HYDRO=ELECTRICITY.

Taranaki Daily News, 20 August 1921, Page 9

HYDRO=ELECTRICITY.

THE WAIWAKAIHO SCHEME.

EXTENSIONS IN FULL PROGRESS.

A VISIT TO THE WORKS. The extent of the New Plymouth hydro-electric extension works now in course of construction can tmly be appreciated by a visit to the locality. And a visit id well worth while. On Monday afternoon a party, including Mr. Veitch, M.P., Mr. 8. G. Smith. M.P., and four or five members of the Chamber of Commerce, Accompanied, by the borough manager ; (Mr. F. T. Bellringer), and the electrical engineer (Mr. R. H. Bartley), visited the works. On arrival at the foot of Kent Road, the party were met by the resident engineer (Mr. R. L. Pearless). Here a storeroom and a bin for crushed stone have been built. A tramway has been laid down, and an electric engine does the haulage. It is a diminutive machine, but a very serviceable one. It can pull a load of •20 tons, has a speed of five miles an hour, and costs about a half-penny a mile for fuel. Truly an economical outfit! The engine was ready to go in with a couple of trucks of heavy timber, and the party hopped aboard. As the. novel little train sped along the side of the valley of the Mangamahoe, one could not help but observe the workmanlike way in which the tramway had been laid down, the ease of the gradients. and the grace of the curves. “A splendid job.'’ -said one of the party, and he expressed what all the other visitors must have thought. The tramway goes in for about a. mile to what is known as No. 2 tunnel, about which so much has been lu’ftrd of late. About hair way are to be seen on the right, towards the valley of the Waiwakaiho, cuttings in the hill. They are connected with the driving of No. 1 tunnel, and, looking more closely, one may see the opening of the tunnel that is to tap the Waiwakaiho river and bring the water across to a race that has been excavated just below the tramline.

The engine stops to unload its freight, the passengers jnfnp in the open trucks, and speed on their way again. On the left, nestling among the low hills and lying nicely to the sun, hutments come into view. Here the men engaged on the tunnel live. Near by is a whare. and from it emerge a wahino and her picaninny. Further along may bp seen, two more substantial structures. One is the engineers’ shop, and the clanging betokens activity. The other is an electric charging station. An inspection reveals a spare set of storage batteries, Edison's latest, that improve with age and do not deteriorate as is the case with the old form of batteries. They are used to drive the ••mule.',’ or electric engine, and each set contains power sufficient for at least three days’ work.

THE BIG TUNNEL. The ‘Train” stops here, and the party proceed across to the tunnel, a little r.o the north.

‘'Want waders?” asked one of the party of Mr. Pearless. “Oh. no; it's quite dry!” came the answer. It wa« noticeable that gome of the party did not essay the trip into the tunnel, and the reason was afterwards apparent. The tunnel at the mouth is a little over 9ft in diameter, and for some distance it is concreted. The floor was wet and’muddy,* and the only way to escape the mud waa to balance oneself and keep on the rails or hop from sleeper to sleeper, which, placed as they are somewhat irregularly, and in the semi-darkness, was no easy matter, .as some of Ihe venturesome one* soon discovered to their cost. At the end of the concreting, workers were seen busily engaged timbering the tunnel, which has been pierced for a distance of 424 feet out of a total length of over 4000 feet. The actual digging does not present great difficulty, «<s the material met with so far is of a soft nature. The idea is to put in three more, drives, so as. to expedite the work, which, it is estimated, can then’ be finished within a year, but the council have not yet been able to obtain authority to go on the neighboring private land in order to put in the drives. It is this tunnel, the essential feature of the whole scheme, over which there has been so much controversy. As plan ned it will deal only with water producing 9000 h.p. By slightly increasing its diameter it can accommodate water for 12,000 h.p. The extra cost of the widening is only about .£lBOO. Alterations to forbay, valves, screens, etc., increase the cost to approximately .£4OOO. It seems a fshort J sighted policy .not to make the provision now, for later on it obviously will be impossible to do so.

