IMPROVE- MENTS IN STEAM BOILERS FOR TRAMWAY ENGINES AND OTHER MOTIVE POWER
Year: 1875

page_text: LETTERS PATENT to Thomas Claxton Fidler, of Richmond, in the
☐ County of Surrey, Civil Engineer, for the Invention of "IMPROVE-
MENTS IN STEAM BOILERS FOR TRAMWAY ENGINES AND OTHER MOTIVE
POWER."
:
PROVISIONAL SPECIFICATION left by the said Thomas Claxton
Fidler at the Office of the Commissioners of Patents, with his
Petition, on the 17th December 1875.
I, THOMAS CLAXTON FIDLER, of Richmond, in the County of Surrey,
Civil Engineer, do hereby declare the nature of my said Invention
for "IMPROVEMENTS IN STEAM BOILERS FOR TRAMWAY ENGINES AND OTHER
'MOTIVE POWER," to be as follows:-
This Invention relates to the application of steam power upon street
tramways and underground railways, and in other situations in which it
may be desirable to avoid the production of smoke and noise, or to
dispense with the supply of fuel and air which is necessary in ordinary

page_text: steam boilers, the main object being to obtain a supply of steam for a
certain limited period of time at a nearly uniform pressure and without
the combustion of fuel, and I do this by means of heat stored in a
heater which is contained in the fire-box or flue of the boiler, and which
is reheated at intervals or replaced by other heaters already heated in a
separate furnace, in order to continue the supply of steam for another
limited period of time. For this purpose I employ a boiler consisting of
an outer shell of any convenient form, and an inner fire-box or
receptacle for the heater having one or more openings by which the
heater may be introduced, and which may be closed by fire-doors. The
fire-box or receptacle may take the form of an ordinary fire-box; or it
may consist of one or more horizontal or vertical tubes or flues; or it
may be of any other convenient form. The heater consists of fire-clay,
iron, or other suitable material heated to a very high temperature, and
may consist of a number of balls or blocks of any form which may be
conveniently transferred from the heating furnace into the boiler; or it
may consist of tubes or perforated or other blocks which may be so
built up in the flue of the boiler that they can be readily heated by the
passage of hot gases from a furnace through them.
In order to protect the plates of the fire-box or flue from excessive
heat and to regulate and moderate the transfer of heat from the heater,
to the water in the boiler I employ a lining or fettling of the fire-box
or a partial lining or hearth of fire-brick, or an internal receptacle of
fire-clay or other material surrounding or partly surrounding the heater,
and if necessary I also employ a moveable screen by which the radiation
of heat from the heater may be partly intercepted in order that the
generation of steam may be regulated by the driver according to the
requirements of the engine.
In applying this Invention for the purpose of obtaining motive power
upon tramways or underground railways, I employ locomotives or steam
cars fitted with boilers constructed upon the principle above described,
and containing heaters capable of giving off sufficient heat to supply
steam for a limited trip; and at convenient points I employ stationary
furnaces to which the engines or steam cars have access by means of
sidings, and by which the heaters are reheated after each trip. The
engines or steam cars may either exchange their cooled heaters for
other already heated in the furnace; or they may be placed in con-
pection with the furnace, so that a current of hot gases is sent through
:

