RAILWAY DEVIATION.

Otago Witness, Issue 3713, 12 May 1925, Page 32

RAILWAY DEVIATION.

The following appeared in our Second Sedition last week;—

DUNEDIN NORTH LINE. LATEST SIGNALLING APPARATUS. A work of great importance to the city And the various localities on the northern Suburban line—the change over of the railway track between Dunedin and Ravensbourne —has been completed. Trains commenced running on the new sets of rails on the 4th. These new lines of steel are laid on the harbour side of the old line. When the track was clear on Saturday evening a large staff of workmen commenced the change over of the points connecting the now deviated track, and completed their labours by mid-day on Sunday. Prior to the running of the ordinary suburban service on Sunday afternoon a special train left Dunedin at 1.30 to enable members of the traffic branch of the railway •ervice to get first-hand knowledge of the new signalling apparatus which has been erected on the line, and which is the most important feature of the whole scheme. The mechanical details of the working of the fystem, which is operated by electricity, Were thoroughly explained, and everyone present had no difficulty in grasping the fundamental principles. The chief point of the now system is its safety from the public point of view. Mr G. W. Wyles, assistant sigpal and electrical engineer of the Railway Department, explained the new signalling apparatus on the 4th. He said that the track between Dunedin and Ravensbourne is divided into sections, each being insulated by a piece of insulation from one rail end to the other. Altogether there are four sections, entry to each by trains being governed by three-position daylight coloured-light signals. These signals have three indications—red, yellow, and green. An indication of red means that the section ahead is occupied by a train. A yellow indication means that the section ahead is clear, but that the next signal is at red. A showing of green indicates that the section ahead is clear, and that the signal on the nexb signal is either at caution or at clear—that is that the two sections ahead are clear.

In respect to the control of the signals, Mr Wyles said that when a train was on the rails it prevented the electrical energy from reaching the relay which controls the signals; therefore each train protects itself, quite apart from any., human agency. It is now possible for four trains to be on the line between Ravensbourne and Dunedin in each direction.

A small signal cabin has been erected at Messrs Palmer and Sons’ private siding, and is so arranged that no signalman is required. The train crew will be able to Work the signal on the arrival of the train, the whole thing being automatically controlled to prevent any possibility of accident.

The system of signals installed, said Mr Wyles, is the most up-to-date in the world at the present time, and is similar to that in use on the line from Rolleston to Stillwater, the latter being the longest section of single-line automatic signalling in the British Empire. The whole of the scheme was devised and installed by the signal and electric department of the New Zealand Railways.

The successful completion of the, deviation, together with the installation of the automatic signalling, is an event of importance not only to the city generally but to the residents in the area served by the Dunedin-Port Chalmers service. In addition to the saving of a few minutes on the journey, a more frequent service can be maintained Furthermore, much valuable land will be available on the city side on the rails, and everything is now in readiness to proceed with the construction of the highway ,to the Exhibition grounds. * The official party which passed over the line consisted of Mr Kent (divisional superintendent for the South Island), Mr H. P. West (district traffic manager), Mr Benzoni (district engineer), and Mr G. W. Wyles (assistant signal and electrical engineer, Wellington). There were also present Mr Proud (from England) and Mr Jacobson (from Australia), who are touring New Zealand representing the firm which supClied the- apparatus for the automatic and iterloeking signalling; Mr David Larnach and Mr W. J. Bardsley (Otago Harbour oard). Mr G. J. Errington (Otago Expanlion League), and Mr H. E. Moller (Mayor of West Harbour). The ordinary speed will be maintained by drains until the line has settled firmly. This week, however, it is hoped to reduce the time by two or three minutes, and to investigate the revision of the time-table.