AN IMPROVED LIFEBOAT OR RAFT, AND IMPROVED APPARATUS OR MECHANISM TO BE USED THEREWITH
Year: 1875

page_text: LETTERS PATENT to George Newman Dunn, of Kinsale, in the
County of Cork, Ireland, Surgeon and Physician, for the Invention
of "AN IMPROVED LIFEBOAT OR RAFT, AND IMPROVED APPARATUS OR
MECHANISM TO BE USED THEREWITH."
Sealed the 9th May 1876, and dated the 18th November 1875.
PROVISIONAL SPECIFICATION left by the said George Newman
Dunn at the Office of the Commissioners of Patents, with his
Petition, on the 18th November 1875.
I, GEORGE NEWMAN DUNN, of Kinsale, in the County of Cork,
Ireland, Surgeon and Physician, do hereby declare the nature of the
said Invention for "AN IMPROVED LIFEBOAT OR RAFT, AND IMPROVED APPARATUS
OR MECHANISM TO BE USED THEREWITH," to be as follows:-
This Invention relates to the construction of an improved expanding
life or raft boat, and comprises as material features thereof certain
special arrangements of apparatus by which the expansion is effected;
also a peculiar construction of raft bottom by which it is rendered strong

page_text: and is enabled to assume (in its expanded condition) an approximately
flat and good shape for sea worthiness, a peculiar construction of the
superstructure by which it is also enabled to assume (in its expanded
condition) a shape well calculated for sea worthiness, a peculiar addition
to the tiller handle enabling one man to control the helm and otherwise
manage the boat when under sail, also the provision of means for
collecting rain water for use at sea; a peculiar construction and formation
of a folding keel by which the sailing power and steadiness is greatly
increased, also the provision and peculiar construction and formation
of a water anchor by which the boat is enabled to be inclined or directed
considerably to the right or left, and by such means to avoid danger or
gain a port while making stern way when lying to in heavy weather;
and an advantageous construction and convenient arrangement of cases
for the stowage of provisions, stores, and other necessities for a voyage,
and which are intended to act or lie as thwarts when the boat is in its
unexpanded condition, and serve as stays, and will help to strengthen
the superstructure when in its expanded condition; and the principal
objects of the Invention it will be seen are the provision of a strong,
capacious, light, buoyant well protected and ready fully provisioned and
furnished apparatus or means for saving life at sea when required.
Its advantages may be considered, firstly, as a raft; and, secondly, as
a boat.
As a raft, it is light, strong, and buoyant, flat, and not
easily injured. Two or more can be placed one upon another, and can
be packed together upon a ship's deck ready for instant launching or
floating off. In such a state the raft boat occupies little room, as three
of them will occupy only the space of one ordinary boat of a capacity
equal to one of them, and it is always ready, fully furnished in every
particular, for instant launching. As a boat and in its expanded con-
dition it will rescue as many persons in cases of emergency as can find
room on its floor. In such condition also it is of good weatherly shape,
flat floor, half decked by canvas, affording good shelter to its occupants,
and being provided with a water anchor it will ride head to wind safely
in a heavy sea.
The improved expanding boat raft is thus essentially a combination of
boat and raft formed of or by strong frameworks of pine surrounded
externally by a thick cork buoy, and containing within the area of the
main frame a batten bottom, which is expanded or depressed into place
by mould boards, and a superstructure which is expanded or elevated

