We railroaders call those recesses in the tunnels “coffins”. At speeds of 50 mph on that track and a curve on each end of the tunnel, you have only seconds to get out of the tunnel or duck into a coffin.
Those are limestone mines that were used to provide limestone to railroads. They are known to be haunted . A man died in there in a mine collapse and there was a murder gone wrong. That place has alot of history. Good video
P.S. If it is northern kentucky is known as the Rat Hole above is southern Ohio . The rat hole is tunnels is where trains traveled through in that area, some of the lines are already abandoned. have good one and god bless ! If youre in another location please inform me thanks!