Commuter Rail Electrification

The success or failure of the BEMUs will depend on what the final specifications of the vehicle are.
1. What is empty weight of the vehicle and the gross weight with a full winter's passenger load?
2. What is the kW maximum output of the battery at full charge and at 50% discharged?
2a. what is the battery parasitic load when unit is waiting at station?
3. What is maximum kW draw of the traction motors?
4. Will using CAT only allow for full traction power or will battery need to supplement the traction power draw?
5. What is acceleration CAT rate of unit with full winter passenger load.
6. What is acceleration battery curve rate with full passenger load at various battery charge values.
7. Is transition to/from CAT and battery seamless or will there be a short interval?
8.

4. As I mentioned before, catenary provides effectively unlimited power. You would never need to use the batteries to supplement catenary.

west point wrote: ↑Wed Apr 03, 2024 10:51 pm

R36 Combine Coach wrote: ↑Wed Apr 03, 2024 9:41 pm On the other hand, the ALP45 can run full electric all the way.

That is because they are using overhead CAT. The MTA dual modes cannot draw enough electric juice from third rail shoes. Current draw is too high at 600 Volts VS 12 kV AC from CAT with much lower currents.

Is this a problem with the volume of current the shoes can draw on a P32 or the volume of current available through the third rail? At one time you had P motors with six large traction motors drawing enough current to pull 15+ cars over the road so it seems the amperage is there.

ElectricTraction wrote: ↑Tue Apr 02, 2024 11:06 pm Battery electric heavy rail is unproven. The amount of energy required makes it difficult at best. Overhead AC electrification has been around in roughly it's current form since 1914.

Exactly, which begs the question - why are they trying a big science experiment that could be a disaster when they have neglected to run electric motors to Providence for the last 25 years??? How many times has there been an ability to tack on to a HHP/ALP/ACS order? Maybe 5 plus?

But MBTA has always said "we don't want to maintain another fleet". And now they're going to maintain another fleet that has a better than 50/50 chance of being sidelined way before the end of design life.

Battery busses have not been a good thing for Chicago: https://chi.streetsblog.org/2023/09/14/ ... le-service

But battery electric buses are ... expensive. In 2022, the CTA estimated that shifting over to electric vehicles would cost $1.8 to $3.1 billion dollars, on top of the normal cost of maintaining the bus fleet... total costs from 2022 through 2040 are expected to be $1.7--$2.9 billion higher.

... only half of current weekday routes can be served by buses that charge overnight. For the other half, CTA envisions deploying a series of ‘on-route’ charging stations, to enable buses to charge during their routes. But this creates new challenges—requiring buses to go out of service and staff to oversee the charging process. Even worse, bus batteries can drain up to 40 percent faster in cold weather, when batteries function less effectively and more energy is required to heat the bus interior (diesel buses can rely on heat from the engine).


... Denver has cancelled outstanding orders due to reliability challenges, and Philadelphia has mothballed its electric buses while it re-evaluates the decision to go all-electric. Other transit agencies, including Madison and Juneau, Alaska have struggled with reliability and quality issues.

Not a good look here. Streetsblog is not exactly Fox News or Project Veritas.

The MBTA won’t be maintaining another fleet. It will be Keolis. It’s a Keolis-driven project.

And Boston scrapped the trolley buses, prematurely, in favor of battery.
Septa runs trolley buses, I'd have thought that getting more, and stringing up wire on the busiest routes would be a no brainier, instead of battery buses. Also, trolley buses have a much longer lifespan that internal combustion , and I'd assume battery ones, too.

I suspect battery buses are going to need to wait another generation or two of battery tech before they become widely practical. They need batteries that are small/light enough to not crack the frames and can recharge in just a few minutes while the bus is laying over between trips. There are some promising new technologies out there, but they haven't yet been commercialized.

Tadman wrote: ↑Thu Aug 01, 2024 8:27 amIs this a problem with the volume of current the shoes can draw on a P32 or the volume of current available through the third rail? At one time you had P motors with six large traction motors drawing enough current to pull 15+ cars over the road so it seems the amperage is there.

Probably a limitation on what the shoes can handle. The traction motors on a P32 are much more powerful than those on EMUs, and it has only two shoes for all that current to go through.

wicked wrote: ↑Thu Aug 01, 2024 9:19 amThe MBTA won’t be maintaining another fleet. It will be Keolis. It’s a Keolis-driven project.

The equipment will be leased by the operator. "The operator" meaning when the contract changes hands, so does the lease. Keolis is seeking stake as contract time approaches, but the T isn't that foolish.

Most lithium ion batteries come from China, so yet another sovereign risk in addition to the technology risks. We have already seen the MBTA "voluntarily" pay CRRC extra to cover US sanctions on Orange Line / Red Line cars. Once you string wires over railroad tracks, they last up to 100 years. Traction motors last a long time if they take care of them (keep out snow & water & don't overheat). The battery in a BEMU is going to only last a certain number of charge cycles, maybe 10 years?

Looking at iowa traction, their gear can also last over 100 years,

How the BEMUs operate in a bitter cold day in the winter will be interesting. We only have to look at EV autos in winter to wonder. The battery having to heat car but more importantly keeping the battery warm may prove impossible. Hope not but am very skeptical. Then there is the unknown of a battery fire. How fast can riders evacuate?

BandA wrote: ↑Fri Aug 02, 2024 1:29 pm Traction motors last a long time if they take care of them (keep out snow & water & don't overheat). The battery in a BEMU is going to only last a certain number of charge cycles, maybe 10 years?

Aren't the No. 1 series 01500/01600s still on their original Westinghouse DC motors from 1969? If so, a half century
or more with regular maintenance and overhaul cycles.

The non-rebuilt PCCs motors are even older, almost 80 years. Unless the T kept some spares when they scrapped cars, but still old. Motors can be rebuilt.

west point wrote: ↑Sun Aug 04, 2024 9:22 am How the BEMUs operate in a bitter cold day in the winter will be interesting. We only have to look at EV autos in winter to wonder. The battery having to heat car but more importantly keeping the battery warm may prove impossible. Hope not but am very skeptical. Then there is the unknown of a battery fire. How fast can riders evacuate?

Electric cars are capable of warming the battery off "mains" power while plugged in - since these trains should be hooked to the catenary at rest, it would follow that much of the battery conditioning will be done while "plugged in".

Are the far tracks at South Station used by the Fairmount Line electrified?