provements in Boat Davits and parts connected therewith.
Year: 1899

page_text: Date of Application, 2nd Dec., 1899
Complete Specification Left, 21st May, 1900-Accepted, 7th July, 1901
PROVISIONAL SPECIFICATION
Improvements in Boat Davits and parts connected therewith.
I, JAMES HAMILTON, of Ardedynn, Kelvinside, near Glasgow, Lanarkshire,
Ship Builder and Engineer, do hereby declare the nature of this invention to be
as follows:-
The objects of my invention, are to so construct and arrange rocking davits,
and the tackle connected therewith, that the weight of the boat may be utilized
to assist in the operation of rocking the davits, and swinging the boat away from
the ship's side, preparatory to lowering the boat, and to provide means whereby
the weight of the boat may be transferred from supporting chocks onto the
falls, without hauling on the tackle of the falls in order to lift the boat from
the chocks.
Now according to my invention I employ davits of curved formation; the
lower end of each davit is pivotted upon a support located near the side of the
ship, and below the level of the deck, upon which the boats are to be carried.
The pivots about which the davits are capable of rocking are arranged so that
the davits may rock away from, or towards the vessel. The davits are arranged
having their concave surfaces facing the sea.
At the head of each davit a wheel is mounted, and passing over this head-
wheel is a leading cord, to which the upper blocks of the boat tackles are con-
nected. The leading cord passes to the lower part of the davit, by way of guide
wheels mounted upon the said davits, passing from the lowest guide wheel to
the side of the ship where the end is secured.
When the davits are in their vertical positions, the weight of a boat upon the
leading cord, tends to draw. the lower part of the davit towards the fixed end
on the ship's side, thereby tending to rock the davit about its pivot, and swing
the head over the side of the vessel.
In order to prevent the davits from swinging out, and also to control their
travel, I provide a tackle, one block of which is attached to the side of the ship
on deck, and the other has a ring in it from which pennants are led through
leading blocks to the upper part of each davit where they are made fast. By
slacking out these tackles, the davits can rock outwards, and must both go
together thus preventing strain coming on the span between the davit heads, and
by hauling upon them the davits can be brought inwards, towards their vertical
and normal positions.
In order to enable the port davits to be rocked outwards, in the case when the
vessel has a list to starboard, it may be necessary to use force to put the boat
out and for this purpose tackles are provided between the lower ends of the
davits and the side of the ship, and the same tackles are available for keeping
the davits out when the ship is rolling or for controlling the travel when the
davits are being brought inwards. To provide for the upper blocks of the boat
tackle being kept in position when hauling up the boat, an eye is fitted on the

page_text: leading cord, so that the block can be hauled up close to the wheel on the davit
head and kept there by passing a hook into the eye.
I will now proceed to describe suitable means whereby the weight of the boats
may be transferred from the supporting chocks onto the falls, without hauling
on the tackle of the falls in order to lift the boats from the chocks.
With these objects in view, I divide the boat cover stretcher (which extends
longitudinally along the boat) about centrally and transversely, and I provide
the outer ends of the two parts with iron shods, or hooks, which engage with
ring bolts in the bow and stern respectively, and when the boat rests on the
hinged or other supporting chocks, the adjacent ends of the divided boat cover
stretcher are supported and held up by suitable support or supports which may
be readily removed when required, the adjacent ends of the stretcher being also
provided with tackles, whereby they may be drawn down.
Upon, and at a short distance from the outer hooked end of each of the
stretcher parts, there is a cleat or hook from which a connection (such as a rod
or wire rope) extends upwards where it is fixed to the davit near the head, thus
each stretcher part forms a lever, the connection with the davit forming the
fulcrum.
The boat is further connected with the davit falls in the usual manner.
In order to clear away the boat, the cover is stripped off, and the slip links
on the gripes holding the boat down to the chocks are released. The falls at this
stage are supposed to be as they were left, when the boat was hoisted, that is,
hand slack. Supposing the boat is to be got out by 3 men, which can readily be
effected by means of my invention, two men enter the boat, remove the supports
of the levers and haul down simultaneously by means of the tackles the free
ends of same, thereby lifting the boat a short distance while the other man hauls
over the boat chocks onto the deck, and the weight of the boat and its contents
are then carried by the falls. The men in the boat then ease up the levers until
the entire weight of the boat is supported by the leading cords. The levers can
then be released from the supports and passed on deck, and when this is done
the controlling tackle is slacked up allowing the davits to move out with the boat
over the ship's side as before described.
Dated this 2nd day of December 1800
BREWER & SON,
London & Leeds, Agents for the Applicant.
Improvements in Boat Davits and parts connected therewith.
I, JAMES HAMILTON, of Ardedynn, Kelvinside, near Glasgow, Lanarkshire,
Shipbuilder and Engineer, 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, that is to say:-
The primary object of this invention is to facilitate the hoisting out of ships'
hoats, and to render this operation capable of being effected in a shorter time,
and with the employment of less labour than heretofore. To this end my present
invention refers to the arrangement of rocking davits and the tackle connected
therewith, whereby the weight of the boat may be utilized to assist in, or to
effect the operation, of rocking the davits, and swinging the boat carried thereby
away from the ship's side, preparatory to lowering the said boat.
Such an arrangement and construction for effecting the results above stated,
may, when desired, be advantageously employed in conjunction with the means

