Why would you expect me to stop discussing the challenges with electrifying Worcester-Springfield? There's a lot of things to be taken into consideration when it comes to electrification, especially with regard to vertical clearance issues and the complexity and/or expenses of resolving said potential issues. Also I wouldn't be so dismissive of F-Line's input on the topic of electrification between Worcester and Springfield. He is clearly pretty knowledgeable when it comes to things like this, and he brings up some good points about the challenges associated with potential electrification between Worcester and Springfield.
Multiple of the alternatives considered included service west of Springfield to Pittsfield. Regardless of if it was part of the initial build or not, future East-West rail service to Pittsfield would be anticipated nonetheless and is worthy of consideration with regard to electrification. In the East-West rail study final report, MassDOT seems to assert that electrification between Springfield and Pittsfield would be infeasible due to CSX:
(Source, page #40)
Hello, world.
Don't take my word for it. The American Railway Engineering and Maintenance of Way Association (AREMA) body sets the standards everyone must abide by for railway electrification. Hyper-technical copy of their latest specs is
here (draft of the latest revision...final version is paywalled). The denser it gets the more you need an electrical engineering background to grok it all, but they have a few helpful tables. The AREMA standards are further codified into Amtrak's NEC 25 kV specs from the late-90's NHV-BOS electrification, which were then copypasta'd by Denver RTD, Caltrain, CAHSR, and GO Transit for their modern 25 kV electrifications/studies and namechecked by the T for the Rail Vision. Per the chart on p. 23 of the linky you need
31.5 inches of
total underclearance at overhead structures (i.e. between the structure and the unshielded car roof, with the energized catenary in the middle). Certain hyper-technical operating conditions--speed vs. suspension, curvature vs. suspension, track superelevation, altitude, relative air pollution, position of certain OCS components like resistors--can wobble the total by up to a few inches in either direction, but it's generally accepted that it's a fail-safe blanket +2½ feet over the tallest car roof that currently trawls the 25 kV line in question.
Don't go by the 22 inch. (11" x 2) quote that TransitMatters gave from unnamed "German railroad law" in its recent
Modernizing The Haverhill Line report. AREMA is the law of the land so it's regulatorily irrelevant what somebody in another country did that one time, and based on what's human-parseable from AREMA's tolerances that quote seems to be egregiously cherry-picked from very niche and speed-restricted operating conditions. You might have a game of a few inches to play with here in certain specific layout situations, but no way you're lopping off a half-foot or more from the AREMA defaults.
Double-stack railcars are 20'2" inches tall in absolute height, and double-stack lines are cleared with a 4" cushion (hedge against ice buildup and/or overzealous suspensions at speed) to a minimum of 20'6" clearance. So any electrification on the B&A west of the I-90 overpass @ Westborough Yard has to have between 22'8" and 23' of underclearance at the track centerline of any one electrified track (all tracks usually being at the same level unless it's mid-curve and one of them happens to be superelevated while passing under the structure).
There are only 6 total DS-cleared overhead structures between Westborough and Worcester Union in MBTA territory, but another 35 of them between Worcester Union and Springfield Union. Then at least a few dozen more west of Springfield to Schodack, NY where freights split from Amtrak. All are currently cleared for 20'6" over track centerline (all running tracks) and will need to be cleared for up to 23' (whichever applicable track). The 20'6" mods happened between 2008-2012 and involved some share of bridge raisings that got MassDOT pay-in, a larger share of trackbed undercuttings that were nearly all CSX-paid, and a minority share of bridges that were OK as-is. MBTA territory had only a couple of touches 15 years ago, and at least 2-3 of the current structures Westborough-Worcester are verifiably supertall enough to not likely to need any mods this time around; the T should be able to electrify commuter rail here *almost* scot-free. It's a whole other matter on the 35 WOR-SPG structures, many of which were maxed out of cheaper trackbed undercuts the last time around. The state already knows the exact answer to how many structures would need structural mods and what degree of modding...even though it hasn't published those tallies in any of the E-W or NNEIRI docs...because it was fully privvy to all engineering that went on 15 years ago for the collaborative CSX project. Them already knowing that exact answer informs a lot of their stated reluctance to electrify on the non-cleanroom ROW Alts. being studied. It's only a matter of
when they choose to show the math there; then they will be able to put hard numbers to the poorish investment amortization afforded by running the proposed service levels at the proposed ultra-wide stop spacing under electrification.
The B&A outside of commuter territory has been single-tracked since the early-80's when Conrail redid the whole physical plant and lifted a majority of the second track. In some places the empty berth is blank and to the side; in most others the whole trackbed was re-centered...often for the sole sake of maximizing clearances for the single track under the highest/centermost parts of spans. A considerable amount of the re-DT'ing work here is going to involve re-spacing the current tracks, which is going to change the centerline clearances at some bridges and induce more incidental modding work. Incidental work even with
no electrification, because the current stacks-cleared track may not be resting in the same position under the same clearance as before after the second track comes back. It's highly unlikely that CSX would ever agree to total binding single-track ops anyway because track work and flipping track assignments due to scheduling snafus is a mundane thing that happens on any reasonably-trafficked multi-track line, and "any running track" running is extremely likely to be codified into any future sale/rights agreement since that matches current ops conditions in all DS+DT territory. See the big D.C-Richmond ROW sale that CSX made to State of Virginia a year-plus ago (on a mostly 3+ track-to-be corridor) that partitions the ownership and dispatching down the middle with considerable complexity; the fine print of that deal
absolutely gives CSX the right to run on passenger track when they must, regardless of how neatly traffic ends up segregated by-track during
normal dispatching conditions. "@#$% happens" fail-safes will be baked in. Any B&A cross-agreements are going to borrow heavily from that Virginia template, albeit in much simplified form for a 2 (not 3+) -track RR. Even if by some miracle they signed off on hard split-the-difference running on only 1 DS-cleared un-electrified track ever, it is nonetheless still
not a bankable assumption that the state can shirk considerable quantities of bridge mods. Because lots and lots of track is going to shift position when the tracks are re-centered. Again...they already have the internal math in-hand to answer the cost savings or relative lackthereof for this particular scenario if it needs to be spelled out to its absolute public ends.
Note that for self-exploration purposes you can't easily rely on
Nat'l Bridge Inventory web search for precise clearance measurements at each bridge because the NBI measurements don't take into account track centerline (just an arbitrary spot on the ground). Plus, on the B&A corridor some of their datasets are just flat-out old predating the '08-12 clearance project. So unfortunately individual deep-dives aren't going to answer the thorniest price-tag questions except in a couple edge cases you can check off due to NBI showing literal
feet's worth of slack overclearance. The search is unfortunately not that good for parsing the games-of-inches cases, which majority of these will end up being. You'd need access to the not-public RR official measurements.
