Last night I was watching a Pentrex DVD called "The Rathole". Towards the end of the main feature, there were some run-by shots of NS Triple Crown RoadRailers passing through the (not so newer) Tunnel # 24 at Nemo. I am interested to know what the smaller vertical openings are for on either side of the main tunnel bore. These openings appear to run the entire length of the tunnel itself and are visible at both Portals. Are these side openings there for ROW maintenance purposes or were they intended to be part of some fumes extraction equipment? This seems unlikely given that the tunnel itself is not a long one so I am perplexed somewhat.
Cheers.
Cheers.