IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR PROPELLING SHIPS AND VESSELS
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by Richard Archibald Brooman at
the Office of the Commissioners of Patents, with his Petition, on the 15th
October 1861.-A communication from abroad by Charles Alexandre
Séraphin Victor Marquis de la Baume, of Paris, France.
I, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR PROPELLING SHIPS AND
VESSELS," (communicated to me from abroad by Charles Alexandre Séraphin
Victor Marquis de la Baume, of Paris, France,) to be as follows:-
This Invention relates to feathering propellers, and continuous propulsive
effect is obtained by means of two sets of propellers on each side of the vessel.
The floats are always submerged and nearly vertical, when propelling they act
successively upon fresh bodies of water; after performing their stroke they are
returned in a horizontal position or feathered, and when about to repeat their
stroke they are made to assume a vertical position. When two floats are used
instead of one they are set one below the other. To go astern the Inventor
adopts arrangements whereby the propellers may be made to drive the vessel
backward without altering the stroke of the piston in the steam cylinder. The
propellers may be applied at the stern of vessels, particularly those used on
canals.
The accompanying Drawings shew the manner in which the Invention is
performed.
Figure 1 is a longitudinal elevation of (part of) a steam vessel, fitted with

page_text: a double set of propellers, one of which is shown in action for propelling, while
the other is returning feathered; Figure 2 shows in plan the propelling appa-
ratus, together with the arrangements for changing the course of the pro-
pellers; Figure 3 is a view of a vessel, fitted with the propellers looking on
to her bow.
a is the body of the ship or other vessel; b, b, are frames, supporting the
propellers fixed to the vessel. The frames carry bearings c, c, for the cranked
shafts d, d, which are the axes of the arms e of the floats f. The cranked
shaft of each set of propellers is driven in the following manner:-The piston
rod of the engine is jointed to a rod g, which transmits motion to a crank h,
which communicates a vertical oscillating motion to the lever i. The oscil-
lating motion of this lever i is transmitted to two cranks j, j, jointed to
connecting rods k, k¹, united to the cranked shafts d, d. The to-and-fro
motion of the piston is thus transmitted to the shaft d, and thereby to the
arms e, in such manner as to cause them to describe an arc of about 100
degrees; acting in concert with this arrangement is another for the purpose of
working the levers 7, 1', which act upon the floats, and cause them to assume the
vertical and feathering positions, whether for propelling ahead or astern, as
now next to be described. Upon shafts m, m³, two balance beams n, n³, are
fixed, connected by rods o, o¹, to cranks p, p, which work the links q, q',
carrying the chains r, r, supporting the ends of the float levers 7, 11. One of
these links is always raised while the other is lowered, and their respective
positions must be changed with that of the direction of the vessel, whether to
go ahead or astern. The floats f are constructed thus:-Bars t, t, are fitted
on the axis s of the levers 7, 1, and these bars terminate at bottom in eyes;
the float fis rivetted to and between these bars, and when two floats are used,
as shown in the Drawing, the eyes form a means of attaching the frame u,
which connects the floats and ensures their parallelism. For the proper
understanding of the Drawings, let us suppose the vessel going ahead, and
the two sets of propellers acting alternately, that is to say, one propelling and
the other returning feathered, then the links q' will be up while those q will
be down.
I proceed to describe successively the action of the float when propelling
and when returning feathered. 1st, the float f connected to the lever l is in
full propulsive effect; the chain r connected to the link q is in a state of
tension produced by the action of the float on the water and describes an arc,
the radius of which is determined by the points of attachment of the lever
to the chain, as shown at No. 1, Figure 1, on reference to which it will be
apparent that the different positions of the lever / maintain the float f during

page_text: the whole stroke of the propeller in a vertical position, the chain r being all
the time in a state of tension, while the other chain is slack. 2nd, when
the propeller is at the end of its stroke it is feathered, and assumes the posi-
tion shown at No. 2, Figure 1. In this position the float f' yields to the
resistance of the water, takes the horizontal position, and retains it during the
back stroke, the chain r¹ being now in a state of tension, and acting on the
lever 1, and the chain r being slack. To reverse the direction of the vessel
the positions of the links q, q', must be reversed, and this is effected through
the balance beams n, n¹, moved by the shafts m, m³, which in turn are made
to move by the connecting rods a, a, attached to the excentric y.
It is important that the point of attachment of the chains to the levers 7, l',
should be above a horizontal line drawn through the axis of the bar t, and
the more this point is abovo such line the more rapidly will the feathering
take place.