IMPROVEMENTS IN APPARATUS FOR RAISING AND LOWERING SHIPS' BOATS AND OTHER OBJECTS."
Year: 1880

page_text: LETTERS PATENT to Luke Thomas, of Bayswater, in the County of Middlesex,
for an Invention of "IMPROVEMENTS IN APPARATUS FOR RAISING AND
LOWERING SHIPS' BOATS AND OTHER OBJECTS."
PROVISIONAL SPECIFICATION left by the said Luke Thomas at the Office.
of the Commissioners of Patents on the 20th February 1880.
LUKE THOMAS, of Bayswater, in the County of Middlesex. " IMPROVEMENTS IN
APPARATUS FOR RAISING AND LOWERING SHIPS' BOATS AND OTHER OBJECTS."
My Invention has more particularly reference to the raising and lowering of
large and heavy boats, such as steam launchos, and it has for its object to effect
the raising and lowering thereof by apparatus of great strength but simple con-
struction, that will allow of the several operations being performed with facility,
euse, and dispatch, and will also securely hold such boats with their engines and
boiler or other heavy load in the raised position, in such a manner as to prevent
any straining of the boat by the weight of the load.
For this purpose I firstly construct davits of two, three, or, by preference, four
metal plates secured to each other side by side with distanco pieces intervening.
The upper part of the davit is curved outwards, while the lower part is straight
and widened out considerably so as to afford great strength. The lower ends pass
down to the upper deck within the sido or bulwarks, and near the deckline they
are firmly fixed on a strong horizontal shaft. For raising and lowering boats
having heavy loads, such as engines or guns amidships, I employ three such davits,
which are all fixed upon the said horizontal shaft, the two outer ones serving to
raise, lower, and support the ends of the boat, being by preference situated at
about one fourth the length of the boat from each end, while the middle davit
serves to raise, lower, and support the weight of the engines or other load
independently of the boat, so that when this is suspended it cannot be strained by
such load. On all or any of the davits or on the shaft carrying the same are fixed
toothed wheels, in gear with which are toothed pinions worked by any suitable
hand gear so as to cause the davits to turn with their shafts, to assume either a
position with their curved ends overhanging the ship's side when in the act of
raising or lowering the boat, or to move inwards from that position to one in
which the boat when raised is brought in board within the curved part of the
davits, in which position it is secured by suitable chocks.

page_text: When in such hackward position the davits rest with their back surface against
strong stops, the chocks for the boat being notched out to receive them, and they
may be held in that position by linch pins or suitable catches.
When in the forward position they rest with their outer straight edges against
and upon the side of the ship as a stop, and they may be further supported in
either position by fixed pawls taking into ratchet teeth on the davits or on the
shaft thereof. In addition to their connection by means of the said shaft, the
davits are also by preference connected together at their upper ends by longitudinal
solid or tubular rods. In the spaces between the several plates forming cach
davit are placed the sheaves and guide pullies for the raising and lowering tackle,
which may be arranged and actuated in any suitable known manner.
For smaller boats the backward and forward motion of the davits may be effected
simply by hand levers inserted in sockets provided on the davits or on the
connecting shaft. For small boats only, two davits may be employed as usual.
By arranging the davits to turn on centres near the deck line instead of at
some distance up, as has been heretofore, proposed, the extent to which the boat
has to be raised when the davits are moved from the outward to the inward
position is comparatively small, and consequently the power required for effecting
this operation is also correspondingly small even for large boats.
For disengaging the boat or other load when lowered by the abovo described
apparatus I generally prefer the ordinary block and hook, but in rough weather
I employ with advantage a tumbler hook, namely, a hook the centre of the
curvature of whose nose corresponds with a horizontal pin from which it is
suspended and round which it can turn; extending beyond such pin is a flat broad
piece acting as a weight to cause the hook to tumble over when free, such piece
having a shoulder that bears against the strap or pulley block from which the
hook is suspended when the hook is in position for supporting a load. The
pressure of the load upon the hook provents this from tumbling over as long as
the load is suspended from it, but as soon as the pressure of the load is taken off,
as when the boat touches the water, it immediately tumbles or turns over so as to
draw its nose out of the eye or loop hanging thereon. This tumbling book may
either be used by itself or it may form the hook of the tackle block or sheave.
In large ships having two or three sets of such above described davits, arranged
in line on either side of the ship, these inay be advantageously used in combination
for transporting very large boats, such as torpedo boats, instead of stowing these
away on board, each set of davits acting as single davits for securing the ends and
middle of the boat, and all being moved simultaneously for raising and lowering
the boat.
Although the above described raising and lowering apparatus is specially
intended for ships' boats, yet it may also be employed for catting and fishing ships'
anchors, and for raising and lowering other loads either on board ship, or on quays,
floating stages, or landings."