page_text: into position by a parallel arrangement or motion, these motions being
effected simultaneously. Both of these structures are enveloped or
covered by a single or double canvas, which is rendered water tight
by repeated applications of raw oil, paint, or other suitable preparation.
The mechanical means used to effect these movements are of simple
construction, and are contained within the boat centrally. From them
a single rope passes or may pass out at the stern, and this is coiled upon
a winch or windlass so placed that a man even in the water may be able
to use it, and by the power of his arms expand the ready-filled and
furnished raft into a capacious and buoyant boat. The remainder of the
space within the raft before expansion is so planned or arranged as to be
almost entirely taken up by the galvanized zinc casings, stores, or tanks
containing food, and stores, and clothing in waterproof bags, oars, mast,
and sails, and other necessaries for a voyage of many days' duration.
In case of accident to the canvas covering or bottom a means of
repair is provided by a false bottom of canvas, which can be slipped
from above over the entire true bottom, and which may also serve as an
awning, a spare sail, or a tent for use on land.
The expansion of the raft is effected by an arrangement of levers, the
power being applied by means of the rope from the windlass, and the
levers being provided with an arrangement of blocks giving a double
purchase, and being fulcrumed by pivots in slots in a framing running
in the direction of the length of the boat. The levers are also pivotted
to central hinged mould boards, and by their action they depress the
latter and cause them to expand the bottom of the raft. As the bottom
is thus expanded other mould boards at the stern or other parts of the
raft fall by the action of gravity, and thus the bottom when once
expanded is caused to keep its shape. To the central mould boards are
also attached elevating arms, by which the superstructure is expanded
or raised simultaneously with the expansion or depression of the bottom.
In the unexpanded condition all these appliances lie in a horizontal
or nearly horizontal position, but in the expanded condition they all
assume a position more vertically inclined. These elevating arms act
directly upon the main framing of the superstructure, to which are
attached an arrangement of parallel bars in such a manner that all parts
of the superstructure shall be equally raised at the same time to prevent
any unnecessary strain upon it, and when in this expanded condition it

page_text: may further be stayed and strengthened if required by placing struts at
the bow or other parts giving the least resistance to collapse. The
external layer or layers of canvas may be further protected from
injury by a thick external protecting band of cork or other similar
clastic material.
The bottom of the boat I construct of an arrangement of rounded
and flat batteus, and these I bind or secure together by strong canvas
or webbing. This arrangement I prefer, as it will allow of the flat
bottom of the raft being expanded by the mould boards to the approxi-
mately flat or peculiarly curved or rounded bottom necessary for the
boat, and besides giving great strength and protection from injury it is
otherwise very preferable. This bottom I also fit or provide with a
hinged or folding keel, the half parts of which when required for use
are let down into position, where they stay and support themselves, and
when not so required are hauled up against the bottom of the boat by
an arrangement of wires or ropes, or their equivalents, and they are or
may be thus actuated from the inside of the boat.
I also provide an arrangement of lea boards to aid the keel or for use
instead of it, and when not required these boards will or may lie as
spare thwarts over the water tanks in the length of the boat; and the
provision I make for collecting rain water when required and conveying
it to the said tanks for storage and use consists of a canvas flap, which
when the raft is unexpanded covers the cork buoy on either side and
keeps the folded side covering dry, and when it is desired at sea to catch
the rain water for consumption a cord is run through eyelet-holes therein
and tautened, and this makes a shallow tray of the canvas deck, and the
rain running to the part most depressed is suitably conveyed therefrom
by a short tube to the water tanks.
I also provide the improved raft boat with a water anchor, the angle
of the set of which from the boat I regulate by two cords passing
through a series of floats arranged along the anchor hawser or rope. I
thus am enabled to direct the boat to the right or left as desired while
making stern way.
In the construction of the boat I also leave or provide especial spaces,
cases, or receptacles for the stowage of rockets, blue lights, and other
signalling appliances, and the tiller of the rudder I provide with a
'peculiar appliance designed to enable one man to manage the boat an

