IMPROVEMENTS IN PROPELLING VESSELS
Year: 1853

page_text: LETTERS PATENT to Charles Randolph and John Elder, both of
Glasgow, in the County of Lanark, Engineers, Partners of the
firm of Randolph, Elder, and Company, of that Place, for the
PROVISIONAL SPECIFICATION left by the said Charles Randolph
and John Elder at the Office of the Commissioners of Patents,
with their Petition, on the 24th January 1853.
Wė, CHARLES RANDOLPH and JOHN ELDER, both of Glasgow, in
the County of Lanark, Engineers, Partners of the firm of Randolph,
Elder, and Company, of that place, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN PROPELLING VESSELS" to be as
follows:-
Heretofore, in the use of screw and such like propellers at the stern
or in the dead wood of ships or vessels, steam has not been used
expansively to any considerable extent, owing to the inequality of the
action of the steam, in consequence of its having in the engines heretó-
fore combined with screw and such like submerged propellers been

page_text: expanded in the same cylinder into which it has passed from the boiler.
Now my Invention consists of combining with and thereby giving
motion to the shaft of a screw, or such like propeller, an expansive
engine, composed of two cylinders, the steam passing from the boiler
first to the smaller cylinder and actuating the piston therein with the
full pressure, and then acting expansively by passing into the larger
cylinder.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Randolph and John Elder in the Great
Seal Patent Office on the 16th July 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, wc,
CHARLES RANDOLPH and JOHN ELDER, both of Glasgow, in the County
of Lanark, Engineers, Partners of the firm of Randolph, Elder, and
Company, of that place, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fourth day of January, in the
year of our Lord One thousand eight hundred and fifty-three, in the
sixteenth year of Her reign, did, for Ferself, Her heirs and successors,
give and grant unto us, the said Charles Randolph and John Elder,
Her special licence that we, the said Charles Randolph and John Elder,
our executors, administrators, and assigns, or such others as we, the
said Charles Randolph and John Elder, our 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 PROPELLING
VESSELS," upon the condition (amongst others) that we, the said Charles
Randolph and John Elder, by an instrument in writing under our
hands and seals, or under the hand and seal of one of us, should par-
ticularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, and cause the same to

page_text: 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 we, the said Charles Randolph and Jolin
Elder, do hereby declare that 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):
Heretofore, in the use of screw and such like propellers at the stern
or in the dead wood of the ships or vessels, steam has not been used
expansively to any considerable extent, owing to the inequality of the
action of the steam, in consequence of its having in the engines here-
tofore combined with screw and such like submerged propellers been
expanded in the same cylinder into which it has passed from the boiler.
Now my Invention consists of combining with and thereby giving
motion to the shaft of a screw or such like propeller an expansive
engine, composed of two cylinders, the steam passing from the boiler
first to the smaller cylinder and actuating the piston therein with the
full pressure, and then acting expansively by passing into the larger
cylinder.
Our said Invention consists in the application to the propelling of
steam vessels, by means of the screw or other submerged propeller of
engines having two inter-communicating cylinders of unequal capacity,
with valves thereto properly adapted, by which the steam from the
steam boiler or boilers is made to pass first into the smaller of the
two cylinders, and act upon the piston therein through any required
portion of the stroke at full pressure, passing, after the completion
of the stroke, into the larger cylinder, in which it impels the piston
by virtue of its expansive or elastic force alone; and the object and
purpose of our Invention is, to render this property of expansion of
the steam more fully available in the propelling of steam vessels by
means of the screw or other submerged propeller than heretofore, and
thereby to derive more work or duty from a given weight. of steam
expended than by the ordinary forms of single cylinder engines, and,
in consequence, to diminish the expenditure of fuel in such vessels.
And in order that the nature of our Invention may be most fully