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Luke Thomas in the Great Seal Patent Office on the 11th August
1880.
"
LUKE THOMAS, of Bayswater, in the County of Middlesex. IMPROVEMENTS
IN APPARATUS FOR RAISING AND LOWERING SHIPS' BOATS AND OTHER OBJECTS."
My Invention has more particularly reference to the raising and lowering of
large and heavy boats, such as steam launches, and it has for its object to effect
the raising and lowering thereof by apparatus of great strength but simple con-
struction, that will allow of the several operations being performed with facility,
ease, and dispatch, and will also securely hold such boats with their engines and
boiler or other heavy load in the raised position, in such a manner as to prevent
any straining of the boat by the weight of the load.
For this purpose I firstly construct davits of two, three, or, by preference, four
metal plates, secured to each other side by side with distance pieces intervening.
The upper part of the davit is curved outwards, while the lower part is straight
and widened out considerably so as to afford great strength. The lower ends pass
down to the upper deck within the side or bulwarks, and near the deckline they
are firmly fixed on a strong horizontal shaft. For raising and lowering boats
having heavy loads, such as engines or guns amidships, I employ three such davits
which are all fixed upon the said horizontal shaft, the two outer ones serving to
raise, lower, and support the ends of the boat, being by preference situated at
about one fourth the length of the boat from each end, while the middle davit
serves to raise, lower, and support the weight of the engines or other load
independently of the boat, so that when this is suspended it cannot be strained by
such load. On all or any of the davits or on the shaft carrying the same are fixed
toothed wheels, in gear with which are toothed pinions worked by any suitable
hand gear so as to cause the davits to turn with their shafts, to assume either a
position with their curved ends overhanging the ships' side when in the act of
raising or lowering the boat, or to move inwards from that position to one in which
the boat when raised is brought in-board within the curved part of the davits, in
which position it is secured by suitable chocks.
When in such backward position the davits rest with their back surface against
strong stops, and they may be held in that position by linch pins or suitable
catches. When in the forward position they rest with their outer straight edges
against and upon the side of the ship as a stop, and they may be further supported
in either position by fixed pawls taking into ratchet teeth on the davits or on the
shaft thereof. In addition to their connection by means of the said shaft, the
davits are also by preference connected together at their upper ends by longitudinal
solid or tubular rods. In the spaces between the several plates forming each
davit are placed the sheaves and guide pullies for the raising and lowering tackle,
which may be arranged and actuated in any suitable known manner.
For smaller boats the backward and forward motion of the davits may bo
effected simply by hand levers inserted in sockets provided on the davits or on the
connecting shaft. For small boats only two davits may be employed as usual.
By arranging the davits to turn on centres near the deck line instead of at some
distance up as has been heretofore proposed, the extent to which the boat has to
be raised when the davits are moved from the outward to the inward position is
comparatively small, and consequently the power required for effecting this
operation is also correspondingly small even for large boats.
For disengaging the boat or other load when lowered by the above described
apparatus I generally prefer the ordinary block and hook or a block with its book
arranged as hereinafter described.
In large ships having two or three sets of such above described davits arranged

