IMPROVEMENTS IN THE CONSTRUCTION OF DOUBLE SHIPS, BOATS, CANOES, AND SUCH LIKE FLOATING STRUCTURES FOR THE MORE CONVENIENT CARRIAGE OF PERSONS
Year: 1873

page_text: LETTERS PATENT to Mowbray Walker, of 12, Great College Street, in
the City of Westminster, Agent, for the Invention of "IMPROVEMENTS
IN THE CONSTRUCTION OF DOUBLE SHIPS, BOATS, CANOES, AND SUCH LIKE
FLOATING STRUCTURES FOR THE MORE CONVENIENT CARRIAGE OF PERSONS."
A communication from abroad by Joseph Burnet, of Candy, in
the Island of Ceylon.
-
Sealed the 8th May 1874, and dated the 13th November 1873.
PROVISIONAL SPECIFICATION left by the said Mowbray Walker at
the Office of the Commissioners of Patents, with his Petition, on
the 13th November 1873.
I, MOWBRAY WALKER, of 12, Great College Street, in the City of
Westminster, Agent, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE CONSTRUCTION OF DOUBLE SHIPS, BOATS, CANOES, AND
SUCH LIKE FLOATING STRUCTURES FOR THE MORE CONVENIENT CARRIAGE OF PERSONS"
(a communication to me from abroad by Joseph Burnet, of Candy, in the
Island of Ceylon), to be as follows :-

page_text: •
The object of my Invention is to construct the said double boat or
ship so as to obtain a small area of immersion with great breadth of
beam, so that while it will not be liable to be upset by the action of
winds and waves or to be filled with water it may be propelled by sail or
otherwise with speed; and also that while the body or floating portion
yields to the undulating action of the waves the passenger deck or
platform will be comparatively free from the rolling and pitching
motions incident to sea-going vessels. Thus in building a double boat
on my principle I construct two water-tight tubes or caissons of a
cylindrical or other convenient form in transverse section, but
in length much greater than their breadth, and tapering at the
ends to a conical or wedge inclining upwards. On the upper side
at the centre of these tubes strong but light supports are attached
furnished on each side of the tube with strong socket ring, axle
bush, or other convenient joints, and the two tubes or caissons are
connected together at about ths their length apart by a transverse
beam or axle fitting easily into the said sockets or joints, the object
and effect of which is to rigidly connect the tubes transversely
at their centres, but to allow each free and independent motion in a
vertical plane, turning on the axle joints as a centre. These supports
which contain the axle joints are raised to such a height above the tubes
or boats so as will allow waves of great inclination, such as breakers, to
pass over them and under the platform supported by them. In order to
strengthen this lateral connection between the tubes diagonal stays or
ties may be attached by loose joints from the axle beam to the tubes at
points right and left of the central joint. On the centre of this axle
beam at right angles thereto midway between and parallel to the tubes
is rigidly fixed another longitudinal beam, and towards each end of this
centre beam another (transverse) cross beam at right angles thereto and
parallel to the centre axle beam is attached by a loose fitting collar or
other convenient joint, the ends of such beams resting on suitable
supports on the tubes or boats. It follows from this arrangement of
beams and joints that either end of each tube may rise or fall with the
action of the waves without imparting to or counteracting the vertical
action of the tube opposite. The tubes or boats will oscillate indepen-
dently upon the centre beam as upon an axle or pivot, and however.
counter the direction of motion under opposite quarters of the entire
structure the centres of the transverse beams will be in the same plane
with cach other and the longitudinal beam.

