IMPROVEMENTS IN MARINE STEAM ENGINES
Year: 1859

page_text: LETTERS PATENT to William Tod, of Glasgow, in the County of Lanark,
North Britain, Marine Engineer, for the Invention of "IMPROVEMENTS IN
MARINE STEAM ENGINES."
Sealed the 27th May 1859, and dated the 1st April 1859.
PROVISIONAL SPECIFICATION left by the said William Tod at the
Office of the Commissioners of Patents, with his Petition, on the
1st April 1859.
I, WILLIAM TOD, of Glasgow, in the County of Lanark, North Britain,
Marine Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MARINE STEAM ENGINES," to be as follows, that is to
say:
This Invention relates to the arrangement and construction of a compact
and effective form of marine engines, especially intended for screw propul-
sion, and suitable for war purposes, in as far as they are entirely beneath
the water line of the vessel in which they are fitted, and thus out of the reach
of the enemy's shot.
According to one modification of these engines, they consist in each case of
a pair of parallel horizontal steam cylinders, disposed on a suitable sole plate
or foundation framing on one side of the keel line of the ship, and with their
axes at right angles thereto. These cylinders are bolted together by suitable
contiguous flanges, and they are also attached by their front ends to the

page_text: transverse horizontal main framing, which connects the steam cylinders with
the air pumps and condensers and their apparatus, and which also serves to
carry the bearings for the main crank or screw propeller shaft. The air
pumps are disposed within the condensers, and in the same horizontal plane
with the main steam cylinders, and they balance the latter on the opposite
side of the keel line, so that the entire weight of the engines is properly
balanced on the ship's bottom. Each main steam piston is fitted with four
piston rods disposed in a parallelogram, and working through stuffing boxes in
the front covers or on the ends of the cylinders next the keel, so that thero are
in each an upper and a lower pair of rods. These piston rods are cottered by
end connections to other and corresponding rods, which pass through stuffing
boxes in the front side of the condensers next the keel, and of course imme-
diately opposite the stuffing boxes of the steam cylinders, two being above and
two below the main crank or screw propeller shaft. All the rods pass directly
through the condensers, on the outside of which, noxt the side of the vessel,
they are connected together to work in concert by a suitable horizontal cross-
head with transverse end pieces. To the centre of each cross-head there is
jointed the external end of a horizontal connecting rod, which passes back
transversely through a transverse slot in the condensers to a double crank on
the main shaft. In this way whilst the pistons and rods are well guided, long
connecting rods are obtained, and the effect of the transverse reciprocatory
action of the pistons is transferred to the main shaft in a very judicious
manner. These elongations of the piston rods serve also for working the air
pumps and the bilge and feed or other pumps necessary for the action of the
engines, or for the due working of the ship. Each main steam cylinder has a
pair of air pumps opposed to it, these air pumps being cast in the condenser.
It is the lower pair of piston rods in each case which actuates the air pumps.
These lower rods each pass through a hollow or tubular brass or gun metal
plunger turned to fit, its corresponding air pump being connected to the
plunger by a collar and nut at the external crosshead end. In this way the
air pumps, as there are two to each steam cylindér, may have a small diameter,
whilst they have the same stroke as the steam cylinders. The air pump
plungers work through wide stuffing boxes in the outer sides of the condensers,
and thus form a good guide for the steam piston rods. Each condenser
surrounds or envelopes its corresponding air pumps, which are situated in the
lower part thereof, and the two in each case have one common intermediate
induction or foot valve for taking the water and vapour from the lower part of
the condenser, whilst a similar common valve above affords the means of
discharge to the hot well and elsewhere. The upper pair of elongated steam

