The EGE wrote:It's worth noting as well that DMUs only have any advantage at all over push-pulls on closely packed stops. On the southside that's only Fairmount (maybe to 128 or Dedham or Dedham Corp Center) and Worcester (Needham should be rapid transit by the time DMUs are systemwide); all four northside lines inside 128 are good candidates if you throw in infills*. That's, at most, six route stretching no further than 128 park-and-rides.
Over average stop spacing longer than say two to four miles, loco-hauled is vastly more efficient per seat mile. One big powerplant versus many smaller ones. And you only have to maintain that powerplant.
*Weston/128, Clematis Brook, Alewife, Union Square on the Fitchburg; Montvale Ave (Woburn) and GLX transfer (probably Lowell Street) on the Lowell; Revere and South Salem on the Eastern Route
And the acceleration difference really is overrated. I think perception is greater than reality because of how long we've had to put up with those gimp F40's straining to pull consists way longer, way taller/heavier, and way more packed full with human flesh than they were originally purchased to haul. The difference in acceleration between an HSP-46 pulling anything vs. an F40/Geep pulling that same anything is greater than the difference between an overpowered HSP-46 pulling a minimum-length Fairmount consist vs. a Fairmount DMU. The DMU's savings pulling out from a stop all fall within the range of standard-issue schedule padding for variable dwell times. Have a person in a wheelchair on the platform need assistance getting on that one time, or hold the doors open for that last person sprinting up the ramp to get on that one time...that's about equivalent to the time difference you're talking in acceleration savings. That difference lives wholly inside the built-in schedule margin for error. It's a total non-factor in whether or not to purchase DMU's. It really is only that optimized interior and door layout once you hit service levels where the generic coaches start showing their limitations. If it were only about horses and stops/starts on a dime, a long-term commitment to a fleet of 4600 HP
minimum push-pull power and smarter selection of consist lengths (maybe lifting the sub- 4-car restriction at long last) accomplishes same schedule performance within the default margin for error and 100% of the headways. That's why 'real' Indigo service levels meriting a dedicated fleet are such a narrow target the T has to prove they can execute 100% before we entrust them with play money for vehicles.
EMU's...yeah, they're different. The acceleration difference above-and-beyond all else does save time on short runs, as well as on those 8-car Providence behemoths when the self-propelled trainset can rev up to 90 MPH from a dead stop worlds faster than anything else.
Bramdeisroberts wrote:Wouldn't a far simpler reason why DMU's haven't been implemented in the post-RDC world be because most of the top-tier commuter agencies with the ridership to justify the higher frequencies that DMU's allow all inherited ex-NYC/PRR electrification infrastructure, making EMU's the no-brainer option? That's certainly the case with the MNCR/LIRR/NJT/SEPTA, and the same goes for the Illinois/Northern Indiana lines.
No. Because there's some plenty high-frequency push-pull routes out there on NJT, Metra, and GO. Especially in places where an inner zone has one mainline serving multiple branches where your de facto diesel-belcher frequencies in the equivalent "inside-128" space
are a no-fooling 15 minutes. Electrification--beyond the earliest short-lived experiments--never stretched a whole lot beyond where it currently goes. And between the Harlem Line's 1984 White Plains-Southeast extension, the New Haven-Boston electrification, and some minor post-1980's NJT infill the electric network has gained more route miles than it lost from whatever old PRR electric branchlines fell by the wayside between the Depression and the RR bankruptcies.
Check the all-time RDC roster:
http://en.wikipedia.org/wiki/Budd_Rail_ ... nal_owners" onclick="window.open(this.href);return false;. They were primarily a Northeastern phenomenon other than a fairly significant Canadian, Brazilian, and Cuban (!) investment in them. And Canada mainly ran them in long-distance service because of the number of very remote regions that had gov't-mandated service, so CN's and CP's usage profile for DMU's was quite different (though they did see commuter service in present-day GO and AMT territory). 35% of all the RDC's that were ever built were on the B&M roster; they were 'the' major outlier railroad at going whole-hog with them for near-100% of the fleet. What Boston had from the 50's into the T-logoed late-70's was
very atypical of commuter ops everywhere else. No one else went so heavily to DMU's for such a long time. Other than here, they saw heaviest usage clustered around the Mid-Atlantic...NYC to DC on roads like NYNH&H, NY Central, and B&O. A lot of co-mingling with electric territory. They were very sparsely deployed anywhere else.
