BRIDGE MAKING

New Zealand Herald, Volume LXXVI, Issue 23259, 31 January 1939, Page 6

BRIDGE MAKING

NEW PATENT METHOD - r, NEW ZEALAN-DERS' IDE! A ADOPTION BY WAR OFFICE [from: our own correspondent] LONDON, Jan. 5 A new system of- building bridges, the patent of two New Zealanders, Captain A. M. Hamilton, of Christ, church, and Mr. G. D. White-Pairsons, of Lyttelton, has been adopted by the British War Office and the Ministry of Transport. Briefly, it is building on the "meccano" principle. Instead of bridges being separately designed the New Zealanders' idea is that all parts are standardised and that these parts are then assembled into bridges of any length required. In this way bridges may be virtually ; 'mass produced" and the parts kept in stock ready for immediate use. Hitherto there has been no such system, and its importance may be gauged by the fact that the Science Museum in South Kensington, Lon. don, where all the great advances in the history of science arei recorded, lately acquired a complete set of models of these bridges as being ,a most noteworthy development in the art of bridge building. System Regarded as Invaluable The chief feature is the greatly in. creased speed of erecting bridges., or repairing damaged ones. For alii purposes, such as temporary roads, re. placing bridges damaged wash-outs, for military purposes or as a safeguard against damage to bridges in air raids,' the system is considered by the authorities to be invaluable. Before bolting up the fabricated steel girders are not unlike meccano parts. The principle was first established by Captairf Hamilton in course of constructing the Rowandu*?*Road through Kurdistan. In Persia 1 the Anglo-Iranian Oil Company now has many bridges built on this system in use for the development of its oilfields. The British War Office has been carrying out severe field tests on these bridges for the past four yeai-s, and it has lately been adopted as the standard heavy-duty type —that ia, for transporting the heaviest artillery, tanks and lorries used by the modern army. The remarkable success of the tests to which the bridge was subjected simulating the "worst possibfe conditions of field use"—proved highly gratifying, not only to the inventors, but also to the officials of thei Royal Engineers conducting the trials. The method of assembling and "launching" these bridges will now be taught at the School of Military Engineering, Chatham, and to Royal Engineer Units generally. Replacement of Bridges in' Wartime For air raid precautions the Institution of Civil Engineer now lias the matter of the general use of the bridge in England under review in conjunction with the Ministry of Transport. The well-known journal Engineering has given the unit-construction bridge its repeated blessing and approval for the urgent bridging problems all transport and departmental engineers today have to face —especially in view of the present international situation. To give an indication of the value of this new bridging system during wartime, it is claimed that should, say, Waterloo Bridge, or any. other chief bridge of London, be destroyed by bombs, a temporary structure to carry the same heavy traffic could bo built in most cases within a fortnight if all the necessary measures, such as ample stocks of parts, and the ere<> tion gear, were in readiness for such a crisis. Aeroplane hangars can also be erected from standard parts on the same bolted principle, and the British Air Ministry already has a number of hangars constructed to this particular application of the New Zealanders' invention. Brought to Attention of Dominion Both in the case of the bridges and the hangars the inventors have been closely associated with Cullender's Cable and Construction Company, Limited, which is the joint patentee of these structures, though best known in New Zealand for their electrio cables. The system has already been brought to the attention of the New Zealand Public Works Department, and there is a possibility that two well-known Wellington firms of structural engineers -may soon be fabricating these bridges and hangars for the Dominion ■within the country itself.