been done they are hauled in till the blocks o, o are up to
the blocks n n. Farther than this the boat alone cannot be moved in any direction.
The stops w² are then pulled out of the paths of the davit heels, and the davits
traversed in up to their stops h.
My invention does not confine me in respect of the particular tackle which is
made use of hauling the boat inboards.
I wish to point out that the horizontal bars m and u and the boat cradle may be
dispensed with, as they are not of themselves essential to my invention. When
they are so dispensed with, the standing blocks n, n are made fast to the outer

page_text: ends of the davit guides and the positions of the columns a on deck adjusted
accordingly.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. In an apparatus for lowering a boat, the combination of horizontal davits,
davit guides in or on which the davits can be traversed outwards, a standing pulley
or its equivalent upon or near the foot of each davit, and tackles rove from the
boat falls through the said standing pulleys or their equivalents and held fast to
eyes or cleats standing in a vertical plane to the front of the outermost position of
the said pulleys, as set forth.
2. The hereinbefore described method of using the weight of the boat as the
operative factor in carrying the boat away from and clear of the ship's side and
lowering it, as set forth.
3. The combination of horizontal bar made fast to the front ends of horizontal
traversing davits, a second horizontal bar releasably held, and slings from one
to the other adapted to form a removable cradle or support for the boat, as set
forth.
4. The combination of davits, davit guides in or on which the said davits can
be traversed outwards, and releasable automatic stops adapted to engage behind
the heels of the said davits when they have been so traversed outwards, as set
forth.
5. The combination of horizontal davits, davit guides in or on which the said
davits can be traversed outwards, pulleys on or near the davit feet through which
the boat falls are rove, eyes or cleats in a vertical plane to the front of the outer-
most position of the said pulleys, a horizontal bar made fast to the front ends of
the davits, a second horizontal bar releasably held, slings from one bar to the other
forming with them a removable cradle or support for the boat, and releasable
automatic stops adapted to engage behind the heels of the said davits when they
have been traversed outwards, as set forth.
6. The combination of horizontal davit and davit guide whereby the former
can be traversed along the latter as far as is necessary to carry the boat away from
the ship's side and be then held firmly to the davit guide without sagging, as set
forth.
Dated this 23rd day of February 1893.
PHILLIPS & LEIGH,
22, Southampton Buildings, Chancery Lane, W.C.,
Agents for the Applicant.