Londsdale Investments Pty Ltd v Om (Manganese) Ltd [No 3]

Lonsdale Investments Pty Ltd sued Om (Manganese) Ltd in the Supreme Court of Queensland over the design of a mineral processing plant. The dispute centred on the quality and characteristics of the ore to be processed by the plant, and whether the design engineer had breached the contract and duty of care by failing to investigate these characteristics adequately and by making assumptions about them. The matter involved complex contractual, tortious, and trade practices claims, as well as a claim for restitution.

The court was required to determine if the design engineer breached the contract and duty of care by failing to investigate the ore's characteristics and by making assumptions about them. It was also necessary to ascertain if the engineer was required to advise on the assumptions made, whether those assumptions had been agreed, and the effect of changes in the arrangement of the design work. Additionally, the court needed to assess whether the engineer was negligent in making assumptions about the ore's characteristics and failing to advise on the design assumptions, and what the content of the duty owed was. The court also had to consider if the engineer engaged in misleading or deceptive conduct by making representations about the state of the design work and their future skill and competence.

The court found that the first defendant breached both the duty of care and the contract, awarding damages of $5,474,450.59. The second defendant was found to have breached the duty of care, with damages of $256,425. The first plaintiff was entitled to $1,999.02 on account of work done at the request of the plaintiff. The court ruled that the design engineer had indeed breached the contract and duty of care, and that misleading or deceptive conduct had occurred. The claim for restitution was also upheld, with a quantum meruit claim allowed for the benefit of work accepted.

The court ordered that the first defendant pay damages of $5,474,450.59 and the second defendant pay damages of $256,425. The first plaintiff was awarded $1,999.02 for work done at the request of the plaintiff. These orders reflected the court's findings on the breaches of contract, duty of care, and misleading or deceptive conduct, as well as the restitution claim.