THE CITY WATER SUPPLY.

New Zealand Herald, Volume XLIII, Issue 13096, 8 February 1906, Page 3

THE CITY WATER SUPPLY.

WAITAKEREI FALLS SCHEME.

INSPECTION BY THE CITY COUNCIL.

PROGRESS OF THE WORKS.

While engineering reports, covering many pages of typewritten copy, may be full of interest when read at a City Council meeting, there is nothing like a personal inspection of works to afford public men a knowledge of th© matter- they deal with. With the object of "seeing for themselves," the members of the City Council set off in two drags from Auckland at eight a.m. v-*s-terdav en route for the Waitakerei Fails, where the intake of the new water supplies for the city is situated. There were present: His Worship the Mayor <Mr. A. M. Myers), Messrs. L. J. Bagnall. A. J. Entrican, 11. M. Sm'-'Pton, M. Casey, A. E. Glover, C. Grey. G. Knight. R Tudehope, J. Court, and W. E. Hutchison (councillors). Messrs. H. Munro Wilson, C- K. and J. Carlav,' (waterworks engineer), and Mr. ,7. A. Pond (colonial analyst). Leaving the city one drag went via the Pomoiiby reservoir, and the other via Kingsland. the two meeting at Avondale, and thence travelling to Swanson. At the Ponsonby reservoir the councillors were shown where the big pipe line of patent locking-bar steel pipes, 27in in diameter, commences. " It was al-o explained that the Ponsonby reservoir i- 230 ft, and the Kliyber Pass reservoir 300 ft. above, sea level, but that both' will lie supplied by gravitation from Waitakerei Falls. The present pumping main between Ponsonby and Khyber Pass reservoirs is to be utilised as a gravitating main, the water being turned into Kliyber Pass reservoir from the valve at Ponsonby reservoir when required, and the gravitation being easily obtained, as the break-pressure reservoir will be 475 ft above sea level, and the actual intake between 900 ft and 1000 ft above high-water mark. The line of 27i pipes will extend from Ponsonby reservoir to the Titiraugi Road, where the mixed main from Nihotupu Falls will be turned into it. From Titirangi Road to the break-pressure reservoir the pipes are to be 24i 11 in diameter, and from there, to the falls, 23.ii). the pipe line following the roadway to New Lynn, thence by way leaves (through private property) to Waikurnete railway station, along the Waikumetc-West Coast Road to Ganty's Creek, through part of Henderson Valley to near Baxter's, and so up to the break-pres-sure reservoir, a pine line of some 14 miles. LOCKING-BAR STEEL PIPES. At New Lynn a halt was made while the visitors inspected the works now being erected in connection with the £151.668 contract for supply of the Mephan-Ferguson lockingbar steel pipes, and a practical idea of how these pipes are made was obtained. From tho road the works appear something like a. huge foundry in course of erection, and that is really what they are. The galvanised structure enclosing the machinery, engines, etc., is 290 ft long by 60ft wide, and the boiler-house attached is 75ft by 30ft. A Tangye gas engine and gas-prctlucer plant is being installed, with a register of CO brake horse-power, and two flywheels, each 7ft in diameter, and a ton in weight. This engine, it was stated by tho foreman of works, is probably the largest gas engine in New Zealand at the present time. The multitubular boiler being bricked in will generate tho power for operating a 32in steam-hammer, and for an auxiliary engine. Overhead, 011 stout beams, travailing cranes of very heavy construction, and a spread extending practically the width of the building, have been placed in position, each capable of lifting from five to ten tons. The most interesting feature to those present, however, were tho enormous masses of heavy machinery used in the actual manufacture of the pipes, and the method of working was most lucidly explained to the councillors by Mr. Wallace, lie said the quarter 11 ch steel plates were first passed through a multiple roller to straighten any bending they had been subjected to on the voyage, and then cut to exact measurements in a uniform size. The plates then passed 011 to a machine, with travelling bench, now being fitted up. Along each side of the machine was a powerful screw, the revolutions of which will carry heavy semi-circular arms. The plates, being held in position on the bench by hydraulic pressure, are planed by the machine to an even thickness, and -a- dovetail is planed along each edg2. Some idea of the size of this machine may be obtained from the fact that its bed