F-Line, you mention getting the speed up to 80mph. Is that the limit for the foreseeable future? Why rebuild the track only to a 79(80)mph limit?
80 MPH is the max rating for Class 4 track, and then because of arcane signal rules the trains are regulated to exactly 1 MPH cushion below speed limit. Works like this:
Exempt: passenger prohibited, 10 MPH freight HAZMAT-prohibited. i.e. typical negligently-maintained Pan Am line like the Watertown Branch where you wonder how a train could stay on those tracks at all.
Class 1: 15 MPH passenger, 10 MPH freight. Foxboro game-day trains the only T service currently running this slow. Most tiny freight branches/stubs maintained to this.
Class 2: 30 MPH passenger, 25 MPH freight. None on T, but Foxboro specials could do this if CSX kept the Framingham Secondary maintained to rated speed. Most competently-maintained freight lines do this.
Class 3: 60 MPH passenger, 40 MPH freight. All current northside lines + dysfunctional Worcester + Fairmount because tight station spacing doesn't allow greater speeds + Greenbush because of curve/clearance compromises to the NIMBY's. Amtrak Lake Shore Limited to Albany on CSX main and Vermonter from Palmer to St. Albans on NECR main also. Typical of major freight mains like CSX's, NECR, and P&W's Worcester-Providence and Worcester-New London lines, as most freight operators consider 40 the sweet spot for mainline profit vs. maintenance costs.
Class 4: 80 MPH passenger, 60 MPH freight. Needham, Franklin, Kingston/Plymouth, Middleboro, Stoughton + Fitchburg after all the ongoing improvements are done. Amtrak Downeaster after the NH border + Springfield Line (current) + Vermonter from Springfield to White River Jct. after the ongoing improvements are done.
Class 5: 90 MPH passenger, 80 MPH freight. None here; some lines on on Metro North do this.
Class 6: 110 MPH passenger, 80 MPH freight. None here; Amtrak/SEPTA Keystone Line, much of Amtrak Empire Corridor do this; Springfield Line aiming for gradual upgrade to this by 2025 (i.e. by end of first decade of full commuter rail service).
Class 7: 125 MPH passenger, 80 MPH freight. Note the freight speeds stop increasing after Class 6; that's the absolute max allowable in the U.S. Most of NEC is Class 7; max speed for Regionals, Acela with tilting turned off. MARC's NEC line is the only commuter rail in the country that does 125, because they use same type of engines and coaches as the Regionals.
Class 8: 160 MPH passenger, 80 MPH freight. Top-speed portions of NEC (much of RI and MA). Lower limit of "true" HSR. Currently only Acela with tilting turned on capable of it.
Class 9: 200 MPH passenger. None in North America. California HSR will do this in portions. Not sure if freight allowed to co-mingle at all with 200 MPH trains.
FRA hasn't even defined Class 10 and up yet, but European and Asian HSR have operated at those speeds for years.
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Reasons why no CR trains operate that fast.
-- As mentioned, most freight mains are Class 3, and most commuter rails in the country (outside of East Coast where Amtrak & the states own most track) run on freight-owned track. The most the freight carriers are usually willing to upgrade to is Class 4. Past that it's counterproductive to them unless they sell the line to the gov't. Hence, the 80 MPH cap almost everywhere.
-- Commuter rail station spacing in a big megalopolis is usually too close together to achieve max track speed for very long, so ROI on track maint diminishes rapidly after Class 4. 80 MPH is the cost-effective sweet spot.
-- Diesels don't accelerate/brake quickly enough given above station spacing to hit max track speed. They don't even do it on most of the T's lines (really, could you ever picture a Needham train hitting 79 except on the long straightaway from W. Rox to Hersey?). Not cost-effective without electrics or EMU's like Metro North, SEPTA, and Long Island Railroad run. DMU's only help the between-stop acceleration...no current model has a beefy-enough engine to hit 90.
