Year: 1886

page_text: I WILLIAM WILLOTT POPPLEWELL of the firm of Popplewell Colton & Co. of
17 & 18 Southampton Buildings in the county of Middlesex, Patent Agents and
Engineers do hereby declare the nature of this invention (communicated to me
from abroad by Jacob Joachim Künstadter of the city, county and state of New
York) and in what manner the same is to be performed, to be particularly
described and ascertained in by the following statement :-
Vessels which are fitted with so-called "twin propellers" have the disadvantage
that they can only be steered with considerable difficulty as the rotating motion of
one or the other of the propellers has to be interrupted when it is desired to quickly
turn the vessel to one side or the other.
The object of this invention is to provide means for effectively steering vessels
having twin propellers and the invention consists in arranging a rudder having a
steering propeller intermediately between the twin-screws, said steering propeller
being swiveled to a centre-shaft by a universal joint and the centre shaft geared
with the shafts of both propeller screws.
In the accompanying drawings
Fig. 1. represents a botton view of a vessel fitted with twin propellers and with
my improved propelling and steering device and Figs. 2 and 3, are a side and
an end elevation of the same. Similar letters of reference indicate corresponding
parts.
Referring to the drawings A represents a vessel which is propelled by "twin-
screws" that is to say by two screws B. B. that are arranged symmetrically to the
central longitudinal axis of the vessel. The shafts B¹ B¹ of the propeller screws B. B.
are operated by the engine in such a manner that the motion of either one of them
can be interrupted without stopping the other. A third or steering propeller C is
applied to an auxiliary shaft C supported in bearings of the rudder D and rotated
by a centre shaft C that is located in line with the longitudinal axis of the vessel A
and rotated in bearings intermediately between the bearings of the shafts of the
twin-screws B. B. Rotary motion is imparted to the centre shaft C² by a friction
wheel or bevel wheel a that gears with bevel-wheels b, b on the shafts B' B' or in

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any other suitable manner, so that the motion is transmitted to the shaft of the
steering propeller C by one of the shafts B' B¹ even if the motion of one of them
should be interrupted. The steering propeller may also be driven directly by an
independent engine.
The auxiliary shaft C1 of the steering propeller C is connected to the centre
shaft C by a universal joint C³ preferably of the construction shewn in my
Patent for steering propellers number 2294 and dated the 13th day of June 1877.
By thus arranging a rudder with a steering propeller intermediately to and at
some distance back of the main propelling screws, a more powerful propelling
action is exerted on the vessel so that the same is brought fully within control and
made capable of turning quickly and within a short radius especially as the steering
screw responds to the action of the steering gear and exerts a steering action on
the vessel before the motion of either one of the main screws can be interrupted.
As soon as the motion of either main screw is interrupted the motion of the other
screw will assist in the quick turning of the vessel. In case the propelling screws
should be disabled for some reason or other the steering screw serves also as a
propelling screw for driving the vessel.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what
I claim is
First. The combination with twin-propeller screws and their shafts of an inter-
mediate rotary centre-shaft located in line with the longitudinal axis of the vessel,
an auxiliary shaft supported in bearings of the rudder a universal joint connecting
the centre and auxiliary shafts, and a propeller on said auxiliary shaft substantially
as set forth.
Secondly. The combination of twin propeller screws and their shafts, an inter-
mediate centre-shaft located in line with the longitudinal axis of the vessel an
auxiliary shaft supported in bearings of the rudder, a universal joint connecting
the centre and auxiliary shafts a steering propeller on said auxiliary shaft and
motion transmitting gearing by which the centre shaft is rotated by either one or
both of the main shafts substantially as set forth.
Dated this 90th day of Tul 1886