IMPROVEMENTS IN STEAM ENGINES
Year: 1853

page_text: LETTERS PATENT to Henry William Harman, of Northflect Dock-
yard, in the County of Kent, Civil Engineer, for the Invention of
"IMPROVEMENTS IN STEAM ENGINES."
Sealed the 14th June 1853, and dated the 12th April 1853.
'PROVISIONAL SPECIFICATION left by the said Henry William
Harman at the Office of the Commissioners of Patents, with his
Petition, on the 12th April 1853.
I, HENRY WILLIAM HARMAN, of Northfleet Dockyard, in the County
of Kent, Civil Engineer, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN STEAM ENGINES" to be as follows:-
This Invention relates to an improved arrangement of steam engines,
which is more especially suited for driving the screw propeller direct,
although its compact and efficient design render it useful for a variety
of other purposes. The cylinders and condensers are arranged hori-
zontally athwart the ship, the cylinders on one side and the corresponding
condensers on the opposite side. Each piston of the cylinders is fitted
with four piston rods, which are carried through and supported by the
condensers, and united by cross heads behind. The connecting rods
pass from these cross heads back again through an opening or trunk in

page_text: the condenser to the screw shaft, which works in bearings midway
between the cylinders and condensers. The air pumps, bilge pumps,
and hot water pumps are all cast in the condensers, and worked from the
crossheads of the pistons. By this arrangement of machinery a saving
of space is effected, and an increased length of connecting rod is obtained.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry William Harman, in the Great Seal
Patent Office, on the 5th October 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
HENRY WILLIAM HARMAN, of Northfleet Dockyard, in the County of
Kent, Civil Engineer, send greeting."
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twelfth day of April, in the year of
our Lord One thousand eight hundred and fifty-three, in the sixteenth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Henry William Harman, Her special licence
that I, the said Henry William Harman, my executors, administrators,
and assigns, or such others .as. I, the said Henry William Harman,
my executors, administrators, or 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
"IMPROVEMENTS IN STEAM ENGINES," upon the condition (amongst others)
that I, the said Henry William Harman, by an instrument in writing
under my hand and seal, 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 Henry William Harman, do
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascer-

page_text: tained in and by the following statement, reference being had to the
accompanying drawings, and to the letters and figures marked thereon,
that is to say:
My said Invention relates to an arrangement of steam engines for
marine purposes, and more especially suited for actuating the screw
propeller direct, although its compact and efficient design render it
valuable for a variety of other employments. The cylinders and con-
densers are arranged horizontally athwart the ship, the cylinders on one
side of the keel line, and the condensers on the other side. Each steam
piston is fitted with four piston rods, which are carried through, and
supported by the condensers, whilst they are united by cross-heads at
their projecting extremities. The connecting rods return back again
from these cross-heads, through trunk openings in the condensers, to the
screw shaft, the line of which runs between the cylinders and the con-
densers. The air pumps, bilge pumps, and hot-water pumps, are all
cast in the condensers, and are worked from the piston cross-heads.
In engines thus arranged, peculiar compactness is secured, whilst a
superior length of connecting rod is obtained.
Figure 1, on my sheet of drawings is a side elevation of a pair of engines
of this kind, as built for a screw steamer, the view being taken looking
towards the propeller. Figure 2, is a plan of the engines completé; and
Figure 3, is a corresponding longitudinal section of the same. Figure 4,
is a transverse section through the cylinders, slide valves, and casings.
Figure 5, is an end elevation of the steam cylinders and 'slide valve
gear. Figure 6, is a transverse section through the condensers, air
pumps, and hot water and bilge pumps; and Figure 7, is an end
elevation of the air pumps and condensers. The steam cylinders A,
and the condensers B, are cast with flat bases C, to rest on the level
surface of the cross-sleepers D, of the ship's floor, and they are con-
nected together across the line of keel by the transverse engine
frames D, D¹. These frame pieces are each formed with four
abutting ends, springing from arches or curved portions, and resting
upon the floor, to carry the screw shaft E, and connections, whilst face
pieces are cast on the cylinders and condensers at F, for connection
with the cross frames. Each steam piston G, has four rods II, combined