page_text: and among the heaters, in order to raise them to the requicu
temperature.
The locomotives or steam cars may be of any ordinary construction
in other respects, and may be provided with feed water tanks and with
feed pumps or injectors for the supply of their own feed water in the
ordinary way, and the exhaust steam not being required for producing
a blast may be turned into the cold water tanks in order to condense the
whole or a part of it, and so to avoid the visible puffing of steam from the
exhaust. I prefer however to employ a stationary boiler heated by the
gases of the stationary furnace for the purpose of supplying all
the locomotives or steam cars with the heated feed water between each
trip sufficient to make up the loss by evaporation for the whole trip,
and to fill the boilers, with heated feed water for the first trip in the
day.
The advantages of this Invention as compared with an ordinary boiler
are that all smoke and noxious gases are avoided, the noise of the blast
is done away with and a stoker is not required, and its advantages as
compared with the hot water or fireless engine are that the danger of
excessively high pressure at the beginning of the trip is avoided, and at
the same time the engine being supplied with steam at a nearly uniform
pressure instead of a constantly falling pressure may be proportioned to
work throughout at a higher mean effective pressure, and therefore with
greater efficiency because the effective pressure in the fireless engine
is fixed by the lowest boiler pressure which occurs at the end of
its trip.
To avoid priming in any case in which it may be difficult to apply a
steam dome (as when the boiler is carried under the floor of a car), I
employ a reducing valve leading into a long pipe or vessel within the
boiler, from which pipe or vessel the steam is drawn for the engine, with
the object of ensuring that the steam shall have the temperature due to
the higher pressure in the boiler, and shall therefore be dry or super-
heated steam..
I purpose as aforsaid to apply this Invention for the production of
steam power in all situations where it is desirable to avoid smoke or
noise or to dispense with the supply of fuel or air, and among others for
the-production of steam power upon tramways and underground railways
1

page_text: .
in tunnels and mines, and in submarine operations including the
propulsion of torpedoes.
SPECIFICATION filed in pursuance of the conditions of the Letters
Patent, and of an Order of the Lord Chancellor, by the said Thomas
Claxton Fidler in the Great Seal Patent Office on the 6th July 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, "THOMAS
CLAXTON FIDLER, of Richmond, in the County of Surrey, Civil Engineer;
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of December, in the
year of our Lord One thousand eight hundred and seventy-five; in the
thirty-ninth year of Her reign, did, for Herself, Hér heirs and successors;
give and grant unto me, the said Thomas Claxton Fidler, Her special
license, that I, the said Thomas Claxton Fidler, my executors, admini-
.strators, and assigns, or .such others as I, the said Thomas Claxton
Fidler, my executors, administrators, or assigns, should at any time
agree with, and no others, from time to time and at all times there-
after 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 Inven-
tion for "IMPROVEMENTS IN STEAM BOILERS FOR TRAMWAY ENGINES AND OTHER
MOTIVE POWER," upon the condition (amongst others) that I, the said
Thomas Claxton Fidler, my executors or administrators, by an instru-
ment. 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 on or before the Seventh day of July, One
thousand eight hundred and seventy-six.
.
NOW KNOW YE, that I, the said Thomas Claxton Fidler, 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

page_text: and by the following statement, reference being had to the accompanying
Drawings, and to the letters and figures marked thereon, that is to say:→
: The said Invention relates to the application of steam power upon
street tramways and underground railways, and in other situations in
which it may be desirable to avoid the production of smoke and noise, or
to dispense with the supply of fuel and air, which is necessary in ordinary
steam boilers, and it has for its chief object obtaining a supply of stream
for a certain limited period of time, at a nearly uniform pressure, and
without the combustion of fuel. In carrying out my Invention I effect
this object by means of heat stored in a heater which is contained in
the fire-box or flue of the boiler and which is reheated at intervals, or
replaced by other heaters already heated in a separate furnace in order
to continue the supply of steam for another limited period of time.
For this purpose I employ a boiler consisting of an outer shell of any
convenient form, and an inner fire-box or receptacle for the heater, having
one or more openings by which the heater may be introduced and which
may be closed by fire-doors. The fire-box or receptacle may be con-
structed in the form of an ordinary fire-box, or it may consist of one or
more horizontal or vertical tubes or flues, or it may be made of any
other convenient form. The heater is composed of fire-clay, iron, or
other suitable material heated to a very high temperature, and may
consist of a number of balls or blocks of any form which may be con-
veniently transferred from the heating furnace into the boiler, or it may
consist of tubes or perforated or other blocks, which may be so built up
in the flue of the boiler that they can be readily heated by the passage
of hot gases from a furnace through them..
In order to protect the plates of the fire-box or flue from exces-
sive heat, and to regulate and moderate the transfer of heat from the
heater to the water in the boiler, I employ a lining or fettling of the
fire-box, or a partial lining or hearth of fire-brick, or an internal. recep-
tacle of fire-clay or other material surrounding or partially surrounding
the heater, and if necessary I also employ a movable screen by which
the radiation of heat from the heater may be partly intercepted, in
order that the generation of steam may be regulated by the driver
according to the requirements of the engine.
And in order that my said Invention may be fully understood I
shall now proceed more particularly to describe the same, and for that
purpose shall refer to the several Figures on the annexed Sheet of

