IMPROVEMENTS IN THE ARRANGEMENT AND CONSTRUCTION OF MARINE ENGINES AND BOILERS FOR DRIVING TWIN SCREWS OF BOATS YACHTS. AND OTHER VESSELS
Year: 1872

page_text: LETTERS PATENT to Thomas Pratt Hollick, of the Firm of Wimshurst,
Hollick, and Co., of Limehouse, in the County of Middlesex,
Engineers, for the Invention of "IMPROVEMENTS IN THE ARRANGEMENT
AND CONSTRUCTION OF MARINE ENGINES AND BOILERS FOR DRIVING TWIN
SCREWS OF BOATS YACHTS. AND OTHER VESSELS"
Sealed the 30th July 1872, and dated the 3rd June 1872.
PROVISIONAL SPECIFICATION left by the said Thomas Pratt Hollick
at the Office of the Commissioners of Patents, with his Petition,
on the 3rd June 1872.
I, THOMAS PRATT HOLLICK, of the Firm of Wimshurst, Hollick, and
Co., of Limehouse, in the County of Middlesex, Engineers, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE
ARRANGEMENT AND CONSTRUCTION OF MARINE ENGINES AND BOILERS FOR DRIVING
TWIN SCREWS OF BOATS, YACHTS, AND OTHER VESSELS," to be as follows:-
This Invention consists of certain simple and efficient improvements
in the arrangement and construction of marine engines and boilers for

page_text: driving twin screws of boats, yachts, and other vessels, enabling one
man to attend to the requirements of the boiler, and to control the speed
and direction of each of the engines (which are independent), thus being
able to guide the vessel without the aid of a helm.
The engines are bolted to a vertical A shaped frame, secured to the
sole or bed plate of the boiler, and are constructed with inverted vertical
or nearly vertical cylinders secured to the upper part of the frame, the
part of which between the cylinders forms their common exhaust
passage, the exhaust steam passing therefrom through a single, double,
or branch pipe, divided longitudinally, to the chimney or other suitable
outlet.
The feed pumps are by preference placed immediately beneath the
cylinders, either central or at one side of the pistons, steadying the
action of the piston rods.
The action and arrangement of the engines are vertical, or nearly
so, and so fitted to the boiler as to be placed one on each side of the
furnace, ash-pit, and man-hole doors, so that the latter, together with
the reversing levers and other controlling parts of the engines are all
within easy reach of the driver standing between the engines and abaft
the boiler.
The boiler with which these engines are employed is of the vertical
dome kind, with or without tubes (but they can be applied to, and
employed in connection with, any ordinary form of boiler). In the
form preferred by me the smoke and other unconsumed products of
combustion are conveyed from the fire-box to the upper part of the
central take-up by up-take tubes, placed so as to be a means of drawing
the flames and heated gases to the sides or heating surface of the fire-
box and around the pendent tubes (if any), the central take-up being
fitted with a damper at or near its mouth to prevent the free egress of
the smoke and other unconsumed products of combustion there.
By these means the generation of steam in the boiler is greatly
facilitated in consequence of the action of the flames being more intense
against the sides of the fire-box than it is in fire-boxes which have only
a central take-up.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Pratt Hollick in the Great Seal Patent
Office on the 3rd December 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
PRATT HOLLICK, of the Firm of Wimshurst, Hollick, and Company, of
Limehouse, in the County of Middlesex, Engineers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of June, in the year of our
Lord One thousand eight hundred and seventy-two, in the thirty-fifth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Thomas Pratt Hollick, Her special licence that
I, the said Thomas Pratt Hollick, my executors, administrators, and
assigns, or such others as I, the said Thomas Pratt Hollick, 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 "Iк-
PROVEMENTS IN THE ARRANGEMENT AND CONSTRUCTION OF MARINE ENGINES AND
BOILERS FOR DRIVING TWIN SCREWS OF BOATS, YACHTS, AND OTHER VESSELS,"
upon the condition (amongst others) that I, the said Thomas Pratt
Hollick, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly
describe and ascertain the nature of my 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 Thomas Pratt Hollick, 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 in writing, and on reference being had to the
accompanying Drawings, that is to say :-
:-
. This Invention consists of certain simple and efficient improvements
in the arrangement and construction of marine engines and boilers for
driving twin screws of boats, yachts, and other vessels, enabling one
man to attend to the requirements of the boiler and to control the speed

