TAWA FLAT DEVIATION

Otago Witness, Issue 4042, 1 September 1931, Page 66

TAWA FLAT DEVIATION

SECOND TUNNEL PIERCED.

NOTABLE ENGINEERING WORK. WELLINGTON, August 27. A very big job entered upon its con* i Us *- a Ses when the second tunnel on the Taw-a Flat deviation, two miles 53 chains long, was pierced by the meeting of the preliminary headings at a point 84 chains from the Ngahauranga Gorge end and 129 chains from the TaWa Flat end late last night. The smaller tunnel having been completed and concreted and part of the track laid, all that now remains to be done is the widening of the second tunnel, the concrete moulding, and the laying of the track. Though all this entails much more work, and the line will u°t be ready for handing over to the Railways Department until perhaps the end of 1933, the most anxious part of the job has been done in the very good time of two j-ears and a-half.

The occasion was celebrated by a visit of departmental heads and invited guests, including Mr Hutchings, representing the Minister of Railways, the chief engineer of the Public Works Department (Mr F. W. Furkert), the assistant engineer (Mr 0. G. McKenzie), the inspecting engineer, Public Works Department (Mr J. Wood), the district engineer (Mr R. H. Ronayne), the designing engineer of the Railways Department (Mr F. Wansborough), the engineer in charge of the job (Mr C. Langbein), Messrs Parsons and Hawke, assistant engineers, and Mr Ridsdale, the overseer.

The line levels and distance calculated by the engineers were wonderfully accurate for such a work, the calculations proving almost exactly correct. The ground encountered in the last few chains on either side has been of fine quality from a drilling point of view—hard but firm, and drier than most of the ground encountered since the start of the job. The work has been speeded up considerably by the shaft and pilot tunnel. The shaft sunk near the Johnsonville viaduct enabled the work to be carried on at four faces in.the big tunnel simultaneously. The pilot tunnel, the first to be used in New Zealand, is on a very slightly lower level, 66 feet on the eastern side of the main tunnel.