IMPROVEMENTS IN MARINE STEAM ENGINES
Year: 1881

page_text: LETTERS PATENT to William Allan, of Sunderland, in the County of Durham,
Engineer, for an Invention of "IMPROVEMENTS IN MARINE STEAM ENGINES."
PROVISIONAL SPECIFICATION left by the said William Allan at the Office
of the Commissioners of Patents on the 19th May 1881.
WILLIAM ALLAN, of Sunderland, in the County of Durham, Engineer.
"IMPROVEMENTS IN MARINE STEAM ENGINES."
In constructing marine engines of the inverted direct acting surface condensing
type I form the bed plate, as shewn at Figures 1 and 2 of the Drawings annexed,
with circular seats for the purpose of fitting therein the necessary suction and
delivery valves for the circulating and air pumps, and also as seats for the pump
chambers; I arrange the circulating water passages to and from the circulating
pump valves in a portion of the bedplate, these passages leading to the surface
condenser which is fitted to the bed plate. I form the surface condenser as shown
at Figures 3 and 4 of the Drawings. I arrange it so that the circulating water can
be drawn or forced through its tubes, and I also arrange it that when the engines
are working as common jet engines the discharge water is permitted to escape
through the discharge pipe for the circulating water. In my arrangement of
pumps, which can either be one of each kind to each cylinder, or one of each
worked by each cylinder, I use the port and starboard columns of the engines as
air vessels for the said pump or pumps. I work the air and circulating pumps
direct from the piston rod crossheads by fitting therein a crosshead slab, to the
ends of which the pump rods are secured. The guide plates for the crossheads are
secured to the internal sides of the columns in such a way that they can be readily
moved for adjustment to the crossheads, this operation being performed without
having recourse to liners. I also make the crosshead a casting in steel or other
metal, or a forging, and to it I bolt the piston rod end, the bolts serving the double
purpose of piston rod end and gudgeon keep bolts; but for inverted engines of
the two or four cylinder type, that is, the high pressure cylinder above the low, I
employ two piston rods from the low pressure piston to the crosshead, and also one
central piston rod from the low pressure piston to the high pressure piston, as
shewn at Figure 5, by this arrangement I am enabled to remove the low pressure
cylinder cover by simply disconnecting and lowering the central piston rod through
the boring bar bonnet on the low pressure cylinder bottom. I also work the feed
and bilge pumps from the cross heads by means of wrought iron arms being fitted
into them; to the ends of these arma the pump rods are secured, the feed and
bilge pump chambers being fitted to the bed plate.

page_text: the
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Allan in the Great Seal Patent Office on
19th November 1881.
"
WILLIAM ALLAN, of Sunderland, in the County of Durham, Engineer.
IMPROVEMENTS IN MARINE STEAM ENGINES."
In constructing marine engines of the inverted direct acting surface condensing
type I form the bed plate with circular seats for the purpose of fitting therein the
necessary suction and delivery valves for the circulating and air pumps, and also
as seats for the pump chambers; I arrange the circulating water passages to and
from the circulating pump valves in a portion of the bed plate, these passages
leading to the surface condenser which is fitted to the bed plate. I form the
surface condenser so that the circulating water can be drawn or forced through its
tubes, and I also so arrange it that when the engines are working as common jet
engines the discharge water is permitted to escape through the discharge pipe for
the circulating water. In my arrangement of pumps, which can either be one of
each kind to each cylinder, or one of each worked by each cylinder, I use the
port and starboard columns of the engines as air vessels for the said pump or
pumps. I work the air and circulating pumps direct from the piston rod cross
heads by fitting therein a cross head slab, to the ends of which the pump rods are
secured. The guide plates for the cross heads are secured to the internal sides of
the columns in such a way that they can be readily moved for adjustment to the
crossheads, this operation being performed without having recourse to liners. I
also make the cross-head a casting in steel or other metal, or a forging, and to it I
bolt the piston rod end, the bolts serving the double purpose of piston rod end and
gudgeon keep bolts; but for inverted engines of the two or four cylinder type,
that is, the high pressure cylinder above the low, I employ two piston rods from
the low pressure piston to the crosshead, and also one central piston rod from the
low pressure piston to the high pressure piston; by this arrangement I am enabled
to remove the low pressure cylinder cover by simply disconnecting and lowering
the central piston rod through the boring bar bonnet on the low pressure cylinder
bottom. I also work the feed and bilge pumps from the crossheads by means of
wrought iron arms being fitted into them. To the ends of these arms the pump
rods are secured, the feed and bilge pump chambers being fitted to the bed plate.
The Drawings annexed shew the above described improvement.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a plan view, half in section, of the bed plate of a marine steam engine
formed as above described.
Figure 2 is a vertical cross section of the same. The bed plate is, as shewn,
formed with compartments A, B, for the suction and delivery valves of the
circulating pumps, and these compartments are closed over with covers, as shewn
at Figure 2.
A vertical cross section taken on the line A, A, Figure 1, through one pair of
these compartments is shewn at Figure 3. There is a similar pair of compartments
for each cylinder of the engine. From below the delivery valve there is a passage
way C opening into the circular seating D; to this circular seating is secured the
cylinder of the circulating pump. Tho delivery valve discharges into a hollow
passage E formed in the bed plate. This hollow passage is carried below one of
the bearings of the crank shaft of the engine to the opposite side of the bed plate,
above which the surface condenser is carried.

page_text: A vertical section and end view of the surface condenser are shewn at Figures
4 and 5.
The surface condenser is secured to two columns F, G, which are bolted on to
this side of the bed at its two ends.
The hollow passage E leads to the bottom of one of these columns marked F, so
that the flow from the circulating pumps passes, as shewn by the arrows, to the
bottom of this column, and rising up through it enters the lower half of one end of
the condenser, as shewn at Figure 4. It passes through the lower set of condenser
tubes to the opposite end, returns through the upper set of tubes, and passes away
by a discharge passage H, as shewn.
Steam from the cylinders enters the condenser through the steam passage I at
the top, the condensed water and air are drawn off through a passage J into the
hollow column G, from which they pass by a passage K to the suction valves L of
the air pumps.
The air pump suction valves L are each at the top of a hollow compartment
formed in the bed plate. The passage K opens into one of these compartments,
and this compartment is by a covered passage M connected with the other of these
compartments.
A vertical section taken through one of these suction valves and through the
air pump cylinder N in an adjoining compartment of the bed plate is shewn at
Figure 6.
The columns on the air pump side of bed plate are open to and form air vessels
on the discharge side of the air pumps, those on the opposite side act in the same
way for the circulating pumps.
Figure 1 shews how the air pumps and circulating pumps are worked by an
arm O fixed to the cross head.
Figures 1 and 5 shew how the adjustable guides for the cross heads are secured
to the columns.
Figure 5 also shows the manner of connecting the piston rod with the cross
head.
Figure 7 shews the way of connecting the piston of the high pressure cylinder
with the piston of the low pressure cylinder when a high pressure cylinder is used
above a low pressure one.
Having thus described the nature of my Invention and the manner of performing
the same, I would have it understood that I claim the herein before described
improvements in marine steam engines.
In witness whereof, I, the said William Allan, have hereunto set my hand
and seal, this Seventeenth day of November, in the year of our Lord One
thousand eight hundred and eighty one.
WILLIAM ALLAN. (L.S.)