CITY DRAINAGE

Dominion, Volume 31, Issue 242, 9 July 1938, Page 15

CITY DRAINAGE

Progress Of Tunnelling Work UNDERGROUND INSPECTION Underground workers engaged on the big supplementary scheme dealing with AVellington sewerage have ‘’broken through” on the longest drive in the new svstem— namely, from Tninui Terrace to Martin Square (off Taranaki Street). That means that there is now a completed tunnel from Drummond Street, Newtown, to Martin Square-three-quarters of a mile. Bein' 1 ’ an achievement of no small magnitude, this length of tunnel was traversed by a party of city councillors and engineers on Thursday evening. There were present Councillors T. Brindle and AV. Duncan, who had with them the city engineer, Mr. K. ELuke, the assistant engineer, Mr. E. K. McKillop. the chief engineer and general manager of the tramways and electric light department, Mr. M. Cable, and his assistant, Mr. L. B. Hutton. The party was impressed with the good work done, and interested especially when they were shown where two tun-nel-head workings had met being only one inch out in direction. The going below was quite dry and comfortable. Now the job moves northward. The city engineer stated yesterday that the tunnellers, in three gangs, were employed between Martin Square, A ivian Street, and Upper Dixon Street (near St. John’s Sunday School). The system of working will, however, be changed between Martin Square and Dixon Street, where there is not enough earth overhead to justify tunnelling. , For this section the system of “jacking” circular reinforced concrete pipes will be used. From Upper Dixon Street the new drain will be conducted along the side of the hill to Church Street (off central Boulcott Street) from which point it will go under AVellington Terrace to ■the gully on the other side, thence on ■to Bowen Street, and so to the northern end of the AVellington North district at Grant Road.

The three Broom-Wade electric compressor sets for the drainage system arrived this week, and were carted to the corporation yards, Clyde Quay, yesterday. The heavy concrete foundations 'have been waiting for the erection of the machinery for some weeks, and 41 start will be made with the erection of the sets almost at once. So far the units for the ejector stations have not yet come to iiand. Each station is to have two electrically-driven centrifugal pumps, with which to puinp the sewiage away automatically as soon as it rises in 'the station to a certain level. The change over from the compressed air system, now in vogue, to the electrical pumping system will probably take over a year. The first of the ejector stations to be provided with centrifugal pumps will be those in Wellington North, then the Lambton district, and afterwards Te Aro. Those nearer Clyde Quay will, be run on the present system, and will probably be the last to be converted, though those at Miramar will also be allowed to run <on as at present, being worked ‘by compressed air from units in the old power house at Miramar south.