Here's a photo I took on April 13, 2013, ELEVEN YEARS AGO, of a High Iron Travel / Iowa Pacific excursion that ran on the Pan Am Southern route from Woburn, MA to Mechanicville, NY via the historic Hoosac Tunnel. This is a former Boston & Maine line and I boarded the train at the Anderson RTC station in Woburn, which is situated on MBTA's Lowell line. The photo here shows a run-by that was staged near the east portal of the Hoosac Tunnel, which is near the hamlet of Florida, MA. Here's a GOOGLE aerial photo that shows the bridge and surrounding area:

[maps.app.goo.gl]

The Hoosac Tunnel was an incredible engineering project for its time. Construction crews dug from the east and west portals, and there was also a center ventilation shaft that was dug from the top of the mountain. Construction crews worked outward from the middle of the tunnel, meeting the workers coming in from both ends. This was obviously before lasers and GPS and the measurements were just barely off. This same construction technique was also used on the Central Pacific's tunnel at Donner Summit.

A large portion of the tunnel is lined with brick, something us passengers noticed as we were sitting in the dome cars.

Here's a website that has a lot of information about the tunnel:

[en.wikipedia.org]

It would be interesting to know how many trains usually operate on this line in a twenty-four-hour period. I get the impression that traffic has decreased on the line since Norfolk Southern has worked out an arrangement with CSX where some of their trains can be routed over the Boston & Albany line.

Guilford / Pan Am Railways is another fallen flag, having been gobbled up by CSX. This was a sharp looking train, with F units and two Budd full length dome cars. A very memorable trip. I believe the F units are now part of the executive train and office car fleet of CSX.