page_text: to attend to other requirements besides the helm, especially when under
sail. This appliance consists of a peculiar clip and tightening ring,
which are combined with the tiller handle, and enable the rudder to be
fixed immediately in any position required. The rudder can be shipped
from within.
The above referred to galvanized zinc cases used for the storage of
water, provisions, clothing, and other necessities are all by preference
hinged so as to enable their being immediately turned from their flat
to their upright and strengthening position when the raft is being
expanded into the boat. They are also or may be provided with sliding
doors, so that ready access may be had to their interiors, and with
canvas bag mouths to prevent the water from getting to their contents.
It will thus be seen that the raft boat, all ready and 'fully provisioned
and provided with other necessities for a sea voyage of many days for
as many as its capacity will admit, can be lowered from a ship by a
single rope, or float, or it can be thrown overboard, and from its con-
struction it will be impossible to capsize, and will make fair sailing on a
wind, and will not suffer to any material extent by being knocked by
the waves against the ship's side; also that it can be most easily
expanded into a boat by a single man; and lastly, that it provides for
more shelter for its occupants than any open boat.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Newman Dunn in the Great Seal Patent
Office on the 18th May 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
NEWMAN DUNN, of Kinsale, in the County of Cork, Ireland, Surgeon
and Physician, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of November, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did for Herself, Her heirs and suc-
cessors, give and grant unto me, the said George Newman Dunn, Her
special licence that I, the said George Newman Dunn, my executors,
administrators, and assigns, or such others as I, the said George

page_text: '
Newman Dunn, 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 "AN IMPROVED LIFEBOAT OR RAFT, AND IMPROVED APPARATUs
OR MECHANISM TO BE USED THEREWITH," upon the condition (amongst others)
that I, the said George Newman Dunn, my executors or admini-
strators, 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 George Newman Dunn, 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 in writing, and on reference being
had to the accompanying Sheet of Drawing, that is to say:-
-
This Invention relates to the construction of life or raft boats, in such
a manner as to enable them to be expanded from a flat form constituting
a raft into a boat of greater depth, combining sufficient strength and
capacity with great buoyancy and safety in a seaway, the principal
object of the Invention being the provision of a strong capacious light
buoyant well protected and ready fully provisioned and furnished
apparatus or means for saving life at sea when required.
The Invention comprises as material features certain special arrange-
ments of apparatus by which the expansion is effected, a peculiar
construction of raft bottom by which it is rendered strong and enabled
to assume (in its expanded condition) an approximately flat and good
shape for sea worthiness, a peculiar construction of superstructure by
which it also is enabled to assume (in its expanded condition) a shape
well calculated for seaworthiness, a peculiar addition to the tiller handle,
enabling one man to control the helm and otherwise-manage the boat
when under sail, the provision of means for collecting rain water at sea
for use, a peculiar construction and formation of a folding keel by which
the sailing power and steadiness is greatly increased, the provision,

page_text: externally by a single or double canvas which is rendered water-tight by
repeated applications of raw oil paint or other suitable preparation.
The sides of the main frame consist of planks 2 into which the
thwarts 3 are shouldered and tenoned, the tenons of the end thwarts
pass through and are secured by cross pins 4 and well brace the boat
ends, see Figures 1 and 5. Longitudinal pieces 5 run the whole length
and follow the inner curve of each side; they are suitably secured and
let down for half their substance upon the thwarts and thus act as knees.
Each thwart (except the bow thwart) has an under strengthening piece
6 to which a mould board 7 is hinged; these mould boards are depressed
as herein-after described and determine the shape of the bottom. The
bow is formed of and rendered shapely by bent pieces of wood 8 (see
also Figure 7), securely fastened to and overlapping the side planks 2
which extend beyond the bow thwart to allow of this, and are cut where
the bow pieces join them in a sloping direction so as to form a kind of
splice. The lowest of these pieces 8 having to bear a considerable strain
is connected by a strap of copper or galvanized iron 9 (see Figures 3
and 8) to the upper part of its plank. A broad thick piece of leather 10
is stretched across the under part of the bow and secured all round to
the bent wood 8. This leather bears the strain of all the longitudinal
ribs or battens 11, 12, forming the bottom and which rest thereupon, as
shown in Figure 1.
.
The arrangement of these ribs is illustrated in Figures 1, 6, 9, 10,
and 11, they consist of battens of American elm, hickory, or other light,
strong, and elastic wood, and they are bound and secured together, and
supported and interlaced by strong canvas or webbing 13 nailed to the
said side planks 2, and form a support to the above referred to exterior
waterproof canvas bottom 14, Figure 6, which is nailed, cemented, and
otherwise suitably fastened to the side planks 2, and as many of the ribs
also as may be thought desirable. These ribs differ in number and
shape according to the lines and comparative breadth of the boat, those,
12, at the centre of the bottom may be flat, while those, 11, at the sides
where the curvature is greatest are more or less rounded in order to
submit with freedom to the double curvature to which they are
subjected. They are all tapered off towards the bow (see Figures 12)
and the side ones are also tapered towards the stern from amidships,
allowance being made for the thickness of the interlacing web and
canvas tubing, and so that they easily fit when lying flat within the

