IMPROVEMENTS IN LOCOMOTIVES WITHOUT FURNACES
Year: 1878

page_text: LETTERS PATENT to Léon Francq, Civil Engineer, and Managing Director of
the Continental Company for the Construction of Locomotives without Fur-
naces, of the City of Paris, in the Republic of France, for the Invention of
"IMPROVEMENTS IN LOCOMOTIVES WITHOUT FURNACES."
PROVISIONAL SPECIFICATION left by the said Léon Francq at the Office
of the Commissioners of Patents on the 6th June 1878.
LÉON FRANCQ, Civil Engineer, and Managing Director of the Continental Com-
pany for the Construction of Locomotives without Furnaces, of the City of
"IMPROVEMENTS IN LOCOMOTIVES WITHOUT
Paris, in the Republic of France.
FURNACES."
As an illustration of the machines to which my improvements have reference, I
will here explain their nature.
The steam produced in fixed generators in an economical manner is at the starting
point, or at determined spots in the machine's course, introduced in a reservoir
This reservoir is mounted on
filled with a certain quantity of superheated water.
a frame with four wheels, and by a reasonable distribution of this water saturated
with steam on leaving the reservoir is transformed into steam, and is thence imme-
diately conducted to the cylinders of the locomotive, and after it has acted on the
pistons may escape in the open air or be absorbed by a condenser. Thus the
locomotive is without furnace, and moves without noise, without emitting smoke or
smell, and without projecting light or incandescent residues. The safety of the
passengers in the carriages coupled to the locomotive is assured, and there is no fear
of escapes or explosions.
The improved machine comprises a reservoir of superheated water, a regulator of
the pressure or expander of the steam at its exit from the reservoir, a recipient of

page_text: the expanded steam, a motor, and condenser, with the accessories requisite to each
of these parts.
Reservoir of Superheated Water.-The reservoir of hot water is of steel, with a
dome where the steam is taken in; a perforated division placed beneath the dome
prevents priming. The reservoir and the dome are carefully covered to prevent
waste of heat. At the bottom of the reservoir is placed a pipe perforated above,
through which the steam from the generator passes, fixed by means of a steam
conduit conveniently arranged. This steam diffuses itself in the mass of water of
the reservoir, and communicates to it the pressure and temperature it possesses. A
tube branching externally on the steam conduit serves to empty the reservoir.
A frame on four or more wheels supports the reservoir of hot water.
Pressure Regulator.-The pressure regulator takes the steam from the reservoir of
hot water and passes it to an intermediate recipient between it and the distributer
of the motor at a determined and constant pressure. The steam produced by the
escape of the water stored in the reservoir at a high pressure should be delivered
at a lower pressure. For this purpose it reaches the regulator between two twin
valves, differing very little in diameter, and consequently nearly equipoised. The
rod of the valves is connected at the lower part of a piston which works in a long
cylinder, open below. This piston receives the pressure of the expanded steam,
which passes through a tube into the intermediate recipient. A spring balance
acts by means of a lever on the base of the piston, and regulates the pressure at
which the steam should be delivered to the intermediate recipient. The regulator
or steam expander is furnished with mud cocks and a manometer gauging the
pressure of the expanded steam. This expander may be employed wherever it is
desired to regulate the pressure of steam, air, or gas stored in a recipient or produced
by a generator.
Recipient of Expanded Steam. This recipient, no less than the hot water
reservoir, requires to be perfectly secure from refrigeration. It is to prevent any
condensation of the expanded steam that this recipient is placed inside the super-
heated water reservoir, and to obtain also by the heating a perfectly dry steam and
prevent drawing in hot water, which would evidently be a loss of useful effect, and
prejudicial to the system.
Motor. The steam expanded by the expander to the desired pressure in the
intermediate recipient is admitted to the cylinders of the motor machine placed
below the frame by opening a slide valve, which the driver manoeuvres with a
lever. This motor arranged below the reservoir between the two axles of the
wheels has two connected cylinders, with steam distribution of variable expansion
and reversing motion, and may be inclined, vertical, or in any other convenient
position.
To avoid the noise produced by the steam when it leaves the cylinders to pass
into the air, I have arranged between the two cylinders a capacity sufficiently large
that the steam can there expand, and discharge itself in the atmosphero or be taken
into the condenser.
