§ Mr. John Hynd
asked the Minister of Transport what study he has made of the views of the West Riding County Council, details of which have been sent to him, about the design he has accepted for the Tinsley Viaduct; and if he will make a further statement on the action he has taken in this matter.
§ Mr. Tom Fraser
I am aware of the terms of the statement issued by the West Riding County Council. The cost of 321W Tinsley Viaduct is being borne almost wholly by the Exchequer. The council were appointed the Ministry's agents for preparing the design. The intention was that they should, in due course, supervise its construction.
The original design was evolved by the agent authority in consultation with the Ministry but the council were fully aware that the Ministry, for its part, did not preclude the consideration, on their merits, of alternatives which might be proposed by tenderers. One of the tenderers in fact did submit an alternative design at substantially lower cost. The Ministry considered that this design was worthy of further consideration; and because, during the period of tendering some firms had gained the impression that alternative designs would not be considered, decided that all tenderers should be allowed to submit an alternative design and price. The county council did not agree. Accordingly, the Ministry as principal issued a fresh invitation to this effect to the original tenderers. The consideration of these alternatives was thus, as the council recognise in their statement, not within their province.
The outcome was the acceptance of a tender for an alternative design by the Cleveland Bridge and Engineering Co. Ltd. The amount of the tender, £4.6 million, is subject to negotiation on detail and the contract price is expected to be appreciably lower. This alternative meets design requirements, including accepted standards of public safety, and at the same time saves the taxpayer over £1 million.
As to particular points made in the county council's statement, the accepted design complies with the recommendations contained in the "Report on Mining Subsidence" published by the Institution of Civil Engineers in 1959 and after taking full account of the factors mentioned in the Report the design is considered to be wholly suited to ground conditions at the site.
The width of the viaduct, compared with the original design, has been reduced by narrowing the central reserve to 10 ft. between the off-side traffic lanes. There has been no reduction in the width of carriageways or hard shoulders as might be inferred from the county council's statement. This reduction has resulted in an estimated saving of a little over 322W £100,000. The accepted design, far from requiring more land than the original design, in fact requires significantly less. This is largely because the weight of the structure has been halved and, therefore, less land is needed for foundations. The temporary use of land by the contractor during construction will also be less.
The tenders submitted for alternative designs did not comply uniformly with the technical and contractual requirements issued to tenderers and, therefore, had to be adjusted to place all the tenders on a comparable footing. The Ministry made full allowance for the cost of maintaining the steel work to the extent expected to be required in the Tinsley area. This, on a realistic estimate, amounts to a capitalised cost of £150,000. The sole criterion governing the use of material for the new design has been to secure the requisite standard of performance with maximum efficiency and, therefore, at lowest cost. Structural steel will, in fact, comprise about 15 per cent. of the total weight of the superstructure, the remainder being reinforced concrete.
What the county council appear to be suggesting is that I should not be prepared to take advantage of improvements in design and savings in cost which emerge from the tendering process. This cannot accept.