Just a quick look at the Easten End of Box Tunnel and the rail entrance to spring quarry. The entrance was used by Ammo Trains during WW2 and was a possible entry point to Burlington if evacuation was by train.
Eastern End of Box Railway Tunnel by BlackBunkers, on Flickr
Box Tunnel Branch Line by BlackBunkers, on Flickr
Inside the Branch Entrance by BlackBunkers, on Flickr