Improvements in Boat Lowering and Disconnecting Gear.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in Boat Lowering and Disconnecting Gear.
I FRANK SAMUEL PETT of 3 Blenheim Square, Dover, Kent, 2nd Deputy
Harbour Master Dover Harbour do hereby declare the nature of this invention
to be as follows:-
This invention relates to improvements in boat lowering & disconnecting gear
as described & illustrated in my Blue Book No. 14741 year 1891.
It will be observed the hooks as therein described point upwards & towards their
respective ends of the boat when engaged (when disengaged they point towards the
bow of the boat) the underneath surface of the hooks making an angle of 23° to
the horizontal plane of the boat.
The lower davit block rings being maintained on & at right angles to their
respective hooks by means of a chain or wire span.
My improved gear is designed to retain the great efficiency of the above
mentioned gear in addition to which to keep the bow of the boat higher than
the stern when disengaging also to give additional security by taking the strain
off the span, & placing the weight of the boat directly over & on the engaging
& disengaging hooks; that is to say on the boat being suspended on an even
keel the lower davit block rings will remain on their respective hooks with only
a slight strain on the span, this tension on the span only being necessary to
prevent the span rings from slipping down their respective lower davit block
rings.
I may construct my hooks so that when the boat is engaged the underneath
surface of the hooks are parallel to the horizontal plane of the boat, or they
may point downwards preferably making an angle of from eight to ten degrees
to the horizontal plane of the boat.
It will be readily seen with hooks of this description the only time the span
is subjected to any considerable strain is when the boat is lowered in an improper
manner (on end) or when the boat is being towed by means of the bow tackle.
I may make my lower davit block rings curved or otherwise, having for
object the retention of the span rings in their correct position (when the boat:
is engaged) with minimum strain on span.
The after lever hook may be pivoted between the jaws of a keel bolt or
suitable bracket attached to the boat the end of the lever hook being retained
in position when engaged by any suitable device say a lanyard belayed to a
pin or cleat.
The span rings may be made in the form of a shackle or otherwise as found
most suitable.
My lowering winch may be so constructed & attached to the ship's deck that
in combination with wire whips it will be possible to lower the boat from the
ship's deck by rope brake or otherwise, it may also be so arranged to enable the
officer in charge of the boat to lower without the necessity of leaving the boat.
Dated this 28th day of April 1896.

page_text: Improvements in Boat Lowering and Disconnecting Gear.
1, FRANK SAMUEL PETT, of 3 Blenheim Square, Dover, in the County of
Kent, 2nd Deputy Harbour Master of Dover Harbour 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 for improvements in boat lowering and disconnecting gear relates
to: gear of that class in which the lower davit block rings are kept on their
respective hooks by means of a chain or wire span, more particularly as described
and illustrated in Specification No. 14741 of the year 1891 and also in the present
specification. In this arrangement it was necessary to maintain the lower davit
block rings on and at right angles to the underneath surface of their respective
engaging and disengaging hooks by means of a chain or wire span thus throwing a
very considerable strain on the span.
Now according to this invention instead of making the lower davit block rings
straight they are curved or otherwise shaped so that the middle of the ring
is out of the plane of the ends and in use the rings are both convex to the
centre of the boat, that is, the hollow of the lower davit block rings face outwards.
By this arrangement, on the boat being suspended on an even keel, the pull or
weight of the boat is directly on and over (vertical) their respective engaging
and disengaging hooks in the boat and the span rings cannot slip down the lower
davit block rings (until the boat is disengaged from the davít tackles) as the lower
portion of the rings are inclined outwards.
To maintain the bow of the boat the necessary height above the stern when
disengaging it is necessary to vary the angle of the fore hooks in boats of different
lengths.
In boats of great length I use the fore hook as shown in Fig. 1 and in shorter
boats the fore hooks may be parallel to the boats keel and in some cases point
downwards making say an angle of 5 degrees more or less to the horizontal plane
of the boat.
In a further improvement the after lever hook is pivoted in jaws below the stern
bench of the boat the hook projecting up through a slot in the seat or stern bench,
the lever portion of the hook being maintained in position (when the boat is
engaged) by means of a lanyard (connected to the end of the lever or shank)
passing up through a hole in the stern bench or seat and belayed to a pin or cleat
or set taut by means of a tackle one block of which is fast to the lanyard the fore
block being fast to a band of iron which is secured to the after seat, the tackle fall
being belayed to a pin or cleat.
In the accompanying sheet of illustrative drawings:
Fig. 1 is a sectional elevation of a ship's boat showing the improvements in the
boat lowering and disconnecting gear constructed according to this invention.
Fig. 2 is a sectional elevation of the gear at the after end of the boat.
Fig. 3 is a front view of the improved lower davit block ring and
Fig. 4 is a plan of the span ring..
The lower davit-block-rings a are curved and arranged so that the curved parts
back one another.
In engaging the boat to the davit tackle rings the fore lower davit block ring a
is partly rove through the span ring b on the fore end of the span, after which the
lower portion of the lower fore davit block ring a is passed over the rigid hook s in
the bow of the boat. The after lower davit block ring a is then partly rove
through the span ring 6 on the after part of the span, after which the lower portion
of the alter lower davit block ring a is placed over the after lever hook e. . The

page_text: chain or wire span d is then made taut by hauling taut the tackle o that controls
the after lever hook e e' after which the fall is belayed to the cleat ron the after.
seat.
It will be observed on the boat being engaged the lugs c on the rings a prevent
the span rings 6 from slipping too far up the rings a; the span rings 6-being
prevented from slipping down the rings a by means of the curved outer surface of
the rings a.
In disengaging the boat the after lever hook is released by letting go the tackle-
fall when the after lever hook takes up the position as shown in dotted lines and.
it will be found that the stern of the boat will in all cases take the water first.
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 lower davit block ring shaped substantially as described for the purpose
set forth.
2. The means for retaining the shank or lever end of the pivoted engaging and
disengaging hook in position substantially as described.
3. The combination of the lower davit block rings shaped substantially as.
described for the purpose specified with the horizontal or downwardly inclined
engaging and disengaging hooks.
4. The improvements in boat lowering gear substantially as described with.
reference to the drawings.
Dated this 29th day of January 1897.
WHEATLEY & MACKENZIE,
40 Chancery Lane, London, W.C., Agents.