The claimants, Thames Water Utilities Ltd (TW) brought a claim against the defendants, London Underground Ltd (LUL) arising from a burst water main. They contended that the burst water main was caused by works carried out by LUL on the construction of the Jubilee Line extension (pursuant to powers conferred under the London Underground Act 1992 and the London Underground (Jubilee) Act 1993).

Whether the claimants were able to establish that if it had not been for the works carried out by the defendants then, the state of a water main had been such that it would have continued in use for many years to come. The issue was essentially one of causation.

Reference

As a matter of construction, the court found that the defendants did not owe TW a statutory duty that in relevant and material aspects differed from the obligations arising in the law of negligence and nuisance.

By applying the “but for” test the court also found on the evidence, the probability existed that the effects of the differential settlement cause by LUL’s work (which included deep tunnel excavations, shaft sinking and compensation grouting) led to some of the shallow supporting ground becoming unstable. The state of affairs brought about by LUL was the prime and effective cause for the differential settlement, which led to the imposition of loadings to the joint, causing shearing/prising and thus bursting.

If it had not been for the works carried out by LUL then the state of the water main had been such that it would have continued in use for many years to come. The court therefore rejected the suggestion by LUL that the ground movement caused by LUL was so slight that it could be characterised as “the straw that broke the camel’s back”, by adding a nominal loading to a pipe grossly loaded as a result of historic locked in strains and stresses.

Judgment was given for TW on the issue of liability and causation.

For further information, call Tony Francis or Nicholas Gould on 0207 956 9354

www.fenwick-elliott.co.uk

Postscript

This case serves to confirm that the “but for” test continues to be the normal route to considering questions of causation. In effect a single test of causation is applicable to the same set of facts, irrespective of whether the case is pleaded in negligence, nuisance or for a statutory breach and would have to include the following considerations:(1) The “but for” test is a necessary but not determinative test of causation. It may serve as an exclusionary filter, or to identify viable causes;

(2) Even where the claimant satisfies the “but for” test, the court has an obligation to evaluate that cause in terms of its materiality;

(3) The court approaches the task of evaluation in a “common sense” way informed and guided by reference to the scope of the duty owed; and

(4) There are no “exceptional” or “policy” grounds that would warrant the relaxation of the normal rule as to causation.