THE TAW A FLAT TUNNEL

Waikato Times, Volume 106, Issue 17804, 31 August 1929, Page 9

THE TAW A FLAT TUNNEL

DIFFICULTIES IVIET WITH. AN UNDERGROUND RESERVOIR. (Uy Telegraph.—Press Association.) WELLINGTON, Friday. In 'connection with the driving ol' the big Tawa Elat tunnel, a shaft was sunk, and headings commenced from this, in addition to headings at the two exits. The northern drive of these two extra headings has so far- proved fairly good ground, but going south the hill has been so shaken up by earthquakes of times past Unit timbering lias been necessary right up the face. j To add to the difficulties, a sub- [ Icrranean lake or reservoir was on Tuesday night delivering 20,000 gallons of water an hour. Three Cameron pumps have proved unable to keep Hie water down. On Wednesday afternoon Ihe water had completely filled Ihe heading. The pumps are working away chains under Hie water, hut it is only a question of lime j when Hie foot of Ihe shaft will he j Hooded. The grade is one in I hi, and Ihe whole position has been made very difficult. Underground streams of large dimensions are rare in Ibis kind of work, hut reservoirs are much less so. Jt, is considered that ibis is a reservoir. If (lie present 'pumps fail to get the water down an extra pump will be put on.