page_text: piston rods in each case works the feed and bilge pumps of the vessel, the
respective plungers being directly attached to the rods, as in the case of the air
pumps, and an equally good guide is thus secured. The two condensers are
bolted together and to the framing in the same manner as the steam cylinders.
The steam cylinders are each fitted with a slide valve chest on their external
or fore and aft sides, the slides being arranged to work on vertical faces. The
valves are worked by link motions for expansion and reversing, the eccentrics
of course being on the crank or propeller shaft. The eccentric rods work over
horizontally to the condenser's side, where their ends are connected to the
links, whence a horizontal rod passes back in each case to the slide valve
spindle. The shaft by which the valves are adjusted is disposed in bearings
on the top of the condensers and parallel with the keel line. On one end of
this shaft is a short lever, jointed to a descending connecting rod, the lower
end of which is jointed to the link outside the end of the condenser. The
other end of the same shaft has fast upon it a segmental worm toothed wheel,
carrying a crank stud, from which a similar rod descends to the link on that
side. It is this segmental toothed wheel through which the requisite
expansive stopping or reversing adjustments are worked. A hand wheel is
fitted on the forward end of a short horizontal shaft running parallel with the
keel, and carried by the condenser. This shaft has keyed upon it a bevil
pinion in gear with a bevil wheel fast on a transverso horizontal shaft, also
carried in bearings on the condenser. The outer end of this latter shaft has
upon it a worm in gear with the worm teeth of the segmental wheel already
referred to; thus by turning the hand or spoked wheel the link motions can
be set as desired. The actuating steam is supplied from the boilers from the
main pipe directly to the slide valve chest of the main steam cylinders, and
the exhaust from the main cylinders takes place through a pair of upper
transverse copper or brass pipes, which are connected at their opposite ends to
the inner faces of the condensers. These engines are kept remarkably low
down in the vessel, as they take up but little room both in the width and
height of the hull. Ample space is left for access as well to their central
working details as all round them, and space is still left on each side for coal
bunkers, which when filled aro in themselves a most efficient defence
against shot.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Tod in the Great Seal Patent Office on the
1st October 1859.
TO ALL TO WHÒM THESE PRESENTS SHALL COME, J, WILLIAM
TOD, of Glasgow, in the County of Lanark, North Britain, Marine Engineer,
send greeting.
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 fifty-nine, in the twenty-second year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Tod, Her special license that I, the said William
Tod, my executors, administrators, and assigns, or such others as I, the
said William Tod, 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 Ire
land, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN MARINE STEAM ENGINES," upon the condition (amongst others)
that I, the said William Tod, 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 William Tod, 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 fol-
.lowing 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 the arrangement and construction of a compact
and effective form of marine engines, especially intended for screw propulsion,
¡and suitable for war purposes, in as far as they are entirely beneath the water
line of the vessel in which they are fitted, and thus out of the reach of the
enemy's shot.
According to one modification of these engines, they consist in each case of
a pair of parallel horizontal steam cylinders, disposed on a suitable sole plate
or foundation framing, on one side of the keel line of the ship, and with
their axes at right angles thereto. These cylinders are bolted together by
suitable contiguous flanges, and they are also attached by their front cuds

page_text: to the transverse horizontal main framing, which connects the steam cylinders
with the air pumps- and condensers and their apparatus, and which also
serves to carry the bearings for the main crank or screw propeller shaft: The
air pumps are disposed within the condensers, and in the same horizontal plane
with the main steam cylinders, and they balanco the latter on the opposite
side of the keel line, so that the entire weight of the engines is properly
balanced on the ship's bottom. Each main steam piston is fitted with four
piston rods, disposed in a parallelogram, and working through stuffing boxes
in the front covers, or on the ends of the cylinders next the keel, so that there
are in each an upper and a lower pair of rods. These piston rods are cottered
by end connections to other and corresponding rods which pass through stuffing
boxes in the front side of the condensers next the keel, and of course im-
mediately opposite the stuffing boxes of the steam cylinders, two being above
and two below the main crank or screw propeller shaft. All the rods pass
directly through the condenser, on the outside of which, next the side of the
vessel, they are connected together to work in concert by a suitable horizontal
crosshead with transverse end pieces. To the centre of each crosshead there
is jointed the external end of a horizontal connecting rod, which passes back
transversely through a transverse vertical slot in the condenser to a double
crank on the main shaft. In this way, whilst the pistons and rods are well
guided, long connecting rods are obtained, and the effect of the transverse
reciprocatory action of the pistons is transferred to the main shaft in a very
judicious manner. These elongations of the piston rods serve also for working
the air pumps and the bilge and feed or other pumps necessary for the action
of the engines, or for the due working of the ship. Each main steam cylinder
has a pair of air pumps opposed to it, these air pumps being cast in the
condenser. It is the lower pair of piston rods in each case which actuates
the air pumps. These lower rods each pass through a hollow or tubular brass
or gun metal plunger turned to fit, its corresponding air pump being connected
to the plunger by a collar and nut at the external crosshead end. In this
way the air pumps, as there are two to cach steam cylinder, may have a small
diameter, whilst they have the same stroke as the steam cylinders. The air
pump plungers work through wide stuffing boxes in the outer sides of the
condenser, and thus form a good guide for the steam piston rods..' Each con-
denser surrounds or envelopes its corresponding air pumps, which are situated
in the lower part thereof, and the two in each case have one common inter-
mediate induction or foot valve for taking tho water and vapour from the
lower part of the condenser, whilst a similar common valve above affords the
means of discharge to the hot well and elsewhere. The upper pair of elongated

