I thought perhaps some of these informative postings would be of interest to steam vs diesel power enthusiast.

https://groups.io/g/RepowerAndRegear/message/26306

https://groups.io/g/RepowerAndRegear/message/26316

https://groups.io/g/RepowerAndRegear/message/26319
A small-scale steam plant will never equal the efficiency of a Diesel … the thermodynamics prevent it. This was well known before “Jawn” was ever thought of. Really large steam plants (generating stations & ships) can actually beat the Diesel, but they have advantages a vehicle-sized unit just cannot have. Very high temperatures and pressures are needed. One thing lacking in locomotive steam plants is effective condensing of the used steam. This increases efficiency by reducing the pressure (actually a vaccum) at the exhaust. It also greatly decreases water-treatment needs. Unfortunately this requires either water-cooling or massive air-coolers (cooling towers) for the condensers. Neither is practical in a locomotive sized plant, especially one subject to twisting and high vibration.
Only a few steam locos ever tried condensing (UP’s GE #1 & #2 turbines, and a class of S.A. 4-8-4s), and it never worked well. Only about 30% or so of the steam could be recycled. From an efficiency standpoint this wasn’t worth the greatly added complexity and maintenance. It did work in South Africa for a totally different reason … they had to cross a great desert where water was very scarce, and even a slight increase in range was important.
Dan Mitchell

https://groups.io/g/RepowerAndRegear/message/26323

https://groups.io/g/RepowerAndRegear/message/26325

https://groups.io/g/RepowerAndRegear/message/26326

https://groups.io/g/RepowerAndRegear/message/26332
The increase in range was quite important on a series of German 2-10-0 with condensing tenders (on which the SAR engines were based), class BR52Kon(d), built during WW2. ........