Portland was ideally suited on the South Coast of EEngland, almost midway between the large naval bases of Plymouth and Portland. It was a harbour of refuge and in any Channel engagements would be a vital operational base for the Royal Navy.
The new Portland Coaling Depot was built between 1890 and 1896. The original coaling sheds, built between 1856 and 1860 can still be seen, but the new pier was more elaborate. A railway network supplied the coal to bunkers, and large cranes were stood along the pier to load to coal directly onto warships. This coal depot was further expanded between 1903 and 1906.
By 1905 oil tanks were built in Castletown, indicating the eventual demise of coal.