page_text: parallelogram-wise, and working through corresponding stuffing boxes
in the cylinder covers I, which face towards the screw shaft or keel
line. Each set of four piston rods H, passes right over. the keel line,
and is combined with a single frame by the two vertical cross-heads J,
working outside the condenser, and between it and the ship's side.
This arrangement of the piston rods obviously necessitates their passing
through the condensers, and hence guide trunks K, are cast in the
condensers in a horizontal direction; these guides being fitted with
brasses on each end of the condenser, to answer as the parallel guide
motion for the piston rod movement. This passage of the piston rods
through the condensers is the only guide required for them; and their
cross-heads J, consequently work quite free outside the condensers.
To the straight horizontal bar of each cross-head the double eye or
forked end L, of the connecting rod is jointed in the usual way; and
this rod thence passes back through an elliptical open-ended trunk M,
cast within the condenser, and admitting of the free play of the con-
necting rod within it. The other end of the connecting rod proceeds
direct to the crank N, on the main screw propeller shaft E, which at
this part is carried in bearings on the transverse arched framing
pieces D. The cross-heads J, are connected together by the pin or
spindle P, the head of which Q, is clongated so as to attach the
spindle R, which passes to work the bucket of the air pump S, in the
interior of the condenser. The two air pumps are ranged close
together, side by side, at the junction of the two condensers, or may
be placed outside the condensers. They are open at each. end, con-
municating directly with their surrounding rectangular chambers T,
which are fitted with upper and lower tiers of clack valves U. Each
pump has thus four sets of clacks, all opening upwards; and, as each
end of the pump opens into a distinct division, the pump is double-
acting, the water and vapour of condensation being alternately drawn
into and expelled from each end of the working cylinder from the
base V, of the condenser. The influx is through the bottom tier of
valves, and the discharge by the corresponding upper tier, the
waste steam being brought from the exhaust ports of the steam
cylinders by the two inclined pipes W, opening. into the tops of the

page_text: condensers, whilst the air pump discharge is through the thorough-
fares X. The bilge and hot water pumps Y, Z, are also cast within
the condensers, each main cross-head J, having transverse pieces a, b,
upon it for carrying the pump spindles. The injection valve lever is'
at 6', close to the starting wheel; and a link rod from it passes over
the engines to a bell-crank fixed on a spindle across the engines, whence
short links communicate with the injection valves . The steam slide
valve casings of the main working cylinders are at c, outside each
cylinder. The slide valves are arranged with vertical faces, and each
slide is worked by a pair of eccentrics d, the rods of which are con-
nected to the ordinary link movement e, for reversing and expansion.
The stud pin f, connecting the link with the slide valve, is fast in a
sliding piece g, the whole length of which is fitted to slide in a guide
groove h, on the back of the cover of the slide casing, whilst the other
end is connected at i, to the slide valve spindle. Each link is supported
in position by a connecting rod j, hung to the free end of a lever k,
fast on the end of a horizontal cross-shaft 7, working in bearings m, on
the cylinders. Both links are capable of being raised or lowered
simultaneously for the stopping or reversing of the engines, or the
adjustment of the expansion by the main central hand-wheel n, on the
projecting end of the screw spindle o. This screw spindle has upon it
a traversing nut p, fitted with side studs, from which rods
7, pass back
to corresponding levers 7, on the shaft ; the wheel end of the screw
spindle being supported by a crank, loose upon the shaft l, and between
the fixed levers 7; the other end of the screw spindle o, being supported
by a bearing on the engine framing. The suck discharge and relief
valves s, t, and u, for the hot-water pumps Y, and Z, are fixed on the
top of the condensers in direct connection with the hot wells and
pumps, and both sets are attached by a horizontal pipe running
parallel to the steam pipes, and with a single branch in the centre v, for
conveying the water to the boilers. The steam from the boilers
enters the branch w, in the centre of the horizontal steam pipe, which
diverges in a line parallel to the engine shaft to convey the steam to
each valve chest or casing.
Having now described and particularly ascertained the nature of my

page_text: Invention, and the manner in which the same is or may be used
or carried into effect, I would observe, in conclusion, that I do not
confine or restrict myself to the precise details or arrangements which
I have had occasion to describe or refer to, as many variations may be
made therefrom without deviating from the principles or main features
of my Invention; but what I consider to be novel and original, and
therefore claim as the Invention secured to me by the herein-before in
part recited Letters Patent, is,―
First, the general arrangement and construction of steam engines as
herein-before described.
Second, the system or mode of constructing steam-engines wherein
the piston rods pass through and are supported by the condensers, and
work the air pumps and the other minor pumps therein, whilst the
connecting rods return from external cross-heads, through condenser
trunks, to the cranks; such construction of the condensers giving great
strength and additional external cooling surface.
Third, the system or mode of arranging and constructing steam
engines with the bilge and hot-water pumps inside the condensers, as
herein-before described.
Fourth, the system or mode of constructing and arranging marine
steam engines with the condensers and pumps balancing the steam
cylinders on opposite sides of the engine, shaft, or keel line of the
vessel, with the air and other pumps worked inside the condensers direct
from the cross-head movement.
In witness whereof, I, the said Henry William Harman, have
hereunto set my hand and seal, the Thirteenth day of September,
One thousand eight hundred and fifty-three.
H. W. HARMAN. (L.s.)