IMPROVEMENTS IN THE CONSTRUCTION OF COLLAPSIBLE BOATS
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by William Henry Crispin at the Office
of the Commissioners of Patents on the 23rd February 1877.
WILLIAM HENRY CRISPIN, of Marsh Gate Lane, Stratford, in the County of
Essex. IMPROVEMENTS IN THE CONSTRUCTION OF COLLAPSIBLE BOATS."
"
This Invention consists in certain improvements in the construction of boats
whereby the same are rendered capable of being collapsed and extended ready for
use with great facility, whilst great advantages are gained by reason of the small
space which is occupied by the boats when collapsed.
"
The sides of the boat are formed of wood, or steel, or any other suitable material
or materials, the several planks or strips being built up or connected in the
well-known manner. By preference, for very light boats a compound material,
known commercially as vulcanized fibre," in the form of thin sheets, cut or
moulded into planks or strips, or a combination of such material with wood, is
employed, the same being built up, by preference, externally in a horizontal arrange-
ment, and respectively overlapping each other, the inner sides, which are towards
the interior of the boats, having attached thereto sheets or a series of planks or
strips of the same material or materials arranged vertically, and also overlapping
each other, leaving small cavities or spaces between them.
When great strength is required it is preferred to use two thicknesses of the
vulcanized fibre when the same is employed. Any suitable fastenings are used, and
the small cavities or spaces which exist between the two series of horizontal and
vertical sheets, planks, or strips, by reason of the same overlapping, become filled
with air, and thus tend to increase the buoyancy of the boat, whilst they also receive
any portions of water which may find its way through the joints of the external
planks or strips, the vertical arrangement of the inner planks or strips preventing
the entrance of the same into the interior of the boat. An external and also an
internal keel, constructed of wood or any other suitable material or materials, are
provided, and between -such keels are placed and secured thereto, from end to
end, sheets of metal or of the said vulcanized fibre, and wide enough to form
internal sides of the boat, the same acting at the same time as a hinge, and thus
enabling the sides of the boat to be collapsed or brought into proximity to each
other.

page_text: The respective ends of the boats are formed of sheet steel, vulcanized fibre, or
other material possessing a certain degree of elasticity or flexibility, so that
the
same readily give way or adapt themselves when the sides of the boat are col-
lapsed, and also return to their normal curvature or position when the pressure
exerted to keep the boat in a state of collapse has been removed. When, however,
the sides of the boat are formed entirely of the "vulcanized fibre," such elastic or
flexible material as before mentioned may be dispensed with, as the vulcanized fibre
itself possesses the requisite qualities in a sufficient degree. The thwarts in the
interior of the boat are respectively provided with a joint or hinge at the ends or
centre thereof, stops, stays, or any suitable contrivances being used to keep the
thwarts in an extended state, the removal of such stops or stays, or other con-
trivances, allowing the thwarts to fold upon their joints or hinges.
For the purpose of imparting sufficient steadiness to the boat, cells or chambers
may be provided at the bottom thereof for the purpose of holding water, which may
be admitted through suitable openings therein upon the boat being lowered, and
which water will serve as ballast.
It will be manifest that great advantages result from the construction of boats in
accordance with this Invention; inasmuch as the same will, when collapsed, occupy
very little space, whilst they can be expanded and rendered fit for launching in a
very short time, and when launched are less liable to injury than boats as ordinarily
constructed.