Re: War machines that can be refuelled from the dead..
We will need dead horses for that.
In june 1941 the Nazis invaded the Soviet Union with over 600000 horses. Most of them died.
An unknown number of horses died during the battle of the Somme in 1916 with over 1 (one) million human casualties. And at least the German rations contained plenty of horse meat. Peter Hart, The Somme.