Was this true - Japan's navy still coal powered in WWI?

[raharris1973]

On another forum, someone remarked:

One difference between Japan in World Wars One and Two, was that Japan had a coal powered navy in World War One, and had access to a good amount of coal domestically and in the Empire, including excellent steaming coal from the anthracite coal mines in Korea, and ITTL, the Shandong peninsula in German occupied China.

Is this true?

Was Japan's Navy still coal-fired/coal-fueled through WWI, 1914-1918?

When did Japan switch to oil fired engines for its warships?

What other navies were still coal-fueled in these years, and when did they switch, and reach an engineering point, where they couldn't go back to the old type of fueling?

Is there any way Japan, or any other country, could have deliberately avoided the transition from coal fuel naval ships to oil fueled ones, at least exclusively oil fueled ones, for a few decades? What would have been the technical engineering and navigational or tactical performance or financial cost trade-offs of doing so of deliberately staying old-fashioned about warship, merchant ship fueling?

 

[gral]

What other navies were still coal-fueled in these years, and when did they switch, and reach an engineering point, where they couldn't go back to the old type of fueling?

As I understand it, most navies were still using coal through WWI. Even the RN, who was leading the world in switching to oil, was largely coal-fed in these days - first oil-powered only battleships in the RN were the Queen Elizabeths; all previous dreadnought classes(and the following Revenge-class) used oil-sprayed coal. Destroyers from the... Acorn-class(IIRC) on(also the earlier Tribal-class) were oil-powered. Newer cruisers were oil-powered, older ones used coal. The German Navy was mostly coal-powered, with the exceptions being the newest destroyers(from the Grosse Torpedoboot 1913 type on, IIRC) and the few diesel-powered ships(of course, the U-Boats were all gasoline- or diesel-powered).

The transition to oil for most navies(military, not merchant) started in the later half of WWI and was mostly complete by the 1930s, as new construction replaced many older ships in the 1920s and the older units still in service were modernized in the 1920s and 1930s. You still had many coal-powered merchants around by 1939, but IIRC they weren't the majority of merchant hulls anymore.

Biggest trade-off in using coal is weight; coal is heavier and demands more space(which translates itself into more structural weight devoted for coal bunkers) than the equivalent energy in oil fuel. You won't be able to get coal-fired modern destroyers, cruisers and capital ships on the same tonnage as an oil-powered equivalent(and the Japanese already had the nasty habit of trying to put too much capability into a too-small hull). What the Japanese could have done is have their merchants, slower auxiliary ships and slower ASW escorts be coal-powered, as well as have their powerplants mostly be hydroelectrical and coal-fired(which they already mostly were, AIUI).