IMPROVEMENTS IN CENTRE BOARD VESSELS
Year: 1883

page_text: LETTERS PATENT to Philip Middleton Justice of Southampton Buildings in
the County of Middlesex Fellow of the Institute of Patent Agents for an
Invention of "IMPROVEMENTS IN CENTRE BOARD VESSELS
" communicated
to him from abroad by John S Birch of the City County and State of New
York United States of America
PROVISIONAL SPECIFICATION left by the said Philip Middleton Justice
at the Office of the Commissioners of Patents on the 16th January 1883.
PHILIP MIDDLETON JUSTICE of Southampton Buildings in the County of
Middlesex Fellow of the Institute of Patent Agents "IMPROVEMENTS IN CENTRE
BOARD VESSELS" A communication to me from abroad by John S Birch of the
City County and State of New York, United States of America
This Invention consists of an improved contrivance for centre board vessels
whereby the centre board may be extended lengthwise of the ship nearly the
whole length so that it may be correspondingly diminished in depth, it also
consists of improved means of letting down and hoisting up the centre board to
economize the labour and also to enable the board to bear the same relations to the
bottom of the vessel proportionately whether partially or wholly let down and to
rise when it strikes bottom, also of a contrivance whereby the forward portion of
the centre board may be hoisted up while the vessel shifts about to facilitate the
swing of the bow to windward in making the tacks and also of an alarm signal
attachment to the centre board by which a bell will be sounded when it rises by
striking the bottom to give notice of shoal water all as hereinafter more fully
described
It is proposed to make a centre board space, along the vessel nearly from stem to
stern enclosed by two partitions, a cover and end sections said space opening
through the bottom of the vessel, the two sides of which are to be connected across
said space at suitable intervals along it by strong bolts passing through the timbers
in which they are fastened by screw threads, shoulders and nuts or equivalent
devices so as to stay the sides of the hull properly for substantial construction, and

page_text: in this space it is proposed to arrange a centre board having slots through which
the stay bolts pass the said slots allowing the centre board to be shifted up and
down as is required for such board but the bolts may be omitted in small vessels
For the means of shifting the centre board up and down it is proposed to incline
the slots so that by pulling the board backward it will be raised up flush with the
bottom of the vessel or thereabout and by releasing it it will slide forward and
downward; a chain pulley and lever or any equivalent devices may be used for
raising the said board and a latch and notched quadrant or other device may bo
employed for holding it up The centre board will be sufficiently shorter than the
space to allow of its lengthwise motion when raising or lowering it
It is proposed to make slots in the centro board for all the stay bolts in advance
of the hindmost one and connect a chain with the forward end to raise it on
the sternmost bolt as a pivot to facilitate the swinging of the bow around in
making the tacks. In order to prevent undue pressure on the sternmost bolt by
the overbalancing forward end of the centre board when in the lowermost position
and to avoid too much friction thereon at the beginning of the hoisting movement
it is proposed to attach friction rollers to the centre board near its rear upper
corner and provide rails on the partitions for them to bear against to resist the
upward thrust of the rear end The stay bolts are designed to carry friction rollers
to facilitate the working of the centre board
i It will be understood that a centre board arranged on the stay bolts by inclined
slots as is proposed will naturally rise and relieve the vessel of undue strains when
it touches bottom if hard and it is proposed to attach a signal bell to be actuated
by a rack or any approved means for giving warning, at once of the danger at
hand. It will be understood that the improved-contrivance affords a practical
keel with the advantage of the centreboard arrangement and it is a centro. board
without materially greater draught than the ordinary keel. It is also much less
subject to damage than the ordinary centre board and the rise in the vessel is
much less than the ordinary board rises In small vessels the partition enclosing
the centre board space may be utilized for supporting seats for passengers and
crew It is proposed to vary the inclinations of the slots proportionately to the
required greater extension of the centre 'board at the stern than at the bow, that
is, the angle of the rear slot will be greatest and those forward will be less so that
for a given lengthwise movement of the centre board it will rise and fall as much
more at the stern end than at the bow end as the difference in the desired pro-
jection of the board below the bottom from end to end whereby it will be seen the
centre board will bear the same proportionate relation to the vessel no matter how
much or little it may be let down so that the weights attached to the lower edge
for ballast will not be changed relatively to the vessel except in the degree of the
extension of the centro board and a slight change lengthwise which is a material
advantage as compared with those centre boards that swing up and down ön
one end
I desire it to be understood that I do not limit myself to the slotted arrangé-
ment of the keel for causing it to rise and fall for it may have rollers or studs
attached to the sides and working on inclined ways attached to or formed in the
sides of the partitions
These I consider as equivalent to the slots working on the bottom and are
included in the invention to be used either when the stay bolts are or are
not used

