An Improved Keel for Pleasure Sailing Vessels.
Year: 1896

page_text: Date of Application, 1st Jan.. 1895
Complete Specification Left, 1st Oct., 1895-4ccepted, 1st Jan., 1897
An Improved Keel for Pleasure Sailing Vessels.
I, THEOPHILUS OSBORN SMITH of 28 Walton Well Road, Oxford, in the
County of Oxfordshire, Yacht and Boat Builder do hereby declare the nature of
this invention to be as follows:-
My invention consists of a new or improved arrangement of the fittings and parts of
movable keels for sailing yachts or boats and is designed to increase the speed and
safety of such vessels by affording increased facilities for utilizing and combining the
powers of the centre board or sliding keel and the rigid weighted keel to the varying
requirements of such vessels when racing or cruising. The keel is so fitted and
arranged that, whatever its weight or position, the vessel to which it is attached may
be capable of a pitching motion amongst waves, the keel remaining vertically
suspended from a pivot and not pitching or oscillating with the motion of the
vessel. Where so required, this pivoted pendulous keel may be drawn up or
down, backward or forward or in any other direction by suitable mechanism in or
upon a case or trunk and attached to the keel, the case being so shaped as to
allow the keel to rock or swing upon its pivot and within or partly within the
case.
Whereas it is found advantageous to the speed and safety of sailing vessels to
lower the keel to its fullest extent when sailing on a wind and to raise the keel
when sailing before the wind, and whereas it is also found that the vessel when
encountering waves has a pitching motion which is greatly exaggerated by the
weight of the keel which in many vessels forms a very large proportion of the
total weight of the vessel, I provide by my invention that there may be a limited
freedom of movement of the hull upon the keel or the keel where attached to the
bull. The vessel is thereby relieved of part of the inertia or momentum of the
keel when the vessel is pitching, and thus the hull of the vessel adapts itself
the more readily to the varying inclinations of the waves of the water on which it
is moving. The keel remains vertically suspended and, while following the
motions of the centre of gravity of the vessel in a vertical direction, it does not
follow the oscillating or pitching motion of the vessel when encountering waves.
The buoyant ends of the vessel may thus rise and fall the more readily, being
relieved of the influence of the keel in this motion more particularly. The keel
would naturally have a different period of vibration or oscillation to the period of
oscillation of the vessel, or the irregular motion imparted by the waves. The
motion of the vessel is easier, it maintains a more constant waterline in the sea and
is thereby faster. The vessel is also less likely to ship a heavy sea and sustain
damage by such means, and is thereby safer and drier for the persons on
board. At the same time the lateral resistance to leeway and the stability
due to the weight of the keel are rather augmented than diminished by this
invention.
I provide a keel of suitable material and of any shape or weight best adapted
to the vessel, and this keel is partially or wholly enclosed in a case or trunk so
shaped as to allow of a certain longitudinal swinging movement of the keel within
the case. I provide the keel with a strong pivot at its upper part and this pivot
forins the point of suspension of the keel and has its hearings upon or in the upper

page_text: part of the case. The keel is so suspended and the case so shaped that the former
may swing or the latter may oscillate through at least thirty degrees without the
ends of keel or case touching.
I provide also as may be required, either or all the following fittings and
attachments. To the pivot are attached rollers or other suitable bearings, and in
or upon the case, slide ways, grooves or other bearings of metal that the pivot
bearings or rollers may traverse them and be movable in a vertical, horizontal,
inclined or curved direction. I may also attach to the pivot or the upper part of the
keel a suitable block purchase, winch, or other mechanism to draw the keel along
the slide ways provided. Where it is desirable to reduce the friction of the keel
within the sides of the case I place rollers or other suitable bearings securely fixed
to the sides of the case or keel.
To further meet the requirements of such vessels as may be fitted with this
invention provide that the pivot may be readily withdrawn and the keel released
so that the vessel may be floated or otherwise lifted off the keel, or the keel may
be lifted through the upper portion of the case.
