Improvements in or relating to Fishing Nets.
Year: 1899

page_text: Date of Application, 1st Nov., 1899-Accepted, 30th Dec., 1899
COMPLETE SPECIFICATION.
Improvements in or relating to Fishing Nets.
We, JOHANNES CHRISTIAN HEINSEN, Captain, Langestrasse 38111, Hamburg, and
GEORG FRIEDRICH WILHELM NUPPNAU, Machinist, Grosse Elbstrasse, 104, Altona,
both in Germany, 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 a contrivance for use with fishing nets by which an
obstacle threatening to tear the nets when encountered by the contrivance is
notified on board the ship trawling the net, whereupon the forward movement
of the ship can be stopped in time to avoid any tearing of the net.
This object is attained by arranging a line forward of the ground rope and
attached to the sheer or otter boards in such a manner that it moves or slips
upon the ground bottom. The said line is provided with an electric contact
apparatus of suitable construction by means of a cable fixed in connection with
a ringing apparatus placed on board ship which also frightens the fish lying at
the bottom of the water and drives them into the net slipping behind.
But in order that our said invention may be more readily understood we have
hereunto appended an explanatory sheet of drawings in which
Fig. 1 is a plan of the fishing net with the contrivance in position.
Fig. 2 a longitudinal section and
Fig. 3 a cross section of the electrical contact apparatus.
As shewn in the drawing, the fish net a with its ground rope e slipping along
the bottom is fastened to the usual sheer or otter boards d d and is drawn
forward by these by means of the hawsers b, c, of the trawler. In front of the
ground rope e is arranged the line f which is also fixed to the sheer boards d
and d'; the said line being formed with a gap in which is interposed a piece f¹
of line of lighter make. The front line f is held shorter than the bottom line e
so that, as seen in Fig. 1, a considerable pitch, (preferably about 4 meters) exists
between the arcs of the two lines. An electrical contact apparatus is fixed
between the front rope f and one of the sheer boards d or d¹ and is connected
to the ringing apparatus or electric bell h on board the vessel by a double
cable g
The electrical contact arrangement is shewn in Figs. 2 and 3 and consists of a
capped casing i or other similar casing one cap of which is provided with an ear
or ring k to enable it to be fastened to one of the sheer boards d or d¹.
an
An
Through the other cap of the casing a sliding rod passes in a water tight
manner by means of a stuffing box ¹ the said rod being fitted with
ear or ring by which it is fastened to the front line f.
isolating body o is placed in the casing fitted with an enclosing protecting tube n,
through which the gliding rod 7 is led. In the upper surface of the isolating
body o a channel m is formed which serves to hold a spiral spring p while the
other end of the spring ? lies against a striking plate 9 fastened on the sliding
rod by jam nuts and ', the said plate being provided with a recess r in

page_text: which a projections fits which projection is fastened on the casing i with its
other end in the isolating body. Between the striking plate q and the nut t
a contact piece w is held which on the rod / being pulled fits in between the leaf
springs and 23 arranged in pairs in the recesses w w¹ of the isolating
body o.
Each pair of leaf springs
and 23 form a pole of the sounding apparatus h
on the ship and are connected by the double cable g which is led out of the casing
by means of a. stuffing box z to the hull.,
The working of the contrivance is as follows:-
.
J
If the ropes of the net a slipping along the bottom of the water should advance
towards any obstacle by which there would be a possible danger of the net being
torn, the obstacle encounters the front running rope f which is held by the
obstacle and a strain put on the rope by the forward movement of the ship
and in consequence of this a more or less strong pull is exercised on the electric
apparatus i fastened to the front running line. The movable slide rod l'of
the contact apparatus fixed in the casing i being only held in position by the
force of the spring p, gives way to this pull and moves within the casing & until
the jam nut tabuts on the end of the tube n protruding from the isolating
body. The contact body u is thus moved forward between the leaf springs v₁v
or and closes the circuit of the ringing apparatus h on board the vessel.
This begins to ring and informs those in charge who can at once stop the ship and
thus prevent the net coming in contact with the obstacle. If the inserted piece
of weaker rope f¹ in the front running rope f should break through the speed
of the ship or strength of the pull, the net a lying a considerable distance behind
permits of the slowing and stopping of the ship before the net reaches. the
obstacle. The working strain on the electric contact apparatus stops on the
breaking of the front running rope f, or the stopping of the ship, where. by
the contact piece u is drawn out from the leaf springs v v₁ and 2 v³ under the
influence of the spring p and returns to its former position. If the front rope f
is not broken by the obstacle the apparatus is again ready to give warning at
once of any new danger to the nets, but if the connecting piece f¹ gives way it
must first be replaced.
More than one alarm sounding apparatus may be fixed on board so that the
captain and the engineer can both be simultaneously warned of the danger.
Having now particularly described and ascertained the nature of our said in-
vention and in what manner the same is to be performed, we declare that what
we claim is :-
1. The apparatus or means whereby fishing nets are prevented from being
damaged by any obstacle towards which they may be advancing, consisting of a
line f, attached to the sheer or otter boards forward of the usual ground rope,
provided with an electrical contact arrangement, which is actuated when pressure
is applied to the said line and gives audible warning to those in charge to stop
the vessel's progress, substantially as herein before described, and shewn in the
accompanying drawings.
2. The insertion in the line f of a piece of rope f¹ of lesser strength than 4
the line, which will give way should the pressure on the line exceed a certain
limit, substantially as and for the purpose hereinbefore described and shewn in
the accompanying drawings.
3. The electrical contact contrivance, interposed between the end of the line f
and one of the sheer or otter boards, consisting of a water tight casing through 5
which a sliding rod provided with a contact piece u controlled by a spring p,
passes, the said contact piece advancing when the line f is pulled and completing :
the circuit through the leaf springs 1 and 223 of the electrical apparatus on
board the vessel, substantially as herein before described and shewn in the accom-
panying drawings.
4. In the electrical contact contrivance, as claimed in Claim 3, the arrange-
5

page_text: ment of the tube n in the casing
which the pressure on the spring
through which the slide rod 7 passes, by
is relieved and the parts enabled to return
to their normal position ready to again give warning of further obstacles, substan-
tially as herein before described and shewn in the accompanying drawings.
Dated this 31st day October 1899.
JOHNSONS,
Applicant's Agents, 115, St. Vincent Street, Glasgow.