AN IMPROVED PORTABLE SAFETY BOAT OR PONTOON
Year: 1841

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
HOLCROFT, of Nassau Street, in the County of Middlesex, Gentleman, send
greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-eighth day of October, in the fifth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Holcroft, my exors, adiñors, and assigns, Her especial licence, full power,
sole privilege and authority, that I, the said Thomas Holcroft, my exors, adñors,
and assigns, and such others as I, the said Thomas Holcroft, my exors, admors,
or assigns, should at any time agree with, and no others, from time to time and
at a'l times thereafter during the term of years therein expressed, should and
lawfully might make, use, exercise, and vend, within that part of Her Majesty's
United Kingdom of Great Britain and Ireland cal'ed England, Her Dominion
of Wales, and the Town of Berwick-upon-Tweed, an Invention communicated
to me by a Foreigner residing abroad, of "AN IMPROVED PORTABLE SAFETY BOAT OR
PONTOON;" in which said Letters Patent there is contained a proviso that I, the
said Thomas Holcroft, shall cause a particular description of the nature of the
said Invention, and the manner in which the same is to be performed, to be
inrolled in Her Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said in part recited Letters Patent,
as in and by the same, reference being thereunto had, will more fully and at
large appear.

page_text: NOW KNOW YE, that in pursuance of the said proviso, I, the said Thomas
Holcroft, do hereby declare that the nature of the said Invention, and the
manner in which the same is to be performed, are fully described and ascer-
tained in and by the following Specification thereof, reference being had to the
Drawings hereunto annexed, and to the letters and figures marked thereon,
that is to say:-
Figure 1 of the sheet of Drawings hereunto annexed, marked Number I,
represents a longitudinal section, Figure 2 a plan, and Figure 3 a cross section.
of the Improved Portable Safety Boat or Pontoon. A, B, is the keelson.
C, C, C, are ribs which spring from the keelson, to which they are secured by
the swivel joints H, H. D, E, is a gunwale to which the ribs are made fast
at top, and which is jointed at 1, I, just beyond the last rib at each end.
G, G, G, are side pieces which bind the ribs laterally together, being nailed or
otherwise secured to them about half-way between the keelson and gunwale.
I, J, M, are the stem and stern pieces, which are secured to the keelson by
nuts M, M, and connected to the nearest ribs by the links K, L, K, L, which
links turn on joints at K, K, and are attached by hooks and eyes to the ribs
at L, L. 0, 0, are girders by which one half of the ribs (that is to say, every
other rib) are connected transverse'y at top; they are linked to the top of the
ribs by swivel joints, and are jointed at the middle; but to support them at
the middle joints when extended, each rod has a short under-stay O¹, which is
secured at one end to one half of the rod, while the other is made fast by a ring
P, which slides on the other half of the rod, and is just large enough to come
over the under-stay when brought forward to the centre of the rod. R, R, are
rollocks for the oars. The parts before described constitute the framework of
the boat or pontoon, and may either be of wood, or cane, or metal, or any other
strong but light substance which will answer the purpose, excepting only that
the joint links and rings should in every case be of metal. When the framework
of the boat has been thus put together, it is covered up to the edges of the gun-
wale with any of the approved sorts of waterproof canvas, or with thin sheets of
metal protected from oxidation (as far as may be) by suitable coatings, which
covering is to be nailed or otherwise secured to the gunwale. To the stem and
stern and sides of the boat, floaters V, V, V, are also attached, consisting of hollow
air and water tight cases, either of metal or of some other impervious material,
or consisting of cases filled with cork shavings or other substances of the like
small specific gravity, or consisting of large pieces of solid cork; and these
floaters, when consisting of cases filled in, either of the modes aforesaid, are
divided into compartments, two, three, four, or more, so that in the event
of the compartment being damaged so as to let in air or water, the injury

