IMPROVEMENTS IN SHIPS AND BOATS
Year: 1884

page_text: I SAMUEL FIRTH Engineer Aberystwith in the County of Cardigan do hereby
declare the nature of my invention for IMPROVEMENTS IN SHIPS AND BOATS to be
as follows:-
This invention consists in constructing Ships or Boats of all kinds with several
hulls, either attached close together side by side or attached so as to leave a space
for the flow of water between the hulls.
I use by preference three hulls, one central driving hull, and two outside or
balancing hulls, one on each side of the central hull, these two outside balancing
hulls are shorter than the central hull and do not draw so much water as the said
central hull.
The three or more ship or boat hulls when connected together in a suitable and
convenient manner form a complete ship or boat which can be raised or lowered at
will by means of a system of pumps the whole vessel can be lowered by pumping
in water balast; the vessel can be raised by simply pumping out the water
ballast, and when so raised the balancing hulls can be adjusted so as to merely
skim the water.
From the very fine lines that the hulls can be built to, and the light draught of
water resulting therefrom; greater speed can be obtained than by an ordinary
vessel of the same tonnage, with a less consumption of power.
It will readily be seen that a 'War Ship' constructed according to my invention
would have so much stability, that in engaging forts or batteries the ship might be
lowered so as to leave little except a strongly armed turret exposed to the enemys
guns, and the outside hulls could safely carry a thickness of armour that has
hitherto not been reached, and from its great speed and light draught of water, it
would not only be a Powerfull Ironclad but also a fast cruiser.
For sailing vessels my invention allows a greater spread of canvass (owing to
the stability obtained in using the triplex hulls) than is possible (in proportion to
tonnage) by any ordinary vessel, thus-an-additional gain in speed is obtainable,
and for boats of all kinds whether propelled by steam power, sails, or oars, greater
speed and stability is obtained in proportion to the displacement, by my method of
triplex hulls than by the ordinary other methods now used.
I can where desireable use more than three hulls, say five or seven, but I prefer
to use the triplex.

page_text: mprovements in snips and Boats.
I SAMUEL FIRTH of Cobden Chambers Corporation Street Birmingham do
hereby declare the nature of said invention for "IMPROVEMENTS IN SHIPS AND
BOATS," and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
According to my Invention I construct ships or boats with three or more hulls
by preference three securely fastened together but with longitudinal waterways
between them. The middle hull I make longer than the outside hulls which
latter by preference do not draw so much water as does the middle hull the said
outer hulls being in some cases (for instance with small craft) used merely as
balance hulls. They are preferably divided into water tight compartments. For
vessels of large size I prefer to make all the hulls of the same immersion or
draught. In the centre hull I prefer to make a false bottom to inclose a space
between itself and the lower part of the hull and this space I divide into water
tight compartments A vessel thus constructed requires no ballast for stability and
cannot readily be capsized and when it meets a wave any water that does not 1
run through the longitudinal water ways between the hulls is divided by or
thrown off the backs of the outside hulls which may be rounded off at the upper
outward edge Should one or more of the water tight compartments be damaged
there is enough buoyancy in the rest of the boat to prevent it sinking and the
whole of the centre hull may be full of water and the boat will not sink,
For war purposes the false bottoms of the hulls may be used as air or water
compartments according to requirements and the whole vessel may be raised and
lowered at will by pumping water in and out This ready means of lowering the
vessel will be useful when engaging shore batteries or for any other reason
great steadiness and stability of the vessel will enable heavy guns to be carried on
comparatively small vessels."
The
The leverage on the water for stability being horizontal instead of vertical the
hulls can be constructed with very fine lines and shallow immersion or light
draught and as ballast for stability is not required great speed can be attained
whether the ships or boats be propelled by steam or by sails or by oars.
In Figure 1 of the accompanying drawing I have shewn in diagrammatic plan an
arrangement of the hulls according to my Invention A is the centre hull and B Ba
are the outer hulls The hull A is made longer than the outer hulls B B³ and
projects at the ends beyond the said hulls B B a b b³ represent the air tight
compartments hereinbefore mentioned and C. C are the longitudinal water ways
between the hulls. The lines at d d represent the gunwales which may surround
a deck extending beyond the sides of the hull A as shewn. Figure 2 is a transverse
section when the three hulls have the same draught; whilst Figure 3 is a similar
section shewing the centre hull having a deeper immersion or draught. Figure 4
is a longitudinal section shewing one of the outer hulls and the connection by
which it is joined to the middle hull which is indicated in dotted lines. It will be
understood that there may be more than three hulls for example there may be five
as shown in the diagram Figure 5 where the centre hull is marked A the hulls

page_text: next it B. B. with the water ways C. C. between them and the centre hull E. E³.
are the additional outer hulls having waterways F F between themselves and the
hulls B. B. The lines indicate the connecting framing, it being understood that
in all cases the hulls are connected together by any suitable means of connection.
•
Having now particularly described and ascertained the nature of my Inven-
tion and in what manner the same is to be performed I declare that what
I claim is
First. The construction of ships or boats with three or more bulls the centre
hull being longer than the other hulls substantially as hereinbefore described and
illustrated by the accompanying diagrams.
Second. The construction of ships or boats with three or more hulls the outer
bulls having a less draught (that is being less deeply immersed in the water) than
the centre hull substantially as herein before described and illustrated by the
accompanying diagram figure 3.