Improvements in Derricks.
Year: 1894

page_text: Date of Application, 13th Mar., 1894
Complete Specification Left, 7th Dec., 1894-Accepted, 12th Jan., 1895
PROVISIONAL SPECIFICATION.
Improvements in Derricks.
We, WALTER ERNEST HUTCHINSON, Mariner of 61 Poets Road, Canonbury,
and ARTHUR EDWARD NEWTON, Mariner, of 16 Linthorpe Road, Stamford Hill,
both in the County of Middlesex, do hereby declare the nature of this invention
to be as follows:-
This invention relates to derricks such as are used on board ship for loading
or discharging cargoes and has for its object to enable them to swing with
greater freedom in one direction of their traverse than in the opposite direction,
advantage being taken of this difference to facilitate the conveyance of the load.
In a derrick constructed according to this invention the swivel post is fixed with
its axis inclined to the vertical so that the plane of rotation is also inclined. The
consequence of this obliquity is, that when rotating the swivel post through half a
revolution the weight of the leg and load tend to accelerate such rotation when
the end of the leg is travelling from the highest towards the lowest point in the
said plane and thus reduce the force required to turn the derrick when loaded, the
opposite conditions obtaining when returning the leg to its initial position with its
outward end ascending the plane of its rotation.
When applying this invention to a pair of derricks attached to a ship's mast or
other support for loading and discharging cargo on board ship the pivot points of
the post, or its equivalent, are inclined in opposite directions so that the tendency
of one derrick is to swing clear to starboard and the other clear to port. By this
arrangement the load is used to assist in turning the derrick from either side,
depending upon the derrick selected. By fixing one derrick a little higher tha
the other either may be caused to swing clear of the other.
We also fit the guys for limiting the swing of the derricks in a special manner if
so desired, viz. as follows:-The standing part is attached to a suitable place either
on the bulwarks, rigging, or derrick and the end is lead through blocks to bring it
to a winch or the like. The guys may be in one continuous length or separate.
Dated this 12th day of March 1894.
1

page_text: improvements in Derricks.
We WALTER ERNEST HUTCHINSON, of 61 Poets Road, Canonbury, Mariner,
and ARTHUR EDWARD NEWTON, Mariner, of 16 Linthorpe Road Stamford Hill,
both in the County of Middlesex, 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 relates to derricks such as are used on board ship or on shore for
loading and discharging cargoes and has for its object to enable them to swing with
greater freedom in one direction of their traverse than in the opposite direction,
advantage being taken of this difference to facilitate the conveyance of the load.
In the accompanying three sheets of illustrative drawings:
-
Fig. 1 represents in elevation two ships derricks adapted for loading and
discharging cargo on board ship.
Fig. 2 is a plan of one of the derricks, and
Figs. 3 and 4 represent in plan a method of connecting the jib chain or span to
the post or mast.
Fig. 5 represents in elevation a pair of derricks having one upright mast for a
common post, and
Fig. 6 represents in elevation two pairs of derricks for working fore and aft and
having one raked mast for a common post.
Referring to Figs. 1 to 4 of the drawings a jih leg a is connected to a samson
post by means of a back chain or span c and an ordinary hinged joint d and swivel
pin e. The chain c may be attached to either of the eyes f g at pleasure.
A vertical line coincident with the axis of the swivel pin e is equidistant from
the two eyes fg so that by connecting the chain c to one or the other of the
eyes f, 9 the plane containing the axis of the leg and the points of its connection to
the post is inclined, by which means the jib is caused to swing automatically through
a semi-circle in a direction depending upon which eye the chain c is connected to.
Advantage is taken of this result to so connect the chain c that the jib a shall
automatically swing in the direction required to convey the load as will be readily
understood. In Fig. 1 the derrick on the left hand is arranged for loading from
the ships side into the hatch while that on the right is similarly connected and
arranged to discharge from the hatch h to the ships side. The hoisting chain is led
through blocks i l to a winch or the like in the usual manner. In order to
facilitate the changing of the connection of the chain c from one eye to another its
end is divided, one end being free when in use as shown in Figs. 1 and 3. When
changing the connection of the chain c from (for example) the eye g to the eye f
the jib is swung into the position shown in Fig. 4 and the end m secured to the
eye, the jib being then rotated in the opposite direction until the end mis in
tension when the end n is released from the eye g. The connection of the chain c
is changed from the eye f to the eye g in the reverse order as will be readily
understood.
.
с
In Fig. 5 a pair of derricks are shown so connected to an upright mast that their
planes are inclined in opposite directions thus producing a tendency to swing
automatically in opposite directions; and in order that they may be worked on
either side of the mast the one o is smaller than the other p and arranged within it
so as to swing inside it.
In the arrangement of two pairs of derricks, fore and aft of the raked mast
(Fig. 6) brackets or fixings rs are fixed to the mast in order to bring the points of
connection of the jibs and chains into the same vertical plane.
In regard to Figs. 5 and 6 there may not be sufficient distance between the
eyes fg to give the necessary swing in which case brackets are mounted on the

page_text: side of the mast for the purpose, the principle in this case being exactly the same
as in Figs. 1 to 4.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. Connecting the back chains of derricks so that the containing plane is inclined
and thereby causes the derrick to swing automatically in one direction substantially
as described and for the purpose set forth.
2. Constructing the back chains of derricks with divided ends in order to facilitate
the operation of changing from one connecting point to another substantially as
described and for the purpose set forth.
3. The arrangement and construction of derricks substantially as described with
reference to the drawings.
Dated this 7th day of December 1894.
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.