A NEW APPLIANCE OF AN ELECTRO-MAGNETIC APPARATUS TO INCREASE THE ADHERENCE OF LOCOMOTIVE ENGINE WHEELS TO THE RAILS
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by Angelo Vescovali at the Office
of the Commissioners of Patents, with his Petition, on the 20th
November 1865.
I, ANGELO VESCOVALI, of Rome, Palazzo Torlonia, in Italy, & 50,
Claverton St., London, do hereby declare the nature of the said Inven-
tion for "A NEW APPLIANCE OF AN ELECTRO-MAGNETIC APPARATUS TO INCREASE
THE ADHERENCE OF LOCOMOTIVE ENGINE WHEELS TO THE RAILS," to be as
follows:-
The magnetism produced by an electric current is thereby applied to
increase in an indefinite manner the adherence of the driving wheels of
locomotive engines to the rails without necessarily increasing indefinitely
the weight of the same engines, and also to render that adherence quite
independent of the weight of the engine, so that in the construction of an
engine the weight may be limited to that strictly necessary to produce a
given amount of working power. This application acquires a special value
when considered in connection with the solution of the problem of the
traction on very steep gradients. When we reflect that the co-efficient of
the adherence of engine wheels can descend to 0.06, and even below, it is
evident that no locomotive can now ascend a gradient of 6 %. Now
with the help of a powerful magnetic attraction the production of an
unlimited adherence becomes possible, so that it will be no longer necessary
to take further trouble on the account of the limit of the acclivity of

page_text: gradients (except with regard to safety), and there will be no other limit
to acclivity than the possible power to be given to the engines in relation
to the quantity of working power which is to be developed in order to drag
a train of a given weight. Besides, by the adoption of this system the
adherence of the locomotive engines being no longer dependent on their
weight, it would become possible to effect the traction of the trains on
inclined planes by means of compressed air acting on piston engines similar
to the usual locomotive engines (minus the boiler that would be suppressed).
The supply of compressed air for these engines ought to be made continual
by means of a pipe extending throughout the line. Thus it would be
made easy to construct locomotive engines of a considerable power, say of
1,000 horse-power, and still comparatively very light, which could not be
done with steam engines requiring a boiler and an extensive heating surface.
The compression of the air can be effected either by stationary steam-
engines, or by hydraulic motors, in such places where they can be
established, which is generally the case in mountain districts; where water-
courses and falls are not wanting, and where precisely steam engine
traction implies an enormous expense both of construction and working.
Only the principal and most prominent advantages of the application of
this principle are mentioned here, as it would be useless to enter into
further details, which can be easily understood by technical persons. We
shall therefore proceed to the description of the apparatus. It is a well-
known fact in natural philosophy that an iron bar surrounded by numerous
fakes of a copper wire helix is transformed into a magnet when an electric
current runs through the copper wire helix; the two ends of the bar
become two magnetic poles that can acquire a power of attraction more or
less considerable according to the length of wire forming the helix and the
number of the voltaic elements used to produce the current.
If a great
length of copper wire be wound round the axle of a locomotive engine
(either steam or compressed air engine), so as to form round that axle a
thick bobbin or coil on all its length, and if a powerful electric current is
caused to pass through that wire both the ends of that axle will become
two magnetic poles as well as the wheels; a force of attraction will
consequently be generated between the wheels and the rails; that force
of attraction can be very considerable, and will produce an adherence which
will prevent the wheels from sliding on the rails, without however opposing
any resistance to their circular motion; in other words, the wheels will find
themselves strongly fixed to the rails, without however being prevented
from turning. It will then be required to proportion this electro-magnetic

page_text: force of adherence to the force of traction that will be requisite, which
will be easy owing to the great length that can be given to the wire forming
the bobbin or coil and the considerable number of voltaic elements that
can be used for the production of the electric current. Experiments made
on a small scale have completely justified all expectations. A small mode!,
weighing about 18 lbs., has easily ascended on a gradient of 0.25 with the
current produced by two small Bunsen elements, while the natural
adherence of the wheels ceased at an inclination of 0.05. But as it would
not have been possible to infer from so small an experiment what ought to
be the power of the current and the length of the wire required to produce
a force of 4 or 6 tons, I therefore tried an experiment on a larger scale.
This consisted in the winding of 2185.185 yds. of copper wire of a
diameter of 15748 inch as a bobbin or coil round the axle of a pair of
wagon wheels, and using a battery of 40 Bunsen elements to produce the
current. The magnetism thus produced gave an adherence between the
wheels and the rails of about 2 tons. It is evident that voltaic elements
different from those of Bunsen, or any other means for producing electric
currents, can be employed without changing the basis of this system. To
give this system the means of developing its powers in the manner best
suited to the electric currents, it is requisite,―
1st. That the axle and the wheels bearing the copper wire, bobbin, or
coil should be of soft iron.
2d. It is preferable that the wheels should be all solid, that is, without
spokes.
3d. The wheels may be encircled with a steel tire, provided it be not
too thick, without causing any sensible diminution in the adhesion. The
rails must however be also of soft iron.
4th. It is absolutely necessary to have in the locomotive an additional
pair of wheels with their axle all of soft iron, acting as an anchor for the
magnetic circulation. These wheels can be of a very small diameter.
5th. The power of the apparatus will be considerably increased by the
winding round the axle of this additional pair of wheels a bobbin or coil
of copper wire, but taking care that the poles are inverted or alternate in
respect to those of the other wheels, that is, so as to have on the same rail
two poles of different name. These wheels can be coupled or not.
6th. It is absolutely necessary that the pillow blocks, the supports, that
portion of the plate that is opposite to the wheels, and the connecting rod
should not be made of iron; they might be made of brass. The cranks
can be made of iron.

page_text: 7th. Finally, it will be necessary in order to regulate in the best manner
the action of the current, to form the bobbin or coil into several concentric
zones independent of one another, so as to render it possible to cause the
galvanic current to circulate either through the whole of the wire, or in one
portion only, or through the different zones successively.