Improvements in Boat-lowering Apparatus.
Year: 1890

page_text: Date of Application (in United Kingdom), 20th June, 1890
Complete Specification Left, 20th June, 1890-Accepted, 26th July, 1890
COMPLETE SPECIFICATION.
Improvements in Boat-lowering Apparatus.
1, THOMAS STROUD HOSFORD of Highfield, Tulse Hill, in the County of Surrey,
Physician, 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 has for its object improvements in boat-lowering apparatus.
At the present time it is usual to lower ship's boats from davits by means of tackles
or falls connected with the boat at two points, one near the bow and the other near the
stern of the boat. This arrangement, however, is not satisfactory and accidents occur
in lowering boats into the water in consequence of the tackles or falls becoming
jammed in lowering or one being disengaged while the other is set or held fast, or
one tackle being payed out more rapidly than the other. I avoid these dangers by
suspending the boat while lowering from one point only and that above the centre of
gravity of the boat, so that she takes the water on even keel. This I do by means of
gear which prevents undue strain upon the boat and which automatically releases the
boat as soon as she rises upon the water, or, in cases where it is preferred, the boat
may be released by hand.
In order that my said invention may be fully understood and readily carried into
effect, I will proceed to describe the drawing hereto annexed.
The drawing shows a longitudinal section of a boat fitted with lowering-gear in
accordance with my invention.
a a are two hooks, or it may be two U-form eyes jointed at the ends at the bow and
stern thwarts of the boat, respectively. The joints are very securely connected with
the keel of the boat by upright bolts bb.
c is a stanchion passing through the centre thwart and entering a socket at the
bottom of the boat. This stanchion can be readily unshipped. This is the whole of
the lowering-gear, which remains with the boat when afloat.
d is a beam suspended from the davits. In order that the beam d may be as light
as possible consistently with sufficient strength, I prefer that it should be of steel and
tubular. The beam has slots d' d' at its ends which engage with the hooks a a.
dare chains upon the beam, which pass to a ring d³, placed as nearly as may be
over the centre of gravity of the suspended boat when on an even keel; but no great
accuracy is required in this adjustment, as the trim can be adjusted by arranging the
load in the boat.
d is a ring fixed on the beam, and passing over the stanchion c. It serves to keep
the gear steady. The boat may be lowered from davits by the ordinary means, either
one fall or both being used and shackled to the ring d³. It is then immaterial whether
if both falls be used they be eased out at the same rate or if one be let go before the
other, for then the boat only draws a little ahead or astern and does not fall off until
she is floated. As soon, however, as the water removes all strain from the lowering
gear, the beam d drops out of the hooks a a and the boat is released. The hooks a a,
as soon as they are free, fall down out of the way. Both ends of the beam escape

page_text: simultaneously from the hooks but even if this should not be so no harm can result.
Simply the beam will be tilted and the looks become free.
While the boat is suspended she may, if necessary, be controlled by bow and stern
lines tended by hands on board the ship. This, however, will only be needed in rough
'weather.
The boat may be lifted to the davits when no longer required afloat by shipping the
hooks into the slots, and in rough weather putting a mousing on the hooks, which is
to be removed on the boat being secured to the davits. She is then ready for lowering
again.
If automatic liberation of the boat when afloat be not required, a disengaging hook
may be substituted for the ring d³, and it may be thrown off by a man in the boat as
soon as the tackles become slack in consequence of the boat being floated.
The
chains d in this case may either pass to a beam d, as shown, or the beam may be
dispensed with, the chains then passing to eyes fixed in the stanchions in the boat.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. The combination, in boat lowering gear, of hooks a a upon the boat, a beam d,
hooks d' d' at the ends of the beam, engaging with the hooks a, and a ring d³, con-
nected with the beam over the centre of gravity of the boat and receiving the tackle
or tackles by which the boat is lowered.
2. The combination, in a boat lowering gear, of a ring d³ over the centre of gravity
of the boat and receiving the tackle or tackles by which the boat is lowered, and
chains d² d² over the keel and passing from the ring 3 to points of attachment, near
the bow and stern of the boat, and liberating gear for casting off the tackles when
the boat is floated.
Dated this 20th day of June 1890