IMPROVEMENTS IN MARINE STEAM ENGINES
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
SLAUGHTER, of Avonside Iron Works, Bristol, Engineer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Twenty-third day of
January, One thousand eight hundred and forty-nine, in the twelfth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Edward Slaughter, my exors, adñiors, and assigns, Her especial
licence, full power, sole privilege and authority, that I, the said Edward
Slaughter, my exors, adiñors, and assigns, and such others as I, the said
Edward Slaughter, my exors, adñiors, or assigns, should at any time agree with,
and no others, from time to time, and at all times during the term of years
therein expressed, should and lawfully might make, use, exercise, and vend,
within England, Wales, and the Town of Berwick-upon-Tweed, my Invention
of "IMPROVEMENTS IN MARINE STEAM ENGINES;" in which said Letters Patent is
contained a proviso that I, the said Edward Slaughter, should cause a par-
ticular description of the nature of my said Invention, and in what manner
the same is to be performed, by an instrument in writing under my hand and
seal, to be inrolled in Her said Majesty's High Court of Chancery within
six calendar months next and immediately after the date of the said in part
recited Letters Patent, as in and by the same, reference being thereunto had,
will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
Edward Slaughter, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are fully described
and ascertained in and by the following statement thereof thereon, that is
to say:-
My Invention consists, first, of improvements in combining the parts
constituting a marine steam engine, whether used for propelling by screw or
by paddle wheels.
i
Secondly, my Invention consists of improvements in marine steam engines,
by combining the effort of more than four cylinders to give motion to the
driving shaft or axis of paddle wheels or a screw propeller.
Thirdly, my Invention consists of improvements in marine steam engines
by so arranging the steam connections thereof that two cylinders, working
separate, shall communicate with one steam chest.
Fourthly, my Invention consists of constructing air pumps of marine steam
engines with annular pistons or buckets, and also the combining therewith
inner concentric air pumps.
Fifthly, my Invention consists of so combining or working the air pump or
pumps of marine steam engines that the same shall make fewer strokes than
the engine.
And, sixthly, my Invention consists of combining the use of a small steam
engine (having a separate boiler) with the axis of a screw propeller, that the
same may be brought into action to keep the screw propeller going when sailing,
so that the propeller may offer no impediment to sailing, thus allowing the steam
engine or engine used for driving the propeller to be put out of action when
the wind is favorable, thereby rendering the lifting of the propeller out of the
water unnecessary.
And in order that my Invention may be most fully understood, and readily
carried into effect, I will proceed to describe the means pursued by me.
Heretofore, in constructing marine condensing steam engines, it has been
usual (whatever be the number of steam cylinders of which an engine may be
composed) for the engine, in addition to giving motion to the paddle wheel or
propeller shaft, also to give motion to the air pump or pumps for maintaining
a vacuum. Now, according to this first pay of my Invention, I combine the
use of what I call a propeller steam engine with a condenser steam engine,
both working by the aid of vacuum, the propeller engine giving motion to the
paddle wheel or propeller shaft, whilst the condenser steam engine ives
motion to the air pump or pumps, so as to keep up a vacuum for itself and
for the propeller steam engine. By this arrangement or combination,