-- The T has really wimpy 3000 HP locomotives. The old F40 "screamers" on the northside in particular. Hilly lines like Fitchburg and rush-hour Worcester trains pulling 7 packed to gills bi-level cars suck because of slow acceleration/deceleration. The new loco order is 4600 HP with much improved starts/stops, more typical of other CR systems. But most of that improvement is zippier acceleration to
current track speed and hauling those long bi-level consists without wheezing, not speed boost.
-- As Urbie noted, most cars/cabs are only rated for 79. Takes better trucks (shocks, brakes, etc.) to go higher and better maintenance against flat wheels. Northside fleet they cap at 72 MPH to lower the maintenance on those Class 3 lines. So they have to step up the maintenance a notch to feed Fitchburg when it's finished and uprated to 79.
-- Signal systems. The shitty old wayside signals on the northside and Worcester out to Framingham aren't configured to allow >59 MPH. Either need cab signals like the southside or a modern wayside installation like Fitchburg's getting to do 79. And can't do more than that at all without cab signals. This is the biggest bottleneck on the Downeaster where it crawls until it hits Plaistow and the fresh signal system Amtrak installed in '01, and biggest bottleneck on the Lake Shore Limited which is one of Amtrak's most oft-delayed long-distance trains.
Basically, Providence is the one and only line capable of a speed boost. Run exclusively the new locos and new bi-levels being built, and it'll probably be doing 90 by 2014-15 when all the new vehicles and all the option orders in those contracts are exhausted. The rest of their work is just getting full Class 4 on the northside and Worcester. Which they have to do by the 2015 Positive Train Control federal deadline because the Amtrak ACSES system the T's adopted doesn't work without cab signals (rumblings from actual railroad employees on RR.net are that NO extensions will get granted by the feds because every other northeastern CR agency except the T is on-schedule for the deadline...meaning heavy fines and some sort of compliance 'probation' are possible).
But no question Worcester is 'the' one where the current trip gets orders of magnitude better with a speed bump. Add the dispatching getting unclogged and more powerful equipment coming in a couple years for those long consists and the current trip will be a completely different and far less frustrating experience. But South Station expansion is the ONLY thing that's truly going to revolutionize it, so all this other foot-in-mouth talk by Murray et al. is ridiculously premature until they
take care of business on the existing infrastructure, the terminal, and these FRA deadlines striking midnight on the signal system.
It's not that they SHOULDN'T talk about these things, because following through and uncorking the capacity constraints flushes so many new CR riders and so much more Amtrak into the mix--at very high ROI--that the service expansion becomes inevitable. And fundable when the existing-line ROI begets concrete expansion ROI for multiple stakeholders. If done in the right places at the right time like Lowell-NH, the North Shore Transit Improvements on the Eastern Route, and Worcester-on-steroids where 79 MPH and frequent, delay-free trips crest demand for more infill stations, upgraded stations, short-turns and DMU's, and fleshing out the network with judicious Nashua, Peabody, WOR-NS expansion.
But do it very deliberately with years of low-level data collection, community involvement, and ways of breaking it into manageable chunks like RIDOT's one-station-at-a-time buildout for in-state CR or milking the one-appropriation-at-a-time Haverhill/Downeaster improvements. It doesn't matter when they're still behind on a maintenance backlog, generally fucked on a unmoving 2015 signal system deadline, have lots of substandard non-ADA stations to bump, and an overclogged terminal that Amtrak will be very very angry if doesn't get expanded on schedule. But they WILL want to be ready to ride that demand wave when the backlog (including the ones they can't delay) gets caught up. So plan in proper proportion for the long-term.
Same exact problem with everything. They won't engage brain on "unsexy" improvements no matter how vitally needed, critical, or law-required they are. Only the South Coast FAIL panders and press conferences in Cambridge where the Lt. Gov. says an earful of crazy things without telling the confused locals. Growth is a process, not instant gratification. You want to grow...give Worcester a sane speed-limit commute first and you'll have all the growth you can handle and every means to capitalize on it.