In all cases where this invention is applied to sailing vessels it is desirable, but
obviously not essential, that the pivot or point of suspension of the keel
should be arranged to come as near as possible to the centre of gravity of the
vessel.
Doted this 30th day of December 1805
THEO. OSBORN SMITH,
28, Walton Well Road, Oxfcrd.
1, THEOPHILUS OSBORN SMITH of 28, Walton Well Road, Oxford, Yacht and
Boat Builder 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 relates to improvements in keels for sailing yachts or boats, and
has for its object to provide means by which the speed of such boats may be
increased, at the same time rendering them safer.
It is well known that vessels on the sea receive impulses from the waves,
causing them to roll or pitch, and it is also known that a vessel with a heavy keel
or cargo does not adapt itself readily to the inclination of the waves and preserve
a constant water line, but rolls or pitches much more than is required to adapt its
water line to the varying surfaces, while a vessel less heavily loaded more readily
adapts itself to the waves.
According to my invention I arrange that the weighted keel required in most
pleasure sailing vessels shall be free to swing upon a pivot within the vessel in a
fore and aft vertical direction at its own normal period of vibration if disturbed by
any wave or other impulses. By this means the hull of the vessel may pitch
independently of the keel and at its own period of vibration, or according to the
waves it encounters, so that the mass of the keel is not added to the hull of the
vessel in its movements. By this means the notion of the vessel is reducel to a
minimum. The keel is so arranged that the vessel may have a normal pitching
motion amongst waves whilst the keel remains vertically suspended from its pivot,
and does not oscillate with the vessel. The keel is also movable so that it inny be
raised or lowered from its point of suspension and also if required moved backwards
or forwards, or in any desired direction. For this purpose a case or trunk is

page_text: employed containing or carrying suitable mechanism, and shaped so as to allow the
keel to rock or swing within it, the case enclosing the unexposed portion of the
keel. This keel is also easily detachable, arrangements being made by which
the pivot can be readily withdrawn and the keel thus released, so that the vessel
may he floated or otherwise lifted off the keel, or the latter may be dropped
should occasion require. Means may also be provided by which the keel can be
lifted through the upper portion of the case.
In order that the invention may be more clearly understood, reference is had to.
the accompanying sheet of drawings, in which
Fig. 1 is a longitudinal section of the keel and case, Fig. 2 is a vertical section
of the same on a line passing through the point of suspension,
Figs. 3 and 4 are longitudinal sections of a slightly modified arrangement
showing the invention applied to a light keel.
Referring to Figs. 1 and 2 the keel A. is formed from a strong metal plate of
shape and dimensions adapted to the requirements of the vessel to which it is to be
fitted. To the lower part of this plate the weight B of suitable shape and size
may be secured increasing the weight of the keel. The keel or plate A is carried
by the pin or pivot C at the upper end, this pin being provided in the arrangement
shown with the wheels or rollers D for the purpose hereinafter described.
The pivot may consist of a bolt passing through the keel plate, which may or
may not be provided with the strengthening plates E. These plates may project
beyond the end of the keel plate so as to form a shackle e to which a chain e', rope
or other device can be attached. The pivot must be placed at the extreme upper
corner of the keel plate, and the whole weight of the latter with its attachment is
suspended from this pivot.
The upper part of the keel is enclosed in a casing made entirely of wood or
metal or partly wood and metal, the sides F of which are fastened in a water tight
manner to a framing, of which the main keel or keelson G may form a part. The
upper part of this framing is arranged so that the case or trunk may rotate
through at least 30 degrees without the keel plate meeting any part of the case,
the keel being allowed to swing from the pivot through that angle without coming
into contact with any other part.