page_text: Drawings, the same letters of reference indicating corresponding parts
in all the corresponding Figures.
Figure 1 of my Drawings represents a longitudinal section of a hori
zontal cylindrical boiler, constructed and arranged in accordance with
my Invention, and Figure 2 is a transverse section of the same. a is
the outer shell, and b, b, b, are flues, forming the receptacle for the
heater which consists of a number of balls or blocks h, h, h, of fire-clay,
iron, or other suitable material, which are heated in a separate furnace,
and introduced into the boiler at either end of the flues by the fire-doors
d; d; c, c, is a lining or internal tube of fire-clay or other material;
and e a partial lining or hearth of the same material, to protect the
plates of the flues, and to moderate the transfer of heat when the heated
blocks are first introduced.
Figure 3 is a cross section, and Figure 4 a horizontal section, illus-
trating a modified arrangement of horizontal cylindrical boiler. a is
the outer shell, and b, b, are flues forming the receptacle for the
heater, which consists of perforated blocks h, h, of fire-clay or other
.suitable material built up in the flues, so that they can readily be heated
by the passage through them of hot gases from a furnace not contained
in the boiler.
Figure 5 represents a vertical section of a vertical boiler, constructed
and arranged in accordance with my Invention, and Figure 6 is a hori
zontal section of the same. a is the outer shell, and b the fire-box
forming a receptacle for the heater h, which consists of a cylindrical
block of fire-brick or other suitable material, and which I prefer to make
hollow, as shewn, and w is a large water tube depending from the roof
of the fire-box inside the hollow heater for the purpose of increasing the
heating surface. The heater is carried upon the hearth or platform.d
by which it is lifted when hot into the boiler from below, and which
'also closes the opening at the bottom of the fire-box.
Figure 7 is a vertical section, and Figure 8 a horizontal section of
another form of vertical boiler, in which a is the outer shell, and b, b, b,
are vertical tubes or flues open at the top and, by preference, open also
at the bottom, as shewn in my Drawings. The heater h, h, h, consists
of a number of rods or bars, or cylinders of iron, or other suitable
material, which after being heated in the separate furnace are lifted and
dropped into the tubes b, b, from above.
Figure 9 is a vertical section, and Figure 10 a horizontal section of

