Jury Masts.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Jury Masts.
I, BENJAMIN JOSEPH BARNARD MILLS, of 23 Southampton Buildings, in the
County of Middlesex, Patent Agent, do hereby declare the nature of this invention,
a communication to me from Alexander McDougall, of Duluth in the County of
St. Louis and State of Minnesota, one of the United States of America, Shipbuilder,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The invention relates to a number of jury masts, which are connected together by
triatic stays, and which are to be elevated simultaneously when desired, and then
rigidly secured in position by shrouds. To better understand the invention, attention
should be had to the drawings, in which:
Figure 1 is a side elevation of a tow-boat with the jury masts and sails in
position.
Figure 2, a plan view of the same.
Figure 3, a front elevation.
Figure 4, a side elevation partly in section of one of the mast steps with a portion
of the mast in position.
Figure 5, a plan view of the mast-step.
Figure 6, a side elevation of the cap for the mast head.
Figure 7 a plan view of the same.
Figure 8, a side elevation of a shroud-plate.
Figure 9, a plan view of the same.
In all the above views, corresponding parts are designated by the same letters of
reference.
The vessel illustrated in the first three views is a tow-boat adapted to be towed
by a steamer. It is with this variety of vessel that I prefer to use my present
invention although it will be understood that it may be used in connection with
other vessels.
A, is the mast-step which is to be bolted or screwed to the deck when it is
necessary to use the jury-masts and sails. This mast-step is provided with a flange, a,
with an annular ring, b, and with a knee, c, at the front part thereof. f, is an
auxiliary plate which is to be secured in place beneath the deck, as is shown in
Figure 4, to strengthen the deck at the points where the mast-steps are to be placed.
The knee, c, is provided with two cleats B, and C, which are used for belaying the
throat and peak halyards respectively. D, is a ring which is secured to the knee c,
and by which the mast-step may be easily handled when being placed in position.
E, is one of the masts, which is adapted to fit in the annular ring b, and abut against
the knee, c.
This mast is to be made either of wood or of hollow metal and should
be about thirty feet in height when used on vessels having a length of two hundred
and fifty feet. F is a metallic cap which is to be placed at the top of the mast.
This cap is provided at its forward portion with an integral ring or eye, g, for the
forestay and with a double eye, h, at its after portion. The upper opening in the
double eye, h, is used for the attachment of the triatic stay and to the lower opening
is attached the usual halyard block. i, is an integral ear which is cast to the side
of the cap F, and to which is bolted by means of the bolt, i, the swivel k, to which
the shrouds are attached. The bolt, j, is provided with a hollow head from which
extend the usual topping-lifts. The shrouds are secured at their lower ends to the
plate or link G, which is of the general form shown and which is adapted to be
screwed to the side of the vessel by means of screw-bolts or other means.
links G, are out of the way of the hatches and they may therefore be made
permanent fixtures of the vessel. There are as many masts E, as can be conveniently
These

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arranged on the vessel, and for convenience, the masts are all to be of the same size.
It is preferable to make use of the after mast shown in Figure 1, on which no sail
is mounted, and this mast is used for the purpose of elevating the back-stay n, above
the cabin or wheel-house. All of the masts are connected together by triatic stays
which extend from the double, eye, h, of, one mast, to the eye, g, of the cap of the
mast directly in the rear. When the jury-masts are to be erected on the vessel, 1
proceed as follows:
:
.
All the masts are laid flat upon the deck with the lower end of each loosely in
engagement with its respective knee c, as is shown in Figure 4 and with the shrouds
loosely connected to the links G. The fore-stay, o, from the eye g of the cap of the
foremast is now passed through the block at the forward end of the vessel, or
instead it may be passed through the eye which is used for guiding the tow-line.
The stay then passes to the capstan 9, which is mounted on the forward working
deck and which is now operated. The forestay, o, will be wound upon the capstan
and the foremast will be elevated and will be kept from falling to one side by means
of the shrouds. The foremast will elevate the next succeeding mast by means of the
triatic stay m, and in this way all the masts will be elevated until the backstay and
triatic stays, m, and the forestay, o, are all perfectly taut, as shown in Figure 1.
The shrouds are now tightened by turn-buckles or by other means so that, each
mast will be held very rigidly in position. I prefer to use ordinary gaff-sails, H,
on the masts which will be handled in the usual way, but other sails may be used,
with equal efficiency. When desired, a stay-sail may be mounted on the forestay o,
and numerous other changes may be made.
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
First: A system of jury-masts and sails consisting of a number of masts connected
together by triatic stays and bearing in steps at their lower ends, and adapted to be
elevated by means of a forestay, and when so elevated to be rigidly held in position
by shrouds, and carrying sails, substantially as set forth.
Second: A system of jury-masts and sails consisting of a number of masts
connected together by triatic stays, and bearing at their lower ends in steps, which
are provided each with a knee said masts being adapted to be elevated by means
of the forestay, and when so elevated to be securely held in position by means of
shrouds, and carrying sails, substantially as set forth.
:
Dated this 20th day of July 1891.
Oury 1091,
B. J. B. MILLS.
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.