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218
three slow speed engines and alternators. The alternators are not
coupled to the engines, but form an integral portion of them.
The fly-wheel being in the centre and having upon the outside
of its circumference the field magnets which revolve inside the
stationary armature. The condensors are connected up to an
intake pipe which lies inthe trench behind the cylinders, and
is carried 250 yards to a point in the Camber where tolerably
clean sea water is obtained. The discharge of each condensor
is connected to a discharge-pipe which discharges its water
into the Camber. In addition there is one steam turbinealternator
and exciter side by side with the engines but the
Committee were informed it has not been found to answer well.
The system of distribution is the alternating current with
transformer stations beneath the surface of the streets, and
about 300 yards apart. The boxes containing the transformers
are of cast-iron, and are placed in brick chambers. Three
separate sets of conductors are provided:—
1. High tension feeders to supply the primary windings
of the various transformers.
2. Low tension distribution wires receiving the low
sion current from the transformers, and distributing
it to the premises of the consumers; and
3. High tension arc lighting mains containing the arc
lamps in series of about 40 each.
The high tension feeders and the arc lighting mains proceed
straight from the generating station, but the low tension distribution
wires are entirely disconnected from the generating station,
and are only connected with the transformers which feed into them.
The Committee noticed that where the arc lamps are used in
street lighting that there are two incandescent lamps on the
same post, one on each side; and these are used after midnight,
the arc light being switched off at that hour.
It is the practice where the system of supply is on the
alternating current, and where public lighting is provided in
addition to the private lighting, that an entirely separate plant,
adopted for running the arc lamps in series, is used for the
production of the current. The plant usually consists of two or
three sets of engines of comparatively small power running
high tension continuous current machines; this is found a great
disadvantage owing to the smallness of the engines, and also
that the engines working the private lighting plant are running
with very little load. It was decided, therefore, to use Rectifyers,
making the alternating currents into direct ones, and the Committee
were informed that although this was the first station
where they had been used it was most successful. They cost
about £300 each, and three of them were fixed down one side of
a small room.