Contractor Mowlem is suing engineer White Young Green for 拢2m in a row over a store for thousands of feet of film dating from the First World War and owned by the Imperial War Museum

Mowlem blames the engineer for delays in building a store for the irreplaceable films, which was finished 21 months late. The film store, in Duxford, Cambridgeshire, was not completed until May 2003, instead of July 2001, at an alleged extra cost of 拢2m.

The museum needed to store 45,000 reels of sensitive nitrate film, which requires special storage conditions as it is liable to decompose if left exposed to the open air, and, because of the toxic gases it releases, could even catch fire or explode.

The contractor agreed to build separate 500-roll cells made out of reinforced concrete and to bury them in the earth to minimise the risk of explosion.

Mowlem alleges that White Young Green鈥檚 cells did not meet the specified temperature and humidity levels until two sets of remedial works had been carried out.

Although the film was unharmed, Mowlem also alleges that the engineer failed to specify the performance requirements of important equipment, which could not operate under winter conditions.

It was also negligent over the specification of dehumidifiers, fan coil units and a central chiller unit, according to the High Court writ.

We think we have a strong defence

Denis Connery, commercial director, WYG

Mowlem says it is liable to pay 拢480,000 in damages to the museum trustees, of which it has so far paid 拢350,000. It therefore claims damages from White Young Green.

A spokesperson for Davies Arnold Cooper, Mowlem鈥檚 solicitor, said the 拢2m figure included prolongation costs and liquidated damages.

White Young Green commercial director Denis Connery said the firm was contesting the claim by Mowlem and considered that they had a robust case.

He said: 鈥淲e have referred the matter to independent legal and technical advice. We think we have a strong defence to the allegations.鈥