F-Line to Dudley
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Re: Fairmont Line Upgrade
It'll be overhead. 60 Hz/25 kV AC like the NEC to New Haven, all non-NEC NJ Transit lines, AMT in Montreal, and the planned GO and Caltrain electrification. That is the worldwide standard for modern installs with the most widespread equipment availability (including transmission infrastructure). All Euro rolling stock built for 50 Hz/25 kV on that continent runs unmodified here. Of course, Congress and Amtrak didn't follow its own advice and abandoned plans their plans to change the whole NEC over to that. But the T would be able to order much cheaper and lighter single-voltage vehicles that don't have extra transformers for changing voltage on the fly. Nothing they run is ever going to cross the New Haven voltage break.
Third rail is DC power vs. AC for overhead requires extremely different transmission infrastructure. DC needs very frequent substations...advantageous for a compact subway system which is why nearly all metro systems (including Green + Blue overhead) are DC. It's much poorer for a suburban commuter rail. LIRR does it because they only have 1 connection (Penn) to the national network, so its original experimental electrification scheme matured in isolation. Metro North only does it because they have no choice: it's physically impossible to retrofit the Grand Central tunnels for overhead clearance. They're permanently consigned to being special like that.
Electrification also requires a threshold of train frequencies to really pay off on ops when there's not an unventilated tunnel (i.e. N-S Link) in play forcing its use. The only lines that are slam-dunk for that kind of investment in the near future are Worcester and Fairmount. Fairmount for obvious reasons of frequency, short length, and pre-existing wires at each end. Worcester for dense overlapping service patterns.
But there's very little else on the system that meets the frequency threshold because of branchlines forking out before 128 (Old Colony and Eastern Route) and branch schedules too diffuse for it. Dual-mode push-pulls also don't make a lot of sense on the mainlines with branches unless the tunnel forces that hand by necessity. An ALP-45DP guzzles a lot more fuel in diesel mode than any regular diesel loco because the only way to fit two modes in one carbody is by using a physically small engine that spins way faster to output the same power. It's the train equivalent of a Ferrari engine. They would never make back the cost of their higher fuel consumption on only 10 miles of Old Colony main wire to Braintree and 10 miles of Eastern Route main wire to Salem/Beverly. Whereas an Amtrak Inland probably would save money on a dual-mode using 30 extra miles of wire from Worcester, future 60 extra miles when the Springfield Line gets wired, and no need any longer to tie up 2 locos for the New Haven power switch.
Other places it's simply impossible because of freight. You need 25 ft. wire clearance to clear a double-stack freight car without danger of an electric arc. That's the default height for all wires out in the open which is why small parts of the Keystone and NEC do handle double stack freight under the wires. But it gets hideously expensive when you've got many bridges to raise, and nearly impossible with tunnel bores. Worcester-Westborough would be easy because there's only 5 overhead structures already cleared to 20'2", and it's an ex- 3 track line so if finding up to 4'10" extra is a problem the freight can flow just fine if there was a 3rd unpowered track. But Fitchburg west of Willows Jct., Haverhill/Downeaster north of Wilmington Jct., and the B&A west of Worcester are nearly impossible with sheer quantity of bridges.
For Haverhill you've got the same dual-modes fuel efficiency issue after the first 10 miles. For Fitchburg the frequencies past 128 just aren't high enough (and even if you did wire to 128 for an EMU shuttle nothing thru-running would touch those wires). For Needham the frequencies are too constrained and it's better off going rapid transit. For Reading you've got duplicate Orange Line DC electrification for half the distance that makes little economic sense to duplicate with all-new AC (see also Haverhill thru-running and dual-mode efficiency). For Franklin you've got no intercity anchors and possible frequency diffusion with future branching at/past Walpole. Stoughton's logical if it stays a stub, but South Coast FAIL has pathetic branch frequencies and the NEC imposing a Taunton capacity cap that's probably not quite at the payoff threshold. Taunton and Franklin are dual-modes candidates since they'd fork much further out, but are 2 lines or relatively mundane strategic importance enough to float that expensive a purchase? That's scale as lousy as buying expensive-ass DMU's for just one line.
That leaves...Lowell/Nashua. EMU's to Nashua, maybe some NHDOT-owned dual-modes exclusively for Concord with eventual full wiring. Would most definitely hit paydirt on frequency, ease/speed, and bringing Lowell very close indeed to Boston. But does that really work as the only northside outpost feasible until the Link gets built? Do we really want to electrify every North Station platform, the whole Boston Engine Terminal complex, and the Grand Junction so the vehicles can physically get there for one line? I don't think that's going to float itself until northside and southside get a real thru interconnection.
RE: Worcester...Beacon St. is the worst of the inside-128 bridges. That has to get raised, although it's in bad structural shape so replacement's probably < dozen years away. The ones west of Beacon Park to Framingham are clear for single freight cars a little taller than a commuter rail bi-level, and would only need safe wire clearance over a bi-level since the freight's all gone. You're talking inches, so undercutting the trackbed works in nearly every spot. Framingham to the 495 overpass at Westborough yard is probably OK since they used to run autoracks there (a bit than bi-levels) and the largest freight run out of Framingham today goes under NEC wires between Mansfield and Attleboro. I'm going to guess if there's any tight squeezes it's a game of inches and inexpensive trackbed shaving.
