CERTAIN IMPROVE- MENTS IN STEAM BOATS, SHIPS, OR OTHER VESSELS, WHICH ARE PARTLY APPLICABLE TO OTHER PURPOSES
Year: 1837

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
GEMMELL, of Stockwell Street, in the City of Glasgow, in the County of
Lanark, Merchant, send greeting.
WHEREAS His late most Excellent Majesty King William the Fourth,
by His Letters Patent under the Great Seal of Great Britain, bearing date
at Westminster, the Sixth day of February, in the seventh year of His
reign, did, for Himself, His heirs and successors, give and grant unto
me, the said John Gemmell, His especial licence, full power, sole privilege
and authority, that I, the said John Gemmell, my exors, admors, and
assigns, or such others as I, the said John Gemmell, my exors, admors,
and assigns, should at any time agree with, and no others, from time
to time and at all times during the term of years therein expressed, should
and lawfully might make, use, exercise, and vend, within England, Wales,
and the Town of Berwick-upon-Tweed, my Invention of "CERTAIN IMPROVE-
MENTS IN STEAM BOATS, SHIPS, OR OTHER VESSELS, WHICH ARE PARTLY APPLICABLE
TO OTHER PURPOSES;" in which said Letters Patent is contained a proviso that
I, the said John Gemmell, shall cause a particular description of my said
Invention, and in what manner the same is to be performed, to be inrolled
in the High Court of Chancery within six calendar months next and imme-
diately after the date of the said in part recited Letters Patent.
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Gemmell, do hereby declare that the nature of my said Invention, and
the, manner in which the same is to be performed, are correctly explained

page_text: and specified in the annexed description in connection with the Drawings
attached thereto, and referred to therein.
For the more easy comprehension of my various improvements I have placed
them under four distinct heads of Invention.
The first head consists in giving certain new forms and additions to the
paddles and paddle wheels for propelling said vessels.
The second head relates to ameliorations in the construction and arrange-
ment of twin cogar or tube boats.
The third head consists in the construction of a vessel or vessels for facilitating
the passage of ships or other bodies through shallow waters, which vessel I
denominate "Gemmell's Marine Vehicle."
The fourth head relates to a novel arrangement of a vessel calculated for
navigating narrow canals or other waters.
I will now proceed to specify the details embraced under my first head of
Invention. In the Drawing, Figure 1, is represented a side view or elevation
of an ordinary paddle wheel, but having at the back of each paddle a curved
tapering piece a, a, a, the Figure of which will be best understood by reference
to a perspective sketch of the back of one of them given in Figure 2. The
object of these curved projections is to enable the paddles, as they successively
rise out of the water, to leave it with less abruptness, and consequently without
that violent agitation which has a tendency to destroy the solidity of bearing
in the immerged paddles that is essential to giving a proper resistance to the
impelling force. My next improvement consists in substituting for the ordi-
nary paddles others of a triangular form, in such manner that the paddles
may enter and leave the water softly and progressively. Figure 3 affords an
illustration of this contrivance, and one of the modes of applying it. b is the
axis of the wheel; c, c, c, the arms, to which are fastened the paddles
d, d, d¹, only three of which are introduced, to avoid complexity, in order that
the form may not be misunderstood, those at d, d, being seen in plan, and that at
d edgeways. Figure 4 is designed to exhibit another beneficial arrangement
of my triangular paddles, in which the broad and narrow ends are placed alter-
nately to the opposite sides of the wheel; but for the sake of distinctness in
this case also, only four paddles are introduced, two at the upper and two at
the lower side of the wheel, those paddles which are in shadow being supposed
to be the next in succession to the others which are in bright colour. Like-
wise, instead of each paddle being alternately reversed, they may be placed in
series of two, three, or more in one direction, and then in a similar number
in the contrary direction, alternately. And again, as a substitute for the ordi-
nary paddle, I divide its parallelogram longitudinally into three pieces, and

