Improvements in Centre Boards for Boats.
Year: 1899

page_text: Date of Application, 27th May, 1899
Complete Specification Left. 27th Mar., 1900-Accepted, 19th May, 1900
I, DAVID MALCOLM BOWYER-SMYTH, of 20, Piccadilly, in the County of London,
Gentleman, do hereby declare the nature of this invention to be as follows:-
This invention has reference to an improved form of centre board for boats
whereby not only is leeway prevented but a tendency to forward movement is
imparted to the boat.
In one construction, a vertically adjustable rod or stay extends through the
bottom of the boat and is provided near its lower end with one or more laterally
extending and normally horizontal or approximately horizontal (e. parallel
or approximately so to the surface of the water) plates formed with forward
or advance edges which compared with their rearward portions, are rigid and
which are preferably connected to the said vertical rod or stay at or near the said
forward or advance edges only.
By this construction the centre of gravity of the boat may be kept low and a
forward movement given to the boat during its rocking or pitching motion owing
to the inclination or bending of the rear portions of the plates caused by the
pressure of the water against the upper side of one plate or lateral portion there-
of and the lower side of the other plate or lateral portion thereof, according to
the direction in which the boat is rocking or pitching.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London. W.C.,
Chartered Patent Agent.
Improvements in Centre Boards for Boats.
I, DAVID MALCOLM BOWYER-SMYTH, of 20, Piccadilly, in the County of London.
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 has reference to centre boards or devices whereby leeway of
the boats to which they are applied is reduced, but which according to my in-
vention are so constructed as to tend to impart forward movement to the boats.
Referring to the accompanying illustrative drawings.
Figs. 1, 2 and 3 represent diagrammatically in side elevation, plan and cross
section respectively a boat provided with a centre board or device constructed
according to this invention.

page_text: Figs. 4 and 5 represent diagrammatically in side and end elevation respectively
a modified construction.
Figs. 6, 7 and 8 are similar views to Figs. 1, 2 and 3 respectively, showing a
steamship with my improvements applied thereto.
Figs. 9 and 10 are detail views hereinafter referred to.
In Figures 1 to 3 a, a is a rod or stay that extends upwardly through the
bottom of the boat 6 and is capable of adjustment in a vertical direction by
means of a nut c fitted upon the screwed upper part of the rod or stay a, and
mounted so as to be capable of rotation, but not of endwise movement, upon a
water-tight guide tube d, which terminates above the water level; the nut c
may be provided with projecting pins or lugs e to facilitate its rotation in one
direction or the other so as to cause the rod or stay to move up or down as
required. k, k are two laterally extending and normally horizontal or approxi-
mately horizontal (i.e., parallel or approximately so to the surface of the water
see Fig. 1) plates or blades of steel or other suitable material provided with
forward or advance edges m, which, compared with their rearward portions, are
rigid, which plates are preferably connected, as shown, to the vertical rod or
stay at or near the forward or advance edges m only. In the example, the
forward edges of the plates are connected by bolts to arms extending laterally
from the lower end of the rod or stay a, the said edges being thus rendered
more rigid than the rear portions of the plates k.
By this construction the centre of gravity of the boat may be lowered, as is
usual with ordinary centre boards, as may be required by adjusting the position
of the plates k, and a forward movement will, moreover, be given to the boat,
during its rocking motion, owing to the inclination or bending of the flexible
rear portions of the plates, as indicated by dotted lines in Fig. 1, caused by the
pressure of the water against the upper side of one plate k and the lower side of
the other plate k according to the direction in which the boat is rocking. In pitching
both plates will be simultaneously bent one way or the other, according to whether
they are being raised or lowered in the water. The two plates k may in some
cases be formed as one, if desired. Figs. 4 and 5 illustrate a modified construc-
tion of apparatus in which the two plates or blades k are fixed to the keel » of
the boat by their forward or advance edges m, and, in this example, are inclined
from the keel of the boat downwardly, as shown,
in
My invention is applicable to various kinds and sizes, of sailing, steam or
other boats or vessels, the number and arrangement of the plates or blades being
suitably modified to suit the particular requirements of each case. For instance.
the case of a steamship, the plate or blades k may be arranged
two groups, one at each side of the ship, at or about the usual
position of bilge keels, as shown in Figs. 6 to 8 inclusive. Each plate or blade k
extends laterally from the side of the vessel and is secured thereto by its forward
or advance edge m; ss are fixed fenders for protecting the plates or blades k.
in
The plates or blades k may be so secured as to enable them to be reversed when
desired. Figs. 9 and 10 show in end and front elevation respectively an arrange-
ment in which the forward edge m of the plate or blade is formed with an
extension which passes in a water tight manner through the side of the boat
and has fixed to its inner end a hand wheel or disc u whereby it can be turned.
To fix the plate k in any desired position, through one of a series of holes r
in the hand wheel, a pin is passed into a hole in a plate or casting y fixed
to the side of the boat: the pin may be removed when the boat is anchored
or moored, so that the plate or blade & may swing freely and thus be rendered
inoperative for the time being.
Though the number of plates or blades and their arrangement and position
relatively to the boat to which they are applied may be varied, care should be
taken to have on each side of the boat plates or blades of equal area and conse-
quent propelling force.

page_text: Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. The application to a boat of one or more horizontal or approximately hori-
zontal plates or blades formed with forward or advance edges which, compared
with their rearward portions, are rigid, said plates or blades being attached to
the boat, substantially in the manner described.
2. A device for preventing leeway of and imparting motion to boats com-
prising a rod or stay provided with one or more laterally extending and normally
horizontal or approximately horizontal plates each formed with a forward or
advance edge, which as compared with the rearward portion is rigid, and con-
nected to the said rod or stay at or near the said forward or advance edge only,
substantially as described.
Dated this 27th day of March 1900.
For the Applicant.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.