Pretty much everywhere but this region: steam gave way directly to diesel push-pull and self-propelled units were never part of the equation.
What's left in North America that honestly has similar per-mile ridership #'s to the T? There's Caltrain, which can and does fill its all-bilevel sets to crush capacity to the point that they're now electrifying. There's AMT, which electrified. Then there's the diesel METRA lines and GO transit, which both are closer in terms of ridership to Caltrain than they are to the T and have much more pressing platform constraints that severely limit service frequency and force them to increase capacity instead of frequency to add service.
85% of the daily commuter rail riders in North America ride LIRR (#1), NJT (#2), MNRR (#3), Metra (#4), GO (#5), SEPTA (#6), and the T (#7). Yes, Metra and GO (which, yes, is on a frequency-increase binge in addition to planning electrification) both blow the T out of the water on total riders; Metra has double the daily riders, GO with over 1.5 times as many. Ridership-per-mile is a flawed metric when some systems (Metra) cover way more total miles because Greater Chicago is way more spread out than Greater Boston, and some systems (Caltrain) pack all their service patterns onto 1 line instead of 13. Extend the list out to the full Top 10 (#8 Ferrocarril Suburbano, #9 AMT, #10 Caltrain) and you're at over 92% of total North American ridership. Throw in Metrolink (#11) and MARC (#12) to include every agency that does 30,000+ daily riders (it's a cavernous drop-off after MARC to 15K or less) and you're over 96%.
That's every EMU-running railroad on the continent except the South Shore Line (whose ridership really could be lumped in with Metra Electric's), and not a single DMU in sight. The first DMU user on the list, now that Tri-Rail has sold off its Colorado Railcar lemons and gone all push-pull, is TRE at #19 (8000 daily riders).
OK? DMU's serve a very tiny fraction of bottom 2% of ridership on the continent. That is the very definition of niche specialty service. It backs exactly up the big boys' fleet management plans and supporting data: only invest in specialty vehicles when the service is guaranteed to hit its target mark with the specialty vehicles and
won't hit that mark running "every-vehicles". Fleet standardization with "every-vehicles" in all other situations where common equipment scale trumps all else on value. DMU's are not a vehicular revolution about to be uncapped and sweep across the continent if only someone were outside-the-box thinking enough. It's been number-crunched to death, and those fleet plans philosophically universal to the top carriers are a correct assessment of cost/benefits. Counterarguments need to show their math against such a mountain of evidence. There
are real specialty services out there to be tapped, and Indigo is definitely one of them if the T hits every mark in the service implentation plan. But it is absolutely false that wholesale turnover is going to come to the 98% of the continent's ridership who take an "every-vehicle" for their commuter train. That trending doesn't exist to the degree some people assume it does.
I think that the DMU in the US was a real victim of bad luck and unfortunate circumstances. The RDC was a great, if flawed product, and the SPV-2000 was a turkey at the worst possible time, where all the railroads that had the need for and could afford MU's were all under wires, and the roads that could have used them (like the T) simply didn't have the funding to take a gamble on a new product with any chance that it'd be a lemon.
Once Budd went belly-up, they took with them all of that experience building FRA-compliant DMU's and thanks to those regulations, it only made sense for the Bombardier/Adtranz/Alstom/Kawasakis of the world to do that R&D legwork if there was a big enough order to justify it. Since the commuter railroads with the money were all running under wires or over third rails, or in the GO Transit/Caltrain situation, there never was that big buyer that could snag one of the big manufacturers for a proper DMU build, and the smaller startup commuter railroads just didn't have the money/numbers to afford new push-pull equipment let alone clean-sheet DMU's from someone like BBD or Siemens.
