Engine builders often did provide specific fuel consumption numbers, and sometimes the derived efficiency numbers. I don’t have any such data for EMD engines on hand, but the attached brochures from English Electric/Ruston are indicative as to how these numbers were presented. As may be seen, such numbers are referred to quite tightly controlled conditions, so how they translate into everyday service is difficult to say.
In making comparisons of locomotive and marine engines, it may be noted that the latter category covers a wide range of basic types. One relatively coarse approach to categorization has at the top end, power-wise, the very large low-speed two-stroke crosshead engines, burning heavy fuels, used to power the large ocean-going vessels, tankers, bulk carriers, “box boats: and so on. Then come the medium-speed heavy four-stroke trunk piston types, ranging in bore size from 200 to 600 mm or so, and also usually burning heavy fuels. Still in the medium-speed four stroke trunk piston class are the lighter-built engines, with bore sizes up to around 280 mm, often used as “fast ferry” powerplants, which usually burn distillate fuels, but are sometimes capable of burning heavy fuels. A separate category is usually referred to as “North American inland marine”, covering distillate-burning medium-speed engines, and which historically been dominated by the EMD 567/645/710 two-stroke trunk piston engines. High-speed engines in marine service are usually multipurpose designs and distillate fuel burners. Of the major marine engine builders, Wärtsilä is active in the low-speed two-stroke and medium-speed heavy four-stroke fields, whereas MAN, as well as these, also has a “fast ferry” range. That kind of engine would be closest to the locomotive type in general terms. In fact the MAN 28/33D (https://www.man-es.com/docs/default-sou ... 595f30f6_1
) was derived from the Ruston RK280, successor to the earlier RK engines. That category would include the North American locomotive engines when used in worldwide marine service, and also the Caterpillar C280/3600.
Wärtsilä claims that its recent 31 series (https://www.wartsila.com/marine/product ... artsila-31
), which falls into the heavy marine trunk piston category, is the most efficient four-stroke engine currently available.
An interesting aspect is the EMD 567/647/710 engine is a rare survivor in the two-stroke medium-speed trunk piston category. Until the late 1960s or thereabouts, the marine heavy medium-speed market was occupied by both two-stroke and four-stroke types, including some basic models that could be configured either way and swung from one to the other without overly major surgery. But in the 1970s, there was a decisive swing to the four-stroke type, and the two-strokes faded away. One of the last, to circa 1997, was the Wichmann.
You do not have the required permissions to view the files attached to this post.