[Illustration: AN ENGLISH STEAM FIRE ENGINE.]
The machine which we illustrate has lately been constructed by Messrs.
Merryweather & Sons, of Greenwich Road, with the view to combining the
advantages of both horizontal and vertical steam fire engines.
Hitherto the horizontal engine has been considered by some firemen to
be less handy of access than the vertical, and the vertical engine has
had the undoubted disadvantage of not being stoked from the footplate.
By shortening the length of stroke and constructing a special pump,
the makers have been able to keep the engine sufficiently high in
relation to the boiler to enable the firedoor to be placed directly in
the rear of the boiler and underneath the engine, thus enabling the
boiler to be stoked en route, and allowing access from the footplate
to the starting valve, the suction and delivery connections, the whole
of the boiler fittings and feed arrangements. This enables one man to
drive and stoke the engine, and to attend to the suction and delivery
hoses, and it does not interfere at all with the stability of engine
in traveling or at work, as the center of gravity is well below the
top of the side frames. Another feature is the absence of a main steam
pipe, a bracket being arranged on the cylinders containing the steam
passages, to bolt directly onto the top of the boiler. The close
proximity of the engine to the boiler renders it peculiarly suitable
for cold climates, and times of frost, reducing the chances of the
pump or feed arrangements being frozen up. The pump valves are
arranged between the barrels, and are all accessible by the removal of
one cover, which weighs but 12 lb. The engine, we understand, may be
stopped, the cover removed, a damaged valve replaced, the cover put on
again, and the engine restarted in two minutes. A slotted link is used
with a crankshaft for regulating the length of stroke. All the
bearings have large wearing surfaces, and substantial eccentric straps
are used, the whole of the motion being simple and accessible. There
are three different methods of feeding the boiler, viz., by feed pump
driven by the crosshead of the main pump, by forcing water directly
into the boiler from the main pump, and by an injector taking its
water from a tank either supplied from the main pump or by a bucket
when pumping dirty water. All the feed pipes are fitted with strainers
where attached to the main pump. Drop feed lubricators are fitted on
the cylinders, and an efficient system of lubrication is provided for
the rest of the working parts. The carriage frame, hose box, etc., are
of the same design as usually employed for engines of this class, with
the exception of the fore carriage, which is fitted with a cross
spring in the rear, as well as the two longitudinal springs. This
arrangement makes the engine run more lightly, and removes much of the
strain on the side frames when traveling rapidly on a rough road. The
wheels are fairly light for the weight they have to carry, and have
gun metal stock hoops with diamond pent rims to prevent the men
slipping when mounting in a hurry. The engine and boiler work is
brightly polished where-ever possible, and the whole machine has a
handsome appearance.--Engineering.
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