The numbers do not support this. See above. RDC dominance was a uniquely Northeastern thing and ESPECIALLY a Boston/B&M thing. We were the outlier, not the trend-setter. There's no historical precedent for what you're suggesting could've happened had history broken differently.
Meanwhile the MBTA/CR is a bit of an odd duck because while there certainly has been a need for MU-like service frequency in places like Fairmount, Chelsea/Lynn, and Waltham, we never had electrified service there like they do in NYC, Philly, or DC. Electrification a la AMT or Caltrain is the obvious answer, but there's never been the political will to spend the money on increased frequency, much less on any new hardware or infrastructure to serve our fairly unique needs. And so, to me, it's no surprise that with all of that in mind, we have yet to see DMU's properly implemented anywhere, much less in our backyard.
Yes. But I outlined why that was the case. It takes hitting a specific service niche to make them pay off. Otherwise there's no compelling reason to deviate from the scale of a universal "every-vehicle" fleet. The T has that opportunity with the Indigo network clustered around very common usage on all the candidate inside-128 lines.
Other railroads can't find enough commonality. You'd be hard-pressed to match up enough equal-characteristic LIRR, MNRR, or NJT diesel routes that would support that kind of vehicle order. The ones in innermost-shuttle territory would need a more Fairmount-like seat/door configuration, the ones in outermost-shuttle territory (like LIRR/MNRR transfers into electric territory) wouldn't work so well in that same configuration with longer stop spacing, longer sitting, more luggage storage needs, etc. So they either buy two different interior configurations of DMU and lose too much vehicle scale, hedge on one configuration that's going to be good for one user but kinda stinky for another...or, just keep using the every-vehicles because they can't economically split the difference with specialty cars.
And other-other railroads that do have that commonality tend to be clustered in that 2% at the bottom where they're starting real small.
I'm sorry...all of this stuff has been thought of long before. A commuter railroad of any heft is going to butter its bread with every-vehicles...be they push-pull or EMU's, but probably similarly configured bi-levels of either type if they're not in a one-of-a-kind clearance or AC/DC power situation like the MTA with the M# cars. And specialty purchases are going to break along the consistent guidelines in these fleet-management plans: buy niche vehicles only when the niche vehicles hit paydirt that the every-vehicles can't. If every large commuter railroad and Amtrak are staking their futures to this philosophy and being very careful about that paydirt part viz-a-viz specialty rolling stock, counter-examples kind of need to prove their numbers.
The good news is a fully-realized Indigo service plan proves those numbers. We are one of the only installations in the country where the stars align enough to carve out a significant-scale DMU network with the same specialty configuration serving that many potential routes. That's luck of geography more than trend-setting. What they have not--at all, at the most basic level--proved is that they have the means to implement that fully-realized service plan. And if they don't, taking the plunge is financial and operational suicide. It doesn't have to be that way. They can substantiate a lot more detail about HOW the service plan is going to be realized...at those clock-facing frequencies...with that necessary fare flexibility. And then start walking the talk with push-pulls. And then...and only then...buying the specialty DMU's when the service plan has some present-day reality to it and is not such a risky proposition of will-they/won't-they commit on the ops side. That is the only way they're going to avoid shooting themselves in the exact way those big RRs' fleet strategies warn against shooting yourself.
As I said a few posts up, it is gonna take a few years to build up the ridership to the point where this new mode is attracting short-trip riders at the Talbot Ave.'s of the world. The crowds aren't going to be there at critical mass for 3-5 years if they started a 15-minute Fairmount schedule with Charlie fixins' tomorrow morning. There is no reason in the world why they have to wait until new vehicles are on the property to get started. Make the decision in 2020 when service is established enough that the optimized interior DOES offer up a real extra gear for escalating ridership. That moment is not going to happen in the 2010's decade even if they start delivering on long-deferred promises. Get the bloody schedule running like it should be tomorrow and worry about utter vehicular perfection when the momentum catches up. Doing it the other way around is rank political dishonesty on their part that is probably going to cost the T more riders than it gains if it raids the equipment replacement budget to the point where old junk starts breaking down en masse...again.
