IMPROVEMENTS IN APPARATUS FOR PROPELLING VESSELS
Year: 1873

page_text: PROVISIONAL SPECIFICATION left by George William Smith at the
Office of the Commissioners of Patents, with his Petition, on the
18th November 1873.
I, GEORGE WILLIAM SMITH, of Glasgow, in the County of Lanark,
North Britain, Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR PROPELLING VESSELS," to be
as follows, that is to say:-
This Invention relates to the propelling of vessels when there is little
or no wind, but when there is more or less swell or wave motion, and it
has for its object to provide sailing vessels with simple, efficient, and
convenient appliances which can be easily put into or taken out of
action, and which will enable them to cross the belts of calm un-
avoidable in many voyages, and especially met with in the tropics.
In carrying out the Invention propelling blades or paddles arranged
to reciprocate and to propel when moving backwards, but to feather
when moving forwards, are supported by floats near the side of the
vessel, and are connected to spars or arms fixed to the vessel so that the
rolling or pitching of the vessel will cause the paddles to operate.
In one modification an additional stern post is fixed astern of the
rudder, and a small truck is fitted to run easily up and down on this

page_text: outer stern post with antifriction rollers working on its inner and outer
edges. A main spar or beam is jointed to the truck so as to be capable
of easy angular motion in a transverse vertical plane, and the ends of
this beam are constructed so that auxiliary spars or bars can be easily
hooked to them and be fixed by sliding thimbles, the combination
forming a long rigid beam which is supported at about the water level
by floats attached at each end. These floats may consist of flexible air-
tight casings easily inflated with air when required, and occupying little
stowage room when out of use, whilst they may do important service as
life preserving floats in case of shipwreck. Near the floats the auxiliary
spars or bars have jointed on them light frames projecting downwards
with the propelling paddles or blades jointed on them near their lower
ends. The paddles are connected to levers centered at or near the upper
parts of the paddle frames, and the other ends of these levers are con-
nected by rods to the spars or bars fixed to the vessel's quarters. The
rods are formed with spring hooks to admit of their being easily engaged
with eyes on the ends of the fixed spars or bars, notwithstanding the
rolling or pitching motion of the vessel. The connecting of the rods to
what may be termed the feathering levers instead of to the paddle
frames, makes the changing of the paddles at the commencement of
each stroke more certain and speedy, and secures more propelling action.
Guy ropes are fastened between the floats and forward points of the
vessel's side at about the water line.
If preferred the float supported beam may be arranged at the vessel's
bow, and whether at the bow or stern the truck and fittings may be
connected to the vessel by a jointed bow piece instead of by the outer
post, or by vertically placed ropes from the keel to bowsprit or tafrail, or
in any equivalent manner.
When not in use the apparatus can be easily detached in parts and
stowed away on shipboard, and the main spar or beam may either be
detached or it may simply be raised to its highest position, and be then
fixed at the vessel's stern.