Improvements in Apparatus for Raising and Lowering Boats.
Year: 1888

page_text: Improvements in Apparatus for Raising and Lowering Boats.
I, WILLIAM JOHN GELL, of 3 West Seacombe Terrace, Seacombe, in the County of
Chester, Master Mariner, do hereby declare the nature of this invention to be as
follows:
Among the objects of this invention are, to enable the davits to take in succession
several boats arranged one after the other on a gangway such as is described in my
previous specification No. 14365 of 1886 or otherwise, and to enable the block tackles
to always stand vertically over the boat no matter whether the boat is in its exact
position on the chocks or otherwise.
In place of having an ordinary davit I form the davit with its upper portion as a
horizontal bean of rectangular or other equivalent shape. Upon this beam a carriage
runs by means of pulleys and with side sheaves or friction pulleys to prevent the sides
of the carriage binding on the beam. The carriages on the pair of davits are united
by means of a spar swivelling on each. The carriages carry the block tackle for use
with the boat, but one end of the block tackle is fastened to an eye-bolt or shackle on
the beam and the hauling end passes over guide pulleys down to the deck; the
carriages from which the block tackle are suspended being free to run on the bean
and thus accomodate themselves to the position of the boat, there is much less difficulty
in getting out a boat than there otherwise would be. Furthermore where two boats
are arranged gunwale to gunwale on the deck or other portion of the ship, the inner
boat can be raised up and passed over the outer one.
Dated this 23rd day of March 1888.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool,
Agents for the Applicant.

page_text: Improvements in Apparatus for Raising and Lowering Duaus.
1. WILLIAM JOHN GELL, of 3, West Seacombe Terrace, Seacombe, in the County
of Chester, 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 ascer-
tained in and by the following statement :-
This invention relates to certain improvements in apparatus for raising and
lowering boats from a ship's deck, quay, pier or the like.
The main objects of these improvements are:-
1st. To provide an apparatus in which the block tackles shall stand vertically over
the boat, whether the latter is in its exact position on the chocks or otherwise and
independently of the position of the davit heads; and,
2nd. To so construct the apparatus that the davits are enabled to swing a number
of boats overboard in succession, the boats, in this case, being preferably arranged
gunwale to gunwale upon a gangway such as described in my previous specification
No. 14365 of 1886.
The invention may be described by reference to the accompanying drawings,
in which
Figure 1 is a front view of the apparatus showing its position when the boat is
suspended centrally between the davits.
Figure 2 is an end view, showing the position of the apparatus when the boat is in
its place upon the chocks.
Figure 3 is a similar view showing the position assumed when the boat is swung
overboard.
A A are the hoats, which, in Figure 2, are shown arranged gunwale to gunwale
upon chocks B, which slide upon a gangway B1 as before described. The chocks B
are similar to those described in my previous specification No. 1436586. They are
hinged at their centre and the front portion falls down, as shown in dotted lines in
Figure 2, as soon as the boat has arrived at its dotted position as shown in the same
Figure this position being identical with that shown in Figure 1. By arranging and
mounting the boats as above described they can be run out to the ship's side and
launched in succession, each pair of empty chocks being pushed off the gangway by
the following pair. The davits are preferably provided with a cam arrangement C₁,
such as described in my previous specification No. 661888, whereby they can swing
outwards by the weight of the boat alone.
The davit head D is formed of a horizontal beam, which is preferably rectangular
in cross section, though it may be of other suitable shape. Upon the davit head D
is mounted a carriage E, which is capable of running thereon by means of pulleys or
runners e e. The cheeks of the carriage extend downwards on each side of the beam
and are provided at their ends with a suitable attachment for the tackle block F.
Friction pulleys el are also provided which prevent the cheeks from binding on the
sides of the davit head. In the drawings each pulley is shown mounted between
flanges on the outside of the cheek, a hole being made in the latter through which
the rim of the pulley may protrude and bear against the davit head. Other convenient
modes of mounting may, however, be provided. A shackle may also be secured to
each end of the carriage, to which a rope may be attached when it is desired to
restrain the movement of the carriage, or to move it independently of the movement
of the davit head.

page_text: The carriages on the two davit heads are preferably connected by means of a
spar G which swivels at each end upon a pin e² secured to the top of said carriage.
The spar G is similar to that described as connecting the davit heads, in my previous
specification No. 66188. The object of the spar G is to keep the carriages always at
the same distance apart, independently of the position of the davit heads. This
distance corresponds to that between the boat blocks F, and therefore the tackle H
between the blocks F F always stands vertically in the fore and aft direction when
the boat is in the positions shown in Figures 2 and 3.
In other directions and positions, the tackle is kept vertical by the following
arrangement:
The fixed end of the tackle H is attached to a shackle or eye bolt h on the end of
the davit head. The running end, after being reeved through the blocks F F¹ is
passed through a guide block F³ secured to the opposite end of the davit head.
Thence it passes through an eye bolt F3 or other guiding device, down to the deck.
The carriage E is thus free to run upon the davit head, and accomodate itself to
the various positions of the boat, the tackle between the blocks F F being always
kept vertical, independently of the position of the boat or davit heads. There is thus
much less difficulty in getting a boat in or out than would otherwise be the case.
In Figures 1 2 and 3 the carriage is shown in three different positions on the
davit head. In each case there is the same length of tackle paid out. A glance at
these Figures will show that with the above arrangement of block and tackle, no
matter what the position of the carriage on the davit head, the distance between the
blocks F F remains practically the same. This is a further advantage of the improved
apparatus.
Where two boats are arranged gunwale to gunwale as in Figure 2, the inner boat
can be raised up and passed over the outer one if desired, provided that the height
of the davits and the length of the davit heads are sufficient to permit of this
operation.
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. A boat raising and lowering apparatus, in which the boat blocks of each davit
and the tackle between the same are suspended from a carriage capable of running
upon a straight approximately horizontal davit head, the carriages on the two heads
being preferably connected by a swivelling spar above the same, and the fast end of
each tackle being led from the lower boat block and attached to the outer end of
the davit head, while the running end of said tackle is passed from the said block
over a guide pulley secured to the opposite end of the davit head, substantially as
and for the purposes set forth.
2. In a boat raising and lowering apparatus the combination of a straight
approximately horizontal davit head D, and of a boat suspension carriage E capable
of running upon the top of said head and provided with friction rollers e¹ el bearing
against the sides thereof, substantially as set forth.
3. The boat raising and lowering apparatus as a whole, constructed substantially as
shown and described.
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