Seaport District to Back Bay DMU Plan

F-line to Dudley via Park wrote:

trainhq wrote:

And no current model can couple with an off-shelf coach to quickie-increase the capacity with a trailer. For same reason all the MNRR/LIRR, NJT, and SEPTA EMU's can't. The MU electronics can't correct for generic dead weight of unknown properties. They would have to buy wholly separate custom trailers from the DMU manufacturer akin to the M8/Silverliner/Arrow singlets that are specifically engineered to work seamlessly with the MU trainlining. Which is expensive, not very efficient fleet utilization, and exacerbates the southside storage problem.

Yes, but that's at present. I mean, couplers are couplers. They could arrange the DMUS to tow additional trailer cars if
they want (although the experience of Tri-Rail suggests that only one would be likely). The point is, if they gain wide
acceptance this is a problem that can be solved later. It would take time and $$$, but it's doable.

It's not couplers, it's MU electronics.

It's both actually. The average EMU (and presumably these DMU's as well) do not use standard railroad couplers. They use special spear couplers that contain all air, electrical, and MU lines within the face of the coupler. The only way to couple them to non-MU equipment is using a compromise coupler that plugs into the spear coupler. However, this limits the MAS of the train, and only air connections would be able to be made, with no electrical connections possible whatsoever.

F-line to Dudley via Park wrote:The one great white hope in this is that NJT/Bombardier proposal for "power car" EMU's to replace the Arrows.

......

IF this concept works and IF NJT and the other roads sniffing around (MNRR/LIRR are interested as M3 replacements for rush hour)...then they've solved for the trainlining issue and a DMU platform based on this technology should quickly follow the modestly simpler EMU version. (And, hey, this might be 'the' killer app that finally gets the T using EMU's to Providence if they can use the existing coaches with it). But those vehicles wouldn't appear before 2018 on the most overoptimistic estimate, and any DMU offshoots definitely not before 2020.

This is extremely unlikely to happen. Firstly, because NJT has put this project on hold for now, with no immediate plans for these to be built. Secondly, the Multilevels can only trainline with other ML's. Although there was once the idea of NJT using mixed ML/Comet sets, the cars turned out to be incompatible, forcing the ML's to be used only in their own sets. IF these things were to ever actually get built (and work), I wouldn't count on seeing them anywhere other than on NJT (and I guess MARC, in theory, since they're getting ML's now too). That is, unless the T were to order ML trailers, which is also rather unlikely.

rethcir wrote:This is a cool plan. Will make my life easier as someone who often gets an express bus into Copley. Consider also that this makes it a lot easier to get from the airport to Copley as well.

Your life would be even easier if they just ran some of the Pike express buses to the Seaport District. If the area is important enough for a new rail route, with the associated station and track construction and DMU purchases, then it's important enough for direct express bus service. (Could they use those I-90 HOV tunnels under Fort Point Channel which see almost no traffic? Or are those only accessible from 93?)

For Copley to the Airport, I'd still find it easier to go Green -> Blue -> Massport bus, rather than taking a slow DMU that runs who knows how infrequently -> Silver.

nomis wrote:Operating an RDC & towing a conventional coach behind it was deemed "voiding the warranty" by Budd.

True, although the New Haven RR did it for a while on the Old Colony lines in the 1950s and even repainted at least one commuter coach from green to silver to match the Budds that were pulling it.

Well, I'm still a little confused about the additional trailer problem. I noticed that
DMUs are usually coupled facing opposite directions. If you put a coach in the
middle, (as opposed to pulling one behind) wouldn't they automatically be balanced
correctly? Couldn't you then put in a non-weight matched coach and still run it?

And, over time, I'm not convinced that it would be that hard for Nippon-Sharyu to
produce their own matched cars, as Colorado Railcar (tried) to do. Once the demand
is there, they're capable of doing it if they want. Just not sure how long it will be
before people start calling for them....

Tossing my two cents in here....

Simply put, this proposal is stupid. I am not going to go into details, as they have all been raised, but how about using this money for something useful, like cutting the T's debt so we do not have to have another fare increase/service reduction song and dance next year?

ST214 wrote:another fare increase/service reduction song and dance next year?

We're supposed to be having one this year. In fact, I don't really know why it hasn't been announced yet. What gives? We should have already heard about what the new fares will be by now.

BostonUrbEx wrote:

ST214 wrote:another fare increase/service reduction song and dance next year?