page_text: amongst other advantages, it may be mentioned that the propeller engine may
be arranged to make more numerous strokes than the condenser engine, and
the condenser engine may continue uniformly to work the condenser, the
same not in any way depending on the change or variation of load to which
the propeller engine is constantly liable. The propeller engine may consist of
any number of steam cylinders, the great point of the Invention being that
the propeller steam engine shall not have to work the condenser as heretofore,
but the condenser shall be worked by an engine (consisting of one or more
cylinders), such condenser engine not working the paddle wheel or propeller
shaft; but I prefer that it should work the water pumps as well as the air
pumps, and, in order to obtain uniformity of action or load, I prefer to
employ three air pumps, the pistons thereof succeeding each other in action.
In constructing marine engines according to this part of my Invention the air
pumps are to be of a capacity suitable for the combined requirement of the
propeller steam engine and of the condenser steam engine. This part of my
Invention is not only applicable when paddle wheels are used, but will be
found particularly useful when screw propellers are employed, by reason of the
propeller engine being arranged to make more numerous strokes than the
condenser engine.
I will now describe the second part of my Invention. Heretofore, in con-
structing marine steam engines not more than three steam engines have been
employed. Hence, when very considerable power is required, and quick
strokes for screw propellers desired, engineers have been forced to have
recourse to the use of cylinders of large diameter and of short stroke.
Consequently, large pistons have to be stopped and changed in their direction
of action very quickly, which is prejudicial to the durability of such steam.
engines. Now this part of my Invention has for its object the application of
more than three steam engines; and, in connecting such engines with the
propeller shaft, I by preference cause there to be as many cranks as there arc
engines, and divide the circle into as many parts as there are steam engines,
so that by thus using numerous smaller cylinders (to obtain the desired
power) I obtain a greater uniformity of action on the propeller shaft, and at
the same time the piston and parts of any one engine which are put in motion
are small in weight as compared with those heretofore used. Hence the
direction and motion of the parts may be changed more often, without
prejudice to the durability of such engines, and thus higher speeds for screw
propellers be more readily and usefully obtained. In carrying out this part of
Invention I prefer to employ eight steam cylinders, forming four compound
engines, and therefore giving motion to the propeller shaft by means of four
my

page_text: cranks; but this number of cylinders may be varied so long as there are more
than three steam engines to give motion to the propeller shaft. The desi-
rableness of this arrangement will be readily understood, more particularly as
applicable to war steamers, as the whole of the engines may be more readily
got below the water; and, in addition to the advantages before mentioned, the
repairs of such engines may be more cheaply, handily, and readily effected
upon the several parts, because each of such parts, as compared with those
now employed, will be comparatively of lighter weight and more easy to
handle, and the expense of pairs and of duplicate parts (the parts of each
engine being made alike) will be much diminished.
I will now describe the third part of my Invention, which consists of
applying one and the same steam chest in combination with two independent
marine condensing steam engines. This steam chest is similar to that
employed in high-pressure engines for locomotive engines, but is used in com-
bination with a low-pressure boiler or boilers, and two marine condensing
engines working independent of each other, and giving motion to two cranks.
I will now describe the fourth part of my Invention, which consists of
employing annular pistons or buckets to the air pumps of marine steam
engines, and also, in combination therewith, the use of air pumps of smaller
diameter concentrically within the outer air pump cylinder. For this purpose
I cause the annular air pump to be formed with an inner cylinder, leaving an
annular space between the two cylinders, in which is to work an annular
piston or bucket; and when the inner cylinder is also to be an air pump, I
apply a piston or bucket therein. I connect these air pumps with distinct
condensing vessels by distinct foot valves and passages, and I make the
delivery from the inner air pump in the general cover and the delivery of the
annular pump separate.
I will now describe the fifth part of my Invention. Heretofore the air
pumps of marine steam engines have been caused to correspond in respect to
the number of strokes with those of the steam cylinder or cylinders which
work them; and I have found that, now comparatively high velocities are
required for screw propellers, such high speeds and repeated strokes are pre-
judicial in working large air pumps. And this part of my Invention consists
of giving motion to the air pump or air pumps by secondary in place of
direct action, so that the number of strokes of the air pump may be reduced
as compared with those of the steam cylinder or cylinders, the cubic contents
of the air pumps being varied accordingly.
I will now describe the sixth part of my Invention. Heretofore, in con-
structing steam engines for screw propellers, it has been usual to have them of

