Year: 1896

page_text: I, CHARLES DAVID DOXFORD of Pallion Sunderland in the County of Durham,
Ship-builder, do hereby declare the nature of this invention to be as follows:-
This invention relates to derricks, such as are commonly used on board ship for
loading and unloading cargo, and consists in so arranging the apparatus and
particularly the lifting rope that the weight of the load raised automatically slews
the jib in the direction in which it is desired to move the load, the jib being
controlled by side guys, so arranged as to allow it either to be slewed automatically;
or held in, or swung to, any desired position.
The derrick consists of an ordinary jib having its heel secured to a mast or other
support in the usual way, and its head supported from the mast or standard by a
chain or rope of fixed length, or in any convenient manner.
The lifting rope is carried by a pulley, fixed on the under side of the jib head, as
is usual, but thence it passes to a leading block, placed in any convenient position
in that direction to which the load when lifted is to be swung. From this block
it may be carried as most convenient to its operating winch.
The side guys are fixed in any convenient position, one on each side of the
derrick. Each guy is then carried through a leading block one on each side of the
jib head, thence through a leading block fixed on any convenient part of the mast
or other support, to the controlling winch fitted, preferably on the mast, for the
purpose of working these guys.
This winch consists of two drums fixed on a common shaft, so as to rotate together
and controlled by one brake. The side guys are wound one on each drum but in
opposite directions so that as one is wound in the other pays out.
The operator at this winch controls the swing of the jib when carrying a load by
the winch brake-and after the load has been swung and taken off has only to work
the winch so as to wind up the guy fixed on the opposite side to that on which the
leiding block of the lifting rope is fixed, to swing back the empty derrick.
To describe the working of such a derrick arranged on a ship-suppose the ship
is to be unloaded on to the starboard side: the lifting rope is then rove through a
leading block fixed on the starboard side of the ship: the port drum of the guy
winch has control of the load through the port guy, and this is controlled by the
brake-As the jib swings over to starboard it unwinds the guy from the port drum,
whilst the starboard drum winds up the slack of the starboard guy.
The load being deposited the winch is worked so as to wind up the port guy,
thus bringing the empty jib back to position for another load.
To unload the vessel on to the port side it is only necessary to transfer the
leading pulley of the lifting rope from the starboard to the port side of the
ship.
To load from the starboard side the leading pulley of the lifting rope must be fixed
as when unloading on to the port side and vice versa.

page_text: Although I have described the working of the apparatus as applied to the
loading or unloading of ships I do not confine myself to that use of the
invention.
BOULT & WADE,
Agents for the Applicant.
Improvements in or relating to Derricks.
I, CHARLES DAVID DOXFORD, of Pallion, Sunderland, in the County of Durham,
Ship Builder, 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 cranes and the 'like such as are commonly used
on board ship for loading and unloading cargo, and consists in so arranging the
apparatus and particularly the lifting rope or its equivalent so that the stress due to
the load suspended thereon or to the action of the lifting rope or other hoisting gear
or device upon that load automatically slews the jib in the direction in which it is
desired to move the load athwartship the jib being controlled preferably by side guys
and a span so that it can be either slewed automatically as abovementioned or held
in, or swung manually or otherwise to any desired position.
The invention will be best understood by reference to the accompanying drawings
in which
Figure 1 is a side elevation and
Figure 2 a plan showing one of my improved derricks mounted on a ship of which
only a portion is represented.
Figure 3 is a plan similar to Figure 2 but showing the derrick arranged for
swinging over the side of the vessel opposite to that over which it is arranged to
swing in Figure 2.
Figure 4 is a front elevation of the derrick arranged as in Figure 3 the ship in
this view being represented in transverse section as seen when looking forward or
towards the bow of the vessel the left and right hand sides of this figure correspond-
ing respectively with the port and starboard sides of the vessel.
Figures 5 and 6 are enlarged views of the jib controlling winch and other
adjacent parts.
Figure 7 is a plan of Figure 5, and
Figures 8 and 9 are respectively a side elevation and a plan of a swinging bracket
hereinafter more particularly described.
Like letters indicate like parts throughout the drawings.
As shown in the drawings the derrick consists of an ordinary jib A having its
heel pivotted in the usual way to a mast, standard or other support B hereinafter
termed a mast andits head a' supported by a chain or rope C hereinafter termed a span of
fixed length connected in a convenient manner at b to the mast B to the particular
side thereof towards which it is desired, the jib A shall swing when empty or unloaded,
the span C being connected to an eye or staple B at the port or starboard side of the
mast according to whether the empty or unloaded jib is to swing inwards from the
starboard or port side respectively of the vessel.
The lifting rope D is rove through a pulley block A' suspended from the underside
of the jib head as is usual and thence through a leading block E connected say
for example by an eye or stapleforf the deck Fat a part thereof towards the side to which
the load when suspended is to swing. From the leading block E the rope D may be

