OUR SHINGLE SUPPLIES.

Evening Post, Volume LXXII, Issue 112, 8 November 1906, Page 3

OUR SHINGLE SUPPLIES.

WORKING THE HUTT RIVER BED. INSTALLATION OF A COSTLY PLANT. "What is that big new tower, just north of Belmont?" is the query that has been frequently heard of late from travellers going beyond the Lower Hutt. It was "the big tower" that prompted further enquiries by a member of our staff. It did not take long to ascertain that it is part of a new plant erected by Messrs. R. Pitcaithley and Co. to assist in their work of procuring shingle from the bed of the Hutt River. The plant is tse only one of its kind in operation in the colony, and is characteristic of the enterprise and thoroughness "with which the lessees of the Hutt River ehinglo leases carry out their undertakings. It is chiefly upon this supply that most of the building contractors in Wellington depend for their shingle, and the Hntt River Board's policy of leasing its beaches has proved a paying one for that body. In view of the uniqueness of the plant and its many interesting features, a member of our staff journeyed to the locality known as Belniont Beach this morning, being out by Mr. James Smith, manager for Messrs. Pitcaithley and Co. The beach is situated about 1£ miles north of Belmont, and contains hundreds of thousands of yards of shingle. It is here that the new plant has been erected and is now being worked, though not quite in full working order. The South Island visitor who had seen gold dredges at work would at oace be struck by the familiar general appear- j once of the equipment. Situated on the railway side of the river, the main feature of the plant is a fiat-topped framework tower some 60ft in height, and composed of Australian hardwood timber. Sunning up and down it is a succession of never-ending trough-shaped buckets — the elevator — reminiscent to a large extent of our own harbour dredge at work. At a height of about 45ft is a platform attached to the tower, on which stands "the man behind the gun," who operates the important branch of the process yet to be described. Just below is the engine-shed, containing a 20-horse power Robey engine. On the opposite side of the river is a 40ffc tower. It is between the two towers, a distance of over 600 ft, that the 4-inch main cable runs for the conveyance of men and material from one side of the river to the other. Underneath the main cable is a 3-inch endless rope which works the large bucket backwards and forwards. This endless rope is attached to a ivinch on the platform, together with raising and lowering gear. The main cables are anchored at the back of the eastern tower to a 16-ton block of concrete. Ten feet from the ground, attached to tho main cable, is an "idler," around which the endless rope runs. The river is somewhat high at present, and a 550 ft span was being worked to-day. The huge steel buckets employed are at present being filled by manual labour, but when everything is properly equipped they. will be marked automatically as scoops, and so fill themselves. Then, controlled by a winch designed by Mr. Jarrett, of' Booth, M'Donald and Co., the bucket is swung across the aerial tramway above a shute on the platform already referred to, taking about one minute in crossing. There it is automatically tipped, and the material passes into a revolving screen comprised of meshes of varying size, is washed by water brought -up from the river by a centrifugal pump, and the different sizes of gravel are sorted as required — at present into sand, three-eighths of an inch, one inch, and two and a half inch lots. This part of the work is the most interesting of the whole operation, and in order to inspect it thoroughly the pressman ventured, under the guidance of Messrs. Pitcaithley and Co.'s foreman, Mr. O'Brien, over the huge hardwood girders, and crawled clingingly through quivering machinery and whirring wheels and belts to various vantage points. The staging, by the way, was not made for the convenience of visitors, though if their nerves last out in the vibration and din they are well repaid by the great interest of the process. To say 'that the massive buckets hold one cubic yard wo-dd perhaps not convey much to the average lay reader. He would have a better idea of their capacity if told that they hold from 27 to 30 hundredweight. This mass, as it finds its way into the revolving screen,' begins to be sifted right atray as the washing begins. The- sand is taken away with the water, the small pebbles all pass through the next mos?h, the inch stones through the next, and the 2^-inch ones through the fourth. Meanwhile over all, disdainful of the small openings, crash the large boulders till with a bound they dash into the gaping iron jaws of the groovedmouthed crusher, which unceremoniously puts an end to their pride. A few grinding crushes of the- powerful huge teeth, and the boulder is a broken mass of road metal. No longer a giant among the pigmies, it becomes an uneven battered pigmy iteelf, and in fragments it passes through a shnte into the alwaystravelling elevator, which returns it to the screen, where it weakly finds ita way through the first opening that will admit it. Underneath each differentsized mesh is a shut* that carries tho sorted shingle into- large bins capable of holding 150 yards of metal and sand. At the bottom of each bin is a gate which can be opened over railway trucks running on the track laid beneath and connecting with the main railway line. The bins- themselves stand on solid concrete pillars. Additional stability woud have been given to the whole structure had the wish of th^ owners to carry stout cables to solid concrete blocks placed in the hillside just beyond been allowed to be earned out. But the Railway Department in its wisdom declined to allow this to be done* though the cables would have been "at ledat 50ft above the railway. * Mr. R. Newell is in charge of the machinery itself, and the whole plant, irhich was erected by Booth ,v M'Donald and Co., is capable of turning out about 250 yds of any class of metal daily. Once it is properly at work, there should be no further -delays in the supplies of river metal in the city though these have been greatly minimised under the management of Mr. J. Smith, who afforded our representative every possible facility for making his enquiries. The Belmont Beach is only one of several in the Hutt River leased by Messrs. Pitcaithley and Co., but the other* are being worked in the ordinary man and dray method. Some idea of the extent of the industry may be gained from the fact that it has employed as many as fifty men at a time, while the amount paid to the Railway Department for freight — carriage to Wellington — in two rears exceeded £6000. The result of Mr. Pitcaithley's enterprise in inttalling the costly plant described, an experiment to some extent, will be awaited with interest.