§ Vice-Admiral Hughes Hallettasked the Minister of Transport and Civil Aviation to what extent his recent estimate of 300 tons of steel a mile required per mile of motorway could be reduced if the maximum use is made of modern pre-stressing technique; and whether he is satisfied that full advantage is being taken of such methods in all appropriate cases.
§ Mr. WatkinsonExperiments on the behaviour of pre-stressed concrete when used for carriageway construction are still proceeding and until more experience is available I shall not authorise its use on motorways. If pre-stressed concrete were used it might mean a saving of 50 per cent. in the amount of steel required, but the cost of the work would be greater because of its specialised nature.