IMPROVEMENTS IN MARINE STEAM ENGINES
Year: 1857

page_text: LETTERS PATENT to James Alfred Limbert, Engineer, Royal Navy, for
the Invention of "IMPROVEMENTS IN MARINE STEAM ENGINES."
Sealed the 26th January 1858, and dated the 31st July 1857
PROVISIONAL SPECIFICATION left by the said James Alfred Limbert
at the Office of the Commissioners of Patents, with his Petition, on
the 31st July 1857.
I, JAMES ALFRED LIMBERT, Engineer, Royal Navy, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN MARINE STEAM ENGINES,"
to be as follows:-
This Invention relates to a novel combination of the parts of marine steam
engines, by which such engines may be made of a given power, requiring
considerably less room in the ship, having less dead weight, being simpler in
construction, and less costly to manufacture, whilst the advantages of long
connecting rods, fewness of parts, simplicity of construction, and ready access
to every working part or surface for faciliting of examination or repair are
retained.
The form of engine to which these improvements relate is that known as
the horizontal direct-acting marine engine for driving the screw propeller, the
cylinders being on one side of the crank shaft, whilst the air pumps, con-
denser, hot well, bilge, feed, and other pumps are on the opposite side, and
thereby balance the working of the engine, and the dead weight of the
materials.

page_text: I obtain the advantages which belong to this Invention by adopting the
ordinary form of horizontal cylinder and piston, instead of the trunk arrange-
ment; and I employ two piston rods, but instead of placing them vertically
one above the other over the crank, or as heretofore placed and combined
with other parts of engines as heretofore constructed, I place the two piston
rods diagonally one on each side of the crank, one above and the other below
the crank shaft.
I connect or secure the outer ends of these rods by means of a crosshead,
which working horizontally has a journal for the connecting rod end in the centre
of its length, on each side of which centre bearing there is a guide block,
which works in a suitable flat or V guide over the condenser and air pump,
and the ends of the crossheads are so formed or constructed that the one is
turned upward, and the other downward, forming lugs or bosses through
which the ends of the piston rods pass, and wherein they are secured.
Thus, instead of forming the guide bearings at the outside or extreme ends,
or having only one bearing or guide in the centre of the crosshead, I have
two bearings, and bring them within the extreme ends, and so divide the
strain, equalize the wear, and economize space, whilst each part can be
readily got at. I am enabled by this arrangement, and the novel con-
struction of condenser apparatus arranged on the opposite side of the crank
shaft to that upon which the steam cylinders are, to bring the steam
cylinders closer together side by side, and thus to give greater stability as well
as compactness.to the engine.
I work the air pump belonging to each cylinder direct from the steam
piston, by means of a rod working through a stuffing box in the cylinder
cover, and I use a double-acting pump with valves suitable to such form of
pump, but I arrange the foot valves on the one side of the pump whilst the
delivery valves are placed on the other side, and the valves are connected
with the corresponding ends of the air pump by means of suitable passages.
I work the slide valves of the steam cylinders, which are double ported, by
means of a short weigh.shaft, supported in a single long bearing formed by a
pedestal above the air pump, jacket, delivery pipe, or frame, the slide being
worked by the eccentric gearing in the ordinary way.
The expansion valve gearing is placed in the centre or between the engine,
instead of on the outsides.
I work the starting gear by means of a horizontal instead of a vertical
wheel. I combine the throttle, blow through, expansion valves, and injection
cock handles, together with the starting gear levers, and the pressure and

page_text: vacuum guages, and other indicating or recording instruments or apparatus
may be fixed on the same standard or pedestal.
I require only three bearings for the crank shaft constructed according to
my Invention.
By the arrangement of a high hot well in the centre, or between the two
condensers and air pumps, and by the arrangement of passages across the
condenser connecting the air pumps with the delivery valves as before described,
I am enabled to give larger cubical contents to the hot well, thus forming
a kind of air vessel by which the strain upon the air pumps will be reduced.
By this arrangement the delivery valves at the bottom of the hot well are
at the lowest level of the condenser, which is of great advantage in working,
and enables a better vacuum to be maintained than where they are above the
condenser space, and above the level of the air pumps.
In consequence of placing the air pumps on each side of the hot well, and
condensers on the outside of the engine, greater freedom of access is obtained
to every part of the air pumps, as also to the foot valves and passages, the
doors or covers of which being at the bottom of the frame and unincumbered
may be removed without disturbing any other part of the engine. I convey
the steam from the boilers by means of a single steam pipe, having a double
bend connecting by a T-piece or pipe the two cylinders, and within the
T-piece I arrange the valves, by which the admission of steam is regulated
and may be admitted to both or only one of the cylinders.
I connect the exhaust passages of the two cylinders by means of a semi-
circular disc or plate for closing or shutting off communication with either
engine in case of accident, or when from any cause only one engine is in use.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Alfred Limbert in the Great Seal Patent Office
on the 29th January 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
ALFRED LIMBERT, Engineer, Royal Navy, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirty-first day of July, in the year of our Lord
One thousand eight hundred and fifty-seven, in the
year of Her
and grant unto
reign, did, for Herself, Her heirs and successors, give
me, the said James Alfred Limbert, Her special licence that I, the said
James Alfred Limbert, my executors, administrators, and assigns, or such

