TUNNEL GATES OPENED

Sun (Auckland), Volume III, Issue 777, 25 September 1929, Page 10

TUNNEL GATES OPENED

MORE PROMISING POSITION AT ARAPUNI TO BE INSPECTED TODAY (Special to THE SL'X) ARAPUNI, Tuesday. Yesterday the strengthening of the steel lining below the gates in the Arapuni diversion tunnel was completed, and at an early hour this morning they were reopened. The turmoil of water at the outlet indicates a tremendous pressure at the gates. During the day the gates were gradually opened from one to four feet, when three-quarters of the normal flow of the river was passed, which meant the dissipating of tremendous power, but long before this maximum was reached 50.000 or 60,000 horse-power was represented by the current beneath the gates. Above the gates the velocity is only a fraction of that beneath them, and consequently there is no imminent danger of a block of rock being swept into the tunnel and wedging in tlie gate. A few hours after the opening of the gates there was noticed to be a big difference in the volume of the current below the spillway. There was still a fairly heavy body of water however, at the fall, but even it had dropped a good deal, and it was possible to see much better, the character of the channel and the rocks. There has been no great change in the fall since the heavy one six weeks ago. and the position is much more promising than it first appeared. The gates will be closed at 9 o’clock and after an hour allowed for grit thrown down the shaft to seal the edges, an inspection will be made by Mr. T. Rabone. It is generally felt among tlie staff that the test will prove most satisfactory.