page_text: another form of vertical boiler, in which a is the outer shell, and b, b;
are vertical flues open at each end, and provided with doors d, d, at the
lower end; the heater h, h, consists of a number of small blocks or
fragments, or balls of fire-clay, or iron, or other suitable material, or
of sand or gravel, which after being heated is fed by a hopper or funnel,
or by the shovel into the flues b, b, from above, and when cold is readily
shot out by the doors d, d.
Figure 11 is a vertical section, and Figure 12 a horizontal section of
another form of boiler similar to the fire-box of a locomotive. a is
the outer shell and the inner fire-box, having a fire-door f in the side
near the top, and having the bottom closed by doors d, d. The heater
h, h, (consisting as before of fragments of fire-clay, sand, or other
material,) is introduced by a hopper or by the shovel through the door f,
and when cool is removed by the doors d, to be replaced by a freshly
heated material.
In applying this Invention for the purpose of obtaining motive
power upon tramways or underground railways, I employ locomotives
or steam cars fitted with boilers, constructed upon the principle herein-.
before described and illustrated by my Drawings, and containing heaters
capable of giving off sufficient heat to supply steam for a limited trip,
and at convenient points I employ stationary furnaces, to which the
engines or cars have access by means of sidings, and by which the
heaters are reheated after each trip. The engines or steam cars either
exchange their cooled heaters for others already heated in the furnace
or they are placed in connection with the furnace, so that a current of
hot gases is sent through and among the heaters in order to raise them
to the required temperature.
The locomotives or steam cars may be of any ordinary construction
in other respects, and may be provided with feed water tanks, and with
feed pumps or injectors for the supply of their own feed water in the
ordinary manner, and the exhaust steam not being required for pro-
ducing a blast may be directed into the cold water tanks in order to
condense the whole or part of it, and so to avoid the visible puffing of
steam from the exhaust; I prefer however to employ a stationary boiler
heated by the gases of the stationary furnace, for the purpose of sup-
plying the whole of the locomotives or steam cars with heated feed
water between each trip, sufficient to compensate for the loss by evapo-
ration for the whole trip, and to fill the boilers with heated feed water for

page_text: the first trip in the day, in order to dispense with the weight of tanks,
feed water, and feed apparatus upon the locomotives or steam cars
themselves. The feed water may be supplied by means of a donkey
pump or injector attached to the stationary boiler, or by means of gravity
from the water of the stationary boiler itself.
"The advantages of this Invention as compared with an ordinary boiler
are are that all smoke and noxious gases are avoided, the noise of the
blast is obviated, and a stoker is not required, and its advantages as com-
pared with the hot water or fireless engine are that the danger of exces
sively high pressure at the commencement of the trip is avoided, whilst
at the same time the engine, by reason of its being supplied with steam
at a nearly uniform pressure instead of at a constantly falling pressure,
may be proportioned to work throughout at a higher mean effective
pressure, and therefore with greater efficiency.
I purpose, as aforesaid, to apply this Invention for the production of
steam power in all situations where it is desirable to avoid smoke or
noise, or to dispense with the supply of fuel or air, and among others
for the production of steam power upon tramways and underground rail-
ways, in tunnels and mines, and in submarine operations, including the
propulsion of torpedoes.
The Invention when applied for submarine purposes having the
further advantage that air, which is indispensable when a full furnace
is employed in order to support combustion, is not required for the
furnaces fitted with heaters in accordance with my Invention.
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 I do not confine
'myself to the forms and proportions of the boilers and fire-boxes
or heater boxes or the forms and materials herein-before described
and illustrated by my Drawings, as the same will be varied according to
the situation and the work to be informed, and the same principle is
applicable with almost any form of boiler, fire-box, and heater; but
'what I consider to be novel and original and therefore claim as the
Invention secured to me by the herein-before in part recited Letters
.Patent is,―
.First. The construction and use of steam boilers for locomotives or
1

page_text: heaters carried within the boiler, and heated at intervals by a separate
furnace, or exchanged for other heaters already heated by a separate
furnace, for the purpose of obtaining motive power upon tramways
or street railways, or in other simular situations, without the produc-
tion of smoke and noise, and without the attendance of a stoker upon
the locomotive or steam car, substantially as herein-before described
and illustrated by my Drawings.
Second. The construction and use of steam boilers in which heat for
the generation of steam is supplied by heaters carried within the boiler,
and heated by a separate furnace, for the purpose of obtaining motive
power in submarine operations, and for the propulsion of torpedoes
without consuming or emitting air, smoke, or any other gases, sub-
stantially as herein-before described and illustrated by my Drawings.
In witness whereof I, the said Thomas Claxton Fidler, have
to this my Specification set my hand and seal, the Fifth day of
July, One thousand eight hundred and seventy-six.