§ Mr. Gwynfor Evansasked the Secretary of State for the Environment if he will give details in the Official Report of the allocation of the costs, by spending programme and Department, of the remedial work that is currently taking place on the Severn Bridge, and of the remedial work that has occurred since the construction of the bridge.
§ Mr. HoramI have been asked to reply.
The costs of all remedial and maintenance work on the Severn Bridge are allocated by the Department of Transport in accordance with the Severn Bridge Tolls Act 1965. I am not readily able to give more detail than is published in the annual accounts.
§ Mr. Gwynfor Evansasked the Secretary of State for the Environment what estimates have been made of the expected useful life of the Severn Bridge; and if no such estimates have been made, whether he will consider commissioning them and announce the findings.
§ Mr. HoramI have been asked to reply.
In common with all new highway bridges built for the Department, the bridge is designed for a life of at least 120 years and it will be maintained to meet this requirement.
§ Mr. Gwynfor Evansasked the Secretary of State for the Environment if he will give details in the Official Report of all strengthening operations carried out on the Severn Bridge since its construction which have subsequently proved ineffective, together with the names of the firms responsible for the deficient repairs.
§ Mr. HoramI have been asked to reply.
533WThere have been no strengthening operations carried out on the Severn Bridge which have subsequently proved ineffective.
§ Mr. Gwynfor Evansasked the Secretary of State for the Environment if he will give details in the Official Report of the structural deficiencies that have been detected since the Severn Bridge was opened, together with an estimate of the cost of remedying each of them.
§ Mr. HoramI have been asked to reply.
In addition to routine maintenance, the following items have required attention:
- 1. Flotation diaphragms. Temporary diaphragms were provided to enable 60 ft. sections of the deck to be floated from the construction yard to the site. The connection between these and the deck had to be released in 1971 to avoid detrimental effects to the structure. The cost was not large and is not identifiable.
- 2. Intermediate diaphragms. These were stiffened in 1975 in accordance with the Merrison recommendations at a cost of approximately £564,000.
- 3. End diaphragms and rocker assemblies. During the reappraisal of the design the end support assemblies were found to be inadequate for certain unlikely but possible loading conditions. Remedial work is urgently in hand at present at an estimated cost of about £200,000.
- 4. Deck trough stiffener welds. About 20 short cracks have been detected in a total length of 75 miles of weld. Arrangements for their repair is in hand. The cost has not been established.