page_text: ,
space enclosed by the main framing at the bow and stern. As above
mentioned, these ribs take a good bearing upon the leather 10 stretched
under the bow, and which by its size allows for their shortening when
bent, and lengthening when straightened. At intervals along the length
of the boat the ribs 11 and 12 are supported by outside web bands 15
and by interwoven bands 16 (see Figure 10). Outside all these are
other broad canvas bands 17 extending from side to side, and sewn
longitudinally between every rib to other opposed pieces 18 of lighter
canvas placed inside (see Figure 9), thus forming tubes enclosing the
ribs separately. This arrangement allows of the flat bottom of the raft
being expanded by the said mould boards 7 to the approximately flat or
peculiarly curved or rounded bottom necessary for the boat, and gives
great strength and protection from injury.
.
"
33
"
The expansion of the raft is effected by an arrangement of levers 19
(see Figures 1 to 3) the power being applied by means of a rope 20,
which may be of copper or galvanized iron wire, and which passes out
at the stern and is coiled upon a windlass or winch 21 (see Figures 1, 2,
and 13). This winch, in addition to the recess and hand spike arrange-
ment 100, is fitted with a to-and-fro or up" and down" hand lever
working alongside the wooden stern piece. The pawl of this hand lever
engages in the ratchet wheel 102, and pulls it downward at each stroke.
This winch is also so constructed, arranged, and placed that a man even
in the water may be able to use it, and by the power of his arms expand
the ready filled and furnished raft into a capacious buoyant boat, and
even if the boat in launching should be overturned, the levers 19 arc
provided with an arrangement of blocks 22 (Figures 1 and 2), giving a
double purchase, and they are fulcrumed by pivots 23 in slots 24 in the
said main framing; they are also pivoted to the said central hinged
mould boards 7, as shown in Figures 14, and by their action they depress
the latter and cause them to expand the bottom of the raft. As the
bottom is thus expanded other mould boards 7* at the stern or other
parts of the raft fall by the action of gravity or are pushed or otherwise
actuated (see Figures 2, 3, and 4), and as herein-after described, and
thus the bottom, when expanded, is caused to keep its shape; (if
required the said pivots 23 of the levers 19 may be withdrawn from the
slots 24, and the said blocks 22 and tackling removed, and the said
levers lowered down; the slotted main frame may then be made available
as a scat.) To the sternmost of the central mould boards 7 (which

