THE WINGATUI VIADUCT.

Evening Star, Issue 7247, 25 June 1887, Page 2

THE WINGATUI VIADUCT.

The formal opening of the Wingatui Viaduct took plaoe tips'afternoon, a special train put on by the contractors leaving the Dunedin railway station at 12,55 p.m. Among the excursionists we noticed the Hon. the Premier, Mr V, Pyke, M.H.R. (who turned tjio first sod of the Otago Central on June 7,187i1), Professor Black, Mr W. N. Blair, Assistant Engineer-in-Chit-f, Messrs W. D. Stewart, T. Fergus, and A. H. Rosa, M.H.R.S, L. Q. Beal, J. Edgar, A. Solomon, A,' 1 •. Lubeeki, E, B. Cargill, J. Roberts, Dr Brown, W. H. Pearson, Henderson, Dr Belcher, J. Hapkworth, E.’ p. Ussher, 0. M‘Queen, A. Grant, Harraway, H, Mackenzie, Hpn. T, Dick,' S, Solomoh, Whitson, Mohdy, Shin, D. D. Macdonald, aud others. The viaduct is the largest structure in New Zealand, and probably of Its 'ldr.d in tlie Southern Hemisphere.’ Locally also it has special interest, inasmuch as the necessary material was wholly manufactured in Dunedin or on the ground—even to the bolts and rivets. It crosses the gully at Mullocky Gully. The question of buildfng a’vladuct or the construction of an eihbani ment was fully considered { and it was found that not only would ' the embankment be so huge an undertaking as to he almost without precedent, but that the viadui' t would be the most cheaply constructed; so 'it was determined on. The length of the Viaduct is 690 f t; and there are eight spans-'three of 106 ft each and five of 'o6ft each. The strongest piers those next to the abutments are of concrete; and the main piers, five in number, are of malleable iron, resting on large foundation blocks of concrete and masonry. The largest of these blocks is 40ft long by 25ft wide and 12ft deep. The girders are of malleable iron of the usual construction. The total height of the bridge from the creek bed to the level of tiro top of the buttress is 154 ft Sin. To give some idea of the towering height of the structure, it may be mentioned tb&t to the summ t of Knox Church spire is 150 ft, and of the First Church 175 ft. There are 3,850 oublo yards of masonry and rubble in the bridge, and 574 tons of iron. The cost of the work is L 22,000. The masonry was done by Black and Allison, their contract being about LB,OOO The iron work was supplied by Messrs R. S. Sparrow and Oo„ and cost about L 14,000. The smaller girders were built in their places; but the main girders were built on tho ground and raised by hydraulic presses specially designed and made by Sparrow and Co, The girders weigh forty tons each. The work has been carried out with tho greatest possible care and skill, and so well has the design been worked to that tho contractors say that of the 108,000 rivets in t e structure there is not one more nor loss than what is shown in the contract. This may not bo literally correct, but we believe that no alteration whatever has been made to the design. The work was carried out under the supervision of the District Engineer (Mr Usaber); but the man immediately in' charge of it was the Resident Engineer (Mr Cook), who has lived on the ground and seen to every detail, along with the inspectors (Messrs Fraser anr Barclay). The last-named gentleman had special charge of the ironwork. The manufacture of the work was chiefly supervised by Mr Roberts (Mr Sparrow’s foreman), and tho erection by Mr Henderson.

The bridge was tested yesterday by Mr Blair, Ass’stant Engineer-in-Cnief (who came down from Wellington specially for the purpose) with two of the heaviest locomotives, standing and running over the viaduct in all possible ways. The weight upon each span was about 103' tons, and the deflections were taken With self-registering appliances

specially made for the purpose, which showed the deflections with all variations of the load. The result has been beyond all expectation, the test being thoroughly satisfactory. After passing over the viaduct Sir R. Stout declared it open. Mr John Roberts (chairman of the Taieri County Council) proposed the health of the engineer and of the contractor. Messrs Sparrow and Blair replied.