Drag for Retarding Vessels under Way.
Year: 1898

page_text: Date of Application, 28th Nov., 1898-Accepted, 11th Mar., 1899
COMPLETE SPECIFICATION.
Drag for Retarding Vessels under Way.
We, MITAR DEMETRIO CVETKOVICH, of 17, Landstrasse, Essek, Building Con-
tractor, GIOVANNI KUKAC, Merchant, Fiume Susak 58, CARLO MINGOTTI, Sailor,
Fiume Belvedere 57, and ALBERTO SIROLA, Merchant, Mlaca Ponsal, all in
Hungary, 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:
The object of this invention is a stopping device for ships which has for its
purpose to prevent ships in motion from coming into collision with other ships or
to back them from any impediment to the propulsion of a ship as soon as such an
emergency arises. The characteristic feature of the subject matter of this in-
vention consists in arranging a weir beam or fin at the stern of the ship, or behind
the paddle boxes of ships propelled by paddle wheels, such beam or fin being
usually placed in any suitable position above the level of the water but being
capable of rapid immersion in the water as soon as the ship provided with such
gear is in danger as above explained of colliding with another ship or of running
into any other obstacle or impediment. The beam or fin can be rendered col-
lapsible so as to occupy but a small space; it is not however indispensable that
it should be collapsible, especially for small ships.. The particular construction
of the weir, fin or beam must obviously be left to the judgment of the ship
builder according to the various cases occurring, and we have illustrated for that
purpose a few examples of such construction, which may serve as guides--in
the accompanying drawings wherein Fig. 1 is a side view of the aft end of a screw
steamer showing the weir fin collapsible, Fig. 2 being a corresponding plan or
horizontal section. Fig. 3 is a side view similar to that of Fig. 1 with this
difference that in Fig. 1 the weir fin consists of a combination of fixed parts,
whereas in Fig. 3 the weir fin consists of flexible material such as sail canvas
held in the proper position by iron rods or ribs; or this weir or fin may assume
the form of a carriage hood and be made collapsible.
Fig. 4 shows an arrangement wherein the weir fin is not collapsible, the same
is shown in full lines immersed in the water and in dotted lines raised above the
water level.
In Figs. 1 and 2, a, a, are long and narrow plates made of stiff material such
as sheet iron for instance; Fig. 2 shows clearly the plan form of the same, that
is to say they are curved in a circular or parabolic shape. The expansion or
arching of these plates should be such as not to deviate too much when curved
from the curvature of the ship as clearly shown in Fig. 2. Each free end b of
the plate a is rigidly connected with a draw rod c which is arranged to turn freely
upon a pin d fixed to the ship's side. The pin d may be replaced by any other
equivalent device or projection allowing the rods e to move freely up and down.
The uppermost plate a is firmly fixed to the aft part of the ship by a chain or the
like. Around the edge of this plate runs a horizontal rear flange f upon which
bears the flange g of the next subjacent plate a. The latter is provided in exactly
the same manner with a rear flange f upon which rests the upper and front
flange g of the subjacent plate a. The drawings show clearly the details of this

