Franz Stangl wrote,
"I know that in the beginning (in Treblinka) they used rails from the trolley to build the cremation grill. But it turned out that these were too weak and bent in the heat. They were replaced with real reailroad rails."
Belzec, Sobibor, Treblinka: The Operation Reinhard Camps
Indiana University Press
My question is this: is this another plant in a confession? What are German WWII rails made of? Would they hold up in bonfire-like heat if weight was on them? Conversely, would trolley (lighter) rails bend?