page_text: the power required for propelling, and, when the wind is fair for sailing,
either to raise the propeller out of the water, and allow the steam to go.
down, or else to continue steaming at the cost of a considerable quantity of:
fuel. In constructing vessels suitably for allowing tho screw to be raised, not
only much of the after cabin is taken away, but the machinery and arrange-
ment for raising the screw are costly and inconvenient. Now, according to
this part of my Invention, I employ a steam engine independent of what may
be called the propelling engine; and I use this additional small engine for
giving motion to the screw shaft when the wind is fair for sailing, thus pre-
venting the screw propeller becoming an impediment to the sailing of the
vessel, whilst the main or propelling engine can be put out of action, and the
steam in the boilers thereof allowed to go down, so long as the wind is fair
and the small or additional engine is in action. And such additional steam
engine I construct of the power only sufficient to move the propeller at a
speed equal to that the vessel (under the most favorable circumstances) is
considered capable of sailing; so that the propeller may, when the vessel is
sailing, rotate at a speed equal to; or rather more than, the quantity the vessel
is sailing. I prefer to use a high-pressure engine for the supplemental engine;
for, supposing that engine. to .be of a power to move the propeller, when
sailing at its highest speed, by simply reducing the pressure of the steam in
the boiler, by using less weight on the safety valve the power may be
adjusted with exactness to any lesser speed of the vessel's sailing. A four-
horse power supplemental engine will be sufficient for a vessel having pro-
pelling engines of six hundred horse power, supposing the propeller to weigh
about seven tons.
Having thus described the nature of my Invention, and the manner in
which the same is to be performed, I would have it understood that I do not
confine myself to the details herein described, so long as the peculiar character
of any of the parts of my Invention be retained; but what I claim is,-
First, the improvements in combining the parts of a marine condensing
steam engine herein described, whereby the engines on board any vessel are
divided into a condenser engine and a propeller engine, as explained.
Secondly, I claim the combining of the effort of more than three steam
engines to give motion to the axis of propelling machinery.
Thirdly, I claim the so arranging marine steam engines that two steam
cylinders, working separate, shall be supplied from the same steam chest.
Fourthly, I claim the constructing marine steam engine air pumps with
annular pistons or buckets, and also combining therewith the use of inner
concentric air pumps,

page_text: Fifthly, 1 claim the so connecting and working the air pumps of marine
steam engines that the air pumps shall make other numbers of strokes than
the steam engines.
And, sixthly, I claim the combining the use of an additional small steam
engine with the shaft of a screw propeller in such manner that the small
additional engine may keep the propeller going when the vessel is sailing and
the larger engine put out of action.
In witness whereof, I, the said Edward Slaughter, have hereunto set my
hand and seal, this Eigtheenth day of July, One thousand eight
hundred and forty-nine..

page_text: In the Matter of a Patent granted to EDWARD SLAUGHTER, of Avonside
Iron Works, Bristol, Engineer, for an Invention of "IMPROVEMENTS
IN MARINE STEAM ENGINES," bearing date at Westminster, the
Twenty-third day of January, One thousand eight hundred and
forty-nine, and to which a Specification has been duly inrolled.
DISCLAIMER AND MEMORANDUM OF ALTERATION proposed to bo
entered by the said Edward Slaughter with the Clerk of the Patents of
England, pursuant to the Statutes in that case made and provided.
WHEREAS since the inrolment of my said Specification I have found that
the fifth part of the Invention described and claimed in my said Specification
has not turned out useful, for which reason I wish to disclaim, and I do
hereby disclaim, all parts of my said Specification which describe the same.
And I have been advised that the extent of the first part of the Invention
described in my said Specification is not so clearly ascertained as it might be,
and that it is doubtful whether the making and working of marine steam
engines where the condensation is by surfaces are not included in my
said
Specification, for which reason I wish to disclaim, and I do hereby disclaim,
those parts of my said Specification (if any) which claim marine steam engines
where the condensation is by surfaces. And in order to make the nature of
the first part of my Invention more clear, and to ascertain the extent thereof
with more certainty, I introduce the words "where injection is used" between
the word "engines" and the word "it" in the paragraph commencing with
the words "Heretofore in constructing marine condensing steam engines it has
been usual."