page_text: place the middle piece a little distance behind the other two, in order to soften
the concussion upon their entering the water, and to diminish the elevation of
the "back water" on their leaving it. Figure 5 represents a side elevation
of a paddle wheel in which this arrangement is exhibited, e, e, shewing the
ends of the two fore pieces, and f that of the single middle piece. Another of
my plans consists in forming the paddles of a propelling wheel into successive
steps, but in one continuous piece, as shewn in Figure 6 by three paddles
9,9, 9, 9, of this form, the several side bends in these tending to retard the
water from running off the wheels laterally, and to give more propulsive effect.
My improvements in paddles also consist in making the edges of paddle boards
serrated, as expressed in Figure 7, which form enables them to enter and leave
the water without so much disturbance as the straight-edged paddles cause.
Likewise, in forming the acting surface of paddles with ribs, grooves, or cor-
rugations, so as to retard the running off of the water too speedily, and
thereby add to the propulsive effect. Figures 8 and 9 are illustrative of these
plans. Another of my aforesaid "improvements" consists in giving a curved
form to the paddles, as represented in Figure 10, which gives a side elevation
of a wheel; and the ends of the paddles h, h, shew its direction. Next in order,
to give an improved steadiness as well as buoyancy to paddle wheels, I fix, by
hoops and screw bolts or other fastenings, a circular air-tight iron tube to the
outer ring or arms of each wheel, and contiguous to the inner edges of the
paddles. Figure 11 is explanatory of this contrivance, affording a side eleva-
tion of a wheel; i, i, i, are the ordinary paddles, and j, j,j, my tubular air-tigh
ring. This ring I recommend to be made of sheet iron, and in tubular segments
of the circle, although it may be of one entire annular cavity. The dimensions
of the tube may be one foot diameter in its transverse section to a wheel of
about fifteen feet diameter; but these proportions, as well as the material an
the precise situation of the ring, may be varied to suit particular cases. Another
of my "improvements" upon paddle wheels consists in fixing a ring or rim of
iron around the outer ends of the paddles or float boards, as they are at present
much subject to breakage by coming in contact with the inclined piles of wharfs as
well as other objects. This ring may be fixed on the outer corners or edges of the
paddles, as shewn at k, k, in Figure 12, or otherwise, so that the ends or corners of
the paddles may be protected by the ring receiving the pressure or concussion of
the opposing object. In the construction of the several novel forms of paddles
which I have now described, it will be necessary to affix them to the arms of
the wheels by screw bolts and nuts or other well-known means, and to make
the calculations regarding their number and the areas of their surfaces by the
same rules as are ordinarily applied in the construction of the common paddle

page_text: wheels, wherein the paddles are fixed in radial positions; and it should be
understood that my Invention consists in the forms or shapes of the paddles
described, whether they be fixed or turn upon axes, and in whatever position
they may be placed, or angle they may form, with the radius of the wheel
(excepting that form which is delineated at Figure 5), although I give the
preference generally to the radial position. My Invention also extends to all
practical combinations of the various forms of paddles described.
The second head of my Invention consists in certain improvements in
the construction of double or twin boats (also denominated cigar and tube
boats), and chiefly relates to the arrangement or position of the propelling
mechanism. Steam vessels of this description have heretofore been worked
by placing the paddle wheels or propelling apparatus in the channel or free
waterway in the centre, that is, between the two hulls, and the result has been
that such vessels have not acquired that degree of speed which was expected
of them. This disadvantageous action apparently arises from the rapidity of
the current in the narrow channel where the propellers work, which rapidity
is caused by the enlarged field of water between the hulls at the bows having,
when the vessel is in motion, to pass through the contracted space in the
middle at an accelerated speed before it can escape at the stern; consequently,
paddles so situated (that is, working in the direction of the current) can derive
but a very limited reaction or resistance from the water to propel the vessel.
To obviate these disadvantages I construct these my improved twin boats with
the paddles or propellers on the outsides of them, as represented in the Draw-
ings by Figures 13 & 14, whereof the former is a side elevation, and the
latter (wherein the principal arrangements are exhibited) is a plan. m, m, are
the twin hulls or boats, which are firmly united together by means of stays
and diagonal braces. n, n, are designed to represent the engines, and o, o, the
boilers. p is the cranked main shaft put in motion by the engines in the usual
manner, and driving at its extremities the low paddle wheels q, q. To avoid
the liability to which twin boats are peculiarly subject, of having other
vessels or objects interposing themselves between the hulls, or becoming other-
wise entangled together, I have invented a guard or fender, which, while it
protects them from those liabilities, serves also materially to strengthen the
parts included thereby, and as it were to form the two bows into one. This
fender is exhibited at r, r, s, t, in connection with Figure 14, and by itself
separately in the adjoining Figure 15, marked with the same letters of refe-
rence. My claims under this second of Invention consist in the application of
the propelling machinery, of whatever description, on the outsides instead of the
inside or middle of the twin or tube vessels as already described, also to the appli-

