Why high-pressure boilers would not refit the whole Royal Navy

Could Britain replace all naval boilers with high-pressure plants before the Second World War?

No. Fleet destroyers and larger fleet units could justify the change, while many older ships and slower escorts would not need the extra power.

A complete high-pressure-boiler refit before the Second World War is rejected as unnecessary as well as impractical. Fleet destroyers, cruisers, carriers, and capital ships are the types considered worth equipping with the new plants. Destroyers built in the late 1920s and early 1930s would not automatically be opened up for replacement machinery. V and W-class anti-submarine conversions, Flower-class corvettes, and probably Hunt-class escort destroyers would not need that level of power. C-class anti-aircraft cruiser conversions are another example where the intended employment would offer little benefit from the change.