page_text: according to this first part of my Invention, I combine the use of what I call
a propellor steam engine with a condenser steam engine, both worked by
the aid of vacuum."
And I also introduce the words "I would here state that I make no claim
to the use of condenser engines and propeller engines where the condensation
is by surface without injection "just previous to the description of the second
part of my said Invention.
And in order that the effect of the Disclaimer and Alterations may be better
understood, I annex hereto a copy of the Specification as it will appear when
the Disclaimer and Alterations have been made.
"
E
"TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
SLAUGHTER, of Avonside Tron Works, Bristol, Engineer, send greeting.
"WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Rojal Letters Patent under the Great Seal of the United Kingdom of
"Great Britain and Ireland, bearing date at Westminster, the Twenty-third
day of January, One thousand eight hundred and forty-nine, in the twelfth
year of Her reign, did, for Herself, Her heirs and successors, give and
"unto me; the the said Edward Slaughter, my exors, adiñors, and assigns,
"Her special license, full power, sole privilege and authority, that I, the
"said Edward Slaughter, my exors, adiñors, and assigns, and such others as
"
11
66
દ
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66
grant
I, the said Edward Slaughter, my, exors, adññors, or assigns, should at any
"time agree with, and no others, from time to time and at all times during
"the term of years therein expressed, should and lawfully might make, use,
exercise, and vend, within England, Wales, and the Town of Berwick-upon-
"Tweed, my Invention of "IMPROVEMENTS IN MARINE STEAM ENGINES;" in
"which said Letters Patent is contained a proviso that the said Edward
Slaughter, should cause a particular description of the nature of my said
Invention, and in what manner the same is to be performed, by an instru-
"ment in writing under my hand and seal, to be enrolled in Her said Majesty's
High Court of Chancery within six calendar months next and immediately
"after the date of the said in part recited Letters Patent, as in and by the
same, reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
"Edward Slaughter, do hereby declare that the nature of my said Invention,
"and the manner in which the same is to be performed, are fully described
"and ascertained in and by the following statement thereof, that is to say:'
61
66
66
My Invention consists, first, of improvements in combining the parts

page_text: 36
36
constituting a marine steam engine, whether used for propening by screw
or by paddle wheels."
"Secondly, my Invention consists of improvements in marine steam
engines, by combining the effort of more than four cylinders to give motion
to the driving shaft or axis of paddle wheels or a screw propeller."
"Thirdly, my Invention consists of improvements in marine steam engines,
by so arranging the steam connections thereof, that two cylinders working
separate
shall communicate with one steam chest."
EE
Fourthly, my Invention consists of constructing air pumps of marine
steam engines with annular pistons or buckets, and also the combining
therewith inner concentric air pumps.'
"
.
"Fifthly, my Invention consists of combining the use of a small steam
engine (having a separate boiler) with the axis of a screw propeller, that
"the same may be brought into action to keep the screw propeller going
when sailing, so that the propeller may offer no impediment to sailing, thus
allowing the steam engine or engines used for driving the propeller to be
put out of action when the wind is favorable, thereby rendering the lifting
"of the propeller out of the water unnecessary."
34
"And in order that my Invention may be most fully understood and readily
"carried into effect, I will proceed to describe the means pursued by me."
"Heretofore in constructing marine condensing steam engines where injec-
"tion is used, it has been usual (whatever be the number of steam cylinders
"of which an engine may be composed) for the engine, in addition to giving
"motion to the paddle wheel or propeller shaft, also to give motion to the air
pump or pumps for maintaining a vacuum.
"
Now, according to this first part of my Invention, I combine the use of
what call a propeller steam engine with a condenser steam engine, both
working by the aid of injection and vacuum, the propeller engine giving
"motion to the paddle wheel or propeller shaft, whilst the condenser steam
engine gives motion to the air pump or pumps, so as to keep up a vacuum
"for itself and for the propeller steam engine. By this arrangement or com-
"bination, amongst other advantages, it may be mentioned that the propeller
engine may be arranged to make more numerous strokes than the condenser
engine, and the condenser engine may continue uniformly to work the eon-
"denser, the same not in any way depending on the change or variation of
"load to which the propeller engine is constantly liable. The propeller
engine may consist of any number of steam cylinders, the great point of the
Invention being that the propeller steam engine shall not have to work the
condenser as heretofore, but the condenser shall be worked by an engine
66