page_text: stcam piston rods in each case works the feed and bilge pumps of the vessel,
the respective plungers being directly attached to the rods as in the case of
the air pumps, and an equally good guide is thus secured. The two con-
densers are bolted together and to the framing in the same manner as the
steam cylinders. The steam cylinders are each fitted with a slide valve chest
on their external or fore and aft sides, the slides being arranged to work on
vertical faces. The valves are worked by link motions for expansion and
reversing, the eccentrics of course being on the crank or propeller shaft. Tho
eccentric rods work over horizontally to the condensers' side, where their ends
are connected to tho links, whence a horizontal rod passes back in each case
to the slide valve spindle. The shaft by which the valves are adjusted is
disposed in bearings on the top of the condensers, and parallel with the keel
line. On one end of this shaft is a short lever jointed to a descending
connecting rod, the lower end of which is jointed to the link outside the end
of the condenser. The other end of the same shaft has fast upon it a seg-
mental worm-toothed wheel carrying a crank stud, from which a similar rod
descends to the link on that side. It is this segmental toothed wheel through
which the requisite expansive stopping or reversing adjustments are worked.
A hand wheel is fitted on the forward end of a short horizontal shaft, running
parallel with the keel and carried by the condenser. This shaft has keyed
upon it a bevil pinion in gear with a bevil wheel, fast on a transverse hori-
zontal shaft also carried in bearings on the condenser. The outer end of this
latter shaft has upon it a worm in gear with the worm teeth of the segmental
wheel already referred to. Thus, by turning the hand or spoked wheel, the
link motions can be set as desired. The actuating steam is supplied from the
boilers from the main pipe directly to the slide valve chests of the main steam
cylinders, and the exhaust from the main cylinders takes place through a pair
of upper transverse copper or brass pipes, which are connected at their
opposite ends to the inner faces of the condensers. These engines are kept
remarkably low down in the vessel, as they take up but little room both in the
width and height of the hull. Ample space is left for access, as well to their
central working details as all round them, and space is still left on each side
for coal bunkers, which when filled are in themselves a most efficient defence
against shot.
And in order that my said Invention of improvements in mariuc steam
engines may be properly understood, I shall now proceed to describe the
several Figures on the two Sheets of Drawings, which I have hereunto
appended for the purpose of showing certain modifications under which my
improvements may be judiciously carried out in practice, that is to say:-