page_text: others as I, the said James Alfred Limbert, 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 James Alfred Limbert, 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 James Alfred Limbert, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement and accompanying Drawing:--
This Invention relates to a novel combination of the parts of marine steam
engines, by which such engines may be made of a given power, requiring con-
siderably less room in the ship, having less dead weight, being simpler in
construction, and less costly to manufacture, whilst the advantage of long
connecting rods, fewness of parts, simplicity of construction, and ready access
to every working part or surface for facility of examination or repair are
retained.
The form of engine to which these improvements relate is that known as
the horizontal direct-acting marine engine, for driving the screw propeller,
the cylinders being on one side of the crank shaft, whilst the air pumps, con-
denser, hot well, bilge, feed, and other pumps are on the opposite side, and
thereby balance the working of the engine, and the dead weight of the
materials.
I obtain the advantages which belong to this Invention by adopting the
ordinary form of horizontal cylinder and piston, instead of the trunk arrange-
ment; and I employ two piston rods, but instead of placing them vertically one
above the other over the crank, or as heretofore placed and combined with
other parts of engines as heretofore constructed, I place the two piston rods
diagonally one on each side of the crank, one above and the other below the
crank shaft.
I connect or secure the outer end of these rods by means of a crosshead,
which working horizontally has a journal for the connecting rod end in the
centre of its length, on each side of which centre bearing there is a guide

page_text: block, which works in a suitable flat or V guide over the condenser and air
pump, and the ends of the crossheads are so formed or constructed that the
one is turned upward and the other downward, forming lugs or bosses through
which the ends of the piston rods pass, and wherein they are secured.
Thus, instead of forming the guide bearings at the outside or extreme ends
or having only one bearing or guide in the centre of the crosshead, I have
two bearings, and bring them within the extreme ends, and so divide the
strain, equalize the wear, and economize space, whilst each part can be readily
got at. I am enabled by this arrangement, and novel construction of condenser
apparatus arranged on the opposite side of the crank shaft to that upon which
the steam cylinders are, to bring the steam cylinders closer together side by
side, and thus to give greater stability as well as compactness to the engine.
I work the air pump belonging to each cylinder direct from the steam
piston, by means of a rod working through a stuffing box in the cylinder cover,
and I use a double-acting pump with valves suitable to such form of pump,
but I arrange the foot valves on the one side of the pump, whilst two sets of
delivery valves, having together greatly increased area, are placed on opposite
sides, as shewn in the Drawing, Figs. 1 & 2, and the valves are connected
with the corresponding ends of the air pump by means of suitable passages.
I work the slide valves of the steam cylinders, which are double ported, by
means of a short weigh shaft, supported in a single long bearing formed by
a pedestal above the air pump jacket, delivery pipe, or frame, the slide being
worked by the eccentric gearing in the ordinary way.
The expansion valve gearing is placed in the centre or between the engine,
instead of one on the outsides.
I work the starting gear by means of a horizontal instead of a vertical
wheel. I combine the throttle, blow through, expansion valves, and injection
cock bandles, together with the starting gear levers, and the pressure and
vacuum guages, and other indicating or recording instruments or apparatus.
may be fixed on the same standard or pedestal.
I require only three bearings for the crank shaft constructed according to
my Invention.
By the arrangement of a high hot well in the centre, or between the two
condensers and air pumps, and by the arrangement of passages across the con-
denser connecting the air pumps with the delivery valves as before described,
I am enabled to give larger cubical contents to the hot well, thus forming a
kind of air vessel by which the strain upon the air pumps will be reduced.
By this arrangement the delivery valves at the botton of the hot well are
at the lowest level of the condenser, which is of great advantage in working,