page_text: and direction of each of the engines (which are independent), thus being
able to guide the vessel without the aid of a helm.
On the accompanying Drawings Figure 1 represents a sectional side
elevation; Figure 2, a front elevation; and Figure 3, a plan view of the
engines and boiler; and Figure 4, a sectional plan of the boiler alone.
The engines are bolted to a vertical A shaped frame a secured to the
sole or bed plate 6 of the boiler i, and are constructed with inverted
vertical or nearly vertical cylinders c, secured to the upper part of the
frame, the part d of which forms their common exhaust passage, whence
the exhaust steam passes through a single, double, or branch pipe e,
divided longitudinally, to the chimney for other suitable outlet.
The feed pumps g are by preference placed immediately beneath the
cylinders, either central or at one side of the pistons, to steady the action
of the piston rods h.
The action and arrangement of the engines are vertical, or nearly so,
and so fitted to the boiler as to be placed one on each side of the furnace,
ash-pit, and man-hole doors j, k, l, respectively, see Figure 2, so that the
latter, together with the reversing levers m and other controlling parts
(of any kind) of the engines, are within easy reach of the driver standing
between the engines and abaft the boiler, see Figure 3.
The boiler with which these engines are employed may be of any
kind, but by preference I fit one of the vertical dome kind i with either
flat or curved crown i* to furnace, and with pendent tubes 9 placed
either vertically, or nearly so, and fitted with four or any number of side
up-take tubes o, which convey the smoke and other products of com-
bustion from the fire-box n to the upper part of the central take-up f,
and are placed so as to be a means of drawing the flames and heated
gases more directly to the sides or heating surface of the fire-box and
around the pendent tubes, the central take-up being also fitted with a
hanging damper p at or near its mouth to regulate the draft and prevent
free egress of the heat, smoke, &c., there.
It may be here remarked that the size and position of the tubes q are
not material (hanging tube boilers being hitherto in use), also that it is
immaterial at what part near the top of the central take-up the side
up-take tubes enter it, whether on the same level or not.

page_text: By these improvements the generation of steam in the boiler is greatly
facilitated, the action of the flames being more intense against the sides
of the fire-box and pendent tubes than it is in fire-boxes having only a
central take-up.
Between the sides of the fire-box and boiler at the base thereof I fit a
wrought-iron strengthening ring r, which is also of such a form as to rise
above and encircle the furnace and ash-pit doors, as shown in red dotted
lines in Figure 2.
As a further improvement I fit knives 8 on the stern post (or other-
wise) see Figure 1, which just clear the sharpened leading edges of the
propelling blades, and as the latter revolve act against them as shears,
and cut and free them from the weeds which frequently impede the
navigation of shallow rivers.
Having now described the nature and object of my said Invention
for "Improvements in the Arrangement and Construction of Marine
Engines and Boilers for Driving Twin Screws of Boats, Yachts, and other
Vessels," together with the manner in which the same is to be or may
be performed or carried into practical effect, I would remark in con-
clusion that I claim as my Invention the improvements constituting the
general construction and arrangement of marine engines and boilers for
driving twin screws of boats, yachts, and other vessels, substantially as
above described, and as illustrated on the accompanying Drawings, or
any mere variation thereof, and as regards the boilers the addition
thereto of the side up-take tubes o, and of the hanging damper p to the
central up-take f.
In witness whereof, I, the said Thomas Pratt Hollick, have here-
unto set my hand and seal, this Second day of December, in the
year of our Lord One thousand eight hundred and seventy-two.
30 Witness,
BRISTOW HUNT,
Solicitor and Patent Agent,
5, Serle Street,
Lincoln's Inn.
THO³. P. HOLLICK. (L.S.)