Condenser. The condenser is a surface one, with vertical tubes arranged in an
envelope placed above the hot water reservoir, and forming a draught chimney for
determining the circulation of air. Each of the tubes of the condenser is fur-
nished with wire gauze, by which the effects of absorption of heat is instantaneous.
To produce the condensation of steam I can employ, 1st, compressed air mixed
either with escape steam or expanded steam, or by the compressed air round the
cluster of tubes traversed by the steam; 2nd, cold water; 3rd, packets of wire
gauze 4th, volatile liquids; 5, the evaporation of water round the steam pipes.
The products of condensation are led by the manometer cock to a tank beneath
the frame.
The frame has two axles; these may be articulated one with the other, or by
a combination of superposed frames, to more easily pass over curves of small
radius.

page_text: The coupling of the machine by the bar to the first carriage in conjunction with
a buffer box constitutes a coupling as elastic to traction as to compression.
A brake is established in the usual manner, and a balustrade in sheet iron runs
all round the machine.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Léon Francq in the Great Seal Patent Office on the 3rd December
1878.
LEON FRANCQ, Civil Engineer, and Managing Director of the Continental Com
pany for the Construction of Locomotives without Furnaces, of the City of
Paris, in the Republic of France. "IMPROVEMENTS IN LOCOMOTIVES WITHOUT
FURNACES."
The improvements forming the subject of the present Invention relate to the
disposition and details of a locomotive without furnace, which is specially intended
for traction on tramways and roadways in substitution of animal force generally
adopted.
The principal object, the suppression of the furnace of the locomotive, is attained
by my system by utilizing the heating space with water, and communicating to it
sufficient heat to produce the requisite steam for working each machine. This is
effected by causing to pass in a volume of water contained in a reservoir placed on
the machine a current of steam at high pressure, produced in a generator established
at the starting point or station of departure which gives out all its heat as fast as
it mixes with the water, In virtue of this well-known principle, that the boiling
point, or, that is to say, the temperature corresponding with the escape of steam,
increases and decreases according as the pressure increases or diminishes on the
surface of a heated liquid, the result is that in a closed vessel the more the liquid
is heated the more the pressure increases on the surface, consequently if this heating
is produced by a current of steam the steam heats the water and fills the open space
above the surface of the liquid, gradually increasing the pressure; this augmentation,
which always precedes a little the increase of the temperature of the corresponding
water, has the effect of retarding ebulition and liquefies the stean introduced. Such
is the principle of the steam engine or locomotive without furnace.
In applying the principle it suffices that the reservoir fixed in the locomotive
is capable of resisting a pressure competent of practically varying between 2
and 15. atmospheres.
The steam produced by the fixed boilers established at the departure station is
introduced in the reservoir filled to about with water by a conducting pipe and a
locking joint of the simplest description and rapid manoeuvre.
To supply the water with the heat it should possess at starting it suffices then to
open two taps, one on the conduit of the boilers, the other on the steam reservoir;
then the steam at high pressure precipitates itself with force inside this latter, and
by the effect of small apertures made on an internal pipe placed in a particular

page_text: manner the water is agitated by the steam in different directions, and with sufficient
violence to spread the heat uniformly.
When there is a balance of pressure between the boilers and the reservoir the
taps are closed and the communication is cut off. The locomotive is then ready to.
start, and the heat pent up in the water does not delay in provoking ebulition as
soon as the upper free space of the reservair is put in communication with the
cylinders of the steam engine; the force can then return to the pistons in
mechanical action almost the equivalent of the heat contained in the water, between
the limits established by practice. These limits may be far separated from one
another, that is to say, that the initial temperature of the water may be borne as
far as possible, whilst the final temperature may be maintained much lower.
In practico the initial temperature may attain 200 degress, corresponding to a
pressure of 15 atmospheres at the least, and the final temperature may be fixed at
the minimum pressure indispensable to the engine for ascending inclines, and as
it is merely a question of force, to exercise which a particular arrangement of the
inechanism will always permit, a temperature of 135 degrees corresponding to a
pressure of 3 atmospheres will suffice; in these conditions the steam can act at low
pressure and full expansion if required; the greatest possible effective action can be
thus attained, as will be hereafter shown. This steam can evidently act (when
necessary) with much greater power by employing a greater pressure on the pistons,
whilst during the journey, should some more powerful resistance accidentally occur,
it suffices for this purpose to manoeuvre the spring of a steam expander placed
between the hot-water reservoir and another smaller reservoir, whose action consists
in delivering the steam to the pistons in a constant pressure. Such is the general
basis of the system of locomotives without furnaces.
