IMPROVE- MENTS IN LOCOMOTIVE STEAM ENGINES
Year: 1859

page_text: LETTERS PATENT to Samuel Dobson Davison, of Leith, in the County of
Mid Lothian, North Britain, Engineer, for the Invention of "IMPROVE-
MENTS IN LOCOMOTIVE STEAM ENGINES."
Sealed the 1st July 1859, and dated the 3rd February 1859.
PROVISIONAL SPECIFICATION left by the said Samuel Dobson Davison
at the Office of the Commissioners of Patents, with his Petition, on
the 3rd February 1859.
I, SAMUEL DOBSON DAVISON, of Leith, in the County of Mid Lothian, North
Britain, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN LOCOMOTIVE STEAM ENGINES," to be as follows:-
This Invention relates to the arrangement and construction of what are
technically known as "tank" locomotive engines, and the main improvement
consists in the forming the sides of the tank or water supply holder by means
of the longitudinal side frame plates of the engine, instead of introducing
separate plates for this purpose according to the ordinary practice. By doing
this, one solid box or cistern is provided as the foundation of the engine and
boiler. The whole of the machinery of the engine is brought to the outside,
so as to be easily accessible. The tank may either be carried simply from the
front side of the driving axle to the back plate of the smoke box, a recess
being cut out to enable it to clear the front axle, or it may be carried forward
quite to the front end of the smoke box, a vertical recess being cut out of it

page_text: for the front axle. At the after part of the fire box the tank may also be
carried beneath the foot plate of the engine, whether the latter is four or six
wheeled. The Invention.may be adapted to inside cylinder engines, but it is
proformed for the outside class.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Samuel Dobson Davison in the Great Seal Patent Office
on the 3rd August 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
DOBSON DAVISON, of Leith, in the County of Mid Lothian, North Britain,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of February, 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 Samuel Dobson Davison, Her special license that I, the said Samuel
Dobson Davison, my executors, administrators, and assigns, or such others
as I, the said Samuel Dobson Davison, 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 Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN LOCOMOTIVE STEAM ENGINES," upon the condition (amongst
others) that I, the said Samuel Dobson Davison, 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 Samuel Dobson Davison, 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, 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 what are
technically known as "tank" locomotive engines, and the main improvement
consists in the forming the sides of the tank or water supply holder by means

page_text: of the longitudinal side frame plates of the engine, instead of introducing
separate plates for this purpose according to the ordinary practice. By doing
this, one solid box or cistern is provided as the foundation of the engine and
boiler. The whole of the machinery of the engine is brought to the outside,
so as to be easily accessible. The tank may either be carried simply from the
front side of the driving axle to the back plate of the smoke box, an angular
recess being cut out to enable it to clear the front axle, or it may be carried
forward quite to the front end of the smoke box, a vertical recess being cut
out of it for the front axle. At the after part of the fire box the tank may
also be carried beneath the foot plate of the engine, whether the latter is four
or six wheeled. The Invention may be adapted to inside cylinder engines,
but it is preferred for the outside class.
And in order that my said Invention of improvements in locomotive engines
may be properly understood, I shall now proceed to describe the several.
illustrative Figures on the explanatory Sheet of Drawings which I have here-
unto appended for the purpose of showing certain modifications under which
my improvements may be judiciously carried out in practice, that is to say,―
Figure 1 on the accompanying Drawings is a sectional elevation, showing
one mode of arranging the principal parts of a locomotive engine according to
my improved system. Figure 2 is a half plan corresponding to Figure 1;
and Figure 3 is a transverse vertical section taken through the line 1, 2,
Figure 1.
In arranging and constructing an engine according to my present Invention,
the side frames A are made sufficiently deep to form the sides of the tank;
these side frames may be made either of iron or steel plate. As arranged in
the accompanying Drawing the principal tank is shown as extending from the
front of the smoke box backwards to within a short distance from the fire box.
This tank is formed by connecting the top, bottom, and end plates B to the
side frames A; these plates are connected to the framing by means of the
angle iron C, to which the side frames and plates are rivetted and caulked in
the same manner as in constructing a boiler. The angle iron C is used at all
the junctions of the plates, and in this manner forms a solid and very efficient
framing to connect the tank with the side frames A, and thus secure a
superior foundation for the boiler and engine. At that part of the tank
through which the leading axle D would otherwise pass, a bridge is formed by
the bent plate E; the recess thus obtained leaves ample space for the axle to
pass through clear of the tank. The bridge plate E is connected to the side
frames A by the angle iron F, which is riveted and caulked in the same
manner as the other parts of the tank. At the front part of the engine

page_text: immediately below the end of the boiler the tank is further strengthened by
the interposition of the transverse plate or diaphragm G, which is riveted in
between the angle irons C; the lower part of this diaphragm is cut in an
arched form to allow of the passage of the water. Above the front part of the
tank the smoke-box H is constructed in the ordinary manner, and connected
to the tank by means of the angle iron I. In this modification of my
Invention a smaller tank is also formed beneath the foot plate of the engine,
just behind the fire box J. . This tank is formed by the end and top and
bottom plate K, which are connected to the side frames A by the angle iron L.
The tanks are furnished with man-hole plates M for the purpose of affording
access to the interior of the tanks to clean out from time to time the deposited
matter. In tank engines constructed according to these improvements, the
cylinders and the whole of the working parts of the engine are arranged
outside the side frames A, affording instant access to any of the parts
without requiring a pit to get at the machinery. In the accompanying
Drawings a portion only of the working details are shown, just sufficient to
indicate their arrangement outside the framing. In the transverse section
Figure 8 is shown the foot plate N, which extends along the engine above
the working gear on each side. These foot plates are connected to the side
frames A by means of the angle iron O, and are further supported at the ends
by the bracket pieces P. In this Figure the positions of the cylinders and
wheels are indicated by the red outlines.
Another modification of my present Invention consists in forming the tanks
for these engines of cast iron, and bolting the same to the steel or iron side
frames A, preference is, however, given to the mode of construction I have
herein-before described. In cases where it is not required to carry so large a
quantity of water, the tank beneath the foot plate may be dispensed with, and
the larger tank not extended beyond the front end of the boiler. Where more
than one tank is used they are connected by means of water pipes, which are
not shown in the Drawings; the feed water is withdrawn from the tanks by
the feed pumps in the ordinary manner. With these improvements the
necessary quantity of water is carried with the engine, while at the same time
its. stability and steadiness are increased by the weight of the water being
entirely below the boiler.
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,—

page_text: First, the general arrangement and construction of locomotive tank engines,
as herein-before described and shown in the accompanying Drawings.
Second, the system or mode of arranging and constructing the tanks for
locomotive engines, in which the steel or iron side frames of the engine form
the sides of the tank or tanks, the top, bottom, and end plates being riveted
to the side frames by means of angle iron, with a view of obtaining increased
stability, as herein-before described and shown in the accompanying Drawings.
Third, the system or mode of forming the tank or tanks of locomotive
engines of cast iron, and bolting or otherwise securing the same to the side
frames of the engine, as herein-before described.
In witness whereof, I, the said Samuel Dobson Davison, have hereunto
set my hand and seal, this Thirtieth day of July, One thousand eight
hundred and fifty-nine.
S. D. DAVISON. (L.S.)