Construction of a train servicing depot near Wembley involved substantial excavation and stabilisation of the resulting clay slopes. There were slips in the clay and remedial work was undertaken to deal with shallow instability. Subsequently, however, deep-seated instability was detected. The main contractor sued both the specialist design and build subcontractor for the “soil nailing” work and the consulting engineers. The subcontractor reached a settlement with the main contractor which successfully pursued proceedings against the engineers. The engineers claimed a contribution from the subcontractor but how was that contribution to be assessed and was it limited to the figure at which the subcontractor had settled with the main contractor?

The judge decided the “ just and equitable” apportionment of responsibility between the two defendants was 60% to the subcontractor and 40% to the engineers. This reflected their equal responsibility in the pre-construction stage, the relatively greater responsibility of the subcontractor in the post-construction stages and all other matters advanced - but took the subcontractor’s liability above the settlement payment it had made to the main contractor. There was no authority that suggested that a prior settlement should determine the ultimate apportionment.

Carillion JM Ltd v Phi Group Ltd [2011] EWHC 1379 (TCC)