page_text: should hinge and open in opposite directions) are also attached or
connected, by means of chains 25 held by pins 26, elevating arms 27
(see Figures 2, 4, 6, 11, and 25), by which the superstructure (formed
of a gunwale streak or frame 28) is expanded or raised simultaneously
with the expansion or depression of the said bottom. If required the
superstructure can be lowered independently of the bottom by releasing
the pins 26.
In the raft or unexpanded condition all these appliances lie in a
horizontal, or nearly horizontal, position (see Figure 3), but in the boat
or expanded condition (see Figures 2, 4, and 6,) they all assume a
position more vertically inclined. The elevating arms 27 are duplicated
(see Figures 6 and 11), and connected at the top and bottom by rivets.
The top rivets work to and fro in short slots 101 in the frame 28 (see
Figures 2 and 4); and the lower rivets fasten links of the chains 25.
The arms 27 thus act directly upon the main framing 28 of the super-
structure, to which is also attached an arrangement of parallel bars 29
working on pivots (as shewn) in such a manner that all parts of the
main framing of the superstructure shall be equally raised at the same
time to prevent any unnecessary strain upon any part. When in this
expanded condition the superstructure is stayed and strengthened by
struts or supporting legs 30, the lower ends of which fall into slots in,
or preferably against stop blocks, on the side pieces of the main
frame, and which stop blocks acts as supports to the superstructure
when lowered. A cord 31 (see Figure 4) passing from one to the other
is made fast to each side of the low board 32, which is pulled into
position by another cord passing centrally through its lower end over
a pulley and back to the stern of the boat; the movements of all the
legs 29 are thus effectually simultaneously. The top frame 28 and its
bow frame 33 are further supported by thesaid bow board 32. This bow
frame 33 is connected at 34 by a pin 35 working in a slot 36 to an
elevating arm or bar 37, so that its movements are simultaneous with
the frame 28 in a short slot 36*, in which it also works by a pin 35*.
It can be lowered if wished by pulling the said bow board a little back,
when the lower end of the bar 37 on each side can be sprung off its
pivot 38 (which is made for the purpose without a head) and folded
upwards towards the top frame 28. In its rising the frame 28 takes
up with it the above referred to layer or layers of canvas or rubber cloth
encasing the superstructure to which it is connected by loops or doubles

page_text: of strong leather or canvas sliding on strong wire carriers 39 (see
Figures 15), so that sufficient play is gained for the backward fall of
the frame 28 when lowered. Side strips of similar material are fastened
beneath the gunwale and lap over the sides. If a canvas half deck 40
is fitted to the boat, as herein-after described, these strips may be a
continuation of it, and likewise of the covering of the rising portion of
the bow.
The bow of the boat is formed to contain an air chamber 41 (sec
Figure 2), which fills or is filled with air during expansion; there may
be also air bags 42 provided to fit under the thwarts 3 when required,
and may be used to contain clothing and placed in any unoccupied
portion of the raft. And the top sides of the boat may also by being
made double be formed as air chambers 43 extending the entire length
of the boat, and these chambers are or may be filled by expanding
bellows 44 (see Figures 1, 2, 3, and 16), formed by the stern sheets, and
so situated that they can be worked by means of a lever handle 45 by
a man in the water in the same manner as the expanding windlass 21
or by hand inside the boat.
The canvas deck 40 above referred to, and which is illustrated in
Figure 1, may be made double and connected by a short flexible pipe
to a nozzle of the bellows 44; this arrangement would materially assist
the boat in righting itself if thrown overboard bottom upwards.
In case of accident to the above mentioned canvas covering or
bottom 14 a means of repair is provided by a centre canvas piece which
buttons over the open space of the canvas deck 40 on to tags or buttons
on the strengthening side cord 46 of the latter, and which can be
slipped from above over any faulty part of the bottom, and may also
serve as an awning or spare sail, or a tent for use on land. The said
expanding of the boat may also, as above referred to, be effected and
secured by hand. Between the main thwarts 3 there is a hinged
piece 47, see Figures 4, 5, and 6, which doubles upon itself when the
boat is unexpanded, and which may be raised and its unattached leg
placed against a pin 48 on the foot of the second and opposite mould
board 7. The same may be done to a hinged piece 49 at the stern, the
disengaged leg of which may be placed against a pin 50 of a stop
block 51. On the stern of the boat being a little raised, and moderate
pressure exerted upon the vertex of these legs, there is caused a hori-

