MANGOREI POWER STATION

Taranaki Daily News, 31 January 1930, Page 13

MANGOREI POWER STATION

NEW OPEN-CUT TAIL. RACE. EXTENSIONS TO OLD BUILDING. Rapid progress is being made with the extension works at the Mangorei power station. The present concrete building which houses the turbines supplying New Plymouth has been lengthened 30 feet to hold the Machinery and switch gear for the 11,000-volt changeover, which • is to take place when the Government scheme comes into operation. Although for a time water seepage from the old race and from the surrounding hills retarded work on the new open-cut tail race, the contractors are confident of completing the race within two or .three weeks. When both the old and new races are operating there will be a double capacity water outlet from the station. The main concrete work of the extension to the power-station has been completed and workmen are employed in removing the. old concrete wall.. The deafeniim and nerve-racking scream of a pneumatic drill tearing into the thick concrete wall greets those who enter the new portion of the building. The workman operating the machine seems to vibrate with the knocking of the drill. In a lower pitch to the sound of the drill is the whirr of the turbines in the old. building. It all seems very busy. ‘ •’ ' The new turbine, which is due to arrive on March 1, is to be installed in the new portion. of the building. Developing 800 li.p., this machine will boused in. place of an older turbine in the old building. New switch gear, a continuation of the long blackboards .covered with dials in the old building, is to be installed at the same time. The new open-cut tail race is 200 feet long and is situated to the north of the° present tunnel constructed in 1912 and runs parallel with it. Further to the north and also parallel with the other two races are the remains of the original race constructed in 1905. Water seepage has been the difficulty, as is the case with many such undertakings, and at times four pumps are working. Approximately 12 feet deep, the bottom of the race is partly concreted with a layer about 9 inches thick. At the end nearest the power-station concrete filling up the north side has been commenced. At the other end there is still a small-amount of trimming and excavation to be done. Water trouble at this end is liable to prove a nuisance, but with the efficient pumping set which the ’ contractors, Messrs. Jonqs and Sandforil, are ’ using, , this difficulty should be to a great extent eliminated. The work of excavating the cut-for the new race has been very solid, as it was necessary to gouge a passage through the remains of an old river bed with its rocks and shingle. • The concrete work in the race is all strongly reinforced with iron bars, around which the liquid cement is poured from above the edges of the boxing. PROGRESS AT MANGAMAHOE. •-■■'A,' . WORK ON CONCRETE CORE WALL. Since' the damhge done to foundation work and the seepage walls at the Man-'o-aniahoe dam about Christmas time repair work has been pushed ahead and the core wall and earth filling have been raised sufficiently high to preclude the possibility of a similar occurrence. It- is hoped to complete the work early in December. On the earth filling for the “batter,” which is to cover the concrete core of the dam, work has progressed faster than was expected. -Two caterpillar tractors, one employed in ripping and loosening the clay and one with a “bull-, -dozer” attachment for pushing e gear’ll into position at the foot of the. core wall, have been working day and night. There are two shifts of men each working ten hours daily. It is a weird scene at°night with the brilliant lights shining on the rising earthwork. i ' The concreting of the core wall, below the level of the old river, bed, has just been completed. The wall, which is founded 12 fet below the river bed level, is now perceptibly rising. Eventually it will tower 80 feet above the river and will taper as it rises. Long shifts are being worked on the wall with excellent results. On Wednesday 140 yards of concrete were put into the wdll. Water seepage in the lower levels of the wall has been a difficulty for some time, and a 4-inch pump has been used persistently. Now that the wall has risen above the river bed this trouble is no longer present.