§ Mr. Neil TurnerTo ask the Secretary of State for Transport when he expects work on the Thelwall viaduct on the M6 will be completed; and who will bear the costs incurred. [115245]
§ Mr. JamiesonI have asked the Chief Executive of the Highways Agency, Tim Matthews, to write to my hon. Friend.
Letter from Tim Matthews to Mr. Neil Turner, dated 10 June 2003:
I have been asked by David Jamieson to reply to your recent Parliamentary Question about on-going works to the northbound bridge of the M6 Motorway Thelwall Viaduct, in Warrington, Cheshire. As you may be aware, this matter was the subject of an Adjournment Debate in the House on 12 May, secured by Helen Southworth MP.The Highways Agency is responsible for the operation, management, maintenance, and improvement, of the trunk road and motorway network in England, including the Thelwall Viaduct, which typically carries some 150,000—160,000 vehicles per day. All but one lane of the viaduct carrying northbound traffic was closed in July 2002 following the discovery of a failed roller bearing. Detailed investigations were urgently earned out and these revealed other failures in the bridge roller bearings. Continuing intensive investigations found that all 136 roller bearings on the northbound viaduct should be replaced, before further traffic lanes can be opened on that structure. As you may be aware, the Minister stated during the Adjournment Debate, that it might take until March 2005 to complete all the remedial work. The Minister also acknowledged that the cost of the remedial work is likely to be substantial, but did not wish to say anything further on that aspect, given that the question of liability for the failed roller bearings is likely to be decided through litigation and the courts. Notwithstanding that, he also said that funds would be made available to the Agency to enable the remedial work to be carried out.The current restrictions comprise three narrow lanes in each direction on the new southbound viaduct and a single lane on the northbound viaduct, to facilitate traffic leaving the M6 at Junction 21, for Warrington. There are advance warning signs on 742W all the motorway approaches to the works advising of likely delays, but there is no convenient diversion route using the motorway network. We will continue to monitor traffic patterns closely and keep under review all possible diversion routes to mitigate the effect of the restrictions.Laboratory testing and investigations into how the roller bearings have failed is substantially complete. These findings are being used to inform the design process for the replacement of the bearings and associated works required to bring the structure back fully into long-term service.The Agency is conscious of the need to re-open the northbound viaduct as soon as is practicable, and is investigating the possibility of phasing the work to secure the early release of additional traffic lanes on that structure.I hope this is helpful. If you would like any further information about this matter, you may wish to contact the Agency's Project Manager for the viaduct repairs, David Brindle, Room 406. Sunley Tower, Piccadilly Plaza, Manchester, MI 4BE (Tel 0161 930 5653).
§ Mr. Peter RobinsonTo ask the Secretary of State for Transport what research was undertaken on the impact of corrosion from de-icing chemicals on the bridge bearings of the Thelwall Viaduct on the M6 at the design stage: and what research has been undertaken since into alternative technologies that could reduce the levels of corrosion. [118096]
§ Mr. JamiesonThe risk of corrosion from environmental pollutants including de-icing chemicals on Thelwell Viaduct was minimised by using stainless steel and provision of enclosures (skirts) around the steel roller bearings. The majority of the bearing locations do not have expansion joints at the road level, thus reducing the risk of surface water and de-icing salts reaching the surfaces of the roller bearings.
The effectiveness of non-corrosive de-icing agents has been researched over many years in UK and other countries. There are limitations on their effectiveness at low temperatures and the use of rock salt is then necessary. Such agents are used in the UK on some major bridges where the higher cost can be justified in whole life terms.