page_text: zontal thrust of great force, increasing when most required, viz., when
expansion is nearly complete, pins are then inserted in staples, and all
is secured.
The hinged or folding keel 52 with which I provide the boat is
illustrated in Figures 17. It is formed of half parts 53, hinged at their
ends to a main piece 54, bolted through the middle flat battens or
ribs 12 and to blocks 55 and 51 above them. When required for use,
the parts 53 are drawn down into position, where they stay and support
themselves, as shewn, by an arrangement of wires or ropes 56, and when
not so required they are hauled up against the bottom of the boat
(see Figure 11) by similar wires or ropes 57, or their equivalents, and
they are or may be thus actuated from the inside of the boat.
I also provide an arrangement of lee boards 58 to aid the said keel or
for use instead of it, and when not required, these boards which are
shewn detached with their sheaths or fittings 59 in. Figures 18 may lic
aš spare thwarts over the water tanks 60 (Figure 1) in the length of the
boat, or they may be fitted between the mould boards 7 and 7* and act
as permanent extenders. And the provision I make for collecting rain
water when required, and conveying it to the said tanks 60 for storage
and use, consists of a canvas flap 61, which when the raft is unexpanded
covers the cork buoy on either side and keeps the folded side covering
or top sides dry, and when it is desired at sea to catch the rain water
for consumption a cord is run through eyelet holes 62 therein and
tautened, and this makes a shallow tray of the canvas deck 40 and the
said additional piece, which when laced up adds to the safety and the
comfort of the boat and serves to collect the rain water, which running
to the part most depressed is suitably conveyed therefrom by a short
tube 63 to the water tanks 60. This provision is illustrated in Figures
1, 2, 4, and 5; and when it is required to row the boat the canvas 40
and the said additional piece can be quickly unlaced.
I also provide the improved raft boat with a water anchor 64 (see
Figures 19), the angle of the set of which from the boat can be regulated
by two cords 65 passing through a series of floats 66, arranged along
the anchor, hawser, or rope 67, to regulate the direction of the backward
drift of the boat. The hawser may be from two to four or five fathoms
long, and secured to the bridle proceeding from eye bolts 68 on each
side of the bow (see Figure 1), the bridle should also be sufficiently long

page_text: to pass backward and forwards over the bow of the expanded boat.
And the tiller, 69 of the rudder 70 I provide with a peculiar appliance
(see Figures 4 and 5) designed to enable one man to manage the boat
and to attend to other requirements besides the helm, especially when
under sail; this appliance consists of a peculiar clip 71 with an under
projecting rib which engages with a groove in the tiller handle 69, and
of a tightening ring 72, these being combined with the tiller handle 69
enables the rudder 70 to be fixed immediately in any position required.
The rubber can be shipped from within.
In the construction of the boat I also leave or provide especial spaces
under the fore thwart 3, in which I place sliding cases or receptacles 73
for the storage of rockets, blue lights, and other signalling appliances,
for use at night or other times,
i
The remainder of the space within the raft is in great part occupied
by the previously referred to galvanized zinc cases 98, used for the
storage of water, provision, clothing, and other necessities; these are all
by preference hinged, so as to enable them to be readily turned down-
wards from their flat (Figure 11) to their upright and strengthening
position (Figures 6 and 20) when the raft is being expanded into the
boat, and they are provided with sliding or turning plug doors 74
(see Figures 21) which allow of ready access to their interiors and
prevent the entrance of water. These doors are constructed of a cork
plug 75, a galvanized iron plate 76, and a wooden wedge shutter 77,
which jambs in side clips 78 of the door frame 79. These cases thus
fitted also materially increase the power of flotation of the boat in the
event of the bottom getting much injured.
The boat is also provided with a suitable water exclusion valve 80
(see Figures 1, 16, and 22) to prevent the entrance of water and to
allow of the necessary entrance of air during the expansion of the raft
even if it should be overturned in launching. It is formed of a
galvanized iron case 81, and with cork 82, wood 83, and leather 84, top
and bottom floats secured by rods 85 sliding in tubes 103 soldered to the
case 81. The lowermost float plugs the bottom and prevents the
entrance of water, and the uppermost float keeps the top open for the
entrance of air, thus for the purposes of expanding and inflation it is
immaterial which side of the boat is uppermost or which end of the
valve is immersed.

