IMPROVEMENTS IN MARINE STEAM ENGINES
Year: 1883

page_text: LETTERS PATENT to John George Kincaid of Greenock in the County of
Renfrew North Britain for an Invention of "IMPROVEMENTS IN MARINE
STEAM ENGINES"
PROVISIONAL SPECIFICATION left by the said John George Kincaid at the
Office of the Commissioners of Patents on the 5th June 1883.
JOHN GEORGE KINCAID, of Greenock, in the County of Renfrew, North Britain.
"IMPROVEMENTS IN MARINE STEAM ENGINES,"
This Invention has reference to improvements in the general arrangement of the
important or functional parts of single compound marine steam engines, and also
in the new or improved construction of some of these parts for the purpose of
making such engines work more efficiently on the high and low pressure condensing
principle, and also as separate single expansive engines; thus enabling these
engines to be more easily changed from the former to the latter, when such single
compound engines are required to drive twin screw shafts, or double paddle shafts;
either regularly as one compound engine, or as separate engines, for also giving
intermittent or separate action and propulsion for manoeuvring or steering. These
engines have their high pressure cylinder and low pressure cylinder, or cylinders,
when there are two of these, connected to the different shafts; and also have
improved steam connections, valves and fittings from the steam boiler, and between
the cylinders, and from these to the condenser.
The nature of this Invention or its improvements, consists as follows:-First,
in regard to the general arrangement of the parts as applied to a twin screw steam-
boat, the high and low pressure cylinders are of the inverted type, erected over
the cranks of their respective screw shafts, to which their piston-rods and
connecting rods are connected, having separate eccentrics, rods, and link motions
to their respective slide valves, to work as separate single engines, each with a
cut-off valve worked by a separate eccentric, or slide blocks to each valve, set by
a right and left screw spindle and hand wheel outside the valve casing to regulate
the degree of expansion in each engine as desired. The condenser would be of the
ordinary tubular surface-condensing class, but ranged transversely parallel to the

page_text: two cylinders and below their front or back, opposite to their valve casings.
The exhaust steam would be led from both cylinders by different channels or
branches to the condenser to condense the steam from either cylinder, or from
both when working at the same time as separate engines. The condenser would
be made large to condense the exhaust steam from both cylinders, and the exhaust
chamber from the high pressure cylinder, would also be made large by an annular
space round it connected by a special double-ported or branched piston valve
chamber and branch to a large annular space round the low-pressure cylinder,
which is connected by a branch pipe to the condenser to lead the exhaust steam
thereto from the high pressure cylinder, or from the low pressure cylinder. For
making the cylinders work in concert as compound engines, the said exhaust
chamber round the high pressure cylinder is connected through the before
mentioned valve chamber by one port or branch (leading from the ordinary
exhaust pipe from the high pressure cylinder) to the slide valve casing of the
low pressure cylinder, which exhausts through the said annular passage round
the low pressure cylinder direct to the condenser. The high pressure steam would
be led from the boiler direct by a pipe as usual through a stop or throttle valve
to the casing of the high pressure cylinder, for working this cylinder either
compound with the low pressure cylinder, or as a separate engine. But for
working the low pressure cylinder separately as a single engine, a branch from
the main steam pipe from the boiler would conduct the steam through a reducing
valve and branch to the exhaust pipe from the high pressure cylinder leading to
the valve chamber of the low pressure cylinder, to reduce the pressure of the steam
to the requisite degree when working as a separate engine.
For the purpose of directing or controlling the passage of the steam from the
high pressure cylinder to the condenser and from the boiler to the low pressure
cylinder, a novel construction of double ported valve chamber is employed, and is
fitted on the exhaust steam pipe connecting the cylinders. In this chamber is
fitted a piston valve which when traversed in one direction shuts the exhaust port
and prevents the admission of the exhaust steam to the valve casing of the low
pressure cylinder, and opens one port for the passage of the exhaust steam from
the high pressure cylinder to the exhaust chamber round the low pressure cylinder,
and thence to the condenser, when this cylinder is to act as a separate engine.
