>>1069974Depends how you define it because there is no straight answer.
Is it running loose or at full throttle?
If at full throttle...
Typical steam without on the road water troghs - not very far. You would problably be out of water within an hour or so.
Add water trough to replenish water without stopping and you are limited by coal capacity - so something about 5-6 hours non-stop.
Switch to oil burning and you are limited to fuel capacity and your capability to haul it.
However - most steam locos would be out of water very fast.
Diesels are a different beast. Current diesel locomotives can run at maximum throttle for hours - up to a full 24 hours. Add fuel tenders and you get even more range.
