IMPROVEMENTS MARINE STEAM ENGINES
Year: 1869

page_text: LETTERS PATENT to William Allan, of Sunderland, in the County
of Durham, Engineer, for the Invention of "IMPROVEMENTS
MARINE STEAM ENGINES."
Sealed the 24th August 1869, and dated the 1st April 1869.
PROVISIONAL SPECIFICATION left by the said William Allan at the
Office of the Commissioners of Patents, with his Petition, on the
1st October 1869.
I, WILLIAM ALLAN, of Sunderland, in the County of Durham,
Engineer, do hereby declare the nature of the said Invention for "Im-
PROVEMENTS IN MARINE STEAM ENGINES," to be as follows:-
In constructing surface condensing marine steam engines applicable
for driving screw propellers I place the condenser below the crank shaft
and make it to form part of the bed plate. The two ends of the bed
plate rest on and are secured to beams or girders which run athwart
ship, whilst the casing of the condenser is carried down between these
beams or girders until it rests on the centre keelson. The tubes of the
condenser are placed athwart ship so that the condenser doors or covers
through which the tubes are got at are at the two sides of the condenser.
The end bearings of the crank shaft can either be carried in separate

page_text: castings, which castings contain the air or circulating pump chambers,
and may be bolted or otherwise secured to sides of condenser casing, or
the whole bed plate may be in one casting. I support the cylinders of
the engine in the following manner:-At the fore and after ends of the
engine I place two columns; these columns have the guide plates
affixed to them, and may be either wrought iron, steel, or cast iron;
these columns are firmly secured to the cylinders and to the ends of the
bed plate. Centrally between the two cylinders of the engine I introduce
other two columns of cast iron; these columns not only form supports
for the cylinders, but are also the exhaust columns to the condenser, and
are firmly secured to cylinders and condenser. The piston of each
cylinder is furnished with two piston rods, which are fixed to a cross
head, to which cross head are attached other rods which work the
air and circulating pumps, also the feed and bilge pumps. To the centre
of the cross head is jointed the connecting rod which gives motion to
the crank shaft. I prefer to use single-acting lift pumps for the air
pumps, and for circulating pumps I use either single-acting lift or single-
acting force pumps, the injection water being either drawn or forced
through the condensing tubes. I also arrange the hot well so that the
exhaust steam from the cylinders passes through it, thereby heating the
feed water. I also arrange ordinary injection engines in a similar
manner to that above described. For the removal of any of the
condenser tubes a recess is left in the bottom of the bunker at one side
of the vessel to facilitate the drawing of the tubes. The advantages of
the above described arrangement of surface condensers for screw engines
are that the centre of gravity is got as low down as is possible, the
heaviest weights being near the keel; great rigidity is also obtained;
the condenser is at all times easily examined or repaired, and the
engines occupy but little space longitudinally; the feed water also
enters the boiler hot.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Allan in the Great Seal Patent Office
on the 1st October 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ALLAN, of Sunderland, in the County of Durham, Engineer, send 3
greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the First day of April, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Allan, Her special licence
that I, the said William Allan, my executors, administrators, and
assigns, or such others as I, the said William Allan, 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 "IMPROVEMENTS IN MARINE
STEAM ENGINES," upon the condition (amongst others) that I, the said
William Allan, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and scals, 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 William Allan, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say:-
In constructing surface condensing marine steam engines applicable
for driving screw propellers I place the condenser below the crank shaft
and make it to form part of the bed plate. The two ends of the bed
plate rest on and are secured to beams or girders which run athwart ship,
whilst the casing of the condenser is carried down between these beams.
or girders until it rests on the centre keelson. The tubes of the con-
denser are placed athwart ship so that the condenser doors or covers
by which the tubes are got at are at the two sides of the condenser.
The end bearings of the crank shaft can either be carried in separate
castings, which castings contain the air and circulating pump chambers,
and may be bolted or otherwise secured to the sides of the condenser
casing, or the whole bed plate may be in one casting. I support the
cylinders of the engine in the following manner :-At the fore and after
ends of the engine I place two columns; these columns have the guide
plates affixed to them, and are firmly secured to the cylinders and to the

page_text: is opened wide when the engine is used as a common jet condenser
engine, thereby allowing the water lifted by the air pumps to be dis-
charged overboard; I, I, are the circulating pumps with their foot and
head valves; J, J, are the air pumps with their foot and head valves;
K is the discharge pipe. The ordinary injection apparatus is attached to
the exhaust columns C, C. Thus it will be seen that the top of the
condenser or bed plate forms the hot well and also the condensing water
discharge passage, and by the simple means of a valve connecting the
said hot well and discharge water passage a free communication over-
board is obtained for the hot well, all the water being discharged
overboard through one discharge pipe. I prefer using lift pumps both
for air and circulating pumps. I draw the condensing water through the
top rows of tubes first, and by the means of a valve box secured to the
bed plate or condenser door (and operated upon from the starting
platform) I am able to pump by the circulating pumps thr ugh the
condenser overboard either from the sea tanks or bilge, a great
desideratum in the event of any extraordinary leakage. The air and
circulating pumps are worked off the cross head secured to the T end of
the piston rod. The feed and bilge pumps are worked off the T end
of the piston rods.
Having thus described the nature of my said Invention, and the
manner of performing the same, I would have it understood that what I
claim is,―
First. The constructing surface condensing marine steam engines
applicable for driving screw propellers with a bed plate resting at its
ends on transverse bearers, and with the surface condenser forming part
of this bed plate descending between the said bearers, and having the
tubes at right angles to and under crank shaft.
I also claim the general arrangement of marine steam engines sub-
stantially as above described.
In witness whereof, I, the said William Allan, have hereunto set
my hand and seal, this Twenty-ninth day of September, in the
year of our Lord One thousand eight hundred and sixty-nine.