Improvements in Means for Propelling and Steering Vessels.
Year: 1897

page_text: Date of Application, 6th Apr., 1897-Specification Accepted, 3rd July, 1897
COMPLETE SPECIFICATION.
Improvements in Means for Propelling and Steering Vessels.
I, FRIEDRICH KREFFT, of Oranienstrasse 106, Berlin in the Empire of Germany,
Gentleman, 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 the means for propelling vessels, where water under
pressure is caused to escape through tubes, which end under water, so that the
escaping water jet finds a resistance in the water opposite the tube mouth, so that
the ship is moved.
The improvement relates to the form and arrangement of the escape nozzles, which
are formed as long narrow slots and may be so turned, that the water jet can be
used for steering the vessel and also for the backward movement of the latter, without
the pump requiring to be reversed or to have nozzles, which are double and directed
opposite one another. Also by use of long slotted nozzles a much greater effect is
obtained than by round outlet openings.
In the annexed drawings Fig. 1 shows the back part of a ship provided with such
propellers. Fig. 2 shows a plan view of horizontal section, whilst Figs. 3 to 14 show
details of different forms of construction. The water comes from two pumps through
the pipes A A¹, which are united in the pipe B, which is provided at or near one end
with lateral pipes C C and divided at the other end into the three branches D D E.
The pipes C C are provided with stop cocks C¹ C¹ and lead to the fixed nozzles F F
which pass laterally through the sides of the vessel and which are formed in the
drawing simply as rectangular slot holes parallel to the longitudinal axis. The
branches D D pass through the sides of the vessel and continue on the outside in
upwardly curved pipes D¹. On the pipe D¹ are arranged the rotary nozzles H and
both parts are tightened by the socket D2 turned and screwed on the pipe D', through
which socket passes on the upper part the nozzle pipe H tightened by the collar d.
The nozzle H is connected by a key to a rod h which guided in bearings passes up to
above the deck of the ship and is held there in a bearing J and provided with a
worm wheel N, the worm N¹ of which can be moved by means of the handwheel M
and the bevelled wheels n n¹.
These nozzles H are shown in several forms of construction. Upon the bent tubes D¹
are fixed the bipartite sleeves D2 by means of screws d and both parts of the same
are connected by flanges d² and screws d³. The tube H is kept in the sleeve D² by
means of a flange h and is tightened by means of the collar f¹.
In the construction shown in Figs. 6 and 7 the water passes from the tube H in the
form of a flat and narrow water jet from an opening m; in Figs. 3 and 4 the slot is
not continuous but consists of a row of round holes n lying vertically under one
another. A similar construction is shown in Fig. 5, where however the holes o are
flat and rectangularly shaped. By the two last forms there is obtained a more
favorable effect than by the coherent slot of Figs. 6 and 7; as the water jets
escaping through the single holes are successively enlarged after their leaving the
openings n or o and give then also a coherent pressure surface, as shown in Fig. 1
at Z so that therefore a number of holes of together about half the cross sectional
area of the slot m gives the same effect as the latter and thus also correspondingly
less pressure water is required.
The rudder H (Figs. 8-9, 13, 14) is also formed as reaction propeller, partly in order
to increase the propelling power, but essentially in order to use the escaping broad
water jet as a rudder. As can be seen from the drawing, the body H¹ is formed
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page_text: hollow only in the under part and is formed with a flat, hollow chamber L, in the
rear edge of which are the escape holes . These holes may be round or elongated or there
may be only one single continuous slot corresponding to Figs. 6 and 7; also the
rudder could be formed throughout its whole height with the chamber L.
When the steering nozzle H¹ is turned sideways, the flat water jet operates as a
rudder and gives not only a sideward resistance like a solid rudder but also operates
by the force of the jet, this rotary nozzle thus gives a very sensitive steering. The
nozzles H with the fixed nozzles F F give forward movement to the ship, if the
nozzles, H are so turned that the nozzle openings come into a position contrary to
that in Fig. 2, after the pipes to F F are closed, the ship will move in the opposite
direction; although by the near position on the ship walls the effect would be here
less favourable, the reaction will become sufficient for backward movement, which
however will be necessary only in special cases and for a short time. In Fig. 3 such
device is represented with these openings where the enlarged jets give a pressure
surface which is longitudinal, double as great as in an equally long continuous slot
opening.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed I declare that what I claim is :—
1. In hydraulic ship reaction propellers the arrangement of propelling tube like
nozzle pipes arranged to rotate on tubes and closely secured on the latter, which
nozzles are provided with long narrow slot openings or a row of holes lying under one
another.
2. The arrangement of the nozzle characterised under claim 1 as a steering rudder.
ed this 6th day of April 1897.
HERBERT HADDAN & Co.,
18, Buckingham Street, Strand, London, Agents to Applicant.