Description. Fig. 1 of the accompanying Drawings represents this machine in
vertical section, following the longitudinal axis of its reservoir; Fig. 2 is a trans-
verse section, following the axis of the condenser; Fig. 3 is a horizontal projection,
showing cut in two the steam reservoir and condenser in section, and a similar
illustration of the motor mechanism seen externally; Figs. 4, 5, and 6 show in
detail the expansive apparatus, that is to say, the apparatus by means of which the
steam taken at very high and variable pressure into the reservoir is nevertheless
distributed to the cylinders at normal pressure.
General Arrangement.-In conformity with the conditions of construction I
have expressed this locomotive consists principally of a vast cylindrical reservoir of
sheet steel A, surmounted by a dome A¹, and a motor mechanism precisely similar to
that of an ordinary locomotive. This mechanism comprises two cylinders B,
actuating by their piston rods and the shafts C a bent axle D, bearer of the two
first driving wheels E, these, connected by the outside rods C₁ with the other two
wheels, E also become driving ones, and are mounted on a straight axle D¹.
The motive mechanism is placed inside the two stringers F, forming the principal
parts of the sheet-iron frame, which serves as base to and supports the whole. This
frame is surrounded by panels of sheet iron F1 bound to the platform. The
reservoir A may contain 1800 litres of water, which, introduced cold into the
apparatus, should be heated at a very high temperature before starting the loco-
motive, and by aid of a fixed generator itself capable of producing saturated steam
at a pressure which can reach 16 atmospheres, and consequently a temperature of
203 degrees centigrade.
It will be understood that in causing to pass from this fixed generator into the
reservoir A a sufficient quantity of steam the cold water that is contained in this
reservoir should equally balance in temperature and pressure.
If it is admitted there is no loss of heat through the sides of the reservoir
matters will remain in this state so long as no steam is taken in outside; but if the
steam is liberated, and consequently the pressure which acts on the surface of the
water, the temperature of the latter diminishes by degrees and the steam as fast
replaces that which in liberating itself it has allowed it to produce. It is this

page_text: normal property of the water under pressure that is utilized in the furnaceless
locomotive to supply its motor cylinders with the steam taken from the hot water
of the reservoir. This water under the influence of the heat it has absorbed
evaporates as fast as the efflux of steam, and as long as the quantity of heat it
contains is sufficient to supply the latent heat necessary for changing its condition.
As the filling of the reservoir presents no new feature I shall commence by
The steam comes from the fixed
describing the introduction of the heating steam.
generator into the reservoir A by the pipe a, Fig. 1, connected by a wormed joint a
to the tap valve G, which at the same point unites with a pipe G' passing through
the mass of water, and which branches with another horizontal conduit Q2 closed
at its two ends, but pierced along its upper generating line with a row of orifices;
this arrangement, when working, is replaced by a screw plug or cap a³ (Fig. 3) with
a handle. The steam so introduced by opening the valve tap G escapes through all
the openings of the rose G2, and brings the water of the reservoir to the requisite
heat and pressure.
In taking in steam and distributing it to the cylinders there is inside the dome a
tube b whose upper end raised as high as possible is pierced with longitudinal
openings, by which the steam can introduce itself; this tube, bent horizontally,
joins an apparatus arranged externally (the steam expander, Figs. 4, 5, 6) consisting
of a part H forming a simple cock valve, but which belongs to a much more
important organ H¹ which forms the expander proper, and whose action consists in
delivering the steam to the cylinders at a certain constant pressure independent of
the variable pressure of the reservoir. This part of the expander is mounted with
a flange on the dome A¹ to communicate with a vast conduit I, which, traversing
the reservoir and the mass of liquid, abuts at its lower orifice in the box I', in
which is lodged a small slide valve c, which, as in ordinary locomotives, constitutes
the regulator or starting gear. The governing parts of this apparatus are outside,
and are arranged so as to be worked the same at each end of the locomotive. This
arrangement admits of working normally in one or other direction without the
necessity of turning the machine, the driver being so placed that he can always see
his road.
