SUBSIDENCE AT TONGARIRO JOB

Press, Volume CIX, Issue 31941, 19 March 1969, Page 14

SUBSIDENCE AT TONGARIRO JOB

(New Zealand Press Association)

NEW PLYMOUTH, March 18. Men left hurriedly about 4 a.m. today as the face of a Tongariro power project tunnel subsided, burying equipment under tons of wet soil.

The fall was the third in the upstream heading of the Tawhitikuri tunnel. It was described by an official tonight as nothing like the extent of the previous falls. However, it is of a similar type to the two major subsidences which delayed work in June and July last year. Mr C. Duming, administration manager for the Italian tunnelling combine, Codelfa Cogfar, said the subsidence occurred in a fault ahead of the tunnel face. “When this happened it took the line of least resistance. through the face,” he said. About eight men were at

the face at the time and were making good progress, he said. However, conditions had indicated that a fall might be likely and the men tlfere ready to get out in a hurry. Mr Burning said that engineers were still assessing the damage and he could not give an accurate estimate of the magnitude of the subsidence.

In one of last year’s falls, tunnelling equipment worth $lOO,OOO was buried. Some equipment had been buried in the latest fall, Mr Durning said. The mass of spoil was still moving most of the morning and clearing could not begin until the afternoon.