How turbines and diesels displaced expansion engines

How did vertical triple-expansion engines compare with turbines between 1920 and 1950?

Turbines were better for high speed by 1920, while diesels increasingly became the preferred efficient cruising machinery and had largely overtaken expansion engines by 1950.

Fuel availability and operating region affected whether a ship adopted diesel or retained steam machinery through the interwar years. By 1950 diesels had largely won the economical cruising contest, although coal and fuel-oil access still shaped practical choices on global routes. Turbines had already secured the high-speed role by 1920, leaving multiple-expansion engines to compete on economical long-range operation. Mixed-firing boilers remained attractive for routes where diesel supply was uncertain because ships could bunker whichever fuel local ports reliably offered.