The internal tube I in diameter is merely that of an ordinary conduit; it forms
the chamber of the expanded steam, that is to say, a measured capacity in which
the steam is expanded to the required degree by the action of the apparatus itself,
H', whose special disposition will be hereafter explained in detail.
The distribution of the steam to the cylinders only differs from that of similar
machines in its mode of action.
Steam escape is not used to urge a furnace which does not exist and cause an
unpleasant noise. This escapement is made in an air condenser formed by a closed
cylinder J traversed by more than 600 tubes J¹, which are open at both ends, so
that air may pass freely through them from top to bottom.
The steam having acted in the cylinders enters the box B¹ common to the two.
cylinders, Fig. 2, from whence the conduit B starts, which is shaped to embrace the
form of the reservoir, and penetrates the condenser. The escape steam can thus
spread in the space occupied by the tubes J¹, condenso in contact with them, and
return to water at the bottom, whence by a conduit j of small diameter, which
directs this condensed steam to a case K placed under the platform of the frame,
and whence it is carefully spread later as feed water. Nevertheless, if condensation
is not complete the little vapour then remaining inside the condenser may escape
outside by a tube g', which debouches in the envelope J2 which hides and ornaments
the condenser.
Such are the general functions of this locomotive. I will now examine the
principal parts and certain details of construction; for instance, the expanding
apparatus, the mechanism by which its action is regulated, the starting mechanism,
the regulator, the reversing mechanism, the brakes, and so forth.
Details of Construction; Steam Expander and Regulator Mechanism, Figs. 4, 5,

page_text: and 6.-As will be seen by these Figures the expander is composed of a brass piece,
whose horizontal part H contains the valve h, governed by hand by its wormed
shaft, furnished for this purpose with a fly h¹. This valve box communicates by its
tube with the conduit b, Fig. 1, by which the steam is taken in at the upper part
of the dome A'; this valve being open then allows the steam to enter by the
canali, which communicates between the two seats of the double valve ¹, which is
placed inside the box H, provided above this valve with a tube which, as has been
shown, is in direct communication with the steam chamber I in which the steam is
to expand, then enters the box I', where the register of the regulator acts. The
double valve i is connected by a lower part with a cylindrical shaft, a part of which
is hollowed, grooved throughout its height, and forms a kind of piston in the tube
with which the box H₁ terminates; this piston is connected by its lower shaft k to
a lever 1, its point of junction being a lug at the bottom of the tube of the
piece H, H. At the upper part of this same piece H¹ a special piston is screwed,
which serving as support articulated to a cylindrical box L enclosing a spring, so as
to make a regular balance similar to those generally applied to safety valves of
locomotives; finally, the lower movable end of this spring terminates in a link l',
between whose branches the slightly bent lever L¹ engages, which, as described, is
in communication with the piston to which the valve i' is attached in such a manner
that the action of the spring tends to keep this valve always raised above its two
seats. If, therefore, the valve is opened the steam is admitted at high pressure
through the canal i; and this steam, since the balance keeps the valve i raised, can
spread inside the box H, and thence enter the expanding chamber I by the upper
channel, but at the same time its pressure is exercised on the piston K, and as it
can overcome the effort of the spring of the balance L, this piston descends and
immediately obliges the valve i¹ to rest on its seat; no fresh steam then enters, and
that which has penetrated the chamber I expands and exercises its action on the
pistons of the motor cylinders; but as soon as this depression is sufficient the effort
that the balance exercises constantly predominates, the valve i¹ is again raised, an
entry of steam at high pressure enters, and the same effects are reproduced so well
that during the working and the progress of the locomotive the valve executes a
series of oscillations almost exactly corresponding with the pulsations of the motor
pistons.
