When the Royal Navy became predominantly oil-fired

When did the Royal Navy become predominantly oil-fired?

By the late 1920s or early 1930s, with the transition accelerating as the remaining large coal-fired ships left service.

The fleet became predominantly oil-fired in the late 1920s or early 1930s, rather than on a single conversion date. The balance changed rapidly once the large coal-burning ships disappeared. This shift affected propulsion, bunkering, storage, machinery support, and operating range. It also made an old coal-fired hull less attractive as a reserve ship even when the structure remained usable.