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Philip Middleton Justice in the Great Seal Patent Office on the
13th July 1883.
PHILIP MIDDLETON JUSTICE of Southampton Buildings in the County of
Middlesex Fellow of the Institute of Patent Agents "IMPROVEMENTS IN CENTRE
BOARD VESSELS a communication to me from abroad by John S Birch of the
City County and State of New York. United States of America
"
In this improvement in centre board vessels, it is designed to use a centre board
having more of the form and qualities of a keel by reason of greater length.and
less depth than the common centre boards; and the invention consists of an
arrangement of inclined ways for its support and on which it may be raised and
lowered, so that while it is made to rise and fall about in the same measure
throughout its whole length instead of swinging as most centre boards do, the
power to raise it needs only to equal about half the weight of the board and the
resistance is no more in any part of its use than another, so that the power that is
competent for moving it in any part of its course is sufficient for all parts. In
order that the centre board may project to a greater extent aft than forward
whether partly or wholly down and that such greater extensions shall be propor-
tionately the same whether the centre board be wholly or partly down, the ways on
which the centre board rises and falls are varied as to their inclinations, the angles
of the forward ways being less than those aft that is to say, if it be desired that
the extensions of the centre board be three feet aft and two feet six inches forward
when wholly down the inclines shall so vary in the angles that when half down
the aft end will extend one foot six inches, and the forward one foot three inches
and so on The essential object of this arrangement is that weight applied to the
lower edge of the centre board for ballast shall bear the same relations to the line
of the centre of gravity of the vessel which rises from stern to bow-from end to
end of the centre board whether it is wholly or partly extended To more fully
describe the nature of the invention and how the same may be practically employed,
reference is made to the accompanying drawing in which Figure 1 is a longitudinal
section of the hull of the vessel along the centre board space showing my improved
arrangement of the centre board, the said board being partly lowered to the bottom
of its range. Fig 2 is a similar view showing the centre board lowered at the
stern and raised at the bow as my improved arrangement enables it to be for
favouring the tacking of the vessel about Fig 3 is a transverse section of the hull
of the vessel taken on the line of Fig 1 Fig 4 is a detail in section on the
line y y Fig 1 and Fig 5 is a partial longitudinal section shewing the application
of a signal apparatus as I propose to indicate the rise of the centre board by riding
on shoal bottom It is proposed to make a centre board space a along the vessel
nearly from stem to stern enclosed by two partitions 6 cover c and the end
sections d said space opening through the bottom of the vessel, the two sides of
which are to be connected across said spaco at suitable intervals along it by strong
bolts d' passing through the timbers e in which they are fastened by screw threads
shoulder g and nut h or equivalent devices so as to stay the sides of the hull.
properly for substantial construction and in this space I propose to arrange a centro
board having slots j through which the stay bolts d¹ pass, the said slots allowing
the centre board to be shifted up and down as is required for such board, but the
bolts may be omitted in small vessels. For the means of shifting the centre board
up and down I propose to incline the slots; 45° or thereabouts to support about