page_text: for raising the boat off the chocks upon which they normally rest, the latter
means forming the subject of a patent granted to myself dated 15 June, 1899,
No. 12494.
In order that my invention may be readily understood, I will describe
same with reference to the accompanying drawings.
Figure 1 shew's in side elevation, a boat carried from davits which are capable
of being rocked, or are assisted in such rocking by the weight of the boat,
according to my, said invention.
Figure 2 is a plan view of the parts shewn at Fig. 1.
Figure 3 is a sectional end view of the boat, davits, and connections.
Figure 4 is a sectional plan view of a part taken about the line a-y of Fig. 3.
Figure 5 is an elevation of a. detail hereinafter mentioned, and drawn to a
larger scale than the previous figures.
Similar letters of reference refer to like parts in the several figures of the
drawings.
Now according to my present invention, I employ davits A of preferably curved
formation, the lower end A of each davit being pivotted upon a support located.
near the side of the ship, and below the level of the deck upon which the boats
are to be carried. The pivots about which the davits A are capable of rocking,
are arranged so that the heads A2 of the davits may rock away from, or towards,
the vessel. The davits A are arranged having their concave surfaces facing the.
sea.
At the head A2 of each davit A, a wheel B is mounted and passing over this
head-wheel B is a leading cord C, Fig. 3, to which the upper blocks D) of the
boat tackles are connected. The leading cord C passes to the lower part of the
davit, by way of guide wheels E E¹ mounted upon the said davits, the cord C
passing from the lower guide wheel E to the side of the ship where the end
is secured.
By this arrangement, when the davits are in the position shewn, and the
supporting chocks G are removed so that the weight of the boat is carried by the
boat tackles, the pull upon the leading cord tends to turn the davits about their
pivots, and to swing the heads A2 thereof over the side of the vessel.
In order to control the outward travel of the davits, and to ensure both of the
latter moving equally, I provide a tackle best seen at Fig. 2, where a cord or
flexible connection H is fixed to each davit, and passing through a block H
fixed to the deck, the ends of the cords H being both connected to a shackle H³,
carried by a block H³, the latter being connected by the tackle II to a block H
fixed to the deck. By slacking out the tackle H, the davits can rock outwards,
and must both go together, thus preventing strain coming on the span between
the davit heads, such as the rod or wire A³, Fig. 1. Obviously by hauling on
the tackle H the davits will be brought inwards into the normal positions as
shewn in the drawings. A* A' are guy ropes connected to the heads of the
rocking davits, and extending to the deck, where the ends are fixed to a point on
the deck or other part, Fig. 3, but in positions somewhat near or above the axis
of the davits, so that lateral strains upon the davits receive support, and friction
of the davits in the slots in the boat deck is prevented. The guy ropes A+ may
be fixed to the deck with tension adjusting screws.
In order to enable the port davits to be rocked outwards, in the case when
the vessel has a list to the starboard, it may be necessary to use force to put the
boat out, and for this purpose, I provide tackles J. Fig. 3, between the lower
parts of the davits, and the side of the ship, so that by hauling on these
tackles J, the davits may be forced outwards, and moreover the same tackles are
available for keeping the davits out when the ship is rolling, or for controlling the
travel when the davits are being brought inwards.
As an auxiliary to, or in some cases instead of using such tackle J, I fit each
davit with a pivotted pawl K, engaging with a ratchet toothed rack K¹ fixed to the

