If torches do burn out after a set amount of time, we're going to need longer-lasting light sources, like maybe lanterns with oil. Oil could be derived from animal fat, plant seeds / plants, or even oil shale rock. I'd hate to be mining and placing torches as I go, only to find I can no longer see the exit path.
yes it be also cool to have a holding tank for that oil then run some small pipes to each torch from the tank this way we could run the laps for weeks you could also use the tank and oil as some sort of fuel storage to run other things like motors