page_text: Figure 1, on Sheet 1 of the accompanying Drawings, is a longitudinal
elevation or side view of a pair of direct-acting engines, arranged according
to one modification of my improvements. Figure 2 is a transverse vertical
section, taken through one of the cylinders and its slide valve casing. Figure 3
is a sectional elevation of one of the condensers, and showing also the central
portion of the engine. Figure 4 is an end view of one of the condensers,
and a sectional view of the contiguous condenser. Figure 5 is a longitudinal
section taken through the air and feed pumps of the engines. In arranging
engines according to this modification, the pair of horizontal cylinders A are
cast with three radially projecting flanged parts B, two of which form a base
on the lower side, to admit of the cylinders being bolted to the transverse
beams of the vessel, which beams form the foundation for the engines. The
two cylinders are arranged parallel to each other on one side of the kecl line
of the ship, the axial line of each cylinder being at right angles thereto, and
they are bolted to each other through the vertical parts of the radial flanges B.
The cylinders are bolted at their front ends to the transverse horizontal main
framing C, the opposite end of which framing is in like manner attached to
the condensers D, in which are arranged the air pumps as well as the bilge
and feed pumps. In this manner the engines are properly and effectively
balanced on each side of the keel line, the weight of the condensers pumps
and connected apparatus serving to balance the weight of the steam cylinders
on the opposite side of the keel line. The main transverse framing C is
arranged to receive the bearing E of the main crank or screw propeller
shaft F. The piston G of each steam cylinder A is fitted with four piston
rods II, which are disposed in pairs parallel to each other, and arranged at a
sufficient distance asunder to admit of the rotatory movement of the crank or
main screw propeller shaft F. The piston rods I work out through the
stuffing boxes I, fitted to the front covers of the cylinders A, and their outer
ends are connected by means of cotters to the rods J and J', which are passed
through the stuffing boxes K in front of the condensers. The two lower
rods J pass through the tubular plungers L, which are made either of brass
or gun metal, each fitting its corresponding air pump M in the condenser.
The two air pumps in each condenser are arranged parallel to one another
at the lower part of the condenser; the rods J pass right through the
plungers L, and the end pieces N of the crosshead O, to which the rods are
fastened by nuts. The end pieces N servo to connect the plungers L
of the air pumps with the plunger P of the upper and smaller pair of
pumps Q and Q', which are worked by the rods J', these rods forming the
continuation of the upper pair of piston rods H. The plungers L and P

page_text: work out through stuffing boxes of corresponding size, fitted in the back or
outer faces of the condensers, this arrangement of the pumps serving as an
effective guide to preserve the parallelism of the piston rods. The connecting
rod R, which imparts its motion to the propeller shaft, is jointed at its outer
end to the crosshead O, and at its inner extremity to the crank shaft F in the
usual manner. In order to allow of the connecting rod passing inwards from
the outer side of the condenser, a vertical opening S is made right through tho
condenser from back to front, which opening is made sufficiently deep to
allow ample space for the reciprocatory movement of the connecting rod. It
is in the internal space of the condenser below the opening S that the foot
valve T, which takes the water and vapour from the lower part of the con-
denser, is fitted. A corresponding delivery valve U, arranged in the spaco
above the opening S, affords egress for the water and vapour, either to the
hot well or elsewhere, the water passing off by the eduction pipe V. The
feed pump Q on the left of the half sectional view, Figure 4, communicates
with the valve chamber W and the feed pipe X, whilst the bilge pump Q' to
the right of the oponing S is connected with the valve chamber Y, tho
induction and discharge pipes of which are shown in the elevation, Figure 1.
The steam cylinders A are each fitted with a slido valve chest Z, extending
along the side of the cylinder, the slides being arranged to work with vertical
faces. The slides are actuated by the eccentrics a, which are fitted on the
crank shaft in the ordinary manner. The free extremities of the eccentric
rods extend across nearly to the outer sides of the condenser, and at this part
the eccentric rods of cach slide are connected to the segmental link b, tho stud
pin c of which is fast to a sliding piece formed on the end of the rod d. The
end of this rod slides to and fro in the guide e, which is bolted to the face of
the condenser. The opposite extremity of the rod d is cottered to the slido
valve spindle f. The valves are adjusted by means of the horizontal shaft g,
which extends across the condensers, and is carried in bearings arranged
thereon. On one end of this shaft is a short lever which is jointed to a
descending connecting rod, the lower extremity of which is connected to the
link at the side of the condenser. The other extremity of the shaft, 9, which
is that shown in Figure 1, has fast to it the segmental worm toothed wheel h,
in the face of which is fixed the laterally projecting stud pin i, to which the
upper end of the link jis jointed, its lower end being attached to the link b. §
It is by means of the segmental wheel h that the necessary expansive
stopping and reversing adjustments are obtained, the movement of the sog-
mental wheel being obtained through the hand wheel k. This wheel is
carried upon a short horizontal shaft which is carried by the condenser; the