For various motives, and principally on account of the necessity of exercising a
greater force in ascending rising ground, it is necessary that the action of the
balance should be modified, and that it should be arranged in accordance with the
degree of expansion required. By the actual position of the balance L, and the
lever, by whose aid it acts on the piston k, it necessarily follows that the effort it
thus exercises is variously multiplied, according as the point of attack of the
lever by the balance is at a more or less distance from the point of articulation of
the lever l. It is precisely in changing the position of this point of attack that the
degree of expansion is varied, by displacing the balance itself and causing it to des-
cribe angles near its point of connection at the upper part of the piece H. There-
fore, the relation between the balance and the lever (whose only mission it is to
raise it by its link provided with a roller), is obtained by a drawing rod L¹, itself.
connected to a handle lever M, applied against a sector m; the result is that this
lever being manoeuvred like an ordinary reversing mechanism, the acting portion
of the balance can be led to different given points of the lever arm L', corresponding
with the dotted lines to 3, 4, 5, 6, and 7 atinospheres.
By examining the results produced by this arrangement, it is evident that if
the balance is near the end of the lever l, its effect on the piston k, corresponding
to 7 atmospheres will be the maximum, and that the pressure should rise in the
box H to its hightest degree, to make it balance and effect the fall and closing of
the valve ; on the other hand, if the balance is brought towards the point of
junction of the lever, the reverse effect will be produced, that is to say, working at
the lowest possible pressure corresponding with 3 atmospheres.

page_text: I will now show that this manœuvre can indifferently be effected at either end
of the machine, as well as the regulator c (Fig. 1) of the reversing mechanism and
brakes.
If the Figures 3, 4, and 5 are consulted, it will be seen that the lever M is.
mounted outside the tube M¹, inside which is a plain axis m¹, which has fixed to it
another handle lever M², in a manner resting on the other; the tube and shaft
extend to near the middle of the reservoir, and there the end of the axis bears a.
small crank to which a rod N is articulated; this latter is attached by the crank
c¹ to the axis which governs the register of the regulator c by a finger. Or the
same mechanisu consisting of the plain axis and tube surrounding it, and the two.
levers and handles M1, M2, and by whose aid they are actuated is repeated on each
side of the reservoir Figs. 2 and 3.
The plain axis on the opposite side to that shown, Fig. 2, is attached to a vertical
shaft similar to that N of the regulator movement, and the two tubes M³ are con-
nected on either side of the reservoir by the two guides m³, and a horizontal rod n,
so that at whichever end one is placed on the platform of the machine, one has at.
one's disposal the means of acting on the balance or the regulator, provided that.
beforehand that the levers M and M¹ (which are not used), are freed from the bolts
which ordinarily keep them in their position on the sectors m against which they
are applied.
Reversing Gear and Brakes.-The reversing mechanism does not differ from
usual, merely it is repeated on each side of the reservoir, and can be actuated from
each end. It consists then on each side of a handle lever P, of the toothed sector.
O, the draw bar P¹, and the lever arm O¹, mounted on one of the ends of the
horizontal axis O, which by the arms 0¹ and suspension rods p allows of displacing
the slides p', to which the rods of the four eccentrics e are connected.
to the rocking shafts
The brakes Q are ordinary brakes connected by the shafts
q, whose ends are attached to the rods Q'; the opposite ends of these latter are
connected by a piece Q³, which is operated by the driver in the following
manner: The end of this lever is connected with a vertical shaft having a disk q
at its upper part, beneath which is a spiral spring, which rises as soon as the pres-
sure is removed from the disk and unlocks the brakes; a similar arrangement
occurs on each side of the platform so that the brakes can be actuated from either side.
Details of the Reservoir.-After what has been already said of the reservoir I
shall merely mention the perforated sheet metal diaphragm d, Fig. 1, intended to
check the water that the steam is disposed to draw into the cylinders, the blow-off
cock d¹, and discharge pipe d. But what I wish to draw attention to is the case
of the reservoir, which consists of a wooden vessel lined with cork and a thin iron
jacket, without counting the separation of this latter from the reservoir itself, and.
which forms an air chamber, a great protector from loss of heat.
Finally, the reservoir is provided with safety apparatus, such as two manometers
or steam gauges, showing the pressure in the reservoir, and two steam gauges.
showing the working pressure, and which reigns in the cylinders at admission, and
three taps indicating the water level; the first corresponds with the steam chamber,.
the second with the initial level of the water, and the third below the level.