THE OLD STORY OF SPOILING THE SHIP. How many thousands of pounds—aye, hundreds of thousands—have been lost in New Zealand because of the lack of vision and the studying of economy at the commencement of the construction of public works and utilities? It is, of course, false economy not to make the fullest provision for future needs, especially as regards hydro-elec-tricity. According to Mr. Parry, the late Government electrical engineer, never in the history of hydro-electricity development has there been found one instance of works as originally planned being able to cope with the demands—extensions have always had to be made, which, had due appreciation of the possibilities been envisaged at the beginning, could have formed part of the original scheme, and thereby saved considerable sums of money. Yet, with this knowledge, the Now Plymouth Council refuses to spend a few pounds in investigating the hydro further [inland that have been so favorably reported upon by experts, so as to ascertain definitely whether it is advisable to make provision for the extra water at the main tunnel!

CONNECTING THE WAIWAKAIHO WATERS. But to continue the account of the trip. It is too late to go over the hills towards the power station where the forebay is to be built, and so the party retrace their steps to a, point where they can cross the valley of the Manganiahoc towards No. 1 tunnel, or “Payne’s.”

Surveying this valley, one can see how Nature has helped New Plymouth in regard to the provision of hydro-elec-tric power for Taranaki, It is a natural storage basis blocked partly at one end (where No. 2 tunnel is being driven) by a low range running at right angles to the Mangamahoe valley itself, and necessitating a dam of 110 ft high and 610 ft go the crest, with a reinforced concrete core wall across the Mangamahoe stream. The area thus enclosed for storage will be 95 acres, and the slur-

age capacity of this huge reservoir over fifty million cubic feet. There will also be two embankments, 1400 feet long, on the southern side of the proposed reservoir, to prevent the water overflowing the adjacent lands. The Mangamahoe valley is at a lower level than the. Waiwakaiho river, about a mile to the east, and it is to bring in the water from the Waiwakaiho that No, 1 tunnel is designed. Is is not so long a tunnel as No. 2, being 1805 ft. in length, but the con tractors (Messrs. Payne and Blanchard), have met with unexpected difficulties, chiefly because of the rocky—or bouldery—nature of the country. Outside the tunnel the broken boulders are lying in profusion, and it is a case of blasting most of lhe way through, which naturally is slow work. Near the mouth of the tunnel are to be seen a couple of horses, doubtless used for bringing out the trucks of ■rock and debris.

From this point one can follow the course of the Waiwakaiho wat :r. Emerging from the tunnel it will run along a ravine until it reaches the valley of the Mangamahoe, which it crosses in pipes, and then will reach an open race along ; the valley of the ■ Mangamahoe until it arrives at No, 2 tunnel. This is the partial scheme that? is now under construction.

Jr. the big scheme, designed to provide 9000 h.p., this open race and the pineway across the valley of the Mangamahoe will be dispensed with. The cost is estimated at £7500, but the extra overhead expenses that would be involved in proceeding forthwith with the big scheme until consumers can be found for all the extra power, would be many times £7500. It should, however, not be long after the completion of the present scheme before a commencement can be made with the erection of the dam at ■the end of the valley of the Mangamahoo. The two tunnels are the important features of the completed scheme.

AT THE NEW INTAKE, The party then walked back to the road, and proceeded by car another mile or so up the road, where they entered the Waiwakaiho valley, and inspected ■the intake, the concrete work of which ■is finished. Nature seems to have provided a perfect place for an inlet—<l •bend, of the river, aproned by boulders, open to-the water without so much as the need for a dam or groin to divert the water. The water will follow what is a straight and natural course, and is not likely to give the trouble through filtering that the present intake, further down the river, causes,. The tunnel connects with the inlet, but it is only pierced for a few feet at this end, work being concentrated upon the western end. That ■the river rises “some" at the new inlet is ■apparent by the debris on the bank and an oil engine being perched high up in order to escape the flood water. The party returned to the road, and thence to town, greatly impressed hy the •immensity of the task to which the town has so cheerfully applied itself, and the hydroiclectrie possibilities before the town and province. But it is a task that imposes upon the borough only 11 nominal liability, and must, as . the schem » is developed, prove a great asset both to the town and province.