OTIRA TUNNEL.

Waipa Post, Volume XXIV, Issue 1397, 26 May 1923, Page 3

OTIRA TUNNEL.

! 101. M! "I'lv IF '!'i; \!.\S TO OPEHATE. I ! The- Arthur's Pass (or, as it is ; j perhaps holloi known. i!io Olira) Min- i j nel is given a good deal oi' promiu- , j (•lira by t lie English Electric .lonnial. ! j tiie .ianiiarv issue of wiiicli contains j n verv i ii formativo arliolo on what is i unique in ilia way of public services | jin i hi-; i )om i nion. Wo repri til il ii"' j i (ho information of our readers, ibis j ] tunnel is on the Midland railway eon ■ Meeting the eas: and west coasts ol ; Hie Souih Islanu. and pierces tile I ’.j.eh range of mountains known as the I Southern Alps, between the Healey ' and Otira streams, under the pass I known as Arthur's Pass. Ihe tunnel | is const meted on a uniform gradient of 1 in dll hoi ween the Otira and the , Healey end. the elevation of the latter above sea level being 4.1a. > loot. The total length of the tunnel is r> j miles ITI chains PS links, and the ■ track is straight. without any curves, j It has always boon recognised that. In,vine regard to the 'lentilh ot the ! turn el and its gradient, electricity ; was the only practicable means ol j haiila.ee. and it remained to be deoid- , ed whether the electrification should j he confined to the tunnel and its up- j proaches, or should cover the wlioie | of the mountain section between j Springfield and Jackson s. or sonic ; distance intermediate between the j two. Altogether four schemes of electriliealion have been worked out in detail, covering four different lengths of route, but it was finally decided by the Xew Zealand Government to coniine the electrification in the first instance to the tunnel and its approaches so as to gain experience in electrical working. Accordingly the total length of route now being e'lectrilied and approaching completion is S miles 31 chains, extending from Arthur's Puss station 'ou the east side to Otira station on the west side of Arthur's Pass. In j addition to this, two miles of track i in yards and sidings is being electri- | lied, making a total of 10 miles 31 chains of single track. The maximum freight load to he hauled is 280 tons, and the weight of the passenger train loaded is 128 tons. The service consists of four freight trains daily in each direction, and one passenger train in each diVection, but it is ani ticipated tjiat this service will be j greatly increased in the near future, j Jn order to handle this service, five | locomotives have been built at the, ! Dick. Kerr works, Preston. England, j and were assembled at Addington I workshops, Christchurch, and hauled !to the Arthur's Pass tunnel a few weeks ago. Two of the locomotives will be required to haul the freight trains up the gradient and one loco- ! motive for the passenger trains. A j battery locomotive for inspection of ! the overhead line and repair purposes lis also provided. The railway is ' equipped with overhead lines at 1500 ’ volts, the contact wire being suspend- | ed from a double catenary outside the j tunnel, and a single catenary inside ■ the tunnel. The bearer wires are of i copper, and act as feeder cables as well as hearer wires. The power for operating the line is obtained from a steam power station situated near the Otira end of the line. The power is generated J>v means of two steam tur- ; bines connected through gearing to 1500 k.w.. 1500 volt. 500 r.p.m. D.O; generators. It is intended that this station shall provide a siand-by for operating the tunnel when the electrified svs tern is extended am; power | obtained from an outside source.