page_text: As the floating tubes are kept equidistant by the centre axle, motion
being only permitted in a vertical plane, it follows that when their ends
are oppositely raised and depressed the distance between any given point
on their surface will be greater than when they are in the same horizontal
plane or level with each other. To allow for this variation of length
the end cross beams which oscillate on the centre longitudinal beam are
not rigidly attached to their supports on the tubes or caissons, but slide
under, over, or between rollers on these supports; or the ends of the
beams terminate in strong oblong loops or metal frames, within which
the sheaves or rollers on the supports work in such a manner that the
centres of all the joints when the tubes are level are in the same
plane.
In order also to maintain a constantly supporting connection between
the tubes while allowing this compensation in conjunction with the
roller arrangement above described the end beams and tubes may be also
united by a short crank, the arm of which lies horizontally in line of
the beam when it is level, and the two tubes are in the same line, but
when the ends of either are elevated or depressed the crank is drawn
over the dead point, and an amount of travel or elongation of the beam
is allowed equal to the radius of the crank. By these means sufficient
variation in the length of the beam is permitted while maintaining the
planes of motion of the ends of the tubes equidistant from cach other.
The transverse axle beam and the centre longitudinal beam are still
further united by diagonal ties to give firmness and strength to the
whole, and at the same time to form a diamond-shaped framework or
base on which to lay a passenger deck or platform.
The effect of the several forms and combinations hercin-before.
described is that while the entire structure is rigid laterally and longi-
tudinally, and while the floating portion is capable of contrary motions in
a vertical direction according to the pressure of the waves a raised
central platform is obtained where these motions are diminished, and if
the size of the tubes or boats be proportionately increased for larger
waves these motions will be almost nullified.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Mowbray Walker in the Great Seal Patent Office
on the 12th May 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, MOWBRAY
WALKER, of 12, Great College Street, in the City of Westminster, Agent,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of November, in the
year of our Lord One thousand eight hundred and seventy-three, in
the thirty-seventh year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Mowbray Walker, Her
special licence that I, the said Mowbray Walker, my executors,
administrators, and assigns, or such others as I, the said Mowbray
Walker, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF DOUBLE SHIPS, BOATS, CANOES, AND SUCH
LIKE FLOATING STRUCTURES FOR THE MORE CONVENIENT CARRIAGE OF PERSONS," a
communication to me from abroad by Joseph Burnet, of Candy (or
Kandy), in the Island of Ceylon, upon the condition (amongst others)
that I, the said Mowbray Walker, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Mowbray Walker, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Drawings here-
unto annexed and to the letters and figures marked thereon, that is to
say :-
The object of my Invention is to construct the said double boat or

page_text: ship so as to obtain a small area of immersion with great breadth of
beam, so that while it will not be liable to be upset by the action of
winds and waves or to be filled with water, it may be propelled by sail
or otherwise with speed; and also that while the body or floating portion
yields to the indulating action of the waves the passenger deck or
platform will be comparitively free from the rolling and pitching
motions incident to sea-going vessels. Thus in building a double boat
on my principal I construct two water-tight tubes or caissons of a
cylindrical or other convenient form in transverse section, but in length
much greater than their breadths, and tapering at the ends to a conical
or wedge-like form, the axis of the cone or wedge inclining upwards.
On the upper side at the centre of these tubes strong but light supports
are attached furnished on each side of the tube with strong socket ring,
axle bush, or other convenient joints; and the two tubes or caissons are
connected together at about ths their length apart by a transverse beam
or axle fitting easily into the said socket or joints by corresponding
attachments, the object and effect of which is to rigidly connect the
tubes transversely at their centres, but to allow such free and indepen-
dant motion in a vertical plane, turning on the axle joints as a centre.
These supports, which contain the axle joints, are raised to such a height
above the tubes or boats as will allow waves of great inclination, such as
breakers, to pass over them and under the platform supported by them.
In order to strengthen this lateral connection between the tubes diagonal
stays or ties may be attached by a loose joint or joints from and on the
axle beam to the tubes at points right and left of the central joint. On
the centre of this axle beam at right angles thereto midway between
and parallel to the tubes is rigidly fixed another longitudinal beam; and
towards each end of this centre beam another (transverse) cross beam at
right angles thereto and parallel to the centre axle beam is attached by
a loose fitting collar, loop, or other convenient joint, the ends of such
beams resting on suitable supports on the tubes or boats. It follows
from this arrangement of beams and joints that either end of each tube
may rise or fall with the action of the waves without imparting to or
counteracting the vertical action of the tube opposite. The tubes or
boats will oscillate independently upon the centre beam as upon an axle
or pivot, and however counter the direction of motion under opposite
quarters of the entire structure the centres of the transverse beams will
be in the same plane with each other and the longitudinal beam.

