THIESS CONTRACTORS PTY LTD V PLACER (GRANNY SMITH) PTY LTD  WASCA 102
Supreme Court of WA – 14 April 2000
Placer was the owner of the Granny Smith gold mine and in 1989 engaged Thiess to carry our open cut mining at the mine site.
The original contract was a schedule of rates contract; latent conditions lead to Thiess making windfall profits.
In 1991, Placer therefore proposed that the parties enter into a partnering arrangement with the parties to share the risk of cost fluctuations, the parties working in good faith on all matters relating to the contract, and the contract providing for a fixed profit for Thiess.
Placer terminated the contract in March 1995 and relied upon a clause that stated that Placer could terminate the contract at any time and for any reason.
Thiess issued legal proceedings claiming that the termination of the contract was unlawful.
Placer counterclaimed for damages from a breach of contract alleging that Thiess had not acted in good faith by providing an initial incorrect estimate of its genuine costs according to which Thiess was to be paid.
Did alleged representations by Placer that the contract would remain in place for the life of the mine lead to Placer being estopped from terminating the contract?
Did Thiess fail to act in good faith and breach the contract in that it misrepresented that its rates were genuine estimates of its costs?