We're supposed to be having one this year. In fact, I don't really know why it hasn't been announced yet. What gives? We should have already heard about what the new fares will be by now.

I have not heard it either, so I figured it got cancelled somehow. I think the raise in the gas and cig tax had something to do with it.

F-line to Dudley via Park wrote:It's not that simple.

This much is apparent to me. I knew propulsion isn't as simple as a set of wires from the generator to the traction motors, but I guess I don't know the full extent of the engineering that makes DMUs so finicky. Hauling things that aren't weight-balanced makes for a jerky ride...but why? What system is getting in the way of a smooth ride? Is it wheelslip prevention, the computer between the throttle and the traction motors, or simple slack action? Why is the offending system necessary in a DMU versus a locomotive MU consist?

I'm technically-minded and wouldn't mind doing my own research if you could point me in the right direction, but I don't know where to start. My curious mind wants to know.

My question is, why all this talk about MU cars pulling trailers or regular coaches? From what I've seen, overseas MU trains are built to a given size (which may include trailer cars as well as power cars), and then they just couple multiple sets together if they need more capacity. They don't pull sets apart to insert additional cars (unless it's a fleet-wide modification) or couple single cars to the end.

I'd like to know where the cash for this is coming from. It certainly ain't the T. Look at who was quoted in Shirley Leung's column: Davey, Rooney from the convention authority, and a couple conventioneers/business types.

So the money for this is coming from another state agency. That leaves Massport, EOT or MCCA (ding, ding, ding, here's our probable winner).

In fact, the T (which may or may not be hired to operate this service) may have some of the same objections to this as Amtrak.

P.S. I think it's awesome to have such engaged discussion about a transportation issue in the city. Would be nice if it happened more often, which may happen once the Meninosaurs are out of City Hall and some new blood looks at new ways to tackle issues.

Re: Seaport District to Back Bay DMU Plan

Postby MBTA3247 » Sun Sep 08, 2013 11:29 pm
My question is, why all this talk about MU cars pulling trailers or regular coaches? From what I've seen, overseas MU trains are built to a given size (which may include trailer cars as well as power cars), and then they just couple multiple sets together if they need more capacity. They don't pull sets apart to insert additional cars (unless it's a fleet-wide modification) or couple single cars to the end.

Yes, that's certainly doable. In the end, however, it's a question of $$$$. If you have lines where running 3 or 4 car DMU trains consistently
makes sense, then is it cheaper to buy mated non powered cars, or hook up existing powered units?

wicked wrote:P.S. I think it's awesome to have such engaged discussion about a transportation issue in the city.

Agreed, especially when a topic has multiple viewpoints that are actually discussed responsibly among participating parties (like this discussion) rather than forced down others' throats via a yelling-filled tantrum, which is too commonplace with many face-to-face city related discussions.

wicked wrote:Would be nice if it happened more often, which may happen once the Meninosaurs are out of City Hall and some new blood looks at new ways to tackle issues.

Again agreed, especially if (speaking of transportation) said "new blood" took a serious look at a Red-Blue connector/Urban Ring/potential DMU implementation among EXISTING in-service rail lines/necessary T equipment purchases. With that said, as much as I hate to be a pessimist, I'm going to quote Bob Kaufman and say, "IIII doubbbtt it."

SeaportMike wrote:Now there are a few a few things this article left out.

-After the Convention Center was completed, the tracks/crossings beyond Cypher Street were completely re-constructed, so they are all new.
-Cypher Street at the Convention Center rear entrance has the only gated/lighted grade crossing.
-The grade crossing at New Fargo Street and Pumphouse Road have an odd crossing warning system set up. At the crossings they have their own pedestrian crossing "crosswalk buttons", with signs that read "Train Crossing, Engineer Press Button". When pressed, the normally green traffic light simply turns red. This is a huge issue that will need to be corrected.
-The plan also includes a stop at the Cruiseport for Cruise Ship passengers.

Seaport:
Can you supply a link to this detailed information? This is of high interest to me and the freight possibilities haven't been mentioned either.
Thanks.

Just found this photo essay on Track 61 for those interested in seeing what this now looks like:

http://s369.photobucket.com/user/JohnAK ... %20-%20DMU" onclick="window.open(this.href);return false;

Note in PIC 43 the notch in the new overhead bridge for future double-stack service.

Why not use refurbished RDCs?