page_text: and enables a better vacuum to be maintained than where they are above the
condenser space, and above the level of the air pumps.
My improved horizontal air pumps will not possess the disadvantages which
ordinarily pertain to that kind of pump, viz., that the vacuum attainable and
maintainable is not so good as in vertical air pumps, and that they work by
starts, at one time gorging themselves, whilst at another not drawing at all,
thereby throwing great strain on the working parts; moreover, when giving
the full injection, it is delivered with a blow at each end of the pump. The
first and second of these failings of the ordinary air pumps may be attributable
to the largeness of the end spaces, which are commonly of larger contents than
the pump itself, consequently the air in and above the water is only com-
pressed at every stroke of the pump; hence the cause of defective vacuum,
and, for the same reason, for several strokes, the pump will not draw at all
until the weight of water in the condenser forces its way into the pump and
completely fills it, when, from the contracted area of the delivery valves it cannot
discharge itself freely, and thereby throws undue strain on the working parts.
By my arrangements these difficulties are entirely obviated by making the end
spaces of the air pump much smaller than the barrel, and by making the delivery
valves of larger area than the pump; and on reference to the Drawing, it
will be seen that I effect this by placing the main delivery valves for the water
below the bottom of the pump, and the minor delivery valves for air above the.
top of the pump; and as the passages across the condenser will always remain
filled, the real end space will be that resulting from the measurement from
the top of the water only; thus, the distance from the end of the pump to the
air pump door, multiplied by the area of the pump, added to the cubical con-
tents of the space under the minor delivery valves, would give about 5 cubic
feet, whilst in the air pumps of the Cæsar's engines there is a space of ten
cubic feet for the same horse-power.
The third defect in the ordinary horizontal air pump before referred to may
be found in the contracted area of the delivery valves, which are usually of the
same area as the foot valves, when in practice they ought to be larger, as the
pump draws through the foot valves during the whole stroke, but as to expel
the same quantity of water during only part of the stroke in consequence of
the compression of the air which takes place; and hence it is discharged with
greater velocity, which produces the shock or blow at the end of the stroke, as
before referred to.
In consequence of placing the air pumps on each side of the hot well, and
condensers on the outside of the engine, greater freedom of access is obtained
to every part of the air pumps, as also to the foot valves and passages, the

page_text: doors or covers of which being at the bottom of the frame and unincumbered,
may be removed without disturbing any other part of the engine. I convey
the steam from the boilers by means of a single steam pipe, having a double
bend connecting by a T-piece or pipe the two cylinders, and within the
T-piece I arrange the valves, by which the admission of steam is regulated
and may be admitted to both or only one of the cylinders.
I connect the exhaust passages of the two cylinders by means of a semi-
circular disc or plate for closing or shutting off communication with either
engine in case of accident, or when from any cause only one engine is in use.
DESCRIPTION OF DRAWING.
In the accompanying Drawing Fig. 1 exhibits a side view of a pair of
marine screw engines according to my Invention, with a portion of the con-
denser in section; Fig. 2 is a transverse section, part of which is taken
through one of the cylinders and slide chest, the other part being taken
through the crank shaft bearings; Fig. 3 is a plan partly in section; Fig. 4,
an end view of condensers, part of which is shewn in section, exhibiting the
air pump and valves. A, A, are the steam cylinders mounted upon suitable
base plates, which rest on cross sleepers. To the piston of such cylinders are
two piston rods B, B, placed diagonally, one above and the other below the
crank shaft, the opposite ends of the piston rods are attached to lugs C, C, one
turned upward and the other downward, formed upon the end of the cross
head D; and between the guides E, E, is attached the connecting rod F, the
other end being in connection with the crank; G, G are the air pumps
which are double acting, placed within the condenser, and are worked by
means of rods H, II, from the piston of the steam cylinder. I, I, are the
condensers, arranged on the opposite side of the crank shaft to that on which
the cylinders are. J are the main delivery valves for the water, an: K are
the minor delivery valves for the air. L is a bigh hot well arranged between
the condensers; M, M, are the feed pumps, which may be worked from the
end of the cross heads; N is a hollow pedestal fixed upon the top of the hot
well, through which a vertical shaft passes, having a horizontal hand wheel O
fixed thereupon, for giving motion to a worm P, upon the bottom end of such
shaft; this worn is in gear with a worm wheel Q, upon a cross shaft; upon
each end of this shaft is a small pinion, which gears into a rack R, in con-
neetion with the ordinary link motion. Upon this pedestal is also mounted the
throttle, blow through, expansion valve, and injection cock handles. S is the
cam motion placed upon the crank shaft in the centre of the engine for
working expansively; V is the steam pipe, having a T-piece connection U for

