EXPLANATION OF THE PLATES.
407
Duplicates of such of the parts as are liable to derangement are kept in readiness,
powerful cranes and hoisting girders are fixed, and the various tools so arranged that
the taking to pieces and refixing any part of the engine and pump can be effected
without loss of time.
The engine is calculated to raise 2250 gallons of water per minute.
PLATES LXXXIX. to XCII.
PATENT LOCOMOTIVE ENGINE,
MADE BY MESSRS. R. STEPHENSON AND CO., NEWCASTLE-ON-TYNE,
FOR THE LONDON AND BIRMINGHAM RAILWAY.
This engine was made in 1836 for Messrs. Cubitt, the contractors for constructing
a part of the London and Birmingham Railway near Berkhampstead, and was used
by them for carrying the earth excavated in the construction of the line. The engine
was employed in this manner for about a year and a half; when, the works being
nearly completed, it was no longer required, and was purchased by the Railway
Company for the purpose of carrying ballast for repairing the road, and other similar
purposes, in which work it is now employed together with other engines.
Although the original cost of these engines is very considerable, being about £1400
each, it is found to be advantageous to use them in executing the earthwork of rail
ways when the earth has to be carried to any considerable distance, as they take the
place of so many horses and greatly expedite the work. They are also generally
worth a great deal when done with for the particular purpose, as was the case with
this engine, which was sold for upwards of two thirds of its original cost. The
expense of using them is nearly the same as that of doing the same work by horses,
if the saving of time from the greater speed and heavier loads that can be carried are
not taken into the account; but the advantage in these respects is so great that
locomotive engines are generally used for the works of railways whenever the earth
work is of any considerable importance.
A locomotive engine differs considerably from other steam engines in many
particulars, as the engine and boiler are combined together in one machine, and have
to be carried along at a great velocity, together with the fuel and water required
for supplying the boiler. Very considerable modifications in the construction are
thus rendered necessary, in order to obtain sufficient lightness and compactness
combined with the requisite power. The cylinders are very much smaller than is
usual in other engines, the steam used being of very high pressure ; the boiler is also
made of small dimensions in proportion to the power, for the sake of portability,