plates cover 40ft of floor length, and it. weighs 90 tons. The next.process the plates are called upon to go through is the embrace of a hydraulic press, with a 60ton stroke, which gives the requisite semicircular shape, and the finishing touch is added by rollers. The steel bar which gives its name to the pipe appears at first sight, liko a small tramway rail. It is really a_ box with a square groove cut in either side, and info these grooves the edges of the semi-circular plates are. pressed, the edges of the square grooves of the bars being then squeezed into the dovetail groove of the plate edge. The squeezing process is accomplished by the 4in head of a hydraulic ram. which applies the "gentle" pressure of 300 tons. The pipes are made in a uniform length of 28ft, and the test pressure they have to stand is 4201b to the square inch. The finishing process is a most important one, and upon it rests the future of every pipe. After passing the tests the pipes are coated with the preserving compound. a kind of asphalte, which is to preserve them from rust, the deadly enemy of all steel pipes. A steel dipping tank, 30fr long and 7ft deep, will be provided, and this will be heated by a series of furnaces sufficiently to maintain the coating medium at about 400 degrees temperature. Up to this stage the whole work of making the pipe will have been "cold," that is, that in tin cutting, planing, bending and pressing, etc., the steel plates will be treated cold, 110 heat whatever being applied. TO THE RANGES. Leaving New Lynn, the journey was resumed through the charming country of the Henderson and Swanson districts, pretty views of the harbour and city being obtained from many points of vantage. Swanson was reached in good time, and there the visitors found saddle horses in waiting to relieve the drag horses of portion of their load for the climb to the break pressure tank; presently a procession of riders and vehicles was wending its way up the ridges like a small commando on trek, and it did not matter much whether one had not, been in tho saddle for 13 years and other? had not enjoyed equestrian exercise for various other periods—chiefly lesser periods—the ride was an enjoyable one, and a sporting element was added by a chestnut, pony named " Tommy." Tommy rejoiced in the inheritance of aristocratic blood from some ancestor or another, and in the many and devious ways known to equine* he" challenged the field to a straight-out steeplechase, and raced on his own account, coming home a prime favourite with the field behind him. THE BREAK PRESSURE TANK. On the road up the riders caught up on a waggon loaded with cast-iron pipes being taken from the Swanson railway station for the line between tho big reservoir and the break pressure tank. This waggon load was tho first of Mr. Henry's contract of £346 for cartage, and it. was escorted triumphantly to tho break pressure tank site. This proved to be a clearing on a leading ridge, and when the works are completed there will be a receiving tank there 155 ft long, 77ffc wide, and 14ft in depth, divided into two compartments, each holding half a million gallons. This "tank," receiving its supply from the pipe line from the falls, will discharge into the 2+in pipes, and the water will thus flow, by gravitation, from the "tank," which is 475 ft above sea-level, to the Ponsonby reservoir. Tenders have been called for the construction works. From here a short excursion was made down the ridge to tho left of the track to inspect, Mr. T. Pr&ndergast's £500 pipe track contract. Excellent progress had been made here, the track being cariied almost up to the tank site. One small runnel had been cut, and there were numerous cuttings and embankments, some of them of a heavy nature, but the work had beep, well done. From a vantage point the party was shown the long, snake-like yellow line which marked the pipe track running down to Henderson Valley Road. Thus from the tank to Ponsonby reservoir the water will flow through 24iti steel locking-bar pipes for eight miles to Titirangi Road, and thence for six miles 15 chains through the 27in steel locking-bar pipes, the two miles from the tank up to the big reservoir shore the falls being covered by 21in cast-iron pipes, the supply of which is included in the Mephan-Ferguson contract. Upon return to the tank si to lunch was a very welcome feature of the proceedings, and the visitors were taken in various— always dignified attitudes by the übiquitous camera devotee. 1