page_text: .
understood and readily carried into effect, we have made the series of
Drawings hereunto annexed, exhibiting two slightly differing forms of
the kind of engine we purpose to employ in carrying the same into
practice, and which we will now proceed to describe.
Sheet I, contains a plan of a pair of engines supposed in situ.
Sheet II. contains a vertical section of one engine taken on the line
X, X, and therefore transversely to the direction of the screw shaft;
and Sheet III. contains a side elevation of the two engines, looking
upon the two smaller cylinders, and therefore also perpendicular to the
direction of the screw shaft.
..In these Drawings the same letters are used to indicate the same
parts throughout.
A, the smaller of the two steam cylinders of each engine. The
steam is admitted into this cylinder directly from the boiler or boilers
by means of the slide-valve a, a, (shewn in Sheet II.), and passes
out of it into the larger cylinder by the eduction ports b, b. B, the
larger of the two steam cylinders of each engine. The steam, after
it has impelled the piston in the cylinder A, from one end to the
other, acting through some part of the stroke with its full initial
pressure and through the remaining portion expansively, is admitted
into this cylinder by the slide-valve c, c, which is packed on the back
to separate the upper from the lower end, in the manner of an ordinary
long D slide. The partially exhausted steam thus received into this
cylinder necessarily acts upon the piston entirely by its expansive force,
seeing that the whole quantity admitted during a stroke of the piston
is only that contained in the smaller cylinder, and which, by the time
the larger piston reaches the end of its stroke, is all expelled from the
smaller cylinder and expanded to the capacity of the larger cylinder.
C, the steam pipe, or pipe by which the steam is conveyed from the
boilers to the valve casing of the smaller cylinder, and D, the eduction
pipe, by which the expended steam passes from the larger cylinder to the
condenser. The motion of the pistons of the corresponding cylinders of
the two engines is transferred by means of the down-going connecting
rods d, d, to their respective crank shafts, on which the spur wheels E, E,
are keyed, and which convey the motion to a suitable pinion of equal

page_text: pitch, keyed on the screw shaft M; from which arrangement it is plain
that if the wheels E, E, are made to turn in the same direction by the
pistons with which they are respectively connected the whole effective
power of the two engines will be concentrated on the propeller shaft.
We prefer to effect this by so adjusting the action of the valves as to
make the steam act on opposite sides of the two cylinders of each
engine at the same time, that is to say, the steam acting below the piston
of the cylinder A, causing it to ascend, also acts below the piston in the
cylinder B. and impels it upwards, and vice versa, so that when one
piston is ascending the other is descending.
In the position of the engine as represented in Sheet II., the pistons
are about half stroke, and that of the smaller cylinder is supposed to be
ascending and that of the larger or expansion cylinder descending.
The two cylinders therefore communicate with each other by the upper
ports, the steam passing in the direction indicated by the arrow, and at
the same time the final eduction is supposed to be taking place from
the larger cylinder B, by the lower port b', through the eduction pipe
D, to the condenser. The induction to the smaller cylinder from the
boiler is also supposed to have ceased, and that the steam in this
cylinder is acting upon the piston solely by expansion; and it is clear
that the action of the valve of this cylinder may be so adjusted as to
produce any degree of expansion of the steam in it that may be deenie<l
proper, and any suitable expansion apparatus may further be applied so
as to regulate the amount of expansion according to the particular
circumstances in which the engines may at any time be working.
The steam valves are actuated by means of the two pairs of eccen-
tries e, e', ff, on the crank shaft, connecting the two smaller cylinders
of the engines. The pair of eccentrics e, e', actuate the valves of those
cylinders, and the other pair ff, actuate those of the two larger cylin-
ders. These eccentrics are connected with their respective valves by
means of a series of links so disposed that the valves are made to
travel over different lengths of stroke. The valves of the smaller
cylinders being made with such amount of lap or cover as is required
to give the amount of expansion desired in those cylinders, and the
valves of the larger cylinders having, of course, no lap, the two pairs

