Improvements in Apparatus for Propelling Boats and other Navigable Vessels.
Year: 1892

page_text: Date of Application, 1st Sept., 1892
Complete Specification Left, 1st June, 1893-Accepted, 8th July, 1893
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Propelling Boats and other
Navigable Vessels.
1, HENRY BARCROFT, of The Glen, Newry, in the County of Armagh, Ireland,
Director of the Dundalk and Newry Steam Packet Company, do hereby declare
the nature of this invention to be as follows:-
In the Specification to my Patent No. 6809 of 1891 I described a construction
of apparatus for propelling and steering boats and other navigable vessels in which
two sets of propeller blades revolving in contrary direction were mounted on a
vertically sliding frame carried by horizontal supports overhanging the stern of
the boat amidships, the frame with the propellers being raised or lowered to suit
the varying water line of the boat, while the horizontal supports were mounted on
a turntable so as to cause the propeller axis to assume angular positions for steering
the boat.
According to my present improvements I simplify the construction of such
apparatus by dispensing with the one set of propeller blades, and arranging the
same in such manner that an ordinary rudder can be used for steering so that the
mounting of the framing on a turntable for effecting the steering is also dispensed
with.
The apparatus is by this means rendered very simple and inexpensive and capable
of being readily placed in position and removed, so that it may be applied with
great advantage not only to barges, but also to sailing ships as auxiliary propelling
power.
For this purpose I construct the vertical frame with its vertical shaft and driving
gear in precisely the same manner as described in my said prior Specification, but
in place of providing two sets of propeller blades made to revolve in contrary
directions, I provide only a single set of blades, and instead of placing the horizontal
supports so as to overhang the stern amidships, I place them to such an extent to
one side of the stern post that the propeller blades in revolving will just clear the
latter.
Furthermore, when necessary I extend the stern post outwards to such an extent
that an ordinary rudder hinged thereto can be made to assume the extreme angular
position required for steering without interfering with the vertical frame and its
propeller blades.
The vertical shaft of the propeller blades may be driven in any of the ways
described in my said Specification such as by a small portable motor engine and
boiler on deck or by an electric or other suitable motor, the whole apparatus being
so arranged as to be readily placed in position and removed, so as to be capable of
being transferred from one barge to another when required, thus enabling one set
of propelling apparatus to serve for two barges, one of which is being loaded or
unloaded at the one end station, while the other is performing the journey to and
from the other end station.
With the single set of propeller blades, immersed only to near their horizontal
axis, there would of course be a tendency to a lateral displacement of the stern of
the vessel due to the lateral thrust exercised by the blades. I counteract this
however by causing the propeller blades in passing through, the water to revolve in
the direction away from the stern post, so that the lateral thrust will then tend to
turn the stern of the boat in the contrary direction to that in which the boat tends
to turn owing to the lateral position of the propeller relatively to the longitudinal
centre line of the boat.
When applying the apparatus to larger vessels two sets thereof might be

page_text: employed one on each side of the rudder, and one or more others might also be
arranged on each side of the vessel if necessary.
Dated this 1st day of September 1892.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Apparatus for Propelling Boats and other
Navigable Vessels.
I, HENRY BARCROFT, of The Glen, Newry, in the County of Armagh,
Ireland, Director of the Dundalk and Newry Steam Packet Company, 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 :-
In the Specification to my Patent No. 6809 of 1891 I described a construction
of apparatus for propelling and steering boats and other navigable vessels in which
two sets of propeller blades revolving in contrary direction were mounted on a
vertically sliding frame carried by horizontal supports overhanging the stern of
the boat amidships, the frame with the propellers being raised or lowered to suit
the varying water line of the boat, while the horizontal supports were mounted on
a turntable so as to cause the propeller axis to assume angular positions for steering
the boat.
According to my present improvements I simplify the construction of such
apparatus by dispensing with the one set of propeller blades, and arranging the
same in such manner that an ordinary rudder can be used for steering so that the
mounting of the framing on a turntable for effecting the steering is also dispensed
with.
The apparatus is by this means rendered very simple and inexpensive and
capable of being readily placed in position and removed, so that it may be applied
with great advantage not only to barges, but also to sailing ships as auxiliary
propelling power.
For this purpose I construct the vertical frame with its vertical shaft and
driving gear in a similar manner to that described in my said prior Specification,
but in place of providing two sets of propeller blades made to revolve in contrary
directions, I provide only a single set of blades, and instead of placing the horizontal
supports so as to overhang the stern amidships, I, according to one arrangement,
place them to such an extent to one side of the stern post that the propeller blades
in revolving will just clear the latter.
Furthermore, when necessary I extend the stern post outwards to such an extent
that an ordinary rudder hinged thereto can be made to assume the extreme angular
position required for steering without interfering with the vertical frame and its
propeller blades.
The vertical shaft of the propeller blades may be driven in any of the ways
described in my said Specification such as by a small portable motor engine and
boiler on deck or by an electric or other suitable motor, the whole apparatus being
so arranged as to be readily placed in position and removed, so as to be capable of
being transferred from one barge to another when required, thus enabling one set
of propelling apparatus to serve for two barges, one of which is being loaded or
unloaded at the one end station, while the other is performing the journey to and
from the other end station.
With the single set of propeller blades, immersed only to near their horizontal
axis, there would of course be a tendency to a lateral displacement of the stern of
the vessel due to the lateral thrust exercised by the blades. I counteract this
however by causing the propeller blades in passing through the water to revolve
in the direction away from the stern post, so that the lateral thrust will then tend