page_text: half the weight of the centreboard on the bolts, so that by pulling the board back-
ward with power equal to about half the weight of the centre board it will be raised
up flush with the bottom of the vessel or thereabout, and by releasing it, it will slide
forward and downward, a chain 7 pulley m and lever nor any equivalent device may
be used for raising the said board, and a latch and notched quadrant or other device
may be employed for holding it up The centre board will be sufficiently shorter
than the space a, to allow of the lengthwise motion of the keel board for so raising
and lowering it It is also proposed to make slots o in the centre board for all the
stay bolts in advance of the hindermost one and connect a chain with the
forward end to raise it on the sternmost bolt as a pivot to facilitate the swinging
of the bow around in making the tacks In order to prevent undue pressure on
the sternmost bolt d' by the overbalancing forward end of the centre board when
in the lowermost position and to avoid too much friction thereon at the beginning
of the hoisting movement I propose to attach friction rollers g to the centre board
near its rear upper corner and provide rails t on the partitions b for them to bear
against to resist the upward thrust of the rear end The stay bolts d¹ are designed
to carry friction rollers u to facilitate the working of the centre board It will be
seen that a centre board arranged on the stay bolts d' by inclined slots as
I propose
will naturally rise and relieve the vessel of undue strains when it touches bottom
if hard and I propose to attach a signal bell v to be actuated by a rack w or any
approved means for giving warning at once of the danger at hand It will be seen
that my improved contrivance affords a practical keel with the advantage of the
centre board arrangement, and it is a centre board without materially greater draft
than the ordinary keel It is also much less subject to damage than the ordinary
centre board and the rise in the vessel is much less than the ordinary board rises
In small vessels the partition b enclosing the centre board space may be utilized
for supporting seats for passengers and crew I propose to vary the inclinations
of the slots i proportionately to the required greater extension of the centre board
at the stern than at the bow, that is; the angle of the rear slot will be greatest
and those forward will be less so that for a given lengthwise movement of the
centre board it will rise and fall as much more at the stern end than at the bow
end, as the difference in the desired projection of the board below the bottom from
end to end whereby it will be seen the centre board will bear the same pro-
portionate relation to the vessel no matter how much or little it may be let down
Bo that the weights attached to the lower edge for ballast will not be changed
relatively to tho vessel except in the degree of the extension of the centre board
and a slight change lengthwise which is a material advantage as compared with
those centre boards that swing up and down on one end I desire it to be
understood that I do not limit myself to the slotted arrangement of the keel for
causing it to rise and fall, for it may have rollers or studs attached to the sides
and working on inclined ways attached to or formed in the sides of partition b.
These I consider as equivalent to the slots working on the bottom and I mean to
include them as my invention to be used either when the stay bolts are or are not
used. Having thus described the nature of the invention as communicated to me
by my foreign correspondent What I clain and desire to secure by Letters Patent
is 1st In a vessel, a centre board arranged on two or more inclined ways of 45°
or thereabout wherein it slides or rolls for being raised or lowered also whereon
about balf the weight of the board is supported, and also whereon it is raised or
lowered by means of a cord or chain stretched in the same inclination as the
ways on which the centre board works substantially as described 2nd In a vessel,
a centre board arranged on two or more inclined ways of about 45° but varied
as to their inclination, to enable the centre board to project more at the stern than
the forward end, the difference of extension being proportionately the same for any
extension of the centre board substantially as described 3rd In a vessel a centre
board arranged on two or more inclined ways of about 45° whereon about half its
weight is supported and being provided with curved ways or slots O intersecting

page_text: the inclined ways forward of the sternmost one allowing the centre board to be
swung up at the forward end on the sternmost rest as a pivot substantially as
described 4th In a vessel a centre board arranged on two or more inclined ways
of about 45° whereon about half its weight is supported, the roller q and ways tin
combination with the centre board and located at one end to resist the thrust of
the overbalance of the other end when the board shifts along said inclined ways
substantially as described.
In Witness whereof I the said Philip Middleton Justice have hereunto set
my hand and seal this thirteenth day of July in the year of Our Lord eighteen
hundred and eighty three.
Signed spaled and delivered }
ALLEN P JONES
56 & 55 Chancery Lane
London W.C.
PHILIP M. JUSTICE (LS)