page_text: passed through a leading block G adjacent to the mast B and thence to the steam or
other winch H.
For convenience of description the eyes or staples ff are hereinafter referred to
respectively as the "port" staple and the "starboard staple."
JK are two side guys each of which at one end is secured to an eye-bolt or staple
or equivalent; or k fixed conveniently to the hull F at one side of the derrick.
Each of the guys J K passes from the staple j or k through a leading block or
attached to one side of the jib head a thence through a leading block or carried
by a swinging bracket B (shown in detail in Figures 8 or 9) pívotted to the
miast B.
From the leading blocks 22 the guys J K pass respectively to the drums j³ ³ of
a jib controlling winch I. fitted preferably on the mast as shown in the drawings, the
guys being suitably secured to the said winch drums. The two winch drums La
as shown clearly in Figures 6 and 7 are secured both on the same shaft on which is
also secured a brake drum encircled by a brake band 12 which may be applied or
released by means of a foot lever or treadle 13 14 is the winch handle. As the side
guys J K need to be payed out slower than they are wound in during the sidewise
movement of the jib A from its position in the fore and aft central plane of the ship,
the two drums are formed conical, the guys J K being wound on the drums in
opposite directions so that as one pays out the other is wound in the conicity of the
drums being such as to provide for the necessary difference in the movements of the
two guys and at the same to maintain both of the said guys equally taut.
To retain the jib in any desired position whether loaded or not, the operator at
the winch I presses on the brake lever so as to prevent any rotation of the
drums; when the load is suspended from the jib A and it is desired that the
latter with the load shall swing outwards over the side of the vessel the operator
releases the brake lever l' and winch handle and the desired swinging movement
is instantly brought about automatically owing to the tension in the lifting rope;
the lateral swing of the jib A may be controlled or stopped at any moment by
depressing the foot lever P. By turning the winch handle in the direction
necessary to wind up the guy J in Figures 3 and 4 or K in Figure 2 the jih A may
be returned to its mid-ship or starting position in which it is indicated in full lines
in Figures 2 and 3 though when the load is removed from the jib the latter will
automatically or with very little assistance from the operator through the winch L
return to its starting position (which might be on the opposite side of the mid-ship
line) owing to the span C being connected to the side of the mast B then farthest
from the jib, such arrangement of the span C resulting in a canting of the axis of
rotation about which the jib swings. The lowest point in the arc of travel of the jib,
to which it tends always to gravitate can be placed where desired by suitably
shifting by hand or otherwise the connection b round the mast relatively to the heel
of the jib to cant the axis of rotation as described.
The operation of the before described apparatus is as follows:-
Suppose the cargo is to be removed from say the hatch F2 and unloaded on the
starboard side the leading block E is secured to the starboard staple f' as shown in
Figure 2 and the span C is connected to the staple b at the port side of the mast B.
While the load is being raised by the winch H the operator keeps the brake (2
applied and thus prevents the jib from slewing but when the load is fully raised the
operator releases the brake lever and, as before explained the jib automatically
swings outwards over to starboard under the stress in the lifting rope D as indicated
in datted lines in Figure 2 the winch drums and 4 during this movement of the
jib respectively taking in the guy J and paying out the guy K. After the load has
been lowered and deposited by the operation of the winch H the jib will automatically
or with but little assistance from the operator through the winch L gravitate to its
loading position owing to the cant of the vertical axis about which it turns. The jib
controlling winch during this operation winds in the guy K and pays out the guy J.
To discharge the cargo on the port side it is only necessary to secure the leading
block E to the port staple f as shown for example in Figures 3 and 4 and the span C

page_text: to the staple b at the starboard side of the mast B and operate the apparatus in a
manner substantially the same as that last previously described.
To load the ship the leading block E is attached to the eye or staple for fl at the
side opposite to that at which the jib receive its load, that is to say for loading
from the port side the leading block E is attached to the starboard staple f¹ (as
when discharging on the starboard side) as shown in Figure 2 the jib then being
swung inwards and outwards over the port side of the vessel and for loading
from the starboard side the leading block E is attached to the port staple f (as when
discharging over the port side) as shown in Figures 3 and 4, the jib then being
swung inwards and outwards over the starboard side of the vessel the span C in
all these operations being connected to the mast on the side opposite that at which
the leading blocks E is connected to the deck D.
When the mast B is situated between two hatches as shown in Figures 12 and 3
wherein F represent the second hatch the before described apparatus may be
duplicated the two jib controlling winches L and L' being conveniently mounted on
opposite sides of the mast as shown in Figures 5 and 7. H¹ Figures 1 2 and 3 is the
stean winch for loading and unloading cargo through the hatch F³.
Although I have described and illustrated my improved derrick as applied to the
loading and unloading of a ship I do not confine myself to that application as it may
be advantageously applied to various other purposes both afloat and ashore neither do I
restrict myself to the precise arrangements described as these may be varied without
departing from the essential features of the invention.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. The combination substantially as described of a derrick or the like which
swings in a given direction under the effort of the lifting rope or hoisting gear
on the load, guys for the derrick jib and apparatus actuated positively to tighten
one guy while it slackens another.
2. In a hoisting apparatus of the kind described the combination of a pair of coned
drums, guys and brake gear, substantially as and for the purpose specified.
3. A hoisting apparatus in which when the load is removed from the jib the latter
automatically returns to its loading position.
4. A derrick or the like which swings in one direction under the action of the
lifting rope or hoisting gear and automatically returns when the lifting rope or
hoisting gear ceases to act.
5. A derrick or the like so constructed that when slewed by the effort of the
lifting rope or hoisting gear on the load it tends to return under the action of
gravity.
6. In a derrick or the like constructed to be slewed by the effort of the lifting rope
or hoisting gear on the load, altering for the purpose described the position of an
end b of a span C.
7. In a hoisting apparatus of the kind described the combination of the guys and
winch substantially as and for the purpose described and illustrated in the accom-
panying drawings.
8. The combination and arrangement of parts constituting the complete
hoisting apparatus substantially as described and illustrated in the accompanying
drawings.