page_text: 66
(consisting of one or more cylinders), such condenser engine not working
"the paddle wheel or propeller shaft, but I prefer that it should work the
"water pumps as well as the air pumps, and in order to obtain uniformity of
"action or load, I prefer to employ three air pumps, the pistons thereof
"succeeding each other in action. In constructing marine engines according
" to this part of my Invention, the air pumps are to be of a capacity suitable
." for the combined requirement of the propeller steam engine and of the con-
"denser steam engine. This part of my Invention is not only applicable when
"
paddle wheels are used, but will be found particularly useful when screw
"propellers are employed, by reason of the propeller engine being arranged
" to make more numerous strokes than the condenser engine. I would here
" state that I make no claim to the use of condenser engines and propeller
engines when the condensation is by surface without injection."
"
66
"I will now describe the second part of my Invention. Heretofore in con-
"structing marine steam engines not more than three steam engines
"have been employed. Hence, when very considerable power is required,
"and quick strokes for screw propellers desired, engineers have been
"forced to have recourse to the use of cylinders of large diameter and of
"short stroke, consequently large pistons have to be stopped and changed
" in their direction of action very quickly, which is prejudicial to the
." durability of such steam engines. Now this part of my Invention has for
"its object the application of more than three steam engines; and in con-
necting such engines with the propeller shaft, I by preference cause there
"to be as many cranks as there are engines, and divide the circle into as many
parts as there are steam engines, so that by thus using numerous smaller
cylinders (to obtain the desired power) I obtain a greater uniformity of
"action on the propeller shaft, and at the same time the piston and parts of
"any one engine which are put in motion are small in weight as compared
." with those beretofore used. Hence the direction and motion of the parts
may be changed more often without prejudice to the durability of such
engines, and thus higher speeds for screw propellers be more readily and
usefully obtained.
"
"
66
66
"In carrying out this part of my Invention, I prefer to employ eight
"steam cylinders, forming four compound engines, and therefore giving
"motion to the propeller shaft by means of four cranks; but this number
"of cylinders may be varied, so long as there are more than three steam
engines to give motion to the propeller shaft. The desirableness of
this arrangement will be readily understood, more particularly as appli-
"cable to war steamers, as the whole of the engines may be more readily got
"E

page_text: upon
"below the water, and in addition to the advantages before mentioned, the
repairs of such engines may be more cheaply, handily, and readily effected
the several parts, because each of such parts, as compared with those
now employed, will be comparatively of lighter weight, and more easy to
"handle, and the expense of pairs and of duplicate parts (the parts of each
engine being made alike) will be much diminished.
66
65
"I will now describe the third part of my Invention, which consists of
applying one and the same steam chest in combination with two, inde-
"pendent marine condensing steam engines. This steam chest is similar
"to that employed in high-pressure engines for locomotive engines, but is
"used in combination with a low-pressure boiler or boilers and two marine
condensing engines working independent of each other and giving motion
46
"to two cranks.
46
"
"I will now describe the fourth part of my Invention, which consists of
employing annular pistons or buckets to the air pumps of marine steain
"engines, and also in combination therewith the use of air pumps of smaller
"diameter concentrically within the outer air-pump cylinder. For this
purpose I cause the annular air pump to be formed with an inner cylinder,
"leaving an annular space between the two cylinders, in which is to work an
"annular piston or bucket, and when the inner cylinder is also to be an air
"pump, I apply a piston or bucket therein; I connect these air pumps with
"distinct condensing vessels.by distinct foot valves and passages, and I make
"the delivery from the inner air pump in the general cover, and the delivery
"of the annular pump separate.
"I will now describe the fiftli part of my Invention. Heretofore in con-
"structing steam engines for screw propellers it has been usual to have them
"of the power required for propelling, and when the wind is fair for sailing,
"either to raise the propeller out of the water and allow the steam to go down,
or else to continue steaming at the cost of a considerable quantity of fuel.
"In constructing vessels suitably for allowing the screw to be raised, not only
"much of the after cabin is taken away, but the machinery and arrangement
"for raising the screw are costly and inconvenient. Now, according to this part
"of my Invention, I employ a steam engine independent of what may be
"called the propelling engine, and I use this additional small engine for
giving motion to the screw shaft when the wind is fair for sailing, thus
"preventing the screw propeller becoming an impediment to the sailing
"of the vessel, whilst the main or propelling engine can be put out of action
"and the steam in the boilers thereof allowed to go down so long as the wind
"
is fair and the small or additional engine is in action. And such additional

