During World War One the main source of fuel for ships of all types was coal and there was a need to ensure a regular supply of coal for the ships of the fleet, in all corners of the globe. The mines of Westport produced some of the best coal for maritime use which was in demand by the Admiralty and also the Commonwealth Naval Board for the Royal Australian Navy. So much coal was exported for naval usage that there was a severe shortage of coal for domestic use in New Zealand during the years 1917-19.
One of the more important considerations for the Admiralty when war broke out in 1914 was to ensure a regular supply of coal for the ships of the fleet, in all corners of the globe. This not only included having sufficient supplies but also being able to give it to ships which were at sea. The large expanses of the Pacific made this ocean difficult to supply.