page_text: shaft has fast to it the bevil pinion 1, which is in gear with the bevil wheel m
on the extremity of the shaft n, the bearings of which are bolted to the side of
the condenser. The shaft n has upon its outer extremity a worm o, which
is in gear with the segmental worm wheel h, so that by turning the hand
wheel the slide valves can be set, and their expansive action adjusted as
required. The steam from the boilers enters the slide valve chest of each
cylinder through the main steam pipe p, and the exhaust steam passes off by
the pipe q, which extends upwards from the top of the valve chest Z; passes
over the propeller shaft, and enters the condenser at the front. The general
compactness of engines arranged in this manner, and the little height they
occupy above the sole plate, render them particularly well adapted for vessels
of war, in addition to which they afford peculiar facilities for getting at all the
working parts, either for the purposes of inspection or repair.
On Sheet 2 of the accompanying Drawings I have shown my improvements
as applied to a pair of geared marine engines arranged for working the shaft
of a screw propeller. Figure 1 on the said Sheet being a partially sec-
tional elevation of the arrangement; Figure 2 is a corresponding plan; one
of the cylinders and its slide valve casing is shown in transverse section.
In this modification the superstructure of the engine is carried upon the
sole plate or foundation A, which is disposed at right angles to the keel line
of the vessel; the cylinders B being on one side of the keel; and the con-
denser C on the other, so that the weight is evenly distributed across the
vessel. The pistons D of the steam cylinders are fitted with two piston
rods E, arranged in a horizontal line, and working out through .stuffing boxe's
fitted at the inner or front ends of the cylinders. The extremities of the
piston rods are connected to the end pieces F of the crosshead G, and these
end pieces of the crosshead are attached by nuts to the rods which pass
through and are attached to the plungers H of the air pumps, and those of
the feed and bilge pumps I. These pumps are arranged inside the condensers
in the manner herein-before described, and by means of the crosshead con-
nections the four pumps in each condenser work in concert, and serve also as
guides for the piston rods. To the central part of each crosshead G is attached
the inner end of the connecting rod J, which passes through the vertical
ing in its contiguous condenser, the extremity of each rod being connected to
the cranks of the transverse horizontal shaft K. To this horizontal shaft is
koyed the spur wheel L, which gears with the pinion M, fast to the propeller
shaft N, to which it gives motion. The slide valve chest O is cast on the inner
side of each cylinder, and the slide valves are actuated by the eccentrics P on
the shaft K. The rod of one of the eccentrics is jointed to the link move-
open-

page_text: ment Q, the stud pin of which works in the segmental guide R, in which it
is set so as to regulate the expansion by means of the vertical. rod S, which is
fitted to screw up and down by turning the crosshead T. The lower end of
this rod works through a bracket piece, tho raising or lowering of which
adjusts the position of the stud pin in the link Q. The outer eccentric P is
jointed to the spindle U of the slide valve V, the stud pin at the joint serving
also to connect the valve spindle to the stopping and reversing movement W,
which is actuated by means of the moveable band lever X. The steam is
admitted to the cylinders through the pipe Y, and after it has performed its
duty it passes away by the exhaust pipes Z to the condensers C, in which are
arranged the foot valves a and delivery valves b, the waste water of conden-
sation and vapour passing off by the eduction pipe c. The other parts of the
engines not indicated by letters of reference are similar to those in ordinary
use, and therefore do not require particular description. Direct-acting geared
engines arranged in the manner shown in the accompanying Drawings, are
compact, effective in action, well balanced, easy of access to their several
parts, and the main working details are guided in a very superior manner.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that what I consider 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 marine steam engines as
.herein-before described and shown in the accompanying Drawings.
Second, the system or modo of arranging and constructing marine steam
engines, wherein the main working steam piston rods are guided by the
plungers of the several pumps, as herein-before described.
In witness whereof, I, the said William Tod, have hereunto set my
hand and seal, this Thirtieth day of September, One thousand eight
hundred and fifty-nine.