At the same time, steam is admitted through this valve chamber by the other
port from the boiler through a reducing valve to the valve casing of the
low pressure cylinder direct, so that the low pressure cylinder may act as a
separate engine.
When the valve is traversed in the opposite direction the passage of the exhaust
steam through the valve chamber is reversed, and the exhaust steam passes direct
from the high pressure cylinder into the casing of the low pressure cylinder,
so that the engines work on the ordinary compound principle, the direct passage
of steam from the boiler being previously shut-off by closing the reducing valve.
To enable this single compound engine, or either of its cylinders, to work better
as a separate condensing engine, and give a better vacuum when starting and
manoeuvring, a small separate engine is employed to work the air and circulating
pumps, as also those of the bilge and feed; preferably with a vertical steam
cylinder set on the floor of the large engines on the side opposite the condenser,
with the air and circulating pumps set in a transverse line, so as to be worked
from a single crosshead, steadied in guides over the whole set of pumps.
Although only described as applied to an arrangement of inverted vertical
cylinder engines suitable for driving twin screws, the improvements are equally
applicable to oscillating engines and to horizontal or diagonal engines for twin
screw or paddle steamers in which it is desired to drive one or both screws or
paddles separately.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John George Kincaid in the Great Seal Patent Office on the
4th December 1883.
JOHN GEORGE KINCAID, of Greenock, in the County of Renfrew, North Britain,
"IMPROVEMENTS IN MARINE STEAM ENGINES."
My said Invention has reference to improvements in the arrangement of the
parts of compound marine steam engines, and of the valves which control and
direct the admission of the steam to the cylinders, the object being to enable such
engines to be worked either as ordinary compound engines, or as independent
single cylinder engines when employed to drive twin screw shafts, or double paddle
shafts.
The Invention is illustrated by the accompanying Drawings, in which Figure 1
on Sheet 1 is an elevation, and Figure 2 is a plan (to a smaller scale) of a pair of
engines arranged. in accordance with my improvements, with each cylinder
connected independently to the propeller shafts of a twin screw steam-ship.
Figure 3 on Sheet 2 is a side elevation of the same engines. Figures 4, 5, and 6
are vertical sections showing different positions of the improved valve which I
employ for controlling and directing the admission and exhaust of the steam, and
Figure 7 is a horizontal section' of the valve casing.
The high and low pressure cylinders A, B, are of the inverted type, erected over
the cranks of their respective screw shafts C, D, to which the piston rods a, b, and
connecting rods a¹, b¹, are connected, separate eccentrics, rods, and link motions,
being connected to the respective slide valves, so that each engine may be actuated
independently of the other when required. The condenser E is of the ordinary
tubular surface-condensing class, but is ranged transversely parallel to the two
cylinders A, B, and below on the side removed from the valve casings, and is made
sufficiently large to condense the steam from both cylinders when required. The
exhaust steam from the high pressure cylinder A, passes into a casing A² formed
round that cylinder, and is led thence by an exhaust pipe F, and through a double
ported change valve G, which directs it as may be desired either to the valve
casing B' of the low pressure cylinder B, or to the condenser E, through an annular
casing B, formed round the low pressure cylinder, into which the low pressure
cylinder also exhausts, this casing B³, being connected to the condenser by the
pipe E¹.
The high pressure steam is led from the boiler direct by a pipe H, through a
stop or throttle valve I, h as usual, to the valve casing A¹, of the high pressure
cylinder for working this cylinder either compound with the low pressure cylinder,
or as a separate engine. For working the low pressure cylinder B separately as a
single engine, a branch H¹, from the main steam pipe from the boiler conducts the
steam through a reducing valve J and by a branch H2 leading through the change
valve G, to the valve chamber B¹ of the low pressure cylinder B, the pressure of
the steam being reduced to the requisite degree to compensate for the greater area
of the low pressure cylinder, so that the power of the engines may be equalised
when each works separately.
