Commuter Rail Electrification

There was a discussion on that elsewhere on Railroad.net: coupling-in-motion-t166487-15.html#p1553373

Long story short... indeed, what could possibly go wrong? Without bothering to make a list, let's just go with big fat no all around.

Even if it were safe, not many places you could slip a coach and then it doesn't become an obstruction anyway. Infrastructure is not set up for it.

Ironically, Boston was one location that the practice was once used. The Old Colony, with its many branches, used it until a wreck at Mattapan caused by a failed split at one of the junctions.

Quite a while (20 years or so?) back the Danish State Railways introduced a diesel mu design intended to permit splitting (and merging!) en route, not necessarily while in motion. Anyone know how that worked out?

With the future of Amtrak not needing many of their Sprinter locomotives after more of the intercity trainsets enter revenue service, MBTA could possibly look into using a good number of them for the Providence/Wickford Jct trains. They can accelerate very well and they could make fast speeds between the stations on the Providence Line. If MBTA ever electrifies the Worcester Line, then Sprinters would be great to use on the express trains to Worcester. I think MBTA should still also look into buying MUs for the Fairmount Line if it is ever electrified.

Overhead wire dual-modes do make sense for Amtrak. There are a TON of possibilities for service from the NEC to points beyond the NEC that could use such a locomotive.

Electric has the biggest benefits in acceleration for local service, but it would be beneficial to all services. EMUs have a bit of an advantage over loco-hauled, but if loco-hauled trains are properly powered (about 1000HP/car) then that shouldn't be a big difference. The reason that loco-hauled is so slow on NJT is that they're trying to push/pull 12 cars with one locomotive, they need two to get the trains moving. All of the T commuter rail except for maybe the Old Colony and Greenbush lines should be electrified.

There's nothing technically stopping a train with automatic couplers and electric connections like many modern MU designs from splitting at a station en route, but from a safety perspective, without CBTC installed, the rear half would have to wait for the front half to clear the next block, and when joining, the front half would have to wait for the rear half to approach to restricted speed. If CBTC were used on heavy rail, then it would probably be a lot more efficient.

EDIT: Clarify couplers for join/split

I had to google jargon word CBTC (Communications-Based Train Control) https://new.mta.info/projects/cbtc
The existing HSP46 tier-III diesel locomotive has a maximum of 4300 HP available to the wheel motors and are being used to pull six bilevel coaches, that's much less than 1000HP/coach.

CBTC is currently used by NYCTA, but AFAIK, not on FRA heavy rail. Aside from joining and splitting trains mid-route, it could theoretically increase capacity on extremely busy lines like parts of MN, NJT, and LIRR, but I don't know of any actual plans to use it on FRA heavy rail.

Diesels have two problems, the first being lack of horsepower, as you point out, the second being loading time when starting up. Electrics have more horsepower, but also don't have to wait for the prime mover to load up the traction motors, so they are much faster out of the gate. There are limits to this, however, and while a single ALP-46A has plenty of tractive effort to lug around 12 MLs, it's underpowered from an acceleration perspective and such a train should have two ALP-46As, which would close most of the gap between loco-hauled and EMU.

There is also a significant weight difference between single- and multi-level coaches, meaning that fewer multi-level coaches should be pulled by a single locomotive of any given type, both are about 1000lb/seat, with the multi-level coach designs seating around 135, versus around 100 for the single-level designs. Most NEC commuter operations should stick to single-level coaches, with the exception of NJT, where they have no other way to get the capacity. Bi-levels and gallery cars down south and out west are much more useful than the NEC ML cars, as they have the extra height to provide more room and more seating, while working well with the low-level platforms present there.

It is well known that the MBTA is phasing out all single-level coaches. Seating capacity on the oldest cars in 2+2 configuration is about 99. The single-level 2+3 are about 122. The Kawasaki and Hyundai-Rotem bi-levels are 173 to 185 seats. I haven't timed acceleration, but assume that the HSP46 is adequate, and is about as large and powerful as you can get with a 4-axle diesel locomotive.

ExCon90 wrote: ↑Fri Jul 16, 2021 9:42 pm Quite a while (20 years or so?) back the Danish State Railways introduced a diesel mu design intended to permit splitting (and merging!) en route, not necessarily while in motion. Anyone know how that worked out?

Ah, the donut train:
(And it was supposed to be able to couple and uncouple in motion.)

BandA wrote: ↑Sun Jul 18, 2021 12:28 pmIt is well known that the MBTA is phasing out all single-level coaches. Seating capacity on the oldest cars in 2+2 configuration is about 99. The single-level 2+3 are about 122. The Kawasaki and Hyundai-Rotem bi-levels are 173 to 185 seats. I haven't timed acceleration, but assume that the HSP46 is adequate, and is about as large and powerful as you can get with a 4-axle diesel locomotive.

Several agencies have gone down the double-decker path, even though it really doesn't make sense unless all other options have been exhausted like increasing train length and frequency, i.e. NJT through the North River Tunnels, and even that may eventually become a non-issue when Gateway and an expansion of NYP is completed.

Diesel locomotives come in slow, slower, and slowest. The HSP46s are slow, most others range from slower to slowest. DMUs are better simply because they are lighter, the only thing that can really move quickly is electric. That being said, the HSP46s are an impressive piece of engineering for a diesel locomotive, and are surprisingly less slow than most diesel push-pull locomotives.

Is acceleration causing schedule-keeping problems for the T? How much time would be saved for a Worcester, a Fitchburg, or Providence train if they were electric push-pull or DMU or EMU?

I've read an article that persuaded me that having the commuter agencies use faster equipment on the NEC, so that the Commuter Rail and the Amtrak Regionals run about the same speed, would increase capacity. Would cannibalize the the Regional service...

There's no argument that electric powered vehicles aren't superior in efficiency and performance for service making frequent stops, the argument is over whether or not the benefits gained are worth the prohibitive infrastructure expense. I've opined repeatedly and maintain my position that electrics are a no brainer on some routes but don't make sense on others. I don't see electric trains ever running on the B&A to Worcester, Old Colony, or on the North Side. Diesels on the Dorchester branch or on any part of the Corridor is foolish. Electrifying to Lynn makes exactly zero sense. That kind of capital spending would better serve the ridership by extending the Blue to Lynn.

I agree that stopping the electrification at Lynn is foolish. If they are going to have electrification on the lines to the North Shore, then I would probably say either electrify both branches in their entirety. Let's see what the folks who are living in those communities think.

Agree but as a North Shore resident and a train lover, I would vote to electrify the Blue line to Lynn as that just makes sense on so many levels BUT, I would prefer to see the T try or experiment with using the newer battery or even Hydrogen powered EMUs on the shore lines to Rockport and Newburyport which should be much cheaper and require a lot less infrastructure!

I think batteries will remain impractical except for niches like filling in gaps under bridges, switching engines in covered coach yards, etc. Hydrogen has the fundamental problem that it has to be manufactured from something else, and burning something else is usually cheaper than burning a synthetic fuel.

Much more practical than hydrogen would be natural gas. FEC experimented with natural gas tenders in freight service a couple of years ago. I can't remember if it was CNG or LNG. Any hydrogen or natural gas engine would probably be restricted to northside service for an obvious reason. With the current administrations' policy of increasing our dependency on unfriendly OPEC and other nations and handing pricing power back to the cartel and dictators, the cost of diesel (and home heating oil) will likely soar this winter. Which is another reason to try CNG, LNG, and electrification.