page_text: may not extend to the other compartments, and the boat still remain insub-
mergible. When the boat is not required for use, it can be folded up so as to
carry on the shoulder or under the arm, or like an umbrella. For this purpose
the nuts M, M, which secure the stem and stern pieces to the keelson, are to
be first unscrewed, and then the eyes L, L, by which they are connected with
the nearest ribs, unhooked, after which the links K, L, are to be turned on
their joints K, K, till they are in a line with the keelson; the stem and stern
ends of the gunwale are next to be doubled down (at the joints I, I,) till they
are in the position indicated by the dotted lines J, J¹ (Figure 1), and the
cutwaters J, J, brought round into the position indicated by the letters M, M',
in the same Figure. The rings P, P, are then to be moved back, so as to set
free the under-stays O¹, which will allow the transverse girders 0, 0, to yield
at their middle joints. By then pressing the ribs G, G, G, together, the whole
apparatus will be brought into the folded-up position indicated by the dotted
lines in Figure 3. For transporting heavy goods or cattle, the construction of
the boat may be modified in manner shewn by the midship section, Figure 4.
A is the keel. P, a top piece which extends from stem to stern in a line with
the keel. A, O, E, are ribs which are connected by joints with the keel.
B, D, C, one of several transverse girders which are passed through hooks,
D, bolted to the top piece P, and secured to the gunwale at one end by swivel
joints, B, and at the other by hooks and eyes C. O, O, are diagonal tie rods,
When the
connected by joints to the ribs A, O, E, and to the top piece P.
framework has been thus put together, it is either covered all over, as well at
top as at the sides and bows, with canvas or some other suitable material made
air and water tight, or it is covered up to the gunwale only, as in the case of
the boat just before described, and lined with hollow air-tight cases, or with
cases filled with cork shavings, or other substance of the like small specific
gravity, or with large pieces of solid cork, and with a sufficient number of
each sort to give it the degree of buoyancy required; a deck of wooden planks,
with parapets to prevent cattle from falling overboard, as shewn at F, F, F,
Figure 4, may be readily added when wanted.
For a wager or life boat of still greater lightness than that first herein-before
described, the system of construction may be modified in the manner shewn in the
Drawings, Figures 1, 2, and 3, of Number II. Figure 1 being a longitudinal
section of such a boat. Figure 2, a plan; and Figure 3, a transverse section
through the line A, B, of Figure 1. The transverse girders in this case are only
three in number, C, D, E, and consist of three pieces united together by coupling
links, and when the boat is folded up, and the ribs and the girders assume the
positions indicated by the dotted lines in Figure 3. The bows of the boat are also

page_text: made to double over, each in one piece (the rib pieces b, b¹, being first unhooked
at d, d¹), the cutwater and gunwale pieces of the bows being connected to the
body of the boat by swivel joints c, c, e, and c¹, c, e¹, which all turn in but one
direction. The same means are to be adopted for covering this boat, and rendering
it insubmergible, as have been before directed to be used in the case of the
boats represented in Figures 1, 2, 3, and 4, of Number I.
The same system of construction as before exemplified is carried out on a larger
scale in the life and pontoon barge represented in Figures 1, 2, 3, and 4, of the
Drawings Number III. Figure 1, is a longitudinal section, Figure 2 a plan, and
Figure 3 a transverse section of this barge. A, A, are the ribs made of strong
wrought angle iron, and firmly bolted to B, B, iron straps, which gird a foundation
piece C, which extends from end to end of the barge. I is the gunwale, made of
wood, to which the ribs are secured at top. G, H, are transverse iron girders.
D, D, diagonal iron stays, which connect the ribs at their angles with the
transverse girders. F, F, vertical iron rods, which pass from the transverse
girders at the points where the diagonal stays are linked to them down to the
bottom of the ribs, and thus serve to counteract any undue pressure inwards
of the stays.
The framework so constructed is covered in with a strong
planking, as well at the top as at the sides and ends, and this planking is next
covered over with canvas, or some other suitable material, made air and water
tight. The deck has then another sheet of the air and water tight canvas or
other material laid over it, and secured to it by the packing piece J. L, L, L,
are additional cross girders of wood to which the top planking P, is secured.
T, T is cast-iron railing, the uprights of which are secured to the deck by
the bolts K, K. For the better keeping of the interior of the barge free
from water an air-pump may be kept on deck to force in air as required. M,
Figure 3, is one of two planks with which the barge should always be provided,
to form a communication between it and the shore when horses, cattle, or
goods are required to be landed. A portable footway, made of pieces of wood
linked together, as separately shewn in Figure 4, should also be kept folded
up on deck, by unrolling which and throwing it flat upon the planks M, M,
the landing may occasionally be much facilitated. N, N, are centres on which
the ribs revolve, so that by undoing all the bolts by which the girders and
stays and other connecting rods are connected together, the entire barge, with
its various appointments, may be folded up into a comparatively small compass,
and transferred by any sort of land carriage with great promptitude and
expedition.
And having now described the nature of the said Invention of an Improved
Portable Safety Boat or Pontoon, communicated to me as aforesaid, and the

page_text: manner in which the same is to be performed, I declare that what I claim as
constituting the Improvement by which the same is distinguished from all other
portable safety boats or pontoons heretofore in use, is the mode or modes
herein-before described of constructing the framework of such boat or
pontoon of a number of separate pieces, capable of being connected or
disconnected at pleasure by means of joints, links, hooks, and other like
contrivances, of whatever suitable material such pieces may consist; and
also the mode or modes herein-before described of so covering and buoying up
a framework constructed in the manner aforesaid, as that it shall be impervious
to air and water, or incapable of submersion in water, whatever may be the
suitable material or materials used for such covering or buoying up.
In witness whereof, I have hereunto set my hand and seal, this
Twenty-eighth day of April, in the year of our Lord One thousand.