page_text: cation of a connecting fender to twin vessels of the kind described (so as to
form one bow), but variously modified to suit particular circumstances.
The third head of my Invention consists in the construction and application
of a nautical machine, which I denominate "Gemmell's Marine Vehicle," for
the purpose of buoying up and tugging or otherwise facilitating the passage of
vessels (and other objects that are so deeply laden or draw so much water as
to be incapable of passing through shallow waters, over shoals, rocks, and
other obstructions to navigation, and to conduct them to their destination.
This vehicle is a double-cased vessel of sufficient capacity to hold a ship or
vessel, with a portion of water around it, the size being determined according
to the class of vessels it is designed for, as well as the depth of the water
wherein it is to operate. The mechanical arrangements for effecting these
objects will be best understood by explaining them in connection with the
Drawings. Figure 16 represents a plan of the principal part; Figure 17, an
elevation, partly in section for the purpose of exhibiting the machinery;
Figure 18 represents the stern of a vessel in its place in the marine vehicle,
together with a transverse section of the latter bringing into view an end
elevation of the machinery. In all the Figures which relates to this third
head of my Invention, the same letters of reference indicate the same parts
however differently viewed. a, a, a, is the great central cavity for containing
the ship to be conveyed with water around it. It is left quite open at the
stern, and at 6 there is a large grated aperture or tube which passes (water-
tight at its juncture) through the bottom double casing of the marine vehicle.
The water has thus a free passage through this aperture and the open
stern end.
The form of the double casing which constitutes the marine
vehicle is shown best at c, c, c, c, in Figure 18. The inside partaking of the
shape of the inclosed ship, and the outside such as will, with the requisite
increased bulk, be the least calculated to meet with obstructions or to cause
impediments to the navigation of other vessels. This double case I make pre-
ferably of malleable iron plates seamed and rivetted together in a water-tight
manner, and duly strengthened by angle iron ribs, stays, and braces after the
manner practiced by the manufacturers of wrought-iron boats and large marine
boilers. In each apartment d, d, of the double case I fix by preference a high-
pressure engine of the horizontal kind, having the piston rod passing out
through stuffing boxes out of each end of the steam cylinder, and giving
motion, through the medium of rods and cranks, to two force pumps e, e,
which alternately receive water from the inside of the vessel at cach upstroke,
and expel it at each downstroke. The floor and partitions of these engine
apartments are made water and air tight, for the purpose of giving a proper

page_text: degree of buoyancy to the marine vehicles when immersed. Many of the
minor or subordinate parts of the mechanism (such as the fly wheels at z, z,
which communicate motion to the pumps by means of crank pins), I have
deemed it superfluous to describe by words, and others I have not delineated,
as they are well understood by every competent engineer in the line to be
necessary adjuncts to such mechanism, and as they form, distinctly considered,
no part of my Invention. The mode of operating with the marine vehicle is
to cause as much water to flow through a plughole or stopcock at its side, as
shewn in the Drawing, as will sink the floor or bottom of it below the keel of
the ship to be conveyed, and so that the latter may float into the interior,
wherein it may be drawn up and made fast to a tackle block at f. The sides
and other parts of the ship may then be further secured and steadied by means
of shores, ropes, and packing, according to circumstances. The steam engines
are now to be set in action to work the pumps and expel the water from the
double external case, and this to be continued until the bottom of the marine
vehicle has acquired that reduced draught or depth in the water as will enable
it, together with its internal ship, to float over the shoals or other obstructions
in the navigation. This having been ascertained the pumps are to be discon-
nected from the main axis, and the paddle wheels are to be connected (by
means of a clutch or other well-known apparatus) to the axis instead, when
the whole is to be propelled to the desired haven. At g, g, there are two
helms for steering; but these, if desired, may be connected so as to operate
by one movement, and by means too well understood to need specifying. When
it is desired to separate the ship from the marine vehicle, the latter is to be
again charged with water until the ship inside is afloat at its natural level,
when it is to be drawn out of the marine vehicle. It may be observed, that
the bottom part of the marine vehicle is, like the sides, hollow, which is of
course to increase the buoyancy; but it will be sufficient in many situations
to dispense with this hollow part, and to connect the sides by a solid bottom of
single plates.
In the annexed Drawings, Figures 19 and 20, is exhibited another method
of attaining the same objects, which is to a certain extent a modification of
the plan just described. By the present method the marine vehicle is not
continued underneath the vessel, but consists of two lateral vessels constructed
of wrought iron, in the same manner as the former one, placed on each side
of the ship, and connected to each other by chains or cables passing under-
neath the hull; and instead of the pumping and propelling mechanisın being
contained in the marine vehicle as before, they are contained in a steam tug
vessel represented by Figure 20, by which the marine vehicles are emptied of