page_text: deck, so that the davits are automatically prevented from accidentally swinging
inwards.
The said ratchet and pawl device is also of use when hauling up the boats by
the falls, as it should then be in engagement and prevent the davits being rocked
inwards by the pull upon the boat tackle. The pawl K is lifted out of engagement
when the davits are to be rocked inboard.
The ratchet racks K' are conveniently formed in a piece with the steel castings
forming the slots in which the davits rock.
In the drawings I have shewn, each davit head A³ fitted with a second wheel
or sheave, B over which the hauling lines of the boat tackles pass, so that the
said hauling parts of, the boat tackles do not pull or hold the said tackles near the
ship's side, when the upper blocks 1) may have descended a short distance from
the davit heads.
As previously stated, the herein described arrangement and devices may be
conveniently and advantageously employed in conjunction with the means
described and claimed in the specification of my prior patent, No. 12494/1899
whereby the weight of the boat may be transferred from the supporting chocks G,
onto the boat tackle without hauling on the latter, in order to lift the boats from
the chocks.
In the drawings accompanying the present specification, I have illustrated a
form of the boat raising devices which have been fully described in the said
Specification No. 12494/1899, and which therefore do not now require further
description.
In order to clear away the boat when the said devices, described in Specifica-
tion No. 12494/1899 are employed, the cover is stripped off, and the slip links
on the ordinary gripes holding the boat down to the chocks G are released.
Supposing the boat is to be got out by three men, which can readily be effected
by means of my invention, two men enter the boat, remove the supports of the
levers L, and haul down simultaneously say by means of tackles, the free ends
of same, thereby lifting the boat a short distance, while the other man hauls
over the boat chocks G onto the deck, and the weight of the boat and its contents
are then carried by the falls. The men in the boat then ease up the levers L
until the entire weight, or a portion of the entire weight of the boat is sup-
ported by the leading cords C. The levers can then be released, by means of the
slip link connection shewn at Fig. 5, from the supports, and passed on deck.
It will be understood that although this is an advantageous means of trans-
ferring the weight of the boat from the chocks to the boat tackles, yet I do not
limit the employment of my present invention to the combination with such
means, and therefore other means may be adopted if desired, such as hauling on
the tackle of the falls, and so lifting the boat, after which the leading lines of the
said tackle may be secured temporarily to the davits while the latter are rocked
by the weight of the boat acting through the leading cord C.
Should the vessel have a heavy list and no considerable rolling motion, the
tackles can be used as aforesaid to assist if necessary in hauling the davits
outboard, but if there is rolling motion, it is only necessary to watch the roll,
and ease away the tackle H at the right moment, so that except in the case of the
ship having a considerable list in still water, the weight of the boats even on
the high side of the ship will automatically rock the davits, and thereby become
placed over the side of the vessel when the controlling tackle is eased as previously
stated.
My invention in connection with pivotted or hinged davits, presents consider-
able advantages in practical use, thus for example, it will be noticed that the
lower part of the davit is well out and does not interfere with valuable space
below the boat deck, and by my invention, when the davit head and axis are in
the same vertical line, or even when the head is more inboard than the axis, the
weight of the boat will pull the davit over the dead centre, and overcome the
leverage tending to keep the davit inboard.

page_text: Having now particularly described and ascertained the nature of this
invention and in what manner the same is to be performed, I declare that what
I claim is:
-
1. In hoisting out ships' boats, and in connection with davits hinged at their
lower ends so that they may be turned on such hinges and the davit heads be
brought over the ships' side; suspending the boat from such davits by leading
cords, each passing over a sheave or pulley at each davit head, and over guide
pulleys on the davits, the ends of the leading cords being secured to fixed parts
of the ship, whereby when the weight of the boat is brought upon such leading
cords, the said weight hauls over. or materially tends to turn the davits about
their hinges, and places the boat (the controlling tackle being eased) automatically
over the ship's side, substantially as described:
2. In hoisting out ships' boats, the combination with davits capable of being
turned about hinges to bring their heads over the ship's side; of leading cords
by which the boat tackles are carried, the said cords passing over pulleys on the
davits' heads, over guide pulleys on the davits, and being secured to the structure
of the ship, whereby the weight of the boat when brought upon the said leading
cords, rocks, or materially tends to rock the davits outboard, tackle extending
between the davits and the ship structure, to assist the outward movement, or
control the inward movement of the davits, pawls on the davits normally engaging
fixed ratchet racks on deck to support the davits against backward motion, and
tackle for hauling the davits inboard or controlling the outward motion, substan-
tially as described.
3. In hoisting out ships' boats, the use and construction of davits capable of
being turned about hinges to bring their heads over the ship's side, suspending
the boat tackles by leading cords passing over pulleys on the davit heads, around
guide pulleys, the ends of the leading cords being secured to fixed parts of the
ship's structure, whereby the weight of the boat when brought onto the leading
cords hauls over the davits, in combination with means, substantially as stated
in specification of Patent No. 12494/1899, for bringing the weight of the boat off
the chocks onto the leading cords substantially as described.
4. The arrangement and construction of parts composing my improvements in
hoisting out ships' boats, with or without the means described in specification of
Patent No. 12494/1899 for lifting the boats off the chocks, all combined and
acting substantially as and for the purposes described, and illustrated with refer-
ence to the accompanying drawings.
Dated this 21st day of May 1900.
BREWER & SON,
London and Leeds, Agents for the Applicant.