I think we're all fairly aware that the internal environment of early tanks was really nasty. Hot, high carbon monoxide concentrations, etc.
It struck me there may have been another factor to make the tanker's life even more miserable. The Daimler-Knight engines were noted for high
oil consumption and added oil vapour to the noisome interior of tanks. I've read that oils for WW1 aero engines were basically castor oil which was sprayed around
from total loss oil systems and this had a dramatic effect on the bowels of the unfortunate pilots. Did the oil used in tank engines contain castor oil - anyone know?