It'll be overhead. 60 Hz/25 kV AC like the NEC to New Haven, all non-NEC NJ Transit lines, AMT in Montreal, and the planned GO and Caltrain electrification. That is the worldwide standard for modern installs with the most widespread equipment availability (including transmission infrastructure). All Euro rolling stock built for 50 Hz/25 kV on that continent runs unmodified here. Of course, Congress and Amtrak didn't follow its own advice and abandoned plans their plans to change the whole NEC over to that. But the T would be able to order much cheaper and lighter single-voltage vehicles that don't have extra transformers for changing voltage on the fly. Nothing they run is ever going to cross the New Haven voltage break.
Third rail is DC power vs. AC for overhead requires extremely different transmission infrastructure. DC needs very frequent substations...advantageous for a compact subway system which is why nearly all metro systems (including Green + Blue overhead) are DC. It's much poorer for a suburban commuter rail. LIRR does it because they only have 1 connection (Penn) to the national network, so its original experimental electrification scheme matured in isolation. Metro North only does it because they have no choice: it's physically impossible to retrofit the Grand Central tunnels for overhead clearance. They're permanently consigned to being special like that.
Electrification also requires a threshold of train frequencies to really pay off on ops when there's not an unventilated tunnel (i.e. N-S Link) in play forcing its use. The only lines that are slam-dunk for that kind of investment in the near future are Worcester and Fairmount. Fairmount for obvious reasons of frequency, short length, and pre-existing wires at each end. Worcester for dense overlapping service patterns.
But there's very little else on the system that meets the frequency threshold because of branchlines forking out before 128 (Old Colony and Eastern Route) and branch schedules too diffuse for it. Dual-mode push-pulls also don't make a lot of sense on the mainlines with branches unless the tunnel forces that hand by necessity. An ALP-45DP guzzles a lot more fuel in diesel mode than any regular diesel loco because the only way to fit two modes in one carbody is by using a physically small engine that spins way faster to output the same power. It's the train equivalent of a Ferrari engine. They would never make back the cost of their higher fuel consumption on only 10 miles of Old Colony main wire to Braintree and 10 miles of Eastern Route main wire to Salem/Beverly. Whereas an Amtrak Inland probably would save money on a dual-mode using 30 extra miles of wire from Worcester, future 60 extra miles when the Springfield Line gets wired, and no need any longer to tie up 2 locos for the New Haven power switch.
Other places it's simply impossible because of freight. You need 25 ft. wire clearance to clear a double-stack freight car without danger of an electric arc. That's the default height for all wires out in the open which is why small parts of the Keystone and NEC do handle double stack freight under the wires. But it gets hideously expensive when you've got many bridges to raise, and nearly impossible with tunnel bores. Worcester-Westborough would be easy because there's only 5 overhead structures already cleared to 20'2", and it's an ex- 3 track line so if finding up to 4'10" extra is a problem the freight can flow just fine if there was a 3rd unpowered track. But Fitchburg west of Willows Jct., Haverhill/Downeaster north of Wilmington Jct., and the B&A west of Worcester are nearly impossible with sheer quantity of bridges.
For Haverhill you've got the same dual-modes fuel efficiency issue after the first 10 miles. For Fitchburg the frequencies past 128 just aren't high enough (and even if you did wire to 128 for an EMU shuttle nothing thru-running would touch those wires). For Needham the frequencies are too constrained and it's better off going rapid transit. For Reading you've got duplicate Orange Line DC electrification for half the distance that makes little economic sense to duplicate with all-new AC (see also Haverhill thru-running and dual-mode efficiency). For Franklin you've got no intercity anchors and possible frequency diffusion with future branching at/past Walpole. Stoughton's logical if it stays a stub, but South Coast FAIL has pathetic branch frequencies and the NEC imposing a Taunton capacity cap that's probably not quite at the payoff threshold. Taunton and Franklin are dual-modes candidates since they'd fork much further out, but are 2 lines or relatively mundane strategic importance enough to float that expensive a purchase? That's scale as lousy as buying expensive-ass DMU's for just one line.
That leaves...Lowell/Nashua. EMU's to Nashua, maybe some NHDOT-owned dual-modes exclusively for Concord with eventual full wiring. Would most definitely hit paydirt on frequency, ease/speed, and bringing Lowell very close indeed to Boston. But does that really work as the only northside outpost feasible until the Link gets built? Do we really want to electrify every North Station platform, the whole Boston Engine Terminal complex, and the Grand Junction so the vehicles can physically get there for one line? I don't think that's going to float itself until northside and southside get a real thru interconnection.
RE: Worcester...Beacon St. is the worst of the inside-128 bridges. That has to get raised, although it's in bad structural shape so replacement's probably < dozen years away. The ones west of Beacon Park to Framingham are clear for single freight cars a little taller than a commuter rail bi-level, and would only need safe wire clearance over a bi-level since the freight's all gone. You're talking inches, so undercutting the trackbed works in nearly every spot. Framingham to the 495 overpass at Westborough yard is probably OK since they used to run autoracks there (a bit than bi-levels) and the largest freight run out of Framingham today goes under NEC wires between Mansfield and Attleboro. I'm going to guess if there's any tight squeezes it's a game of inches and inexpensive trackbed shaving.