In order to raise or lower the keel, guides are provided of any suitable shape.
on or between which the pivot carrying the keel can more so as to be adjusted to
any desired position, the chain or other connection e' being employed to raise or
lower the pivot. The arrangement may be operated by hand or block tackle, or
any other device which will enable the heavy keel to be raised.
According to the arrangement shown in Figs. 1 and 2, a sloping metal plate H
is employed at each side of the case ou which the rollers D rest, this plate thus
supporting the weight of the keel. The rollers and pivot can thus travel upon the
sloping plate and can be secured in any position between the extreme points shown in
Fig. 1 in solid and dotted lines. These metal plates may be supported by a portion
of the side of the case, the upper part J of which forms a recess in which the
rollers and other attachments at the top of the keel plate may freely move. By
this means the keel may be raised or lowered, or moved forwards or backwards as
desired. I may, if found desirable, dispense with the special weights B and employ
a thicker keel plate to give the desired weight.
In order to reduce the friction against the sides of the keel when the latter is
forced against the sides of the case or trunk by lateral water pressure or inclination
of the vessel when under sail, 1 form recesses in the main keel of the vessel or
the lower part of the case or trunk in which friction rollers K are fitted, their
pivots being placed vertically and covered by the keel band or specially provided
plates.
Referring to Figs. 3 and 4 the arrangement is somewhat similar to that already
described, the invention being adapted to a light keel commonly known as a
centre board or centre plate. The plate A is suspended from the pivot C at the
upper extremity, the keel plate being free to oscillate round the pivot to an angle

page_text: of at least 30 degrees without touching the front or rear part of the frame F.
The pivot is also provided with the wheels or rollers D which can roll along the
supporting plate H' at the top of the case, so that the pivot can be drawn to the
front or rear as required, similar means being employed to those already described.
Instead of the metal plate H' any other suitable guide or support may be employed.
Fig. 4 shows the keel drawn up into the case or trunk by power applied to the
projection e at the upper extremity through a chain or rope. To raise the keel
into this position all that is required is to draw it forward, the front edge resting
against a metal plate, roller or other suitable bearing placed at the front of the
case so that on drawing the keel further forward the lower portion will be turned
up within the case, so as not to project below the bottom. When it is desired to
lower the keel the chain or other connection is released allowing the keel to drop
into a vertical position and to be suspended freely from the pivot. It can then
be drawn backward into any desired position until it abuts against the stop flat
the rear end of the case. By releasing the connections at the upper end of keel
the latter can be raised completely out of the case, and by removing the pivot it
may be allowed to drop through the bottom of the boat.
I am aware that sailing vessels have been previously fitted with sliding keels
working in trunks or cases, and some of these might under certain conditions be
capable of an independent oscillating motion. This however has not been under
control and properly provided for, and therefore has not contributed to the speed
or safety of the vessel. My invention provides means by which such movable keels
may be employed with safety, and placed in perfect control, and I do not claim as
my invention a sliding or oscillating keel, but improvements in the construction
and fittings thereof.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is.-
(1) In a sailing vessel a sliding keel plate suspended within a case or trunk from
a pivot about which the vessel can rock or the keel swing through at least
30 degrees, substantially as and for the purposes specified.
(2) In a sailing vessel, the combination with a sliding keel plate suspended from
a pivot within a suitable case, of rollers carried by the pivot, and guides on which
the rollers can run carrying the keel plate, substantially as and for the purposes
specified.
(3) In a sailing vessel, the combination with a keel plate pivoted within a case
and free to vibrate, of rollers carried by the pivot, bearings or guides supporting
the keel, and means for raising or lowering, or drawing the keel plate into any
desired position within the case, substantially as described and shown and for the
purposes specified.
(4) In a sailing vessel the combination with a case or trunk, and a pivoted
sliding keel within the said case or trunk, of bearings in the case and means by
which the keel may be drawn unto any desired position or drawn completely into
the case, substantially as described and shown in Figs. 3 and 4 and for the purposes
specified.
Dated this 1st dor of October 1896
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.