page_text: of eccentrics are necessarily different, and require also to have different
amounts of reversing travel, which is effected in the manner to be
immediately hereafter described.
The two eccentrics e, c', are connected by the links g, g, with the
rocking-shafts S, S', which convey the motion to the induction valves of
the smaller cylinders by the links h, h'; the eccentric e¹, is thus connected
directly with the rocking-shaft F, by the link g¹, but the other eccentric
is connected by the link i, with an intermediate shaft G, carrying a
double crank j, j, by which the action of the eccentric is so modified
as to produce the required motion in the rocking-shaft F, through
the link g, when the axes of the two eccentrics are parallel. In like
manner the two eccentrics f. f, are connected by the links k, k, with
the two rocking-shafts H, H, which transmit the motion of the
eccentrics through the links 1, 1, to the valves of the two large
cylinders B, B, and which likewise serve as the eduction valves of
the smaller cylinders. These eccentrics are made pair and pair
together, and, as usual, are loose on the shaft, so as to allow the
action of the valves, and therefore of the engines, to be reversed
at pleasure. The pair of eccentrics e, e¹, are moveably connected
with the pair ff, by means of an intermediate spindle which passes
through an eye formed in one of the arms of the driving wheel E.
This spindle passes through a recess in the body of the eccentric
block c, e', and carries the pinion p, which gears with a loose spur
wheel m, on the same axis as the eccentrics. The recess in the body
of the eccentric block e, c', is a portion of a circular arc concentric
with the axis and with radial teeth inside to connect the eccentrics by a
suitable pinion with the spindle carrying the pin p. The other pair of
eccentrics ff, are permanently connected with an internal whcel n, in
the plate of which a recess is also cast to allow the connecting spindle
to pass through the wheel and carry a suitable pinion, by which such
motion as may be given to the spindle will be transferred or communi-
cated to the eccentrics f. f. This spindle also, in passing through the
slot-recesses in the eccentric block c, c', and through a like slot in the
metal of the internal wheel n, forms driving stops for both pairs of
eccentrics. The system is further connected with the hand wheel o, o,

page_text: by means of the pair of wheels m, p; for the spur-wheel m, is cast
with a hollow boss on one side, on which is keyed the wheel o, o, and
it is permanently in gear with the pinion p.
According to this disposition it will now be easily understood that as
the crank-shaft turns round and carries the large spur-wheel E', with
it, and thereby the axis of the pinions gearing into the wheels m, and,
that the eccentrics will also be carried round at the same rate; but if a
resistance by friction or otherwise be applied to the hand wheel o, o,
so as to retard it or cause it to move more slowly than the axis on
which it is carried, the pair of eccentrics e, e', will thereby be accele-
rated proportionably to the difference of the gearing wheels, and the
difference of the two motions will at the same time be transmitted by
means of the pinion wheel p, and revolving axis to the wheel n, which
will thereby be impelled in the same direction through an are pro-
portionally as much less as its size exceeds that of the wheel,
presuming that the two pinions are of equal diameters..
I, I, are the air pumps of the two engines. They are wrought by
means of the rocking shaft J, J, which derives its motion through the
armis K, K, from the guide blocks L, L, of the piston rods of the large
or expansion cylinders B, B.
The Drawings in Sheets IV. and V. represent a somewhat different
arrangement of engine, by which our Invention may be carried into
effect.
Sheet IV. contains a plan and end view of a pair of such engines
in situ.
Sheet V. contains a transverse vertical section of one engine taken
on the line X, X, of the plan.
These engines differ from those above described mainly in the crank-.
shafts being placed at a relatively higher level, and the pistons commu-
nicating with them by up-going connecting rods; and, as the planes
of the driving wheels overlap each other, one of these wheels is divided
into two wheels of half the breadth of the other and placed one on
cach side of it, as shewn in the plan in Sheet 1V. These wheels all
gear with a suitable pinion on the screw or propeller shaft M. The
valve gear and some other parts of the engines are omitted in these

page_text: Drawings, as they differ in no essential particular from the disposition
depicted in the other Drawings described above.
These Drawings hereto attached represent the application and use of
a pair of engines in the same vessel, which is commonly practised in the
case of vessels of large tonnage, but for small vessels single engines of
the kind described may be employed with suitable modifications, such as
will readily be understood by persons conversant with marine steam
machinery.
Having thus described these modes of carrying our Invention into
effect, we would have it understood that we do not confine ourselves to
these or any other particular arrangement or disposition of engine, nor
do we claim any of the details herein shewn and described apart from
their application and use towards carrying our Invention into effect;
but what we do claim as our Invention is, the application to the
propelling of steam vessels, by means of the screw or other submerged
propeller, of engines having double cylinders, for the purpose of using
the steain expansively, in the manner herein described.
In witness whercof, we, the said Charles Randolph and John
Elder, have hereunto set our hands and seals, this Fifteenth
day of July, in the year of our Lord One thousand eight
hundred and fifty-three.
CHARLES RANDOLPH. (L.S.)
JOHN ELDER.
(L:S.)
Witness,
RICHD. S. CUNLIFF,
of 12, Centre Street, Glasgow.