page_text: a above
arrangement. A chain or the like is connected to the lowermost plate and
passes over a roller i on its way to a windlass or winch by means of which the
whole fin can be, raised out of the water. When such a contingency is conteni-
plated, the chain his wound up by means of the windlass which raises the lower-
most plate out of the water. As the lower front flange of the latter plate bears
against the adjacent plate a above, the latter is carried away with the former.
This last mentioned plate a is also provided with a flange which comes into con-
tact in an exactly similar manner to the above-with the next plate
in consequence of the windlass being revolved, so that the latter plate is likewise
carried up. The same performance takes place with the uppermost weir plate a.
All these plates follow close against one another as the chain is being wound
up, so that when the lowermost plate comes out of the water, the whole weir or
fin has the height of one single plate a. The fin whose height is in such a manner
very greatly reduced can be readily stored above the water aft of the ship without
in any way spoiling the appearance of the ship. While winding up all the
plates a turn upon the two fixed bolts d fixed on both sides of the ship at the
same height. When the weir or fin at the rear of the ship has been entirely
raised out of the water the chain e hangs loosely down like a loop. In this
raised or wound up position the fin is inoperative, but should the vessel as afore-
said be in danger of colliding with another ship or an obstacle or impediment,
the drum of the windlass around which the drawing part or organ h of the fin is
wound, is simply released so as to allow the fin to drop suddenly in the water.
It will be seen from a perusal of Figs. 1 and 2 that the fin spans a water surface,
i.e.. grips a volume of water equal to that of the immersed midship frame of the
ship and that hence the fin must exert on the ship a restraining or stopping
effort of extraordinary power. When the windlass is wound up. it can be fixed
in that position in any well known manner such as by a pawl and ratchet wheel
readily releasable by hand so that the fin should not drop accidentally in the
water. As soon therefore as danger looms in the distance, the pawl is disengaged
from the ratchet wheel, the windlass drum is thus released and the fin drops
down forthwith. As such a locking gear exists in every windlass it must not be
considered as a component part of this invention and hence need no further de-
scription here. It may be remarked that an arm or lever may be fixed above or
below water to the stern of the ship, this arm or lever being struck back as soon
as an obstacle is met with and releasing the pawl of the windlass drum by means
of a suitable connecting rod passing through the ship from fore to aft like a bell
wire in a building. As however such connecting means do not form any part
of this invention it becomes likewise unnecessary to illustrate the same.
it must be well understood that this contrivance has still a more powerful break-
ing or restraining effect upon the ship when after the weir or fin is dropped the
screw is still propelling forwards. The screw throws in such a case the water
against the fin which throws it forward again so as to exert a back pressure against
the weir or fin; so long as the screw propels forward the ship moves backwardly.
Whereas Fig. 1 shows a collapsible weir or fin the several parts of which are
of sheet metal, the arrangement shown in Fig. 3 is carried out in such a manner
that the rods c starting from the fulcrum & run from one side of the ship to the
other uninterruptedly. To these rods-six of which are shown in Fig. 3-are
fixed, in the manner clearly shown in the drawings, the flexible material such as
india rubber or sail canvas m. The hauling and lowering of the weir or fin is
carried out in the same manner as illustrated in Fig. 1. The rods c are laid, as
soon as the drawing cord or chain is would by the windlass, in close proximity
one to the other and allow the material or covering to hang down loosely. This
collapsible fin has a very short height and can be conveniently suspended over
the water on the aft part of the ship. The lower edge of the fin when sunk in
the water and expanded can be held much lower than the hull or the keel of the
ship, so that the fin may also grip the water which runs along below the bottom
of the vessel; the restraining action is accordingly much increased.
But

page_text: Fig. 4 shows, as already mentioned, a method of carrying out the invention
whereby the fin is not constructed in a collapsible form. This fin is represented
in this case by a single plate which has no need to be curved, but forms in
plan a straight line, that is to say this plate n can be plane and hence free from
curvatures of any kind. The upper and lower edges of the plates may as shown
in Fig. 4 be bent slightly in a forward direction in order to better grip the water.
This plate is fixed to rigid rods e capable of turning at d. On each side of the
ship is arranged a rod c of that description, and each rod is fixedly connected
with a chain or other pulling means h in the manner shown in Fig. 4, and this
chain or the like is wound up on the drum of a windlass which is not shown in
the said figure. To allow the chain or the like to be guided along the ship's
side, large openings o or small pulleys can be provided. It will be understood
with reference to Fig. 4 that the fin therein shown being formed of one piece is
not of such general use as the others while its height is much greater than the
other fins and hence it does not tend to improve the aft part of the ship. In the
drawings, the various fins have been shown as applied to a screw steamer, but it
is obvious that they may be likewise applied to sailing vessels or may be utilized
on paddle wheel steamers. Even when sailing ships are provided with paddle or
stern wheels, these fins can still be employed. But in the case of paddle wheel
steamers we may arrange a fin on each side of the ship and preferably close
behind the paddle boxes. These two fins can be actuated by a single windlass
or by two separate windlasses.
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. A braking, restraining or stopping device for ships characterized by the
arrangement on both sides of a ship or at the rear side only of a ship, of a fin or
weir which as soon as the vessel is in danger of colliding with another ship or
with any other obstacle is suddenly dropped down in order to greatly retard the
ship on account of the tremendous resistance which it offers to the water.
2. In retarding devices of the kind above claimed, the construction of the fin
of several parts which lie closely one against the other when the fin is hauled
up after use, so as to greatly reduce the height of the same fin.
Dated this 26th day of November 1898.
CRUIKSHANK & FAIRWEATHER,
Chartered Patent Agents, 62, Saint Vincent Street, Glasgow,
Agents for the Applicants.