page_text: to turn the stern of the boat in the contrary direction to that in which the boat
tends to turn owing to the lateral position of the propeller relatively to the
longitudinal centre line of the boat.
When applying the apparatus to larger vessels, two sets thereof might be
employed, one on each side of the rudder, and one or more others might also be
arranged on each side of the vessel if necessary.
On the accompanying drawings are shewn two constructions of the above
described propeller apparatus.
Figs. 1, 2 and 3 shew one arrangement. Fig. 1 shews a front view of the same
as suspended from the stern of a boat. Fig. 2 shews a side view and Fig. 3 shews
a plan.
A A are beams overhanging the stern of the boat, placed to one side of the
rudder B, and supporting a cross bearer C fixed thereto. This bearer is formed
with eyes D through which slide the vertical bars E E of a frame E F. G, which
can be adjusted in height relatively to the cross bearer C, and is secured in such
position by means of eye bolts or setting screws H. The cross bars F G of the
frame are formed with central collar bearings for the vertical shaft I on which are
mounted firstly an upper bevil wheel J with which gears a pinion K on the driving
shaft L of any suitable motor engine placed either at M or elsewhere on the boat,
and secondly a lower bevil wheel N which gears with a bevil wheel O fixed on or
formed in one with the boss P of the propeller blades Q, the wheel and boss being
preferably arranged to run loose on the axis R which is fixed by lateral wings Ri
to the bracket S bolted to the bottom cross bar G of the frame.
The shaft I is supported by a collar I on the bearing of the lower cross bar G.
Or in place of this arrangement a step bearing of lignum vitæ or other material
requiring only water as a lubricant may be provided for the shaft below the
wheel N on the bracket S.
The adjustment of the frame E F G so as to bring the propeller into the desired
position relatively to the water line, may be effected by a winch temporarily
placed upon the bearers A and from which the frame is suspended by the eye U.
To allow of the free angling of the rudder B the stern post B¹ is made to project
to the same extent as the propeller. The stems of the propeller blades Q are
either screwed into sockets P¹ on the boss P, or they may be otherwise secured.
As before stated, if the propeller is only partially immersed, it is rotated in the
direction in which it will exercise a lateral thrust in the direction of the arrow
shown in Fig. 1, so that it will counteract the tendency of the boat to turn in the
opposite direction owing to the lateral position of the propeller.
A fender T may be fixed to the side of the boat to protect the propeller and
frame from injury.
Figs. 4 to 6 shew a modified construction of the framing; Fig. 4 shews a front
view partly in section, Fig. 5 a side view partly in section and Fig. 6 a plan,
slewing the application of two frames with their propellers, one on each side of
the rudder post.
In this construction the vertical bars E of the frame are of I section, to the
upper and lower ends of which are bolted curved transverse bars F and G, fitted
with step bearings V V₁ for the reception of the ends of the shaft I.
The axis Ron which is mounted loose the boss of the propeller blades as before
described, is fixed by wings R' to the underside of the cross bar G, by means of
the same screw bolts that secure the step bearing V₁.
The frame E E, instead of sliding through eyes in a cross framing C as described
in the first arrangement, is held in position against the ends of the overhanging
beams A A by means of loops H embracing the bars E and having stems H₁
passing through holes bored. longitudinally in the beam to a recess cut therein.
where they receive nuts H2 on their threaded ends, (the beam being strengthened
by a metal straps A¹ at this part) so that by screwing up the nuts, the bars E are
nipped tight between the eyes H and the ends of the beams A. The shaft I is
supported by a neck bearing W fixed upon a wood cross bearer A² fixed to the

page_text: beams A. The bevil wheel J slides with a loose key J¹ upon the grooved shaft,
and when the frame E and shaft have been adjusted in height, the wheel J is
securely fixed thereto by means of setting screws J2 bearing against the loose
key J'.
It will be seen that with this construction the frame E E with its shaft I wheel.J
and propeller can be readily detached. from the beams A by simply unscrewing the
nuts H2 and withdrawing the stems of the loops H and then fitting the frame to
another barge having identical bearers to receive it, and where a number of vessels
are to be propelled by such apparatus, these would all be made identical and inter-
changeable, so that any apparatus can be fitted to any vessel. The motor engines
with their driving shaft L and accessories would in like manner be made identical
and interchangeable.
The framing E E might also be made of plain wrought iron bars of rectangular
section and might be formed in one with either the top or the bottom cross piece F
or G. Also, when the water line of the vessel is practically constant, the bolts H
can be permanently fixed to the. bars E instead of having loops through which the
bars slide.
The wheels N O may be enclosed by any suitable casing.
When two sets of semi-submerged propellers are employed, as at Fig. 6, they
would by preference be arranged to be driven in opposite directions the pitch of
the blades being made respectively right and left handed. The propeller blades
are advantageously made of considerably greater area than usual, as shewn at
Figs. 1 and 2, when the vessels are designed to run in confined water ways.
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 :-
1. In apparatus for propelling boats and other navigable vessels by means of
propellers carried by a frame overhanging the stern of the boat, constructing such
apparatus to operate with a single set of propeller blades carried by a frame con-
structed and arranged so as to be readily removed or transferred from one vessel
to another, substantially as herein described with reference to the accompanying
drawings.
2. In apparatus for propelling boats and other navigable vessels by means of
propellers carried by a vertical frame overhanging the stern of the boat, arranging
the vertical frame to be carried by overhanging bearers situated on one side of the
rudder of the boat, and carrying a single set of propeller blades driven by a
vertical shaft carried by the said frame and receiving motion from a suitable motor
geared with its upper end, substantially as described.
Dated this 31st dov of Nov 1902
ABEL & IMRAY,
Agents for the Applicant.