IMPROVEMENTS IN THE MANUFAC- TURE OF TORPEDO NETS
Year: 1878

page_text: LETTERS PATENT to William Munton Bullivant, of 59, Fenchurch Street, in
the City of London, for the Invention of "IMPROVEMENTS IN THE MANUFAC-
TURE OF TORPEDO NETS."
Sealed the 6th September 1878, and dated the 20th June 1878.
PROVISIONAL SPECIFICATION left by the said William Munton Bullivant
at the Office of the Commissioners of Patents on the 20th June 1878.
WILLIAM MUNTON BULLIVANT, of 59, Fenchurch Street, in the City of London.
"IMPROVEMENTS IN THE MANUFACTURE OF TORPEDO NETS."
This Invention has for its object improvements in the manufacture of torpedo
nets.
Torpedo nets have already been made by me or according to my designs by com-
bining together a series of gruminets or rope-like rings worked in steel wire. In
producing such grummets the wire is laid round and round, the first convolution serving
as a core on which six other convolutions are successively laid, until a grummet is pro-
duced which has a section similar to that of a wire rope, one wire forming the core,
and six others surrounding it. As I have worked heretofore I have formed a chain
of such grummets by working each grummet in turn through an iron ring on the
preceding grummet in the chain, and also upon another ring to serve as the attach-
iment for the succeeding grummet.
The chains thus constructed have then been connected together side by side so
as to form a net by seizings or lashings, attaching one grummet to another. It is
found however that these attachments have not the flexibility which is required.
I am now able to obviate this objection, and to make a net without any seizings or
lashings. This I do by working each grummet through rings already on two other
grummets, which are themselves already connected by an intermediate grummet

page_text: and rings, and also upon a loose ring to serve as a new point of attachment. In
this way I produce a netting which has all the flexibility desired in both
directions.
In setting up these nettings for use I reeve cords through them, by which they
can be drawn up together when desired after the manner of a Venetian blind.
I strengthen the edges of the net with chains or wire ropes.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Munton Bullivant in the Great Seal Patent Office on the
20th December 1878.
WILLIAM MUNTON BULLIVANT, of 59, Fenchurch Street, in the City of London.
"IMPROVEMENTS IN THE MANUFACTURE OF TORPEDO NETS."
One of the methods at present resorted to for protecting ships of war from
torpedoes is by nets so arranged as to catch the torpedo before it reaches the ship's
side. The nets for this purpose are required to combine great strength with
flexibility and comparative lightness. To incet these requirements I have invented
a torpedo net made with wire grummets or rings of wire worked like the strand of
a rope.
My first method was to make chains of such grummets, each grummet in turn as
it was formed being worked through a ring on the preceding grummet of the chain.
Having completed a number of such chains I proceed to connect them together side
by side by seizings" or ties of wire, thus attaching the grummets of the several
chains in such manner as to complete a net. Before the date of my Patent I had
made some torpedo nets in this way, but I found them unsatisfactory and prac-
tically useless, for the seizings rendored the net rigid and difficult, to handle. I
now, according to my present Invention, dispense entirely with seizings or com-
paratively rigid connections between the grummets, and I no longer work in the
manner above described, first making independent chains with the grummets, and
then fastening such chains together; but I cause each grummet to be worked in
its place in the net, and the whole of the connections between the grummets to be
made with loose metal rings, through which as they are made the grummets are
worked. In short my improved torpedo net consists essentially of wire grummets
loosely connected by rings, every grummet being thus coupled with all the adjacent
grummets.
I strengthen the edges of the net with a chain, and in attaching the chain I
again dispense with seizings, and form loose or yielding connections by means of
amall screw shackles.

page_text: I will now describe in detail the method of manufacture as practised by mo.
The grummets are worked in pliable stool wire, No. 14 of the Birmingham wire
gauge. The wire is carefully galvanized, and is cut to lengths of 13 feet; each
length serves to form a grummet. The connecting rings are of round iron rod 3/8"
in diameter. The rings are welded up and galvanized; they are 5" inside
diameter.
In making each grummet a length of wire is taken; it is turned round upon
itself, and the end is throaded through as a knot is tied in a string; thus a ring is
formed which is gauged to an internal diameter of, say, 6 inches and /. The
operation has been so performed that the ring has now two projecting ends, one a
long one and the other of a few inches only. The longer end has now to be threaded
through and through the ring; this operation is performed by two men, or moro
properly by man and boy, the man holding the ring, turning it round, and guiding
each lay of the wire to its place, the boy passing the end and drawing the wire
tight up to the ring.
When the work has progressed so far as to render the ring firm the short end of
the wire is cut off close up to the ring; the remaining end is passed and repassed
until the grummet consists of seven complete turns, one which serves as the core
being surrounded by six other turns laid helically around it, in all respects as in
the strand of a wire rope, except that the work is endless, forming a ring or
grummet.
The first grummet is worked with two of the iron rings upon it, these rings
being included when the first tie of the wire to form the grummet is made. The
next grummet is worked, including one of the rings, on the first grummet and two
other or loose rings. Similarly a third grummet is worked through one of the rings
on the second, and so on until a line or chain of grummets is completed of the
length of the net required. The last grummet however, which will form a corner
of the torpedo not, will require to be worked through two rings only.
Care is required in working the first row of grummets to leave the loose rings
which are to serve to attach the next row all upon the same side. The first
grummet of the second row is worked on to the last of the preceding, and has two
loose rings upon it. The second grummet of the second row is worked through one
of the loose rings on the preceding grummet, and also through the loose ring on
the grummet next before the last of the first row; it also receives two loose rings.
In a similar way all the succeeding grummets of the second row are worked, except
the last, which requires to be worked through three rings only. As before, care is
required in working this row to leave the rings in the proper places for the attach-
ments of the third row.
The third row is worked precisely as the second row, and so on until the net is
completed, except that the grummnets of the last row of the net will each require
one ring less than the corresponding grummet of an intermediate row.
The net being completed I strengthen its edges with an ordinary galvanized iron
chain with welded links of such a length that two links of the chain correspond in
length to one row of the net.
Each of the outer grummets of the net I connect by a light galvanized screw
shackle to one of the links of the chain, so cach alternate link of the chain will
receive a shackle.
The shackles are of such a size that the grummets can work freely through them,
so that the connections between the edges of the net and the chain are as free as
the connections made by the rings between grummet and grummet; thus the net
is completed, and in this state it is supplied to the ship for use.
There is another way in which this torpedo net may be made, but it is much
inferior to that described above, vis., to work the grummets separately, and after-
wards connect them by rings made in parts, which after being put on are rivetted
or fastened so as to enclose the two grummets they are intended to link.
Having thus described the nature of my said Invention, and the manner of per

page_text: forming the same, I would have it understood that I claim as a new or improved
article of manufacture my torpedo net, consisting of wire grummets, each connected
with all the adjacent grummets by loose rings, seizing or rigid connections being
dispensed with.
In witness whereof, I, the said William Munton Bullivant, have hereunto set
my hand and seal, this Nineteenth day of December, in the year of Lord
One thousand eight hundred and seventy-eight.
W. M. BULLIVANT. (LS).