page_text: their water as well as towed along with the ship to its destination. The form
of these side marine vehicles is sufficiently indicated by the sectional view of
one end of one of them at h. In a central line, through each of these, there
are, at uniform distances, a series of vertical iron pipes i, i, i, which are firmly
secured in a water-tight manner to the top and bottom, but so as to leave the
pipes open at their top and bottom ends. Through these pipes the supporting
chains are pussed, hence they descend under the keel of the ship j, j, and up
the pipes of the other lateral marine vehicle on the opposite side of the ship,
where they are fastened to a supporting beam which is firmly fixed on and
along the top of each of the marine vehicles for that purpose, one of which is
seen at k. When tho marine vehicles have been sufficiently charged with
water (through stopcocks or plugholes) to sink the suspended chains below
the ship, the latter is to be floated over them, and then the chains may be
drawn up close to the keel, and the upper ends be made fast to the beam k.
For the purpose of regulating the motion of the marine vehicles when getting
under operation, stout iron rings are fastened at 1, l, to which chains or cables
are attached, and the other ends are secured to the bulwarks of the ship, and
regulated according to circumstances. This part of the operation being com-
pleted, and the paddle wheels being disconnected by well-known means, the
pumps in the tug boat, Figure 20, are put into action by the steam engine
therein, and the water is thereby drawn out of the marine vehicles through
hose pipes m, m, and expelled out of the eduction valves of the pumps. These
marine vehicles may also be emptied of their water by manual labour, and
when the locality of the situation will afford a lower outlet than the level of
the water in them (such as a dry dock), the syphon may be employed to
advantage to discharge them. In the upper part of each of the lateral marine
vehicles is a vertical depending safety tube (one of which is shewn at n in
Figure 19). These tubes are open at both ends, so that when the water has
risen a little higher than the lower orifices, the pressure of the confined air
above checks the flowing in of more water. This arrangement prevents
the marine vehicles from sinking too deep. The same effect may, how-
ever, be produced by a separate air-tight chamber at the top, or by an attached
buoy and chain. The disengagement of the ship from the vehicles may be
effected in like manner to the preceding, or the chains may be gradually
slacked until she sinks to her natural level in the water, or is otherwise
supported underneath; and although I prefer these chains to pass throughout
these vehicles, I do not confine myself strictly thereto, as it is obvious they may
be arranged to act on the outside in various ways. It is also a part of my
plan to empty the water from the vehicles by connecting them to an engine
on land when the locality and other circumstances suits.

