ELECTRICITY SUPPLY.

New Zealand Herald, Volume LXV, Issue 19962, 2 June 1928, Page 12

ELECTRICITY SUPPLY.

THE PLANT AT PENROSE. POWER FROM OIL-ENGINES. INTERESTING WAR HISTORY. Final adjustments have now been made to the three Diesel oil-engines installed by the Government at the Penrose electric sub-station, and power from that source was fed to the Auckland Electric-Power Board's system for the first time yesterday. The board's supply was supplemented to the extent of 1000 kilowatts, although the three engines are each capable of supplying 1250 kw. However, it is not anticipated the full capacity of the plant will be required for some time. The installation of additional plant at Penrose was decided upon by the Government when it was realised that difficulties would follow the delay at Arapuni, 'and power was promised by June 1, in order to assist the Auckland Board during the winter months. The work upon the erection of the temporary power-house and the installation of the plant was commenced last February. The Diesel engines which were secured are the first of their kind to be installed in New Zealand, and an interesting history attaches to them. They were designed and built by the German Government during the war, to be used in commercial submarines for the purpose of breaking through the blockade of the British Fleet with food supplies. However, they were never used, and upon the signing of the Armistice were appropriated by Britain. A total of eleven engines similar to those at Penrose were taken to England, and three of these were purchased by Mr. J. R. Wright, of Gillingham, England, and were later sold to the New Zealand Government.

Considerable work has been entailed in the erection of the engines at Penrose. Each weighs 80 tons, and a deep foundation of concrete resting on solid rock has been provided. This has effectively checked the slightest vibration while the plant is running. The engines are 37ffc. long and 12ft. high, each operating on 10 cylinders, and developing 3300 horse-power, although only 1600 h.p. will be required. Power will be fed into the Auckland or Horahora system at a- pressure of 6600 volts. Both these supplies will be assured by the plant,, which can work in conjunction with either, or with both at the same time.

Special crude-oil tanks have been constructed alongside the power-house, and it is estimated that about 10 tons willbe consumed during an operating-day of 10 hours, with all three engines running. A unique feature of the operation of the engines is that the pistons are all cooled by oil. The oil is supplied by three 1000-gallon tanks below the floor-level, and it in kept continually in circulation and constantly cooled. The cylinders are water-cooled by an elaborate process, and a water-tower over 50ft. high has been erected alongside the power-house.