 The cause was later found to be floor sections lifting from water pressure, and modifications to correct this being approved in November 2001.Also in 2001 Transfield Obayashi Joint Venture agreed to pay Transurban $157 million in damages in an out-of-court settlement over late completion of the tunnel.Transurban launched further legal action against the Transfield Obayashi Joint Venture in 2007, after radar tests indicated the tunnel walls were thinner than that specified in the contract, possibly resulting in the tunnel not lasting for the proposed 100-year design life.