Kriegsloks (indeed war locomotives) were built on military orders, and based on military requirements which are different from civilian requirements.
The famous Br52, but also the 8F and the S160 have all similar underlying requirements:
- reduced size and weight to run on most (if not all) lines of Europe
- can be quickly converted to vacuum braking, driving on the right, ... The Br52 were designed to be quickly converted to Russian gauge and many served there.
- very simple design enabling army style maintenance by personnel with little knowledge and tools.
- standard design, easy to assemble, easy to ship. An amazing 7000 Br52s were built in 1942/1945 (its an average rate of 10 per day). The S160 were "only" 2200.
Of course, these locos were not meant for high performance or durability. The fact that so many survived very late is a complete surprise.
Jean-Patrick