page_text: As the floating tubes are kept equidistant by the centre axle, motion
being only permitted in a vertical plane, it follows that when their ends
are oppositely raised and depressed the distance between any given point
on their surface will be greater than when they are in the same hori-
zontal plane or level with each other. To allow for this variation of
length the end cross beams which oscillate on the centre longitudinal
beam are not rigidly attached to their supports on the tube or caissons,
but slide under, over, or between rollers on these supports; or the ends
of the beams terminate in strong oblong loops or metal frames, within
which the sheaves or rollers on the supports work in such a manner that
the centres of all the joints when the tubes are level are in the same
plane.
In order also to maintain a constantly supporting connection between
the tubes while allowing this compensation in conjunction with this
roller arrangement, above described, the end beams and tubes may be
also united by a short crank, the arm of which lies horizontally, or
nearly horizontally, in line of the beam when it is level, and the two
tubes are in the same plane, but when the ends of either are elevated or
depressed the crank is drawn over the dead point, and an amount of
travel or elongation of the beam is allowed equal to the radius of the
crank. By these means sufficient variation in the length of the beam is
permitted, while maintaining the planes of motion of the ends of the
tubes equidistant from each other.
The transverse axle beam and the centre longitudinal beam are still
further united by diagonal ties to give firmness and strength to the 2
whole, and at the same time to form a diamond-shaped framework or
base on which to lay a passenger deck or platform.
The effect of the several forms and combinations herein-before
described in that while the entire structure is rigid laterally and longi-
tudinally, and while the floating portion is capable of contrary motions 3
in a vertical direction according to pressure of the waves, a raised central
platform is obtained where the motions are diminished, and if the sides
of the tubes or boats be proportionately increased for longer waves these
motions will be almost nullified.

page_text: caissons; B, the centre axle beam connecting the tubes by means of
the loops a on its under side, working in sockets 6 attached to the tubes
by and forming part of the supports c; C, the centre longitudinal beam
fixed at B, D, the end oscillating beams pivoted to E, the diagonal
beams to strengthen the connection of B and C, and form a base for a
deck or platform.

page_text: opening of the oblong frame or loop, which maintains firm but free
connection with the beam by the wheel or roller d³.
Figure 7 also represents another modification of my Invention. In
this case, instead of one heavy beam working between two supports on
the tubes A, I make the end oscillating beams a compound of two lighter
beams D, D, connected at some inches apart by chocks D¹; e, e, are
socket pieces attached to D, D, to contain the short crank arms d', the
crank d³, a block or cylinder pivoted to the support c on the tube (indi-
cated by the dotted lines) of a guide rod working in d and connecting
the double beams D, D, with the floating tubes by a crank ď³.
By this
arrangement I only require one support on the floating tubes for each
end of the beam instead of two, as previously shown; but I desire to
state that I do not confine myself exclusively to the use of one beam in
the other modifications of my Invention, as it is obvious that a com-
pound beam or two independent beams may be used in conjunction
with the forms of compensating attachment shown in the previous

page_text: Third. The compensating arrangement by means of wheels, rollers,
cranks, guides, and slide rods, substantially in the manner herein set
forth and illustrated in the accompanying Drawings.
And, Lastly. The attainment by these means of great stability as well
as elasticity in the entire structure, with a minimum of indulatory
motion on the upper surface or desk.
In witness whereof, I, the said Mowbray Walker, have hereunto
set my hand and seal, this Twelfth day of May, in the year of
our Lord One thousand eight hundred and seventy-four.