Frame and Coupling.-The frame F is the same as ordinary locomotives; the.
wheels E¹ are outside; there axes turn in grease boxes; and the frame here rests by
means of the usual springs R, and when the rout lies through much frequented-
thoroughfares, the wheels are enclosed with a sheet-iron screen F¹, in which doors
are made for examination and lubricating. The water case K, has already been
mentioned, belonging to this frame, in which the condensed vapours from the con-
denser enter by the conduit j, as well as the result of the purge taps by the
conduits r, Figs. 1 and 3. This case is supplied with a tap r, Fig. 1, which is.
manipulated from the platform by aid of a shaft.
As regards the coupling, which can also be effected at each end, it is produced by
metal bars in two parts R¹ and R³, Fig. 1, whose union is caused by the inter-..

page_text: mediary of a spring, the ensemble of this piece is connected by the piece R', tér-
minated by a T iron piece 8, fixed on a truss of sheet iron belonging to the frame;,
the other part terminates in a piece pierced with a vertical hole for the insertion
of a bolt 81, by aid of which the carriage to be drawn is coupled.
The line of rail on which this locomotive travels may be of any description, but
as the machine is heavy and capable of drawing several carriages at a time, the.
arrangement shown in vertical section, Fig. 7, is to be recommended. The line is.
composed of two rails v and v¹, one with the ordinary flange, and the other a
similar half section, and united at regular distances by a bolt traversing an iron
shoe for keeping the gauge, iron bands fix this double rail on the sleepers by means
of wooden pins, and metal cross bars maintain the gauge of the two lines of rails
forming the road.
.Economical Results.-Economically considered, my locomotive can easily travel on
curves of 20 metres radius at least; it is light, compact, and its coupling to the
carriages is flexible, simple, and convenient; all its weight is employed to produce
adhesion, and it runs as well backwards as forwards, so that no turntable is
required.
Instead of the simple fraine represented in the Drawing, I can use a frame which
is jointed so that the machine can turn in a very small radius.
For working the engines the smallest quantity of combustible is required, it.
being reduced to a minimum; as for the fixed or stationary generators those of the
best construction, and which prevent a loss of heat, can be used. The engine
requires one attendant only, as it requires neither watching nor control, and does
not get out of order.
With regard to the public safety of these engines, flame and spark projection,
noise, and whistling are avoided.
The engine-driver is always placed in front of, or facing the road; uncoupling
and stopping are quickly and easily effected. Considered in a sanitary sense these
engines emit no disagreeable odours; there is no smoke from them, nor cinders
thrown on the road, from which it may be concluded that these engines without a
furnaces are not only sightly machines, but eminently suited for small local lines:
of railway and town tramways, and are superior economical engines.
In conclusion, what I claim as my Invention is,-
1st. The ensemble and grouping of the several parts and organs, which by their
union and arrangement constitute a locomotive without furnace as it is described a
with reference to the annexed Drawings; these parts and organs comprising a
reservoir, an expansive apparatus, a chamber for the expanded steam, the motor
mechanism, the case receptacle of the products of condensation, and the accessories
and the arrangements for reversing the engine and the breaks.
2nd. The reservoir of determined form and dimensions, mounted on an articu- 4
lated frame or not, and filled with a calculated volume of water which is heated at
the requisite temperature by an injection of steam taken in from a fixed generator.
This reservoir is, moreover, remarkable in its construction and preservative case,
Figs. 1, 2, and 3.
3rd. The steam expander, its construction and effects as described in reference 4
to Figs. 1, 4, 5, and 6.
. 4th. The chamber of the expanded steam, its disposition in the reservoir of super-
heated water, and its economical effects.
5th. The condenser preceded by a box where the escape steam is first expanded,
and the case receiving the products of condensation.
6th. The general disposition and combination of the organs requisite for the
general working of the locomotive, and the reversing motion and manoeuvring of
the brakes.
7th. The line established as shown, Fig. 7, and presenting all the requisite
solidity for running the furnaceless locomotives, According to the tractive power: 5

page_text: to be developed and the special applications of the engines, so the forms and
materials of construction of the component parts thereof may suitably vary.
In witness whereof, I, the said Léon Francq, have hereunto set my hand and
seal, this Thirtieth day of November, in the year of our Lord One thousand
eight hundred and seventy-eight.
L. FRANCE. (L.S.)