page_text: "steam engine I construct of the power only sufficient to move the propeller
"at a speed equal to that the vessel (under the most favorable circum-
"stances) is considered capable of sailing, so that the propeller may, when
"the vessel is sailing, rotate at a speed equal to or rather more than the
"quantity the vessel is sailing. I prefer to use a high-pressure engine for the
supplemental engine, for, supposing that engine to be of a power to move
"the propeller when sailing at its highest speed, by simply reducing the
pressure of the steam in the boiler, by using less weight on the safety valve
"the power may be adjusted with exactness to any lesser speed of the vessel's
sailing. A four horse-power supplemental engine will be sufficient for a
"vessel having propelling engines of six hundred horse-power, supposing the
propeller to weigh about seven tons.
CE
"Having thus described the nature of my Invention, and the manner in
"which the same is to be performed, I would have it understood that I do
"not confine myself to the details. herein described, so long as the peculiar
"character of any of the parts of my Invention be retained; but what I
"claim is,
"First, the improvements in combining the parts of a marine condensing
"steam engine herein described, whereby the engines on board any vessel are
"divided into a condenser engine and a propeller engine, as explained.
66
"
Secondly, I claim the combining of the effort of more than three steam
engines to give motion to the axis of propelling machinery.
"
Thirdly, I claim the so arranging marine steam engines that two steam
cylinders working separate shall be supplied from the same steam chest.
"
Fourthly, I claim the constructing marine steam engine air pumps with
"annular pistons or buckets, and also combining therewith the use of inner
"concentric air pumps.
"
Fifthly, I claim the combining the use of an additional small steam
"engine with the shaft of a screw propeller, in such manner that the small
"additional engine may keep the propeller going when the vessel is sailing
"and the larger engine put out of action.
"In witness whereof, I, the said Edward Slaughter, have hereunto set
"
my hand and seal, this Eighteenth day of July, One thousand eight
"hundred and forty-nine."
In witness whereof, I, the said Edward Slaughter, have hereunto set my
hand and scal, this Twenty-eighth day of May, in the year of our
Lord One thousand eight hundred and fifty-eight.
EDWARD SLAUGHTER. (L.S.).

page_text: To the Clerk of the Patents of England.
This is to certify, that the above-named Edward Slaughter has applied to
me for leave to enter with you the above-written Disclaimer and Memorandum
of Alteration of a certain Invention for which Letters Patent were duly
granted to him under the Great Scal, dated at Westminster, the Twenty-third
day of January, One thousand eight, hundred and forty-nine, and to which a
Specification was duly enrolled, and on considering the said application, I
directed him to advertise the said Disclaimer and Memorandum of Alteration
in the London Gazette, and in the Times, the Morning Herald, and Bristol
Mercury newspapers, and such advertisements were duly made in the Morning
Herald on the Third, the London Gazette on the Fourth, the Times on the
Fifth, and the Bristol Mercury on the Eighth day of May instant, and no
objection having been made to the said application, I have accordingly granted
leave to the said Edward Slaughter to file his said Disclaimer and Alteration
pursuant to the Statutes in such case made and provided.
Temple. May 29th 1858.
FITZROY KELLY.
AND BE IT REMEMBERED, that on the Twenty-eighth day of May, in
the year of our Lord 1858, the aforesaid Edward Slaughter came before our
said Lady the Queen in Her Chancery, and acknowledged the Disclaimer
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Disclaimer aforesaid was stamped according to
the tenor of the Statute made for that purpose.
Enrolled the Second day of June in the rear of our Lord One thousand
Enrolled the Second day of June in the year of our Lord One thousand
eight hundred and fifty-eight.