page_text: The raft in its unexpanded condition is held together by suitable
broad web bands which are simultaneously released by pulling a cord
led to the stern from one side of the gunwale, and connected to
instantaneous releasing buckles 86 (see Figures 23), which allow of the
immediate setting free of the boat previous to lowering or expansion;
this releasing cord is preferably made fast to the lever handle of the
windlass 21, so that the buckles are released at its first stroke.
In ocean or other steamers these improved raft boats as thus con-
structed, adapted, and fitted may be conveniently stowed and supported
ready for immediate launching upon or immediately under the bridge,
the bridge being provided with dropping platforms lowering to each
side, and otherwise constructed as illustrated in Figures 24. Or the
raft boats may thus form an addition to the real flooring of the bridge,
being lightly covered by tarpaulin and planks.
The platforms are made in two parts hinged and supported centrally,
as shown by iron stanchions 87 which also bind it to the bridge; the
sides are formed double, of galvanized thin iron plates 88 or of wood
planking, held together by ties 89 and supported apart by beams of
wood 90. Between the plates or planks 88 rise rails 91 carrying each a
small roller 92 to assist the raft 93 in going off easily. The platform
carries other rollers 94 upon which the unexpanded raft rests. The two
pairs of blocks 95 are single, the upper one being a tail block, but of the
two pairs 96 the upper of each is double, and so leads both wire rope
falls 97 to the windlasses 99 where they are wound together. These
windlasses are worked by to-and-fro hand levers, and upon releasing
their pawls the platform is immediatly lowered and the boat let go ;
the raft may if time permits be expanded upon the platform before it
falls, other boats of this construction stored upon other portions of the
bridge may be shifted on to the platform and launched from it on cither
side.
A similar guide platform can be arranged at the stern of a ship to be
raised by hand, and so pivotted that the action of it as a lever opens a
port when the small raft boat lying upon it is instantly delivered out at
the stern, and can be let go instead of a mere life buoy to a man over-
board. It will thus be seen that the raft fully provisioned and provided
with other necessities for a sca voyage of many days for as many as its
capacity will admit can be lowered from a ship by a single rope or float

page_text: ·Dunn's Improvements in Life Boats, &c.
off or be thrown overboard, and that from its construction it will be
almost impossible to capsize and will make fair sailing on a wind, and
will not suffer to any material extent by being knocked by the wave
against the ship's side; also that it can be most easily expanded into a
boat by a single man, and lastly, that it provides for more shelter for its
occupants that any open boat which in such cases is of very material
importance.
I would here remark that the improved raft boat may be constructed
without some of the special arrangements herein-above described. In
its simplest form it might, by preference be expanded by hand as above
described, and then lowered and used as an ordinary boat. But when
constructed as described with the complementary adaptations it becomes
a life-saving boat of the best description, as if thrown overboard in great
emergency it can be subsequently (that is while in the water) expanded,
and the air chambers inflated even if it should be overturned and bottom
upwards, the arrangements being, as above described, specially adapted
to cause it to right itself.
Many of the above described improvements may also be applied in or
to the construction of rafts and boats generally.
Having now fully described and ascertained the nature and objects of
my said Invention, together with the manner in which the same is to be
or may be carried into practice, I would remark in conclusion that I
claim as my Invention,-
The construction of life-saving raft boats in such a manner as to
enable them to be expanded from a flat form constituting a raft into a
boat of greater depth, and the formation of the same of three material
parts, namely, a rigid main frame, an expanding bottom, and an
expanding top or superstructure.
I also claim especially the peculiar modes above fully described and
illustrated on the accompanying Drawings of constructing, combining,
and operating the three material parts herein-above claimed.
And I also claim the further provision and combination with boats of
such a construction of the other fully described and illustrated material
features and subsiduary improvements; and the peculiar constructions
of these material and subsiduary parts separately, substantially as

page_text: described and as illustrated on the accompanying Drawings, and their
application in or to the construction of rafts and boats generally.
In witness whereof, I, the said George Newman Dunn, have
hereunto set my hand and seal, this Fifteenth day of May, in
the year of our Lord One thousand eight hundred and seventy-
six.
GEORGE NEWMAN DUNN. (L.S.)