page_text: in line on either side of the ship, these may be advantageously used in combination
for transporting very long boats, such as torpedo boats, instead of stowing these
away on board, each set of davits acting as single davits for securing the ends
and middle of the boat, and all being moved simultaneously for raising and
lowering the boat.
Although the above described raising and lowering apparatus is specially
intended for ships' boats, yet it may also be employed for catting and fishing ships'
anchors, and for raising and lowering other loads either on board ship, or on quays,
An landin
floating stages, or landings.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 of the accompanying Drawings shews a side view of my before described
improved boat raising and lowering apparatus with the davits swung forward into
the position for raising and lowering; Fig. 2 shews the same view with the davits
swung back and the boat housed, and Fig. 3 shews a plan. The davits A, A, A, of
which there are by preference three, as shewn, are constructed of metal plates
secured together at distances apart by distance pieces, the three davits being also
by preference secured together by tie rods B, B, passing through and secured by
screw nuts. At the lower part the davits are widened out considerably, as shown,
so as to impart great strength to them, and they are all keyed on to one and the
same shaft C carried in strong standard bearings D fixed firmly to the main
deck E. The shaft C has a toothed quadrant F, in gear with which is a pinion G
on a shaft that may either be rotated by a capstan wheel or crank handle, as
shewn, or by gearing from the ships' engines controlled by hand. Thus it will be
seen that by rotating the pinion the three davits will be simultaneously swung
from the backward to the forward position, or vice versa. The part of each davit
below the hurricane deck J is enclosed by a housing I, so that the spaces between
them can be utilised for water tanks, seats, &c., and the openings to these
enclosures in the hurricane deck may be closed in with covers J when the davits
are in the forward position. When in the forward position the davits rest with
shoulders at A upon strong stops K fixed to the bulwarks, and other stops K'
are provided at the back of the housings for the davits to rest against when in the
backward position. In addition to these stops there is also provided a break
strap L on the moving gear, by means of which the davits are held in whatever
position they may be moved into, and which also serves to control their motion. The
upper part of the davits is so curved that when in the backward position the boat
will be conveniently housed within such curved part, as shown at Fig. 2. while
when in the forward position the davits overhang the side of the ship sufficiently
for the largest sized boat suspended therefrom to hang well clear of the ship, as
shewn at Fig. 1. When housed the boat is supported upon chocks of any con-
venient arrangement, such as shewn at Fig. 2, where the chocks at M are assumed
to be near the ends of the boat and to turn down upon hinges when the boat is
being raised or lowered. It will be observed than when in the backward position
with the boat housed, the upper extremities of the davits from which the boat is
suspended are situated vertically.over the shaft C on which they turn and which
is as close as practicable to the deck line, so that when turning the davits into the
backward or forward position for the purpose of housing or lowering the boat tho
vertical motion of the boat and its points of suspension is comparatively small, and
is always either an ascending or a descending one, rendering the work of lowering
comparatively easy as compared with pivotted davits of usual construction, in
which the centres are generally so arranged that the boats have first to be raised
considerably from the housed position before they can be lowered. The middle
davit may with advantage be made to support the boat's engine when it has one, as
indicated in dotted lines in Fig. 1, or any other load contained in the boat while it
is being raised or lowered, thus preventing the boat from being strained by the
load, as is frequently the case wliere it is only supported by two davits, one at each

page_text: end of the boat. For the same reason also I prefer to arrange the outer davits at
such distances that they support the boat at points some distance from the ends,
so that the weight of the boat on each side of the point of support shall be in
balance, or nearly so. The ropes pass from the sheaves N over guide pullies 0, 0,
in the spaces between the plates of the davits. The blocks P are by preference
constructed with hooks pivotted at P₁ and formed with a curvature having its
centre at the pivot, so that when the boat or other load is lowered the hook can
be instantaneously released by pulling at a cord Q attached to an eye at the back
of the hook.
With my above described improved boat raising and lowering apparatus
collapsible boats may be conveniently housed against the bulwarks at R, Fig. 2,
beneath the ship's boat, so that after this has been lowered the collapsible boat
may be readily raised up into its place, expanded, and then lowered in its turn.
Having thus described the nature of my Invention and in what manner the
same is to be performed, I claim,-
First. Constructing a ship's davit of two or more flat plates connected together
by distance pieces and having their lower parts widened out considerably and
pivotted on a horizontal shaft near the main deck, so that the davit is swung
backwards and forwards upon such shaft for raising, lowering, and housing boats,
the upper end of the davit being so curved that the boat when housed will lie
within such curved part, while its point of suspension is situated in or near a
vertical line passing through the pivot at the lower end, substantially as and for
the purposes herein described.
Second. Arranging three davits such as are referred to in the preceding claim in
combination, substantially as and for the purposes herein described.
Third. The improved construction of apparatus for raising and lowering boats
and other loads, combined and operating as herein described and shown on the
accompanying Drawings.
In witness whereof, I, the said Luke Thomas, have hereunto set my hand
and seal, this Third day of August, in the year of our Lord One thousand
eight hundred and eighty.
LUKE THOMAS. (LS.)