A revolution in the
methods of signalling and working and locking
points is being made in the New Plymouth railway
yards. Mr R. G. Meyerscough, foreman of works in
the signal and interlocking branch of the
Government railways, is carrying out the work. He
has been engaged in works in this connection for
25 years. The system being introduced is that in
use in Britain. The present system in New
Plymouth would hot be allowed at Home.
The
existing signals will be dispensed with on the
completion of the new system about the end of
January. A signal cabin of English design,
measuring 30 ft. by 11 ft. will be erected
opposite the station verandah. As the distant
signal cannot be seen from the cabin, electrical
repeaters, which repeat the movements of the
signal arm, will be fixed in the box. In the
cabin there will be fifty levers of many colours,
a telephone, and mechanical wire adjusters. It is
these levers, which when pulled in accordance
with a prearranged plan, operate, the points,
lock them, and lower the signal arms so as to put
trains and vehicles on the line on which they
should run, and acquaint drivers of what is being
done or about to be done in that way. The levers
are painted different colours and also have a
plate attached on which is the number of the
lever and its function.
The
signalman first sets the points, then locks them
and finally lowers the signals. Once a signal is
lowered it is impossible for the signalman to
shift the points between any wheels of a train
until the whole train has passed over the points.
Everything will be worked from the signal cabin
and the two lovers on the platform will be done
away with. The levers will control all trains
arriving at or departing from the station The
distance from the cabin to the points will be
about 300 yards. There will be starting signals
from loop, main, and dock lines to the Breakwater
and Wanganui respectively, and shunting signals
from various tracks. The latter of course, have
to do with the working of the yard.
The
system is termed "interlocking system,"
because its principle is that one lever is so
interlocked in the apparatus that it is
impossible to lower two conflicting signals in
opposite directions at the same time. When a
signalman pulls over a point lever, a locking bar
lever, and then a signal lever, the signal must
be restored to "danger" before he is
able to move the points.
Where
there are main loops or junctions, all the points
connected therewith are "trapped."
Facing points are fitted with patent locks, which
are so designed that they have to be drawn before
the signal can be lowered. The main loop line
facing points are fitted with wire detectors to
act as indicators to the signalman that the
points are properly home and correctly set.
Facing points are also fitted with locking bolts
and bars, which prevent the signalman unlocking
any points while a vehicle is passing over them.
In the
event of any wire connection breaking, the signal
arm automatically and immediately records
"danger." As to the despatch of trains
the stationmaster will, as now, give the order to
start from the station. Then the engine driver
will sound the whistle and the signalman will
lower the starting signal. The time-table is the
ordinary guide by which to work.
Special
instructions have to be telephoned to the
signalman. There will be telephone communication
between the signal box and the stationmaster's
office. Under the system a smaller number of men
will be required to admit a train than does the
present system. Shunting work, too, will be done
without the shunter having to run about all over
the yard. But while there will be a reduction, in
labour the chief value of' the system will be the
extra safety to those travelling on the lines and
to the, railway servants.
Taranaki
Herald, Volume LIV, Issue 13558, 8 November 1907,
Page 3
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