For the purpose of directing or controlling the passage of the steam from the
high pressure cylinder to the condenser, and from the boiler to the low pressure
cylinder as described, the novel construction of double ported valve chamber G¹ is
employed, and is fitted on the exhaust steam pipe F connecting the cylinders. In
this chamber G³, as will be seen on reference to figures 4, 5, 6 and 7, is fitted a
piston valve G, which when traversed in one direction, as in figure 4, shuts off the
exhaust port g, and prevents the admission of the exhaust steam from the pipe F
and port to the valve casing of the low pressure cylinder with which the port g
Communicates, and it opens the port f for the passage of the exhaust steam by the
pipe F from the high pressure cylinder A to the exhaust chamber B³ round the low
pressure cylinder with which this port g¹ communicates, and thence the exhaust

page_text: passes to the condenser E by the pipe E' as before described, so that the high
pressure cylinder A acts as a separate condensing engine. At the same time, steam
is admitted through this valve chamber G' by the port from the boiler, through
the reducing valve J, and by the port g to the valve casing of the low pressure
cylinder direct, so that the low pressure cylinder may act as a separate engine.
In this position of the valve the two engines A, B, may obviously be both actuated
at once (but independently) or either engine may be actuated alone. By traversing
the piston valve G only to a mid-position, the exhaust port ƒ may be closed when
the high pressure cylinder is put out of action without screwing down the stop
valve I, and the low pressure cylinder alone is actuated by steam passing through
the reducing valve J and led through the ports h, g of the change valve G. When
the valve is traversed in the opposite direction to the position indicated in figure 6,
the passage of the exhaust steam through the valve chamber G₁ is reversed, that
is, the exhaust entering by the port ƒ passes through the valve G, and by the
port g, so that the exhaust steam passes direct from the high pressure cylinder
into the valve Casing of the low pressure cylinder, and the engines work on the
ordinary compound principle, the direct passage of steam from the boiler by the
port to the low pressure cylinder being previously shut off by closing the
reducing valve J.
The piston valve G is provided with a spindle G2, passing through a stuffing box
in the casing G, and is connected thereby to a hand lever G³ outside, by which it is
traversed and set in any of the positions indicated.
To enable this compound engine, or either of its cylinders, to work better as a
separate condensing engine, and give a better vacuum when starting and
manoeuvring, a small donkey engine K is employed to work the air and circulating
pumps L, L', as also those of the bilge and feed, a vertical steam cylinder being
employed and set on the floor of the large engines, with the air and circulating
pumps set in a transverse line, so as to be worked from a single crosshead.
Although only described as applied to an arrangement of inverted vertical
cylinder engines suitable for driving twin screws, the improvements are equally
applicable to oscillating engines and to horizontal or diagonal engines for twin
screw or paddle steamers in which it is desired to drive one or both screws or
paddles separately.
Having now particularly described my said Invention, and the manner in which
the same is to be performed, I declare that what I claim is,-
First. The arrangement or combination of parts of marine steam engines,
substantially as herein described and illustrated.
Second. In compound marine steam engines, the arrangement and combination
with the exhaust pipe connecting the high and low pressure cylinders, of a change
valve, such as described and illustrated for directing the high pressure exhaust to
the valve casing of the low pressure cylinder, or to the condenser, and for admitting
steam (of reduced pressure) direct to the low pressure cylinder as desired,
substantially as herein described and illustrated.
Third. The improved construction of change valve herein described and illustrated
in figures 4, 5, 6, and 7, as and for the purpose set forth.
In Witness Whereof, I the said John George Kincaid, have hereunto set my
hand and seal this third day of December, in the year of our Lord One thousand
eight hundred and eighty-three
Witness,
W R M THOMSON,
Patent Agent,
Glasgow
JOHN G. KINCAID (L.S.)