The contamination alleged by Caltex was the lowering of the flashpoint of the ADO from about 84°C to about 32°C on discharge. It was asserted by Caltex, and accepted by Carruthers, J., that the cause of the lowering of the flashpoint of the ADO was that the carrier had not isolated the tank in which the ADO was carried from the other tanks in the ship in which the other cargo (tapis crude) was being carried. In particular, it was asserted that light ends from the tapis crude oil had been permitted to enter the tank in which the ADO was being carried via the inert gas system. Expert evidence was called by BHP to suggest that the contamination could have been caused by a leakage of liquid tapis through a butterfly valve. No evidence was called that the particular butterfly valve was malfunctioning and Carruthers, J., accepted the preponderance of evidence called on behalf of the plaintiff to support the theory that the diminution in flashpoint was due to vapour contamination.

There were a number of interesting legal issues which arose from the matters relied upon by the defendant. It sought to argue that it was protected by the exception under Art. IV, r. 2(a) of the Hague Rules (“Act, neglect or default of the master … or the servants of the carrier in the navigation or in the management of the ship”). However, while accepting that “inert gas systems were installed on tankers fundamentally for the protection of the vessel”, Carruthers, J., held that the purpose of the inert gas system “is primarily to manage the cargo, not only for the protection of the cargo but for the ultimate protection of the vessel from adverse consequences associated with that cargo”.2 Thus, in reliance on the authorities which had been reviewed by Macfarlan, J., in The Tenos, he found that misman