page_text: On account of the superior tenacity and imperviousness of iron above that of
wood, as well as its diminished bulk, I consider it as an important improvement
to construct my marine vehicles of that metal; the strength of the material will
of course vary with the size of the marine vehicle to be constructed. An approxi-
mating rule for the power of buoyancy required is, to allow one cubic foot of the
marine vehicle to be under the water, or a cubic foot of displacement thereby, for
every sixty pounds weight to be raised above the water, which weight of course
includes the gravity of the marine vehicle and apparatus employed. It will
be observed, upon reference to Figure 16, that my marine vehicle is also
eminently adapted for a floating bath, which being a part of my claim, I claim
its application for that use. When so applied, the stern and other openings
may be guarded with spars and netting, and proper apartments set up on the
sides with stairs leading to the water in the usual manner for the convenience
of the bathers.
Having thus explained this part of my Invention, I wish it to be understood
that I claim as my sole right the novel combinations and arrangements set
forth and illustrated by Figures 16, 17, 18, 19, 20; yet, it being evident that
considerable variations may be made from the plans described, without depart-
ing from the general principles or characteristic features of the same, I do not
confine myself strictly thereto, nor to the number of pumps, paddle wheels,
marine vehicles, or other apparatus described, nor to the exact mode of
filling or emptying the said marine vehicles; and although I do not claim all
the parts separately considered, I do claim in particular the application of
horizontal steam cylinders, with piston rods working through each end, for the
purpose of propelling said vehicles and other vessels, the employment of four
or more paddle wheels, the construction of such vehicles of iron, copper, or
other metals, and to the employment of steam or other motive power for
emptying and propelling or tugging them.
The fourth head of my said Invention consists in the employment of addi-
tional paddle wheels laterally placed and fixed in the usual manner to the
outsides of vessels generally propelled by steam or other motive force, so as
to enable them to attain a speed adequate to the power of the engine employed,
and that even when the breadth of the wheel is necessarily restricted to enable
it to pass through narrow openings, such as the gates of canals; likewise, to
enable other ordinary vessels to avoid unnecessary breadth of paddles, which
has a tendency to strain them, as well as the vessel, and at the same time to
cause the machinery to work disadvantageously. One of my arrangements for
this
purpose is exhibited in elevation by Figure 21, and in plan by Figure 22.
In a suitable metallic framing a, a, a, are fixed a couple of marine engines
working horizontally; b, b, are the working cylinders,.c, c, the jackets; and at

page_text: d, d, are the valve casings, which valves are worked by eccentrics e, e, through
the medium of rods and levers (not introduced in the Drawing) in the usual
way; ff are the piston rods working through stuffing boxes at each end of
the cylinders, conducted rectilinearly by guides g, g, and connected to the rods
h, h, that operate upon the cranks i, i,j, j, upon two main shafts k, l, and
actuate the two pair of paddle wheels m, m, and n, n. The air pump o is placed
in midships, and is worked by a short crank p on the main shaft k. This
pump is surrounded on its bottom and its two sides by the condenser q, and
on the top by the hot-water cistern r; it has a foot valve at each end opening into
it from the condenser, and a discharging valve at each end opening outwards into
the hot-water cistern. The piston (which is solid) draws in water from the con-
denser, and discharges it into the hot-water cistern every alternate (or single)
stroke of the engine.
My claims to Invention under this fourth head consist in the application of
additional paddle wheels laterally placed to the outsides of vessels, over and
above the single pair in common use, and in the general arrangement of
machinery delineated in Figures 21 and 22, and particularly in the employ-
ment of horizontal steam cylinders having the piston rods working through
each end of the cylinder for the purpose of propelling vessels, also in the pecu-
liar construction of the air pump for said purposes. But it is obvious that an
extra pair of paddle wheels may likewise be worked by the common side beam
marine engines and other modifications thereof by a suitable adaptation of con-
necting machinery well understood by engineers, and that by an extension of the
apparatus a greater number than two pair of paddle wheels might be efficiently
worked with suitable adjustments of the other parts of the machinery; conse-
quently, my Invention is not limited as to number, but extends to any number
of wheels so placed beyond one pair, when the circumstance of the vessel and
machinery will admit such to be worked advantageously; nor do I confine
myself to whether the engine be on the high or low pressure principle, nor
to the number of engines so applied, nor to the form nor the construction of
the vessel, whether of the ordinary kind or of the twin or tube kind, it being
evident that all these may be varied to suit the peculiar circumstances of
the case.
In witness whereof, I, the said John Gemmell, have hereunto set my
hand and seal, this Twenty-eighth day of July, in the year of our
Lord One thousand eight hundred and thirty-seven.
JOHN (L.S.) GEMMELL.

page_text: AND BE IT REMEMBERED, that on the Twenty-eighth day of July, in
the
year
of our Lord 1837, the aforesaid John Gemmell came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
AND BE IT REMEMBERED, that on the Twenty-eighth day of July, in
the
year
of our Lord 1837, the aforesaid John Gemmell came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the
tenor of the Statute made for that purpose.
Inrolled the Twenty-eighth day of July, in the year of our Lord One
thousand eight hundred and thirty-seven.
Inrolled the Twenty-eighth day of July, in the year of our Lord One
thousand eight hundred and thirty-seven.