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Sticking it here for lack of snug-fitting other thread. The legendary 5-mile long Hoosac Tunnel through the Berkshires on the Patriot Corridor / Fitchburg Main Line just reopened after a nearly 6-week closure due to bad ceiling collapse. The 1875-built tunnel slices through the water table in multiple places at the base of the Berkshires and has, throughout its history, been subject to lots of infrastructure issues from water seepage. This time a large length of brick ceiling liner gave way and left a long pile's worth of debris blocking the tunnel in its most serious collapse event in 48 years. Ceiling was repaired with shotcrete patch, much like the 1972 cave-in which is still holding firm. Additional work is continuing, but train service has resumed with Norfolk Southern running extras this week to fetch the huge number of intermodal empties that have piled up in Ayer, with regular service slowly ramping up. Crews had to work 24/7 in tight quarters to remove the blockage and do the repairs...a pretty mean feat with COVID raging (but the Hoosac falls under national defense- protected infrastructure, so it would always be prioritized).
During the outage Pan Am Southern (the 50/50 NS + Pan Am joint venture on the Corridor) has been running emergency detour trains over the Amtrak
Ethan Allen Express's normal route to Rutland (Canadian Pacific trackage in NY, Vermont Rail System trackage in VT), then Vermont Rail System's Green Mountain mainline Rutland-Bellows Falls and 'native' PAS territory Bellows Falls-Deerfield on the Conn River Line. Much slower and a lower-weight rated routing, but equivalent height clearances so they were able to move the normal loads of autoracks to the Ayer autoport.
The MassDOT tie-in is that PAS got grant money a few years ago to kick off design for increasing clearances in the Hoosac Tunnel (which has happened periodically, most recently about 20 years ago, by shaving down the trackbed) to run double-stacked intermodal cars to Ayer so Norfolk Southern gains more competitive parity into Worcester County with CSX. It's not known how the latest cave-in will affect timetables for that enhancement, which was supposed to be self-funded for the tunnel itself with MassDOT later pitching in on some bridge raisings to Ayer (far fewer here than it needed to do for CSX on the B&A). Since the Hoosac's water damage problems are pretty much ever-present and will always pop up in a new unforeseen place sooner or later it's thought that there's not much overall they can do except for "acceptable mitigation", so they probably won't significantly delay the clearance project to front-load any repairs. One of the mysteries is that since Pan Am is a 100% private company it's not known what--if anything--they have for self-insurance on Hoosac incidents. It is speculated that because of the tunnel's ultra long-term instabilities that Boston & Maine could never get fully insured for that trackage, so its successor Pan Am likely operates uninsured through there with the 50/50 PAS partnership simply covering Norfolk Southern's ass.
Anyway...ever since this story broke I was reminded of Alon Levy's NY/New England high-speed rail crayon map he drew a couple months ago and how much "MOAR TUNNEL!" it required to cleanroom a higher-speed corridor across the Berkshires than the existing B&A to hook us up to the Albany-hub juvenation machine. Tunneling justified on rough grounds that because the Euros can do it within-cost us stupid Americans have no excuse. Anyway...it 'was' prefaced as a no-warranties-offered crayon doodle map offered up for discussion so Levy gets some slack for not stanning too hard for that. But this is one reason why--in the absence of a consulting geologist--you just don't crayon-out mass tunnel-thons on a whim. Especially when it involves mainline rail outside of a well-understood city core. The Hoosac is bored straight through the absolute most solid base of the Berkshires...which is why you get a tunnel up there between North Adams-Florida but the B&A has to climb a 5-mile long 1.2% grade over Middlefield Hill further south where the mountains are stalling out into a porous glacial boulder field. But the Hoosac still suffers all the maladies common with base tunnels (at least all those boring through less-'pristinely' solid masses like the Alps or Continental Divide) in that "solid" rock is all-relative and crossing the water table--potentially multiple times--is a bitch carrying lifelong maintenance tax and self-insurance premiums on the structure. Try splitting the difference between the Fitchburg Main's way-north trajectory and the Pike's way-south trajectory to hit Pittsfield through the boulder field with "MOAR TUNNEL!" and the folly immediately becomes apparent given the Hoosac's century-level battles with the water table. Doubleplus so stupidity on NEC FUTURE's insane Shoreline Bypass crayon doodles through hilariously porous Connecticut trap rock. I mean...duh!...the stuff's ground into primary-source road gravel product for paving projects across the Northeast because it flakes off so goddamn easy. You're not burrowing under mass tracts of inland New London County when that geological swill is its primary makeup.