NEW PLYMOUTH ELECTRIC LIGHT

Taranaki Daily News, Volume LIV, Issue 203, 24 February 1912, Page 4

NEW PLYMOUTH ELECTRIC LIGHT

VISIT TO GENERATING WORKS. • IMPORTANT EXTENSIONS. An official inspection' of the New Plymouth electric light generating works was made on Thursday by the Mayor (Mr. G. Browne), the borough councillors, the consulting engineer (Mr. Climie). (he borough electrical engineer (Mr. IT. Black), the borough engineer (Mr. Skitrnp) and the town clerk (Mr. F. T. Bollringer). Extensive additions have been made to the works, and more are under way. In addition to those outlined by Mr. Black recently in a special report, further extensions are either in hand or contemplated. They are embodied in the following report by Mr. Black:— e.

Weir—Before the weir is erected it will be advisable to enlarge the inlet to the tunnel. The present inlet is about the same size as the rest of the tunnel, i 3 totally submerged/and is not protected by any grating, the first grating being just in front of the main sluice. The inlet should be enlarged,, side walls carried above flood level, and a long grating put in at an angle that will allow driftwood, etc., to be carried upward so that it could be raked off. There is a dip in the tunnel where it passes under the Mangamahoe stream. As it is just possible that this might cause trouble in the future, it would be advisable, probably, to have the top of the dip raised to the level of the rest of the tunnel. Both of the above works should be carried out before the weir is put in.

Forebay—This work is now in hand. As no satisfactory tender was received an order was placed with Messrs J.'O. Boving and Co., of London, for the valves and other ironwork, and the Council decided to carry out the work by day labor. The above valves, etc., are due any time now, so work should be started very shortly. Pipe line.—Messrs J. O. Boving and Co. also have the contract for the supply and erection of this line, with the exception of excavating, concrete anchor Wocks and back-filling, which also is to be done by day labor. The second pipe line is a future work to be arranged when required. - Turbine and generator.—The contract for the supply of the turbine and generator was let to Messrs Turnbull and Jones, Ltd., and includes one 420-h.p. turbine, direct coupled to a 200-k.w. 0000-volt generator, one 50-h.p. turbine, direct coupled to a 30-k.w. exciter generator, which would also be coupled to a 40-h.p. induction motor. The contract for the second set has not been settled, but tenders were included with the first set and this should be arranged in time to get the machine running by April, 1913. This machine would act as a reserve for any emergency. We have never so far had any reserve, and as 1 have pointed out from time to time, are running a serious risk, which, if continued, must lead to disaster. CURRENT FOR TRAMS.

Transmission line voltage. This should follow the erection of the plant now on order, say next summer. If' electric tramways are to lie installed in' near future, the position of the converter station should be considered in conjunction villi transmission line alterations. CiHi'-'iil will be generated at 6000 volts, and transmitted at that voltage to the sub-station, or as near thereto as telegraph regulations will i allow. Then it will be transformed' down to 2000 volts and distributed from the present sub-station switchboard. The lighting switchboards and' tramway converter plant should be in I one building and controlled by one | operator. The sub-station is too small < for present- requirements and should be removed to the site in Liardet street purchased for this purpose, but it is desirable if possible to include this in the i tramway arrangements, and erect a building suitable for the whole supply.

Powerhouse switchboard—This is being supplied by Messrs Turnbull and Jones, Ltd., and is included in their contract for the generator sets. Powerhouse building extension.—The foundations for the main part of this have been carried up-to near floor level. We are waiting for working plans of switchboard to get the remainder arranged. Most of the working plans under this contract have already been received, the alterations to s the switchboard being the probable cause of delay with this one. ■''

Tail race.—The authorised work consists of 134 ft of concrete culvert 10ft wide, varving in height from fift to lift, the lowest portion being 22ft below floor level. This was a tedious piece of work owing to most of it being under the present tail race, while about 30ft had to be tunnelled under the powerhouse building 22ft below the surface. A spillway has been provided so that by blocking the lower end of the new race the water will rise and flow into the old race just below the outlet of the 24in pipes. We had proposed to put in this blocking and leave the remainder of the race to be constructed at some future date, but as there is some probability that the new machinas will not be running in time for next winter, I have advised that the race be extended, to the old water course before letting the water into it, so that we may get the benefit of the extra depth of draft at once, and save the cost of putting in and removing the blocking of the race.

Mr. Black concludes as follows: 'Substation alterations and extension of the substation switchboard should, if possible, be held over and designed to fit in with tramway requirements, but if these are not to be decided very shortly these alterations and extensions should be put in hand. If the Council has decided wko is to design the tramway scheme, possibly, the converter station requirements could be arranged at once. If this were done we would then know what provision to make in extending the substation switchboard." The Works Committee held a meeting on the grounds and decided to authorise the completion of the tail race (a concrete channel) to the river, at an estimated cost of £4OO. It was also resolved to proceed immediately with the laying down of the pipe line from the fo'rebay to the powerhouse, and the construction of an enlarged forebay