When the four mile long Hoosac Tunnel was completed, it was the longest tunnel in the world.  The toll in time, money, and life was enormous, and traffic never did justify the expense- really Masachusett's 19th century version of the "Big Dig."  We'd never have found the west portal without the help of locals, and there is only a brief period during the summer when sun hits the portal for an hour or so.  Sometimes you get lucky, as we did when train EDMO (East Deerfield- Mohawk Yard) appeared with borrowed CP power in the lead.