page_text: the admission of steam into both cylinders. Within this T-piece are arranged
two throttle valves v, v, one for each cylinder, and by which the steam
may be shut off from either or both cylinders; W is the exhaust pipe in
connection with the condensers.
The following advantages are possesed by my improved arrangement of a
marine screw engine, say of 400 nominal h. p., with a 3 3 stroke, and
8 1 connecting rod, and 5 81in diameter of cylinder, as compared with
engines of the same nominal horse-power constructed by two of the most
eminent marine engine builders:-
Double piston-rod engine of 1
400 h. p., 30in stroke, and
60" connecting rod, as fitted
to H.M.S. Princess Royal.
First. The extremely small
space it occupies in the ship,
thereby giving great increase of
space for coals, cargo, &c., with-
out the usual disadvantages of
overcrowding the different parts.
The engine-room space will
stand as follows:-
Square feet.
Patent trunk engine of
400 h.p., with 3" 3 stroke,
8 7 of cylinder 28
trunk 58in diameter
of cylinder, as fitted to
H.M.S. Cæsar."
First. The smallness
of space it occupies in
the ship, thereby giving
great increase of space for
coals, cargo, &c., without
the usual disadvantages
of overcrowding the dif-
ferent parts, so as to
render them difficult of
access, both in harbour
and when under weigh.
The engine-room space
198.3 will stand as follows:-
Square feet,
553.5
355.2
For the Princess Royal
class
For my improved ar-
rangement
Difference
Taking the height of
bunkers at
20ft
48)3966.0
For the Caesar
class
For my improved
arrangement
-
Increased space for
coals
tons 82.6
Secondly. The advantages of
longer connecting rods, viz.,
the Princess Royal class being
only 4 times the length of crank,
or
The connecting rods in
my engine being 5
tiines, or -
6.()
8.1
- 514.5
355.2
Difference = 159.3
Taking the height
of bunkers at -
Number of feet to
ton
-
Advantages possess-
ed by my improved
arrangement over the
double-piston rod and
single guide engine in
use in the Royal Navy.
First. Smallness
of space it occupies in
the ship, as the con-
figuration of the con-
denser allows the cy-
linders to come closer
together.
Secondly. The said
arrangement is appli-
cable for all sizes, from
50h. p. up to 1,000 h. p.,
whereas this class of
engine is only appli-
cable up to about 400
h. p., as having only
one guide; it would
not be a judicious
arrangement for more
than that h. p.
Thirdly
There is
less weight in the cross-.
20" head by the said ar-
48) 3186.0
Increase space for
coals
-
tons 66.3
Secondly. Being able
Thirdly. Greater simplicity
of parts, thereby causing less
liability to derangement while to get at the crosshead
at sea, also returning a larger and connecting rod bear-
profit to the contractors, viz.-ing at all times with
1st. There are only 3 bearings
for the crank shaft, and conse-
quently only 3 frames, which
are all cast from one pattern,
facility, which is not the
case with the trunk
engines.
Thirdly. For the bet.
rangement, and less
expense in the con-
struction than that
adopted in engines of
this class.
Fourthly.
There
are 4 bearings, and
consequently 4 frames
instead of 3, as in my
said arrangement, and
also the two middle
bearings are more dif-
ficult of access in those
of this class than those

page_text: engines as herein described, whereby great economy of space is attained
without crowding together the several parts.
Secondly, the novel arrangement of valves in connection with the air pumps
as also the combination therewith of the passages and high hot well as
described, when used in connection with horizontal cylinders having more
than one piston rod.
Thirdly, the combination within and upon one pedestal or column of the
starting or hand wheel, and of the various valve and other levers or handles,
in manner described, which may be required for starting, for working, for
varying the speed of, or for stopping marine steam engines; and whether such
arrangement be applied to marine engines constructed as herein-before
described, or to any modification thereof.
In witness whereof, I, the said James Alfred Limbert, have hereunto
set my hand and seal, this Twenty-seventh day of January, in the year
of our Lord One thousand eight hundred and fifty-eight.
Witness,
GEORGE CHURCHILL,
10, Salisbury Street,
JAMES ALFRED LIMBERT. (L.S.)
Adelphi.