3 ms·

You don’t need massive batteries for short regional/suburban branch lines. We’re not talking about long intercity routes here.

fennecfoxen 4y ago
For NYC diesel trains, you're talking about stretches like the one from Croton-Harmon to Poughkeepsie (by car, it's about 40 miles). I'm not sure whether this counts as "short." https://www.reddit.com/r/nycrail/comments/l57nw2/map_of_the_electrified_sections_of_the_greater/ https://www.reddit.com/r/nycrail/comments/l57nw2/map_of_the_... (LIRR Montauk branch is longer, but I'm less familiar with it.)
dredmorbius 4y ago
It's not the length of the line. It's the duty cycle of the rolling stock. Running a trainset four times along a 100 mile route, or 40 times along a 10 mile route, you're still travelling 400 miles. And the stop frequency is likely far higher on the urban route. It's the acceleration that costs, and batteries only save you so much there, even with regenerative braking. Add in heating/cooling loads, air handling, etc., and there's a lot to consider. About the only place batteries make sense on rail is where you're moving a heavy load one-way down-grade. There are operating quarry and logging operations which effectively work as battery storage. Laden cars (or trucks) run downhill, whilst regenerative braking charges the batteries. Empties return uphill, slowly, on that charge. Other than a Soylent Green operation from a mountain resort, few commute rail systems have a suitably matching travel pattern.
- 7952 4y ago
  Could make sense for short distance, low frequency. I know of a few services on branch lines that have long linger times at stations. They will do a 10 minute journey twice an hour and stay in the station between trips.
- Reason077 4y ago
  > "Running a trainset four times along a 100 mile route, or 40 times along a 10 mile route, you're still travelling 400 miles." We're not talking about 100 miles on battery power here - although there are already battery electric transits that are capable of that and more. For the most part, inter-urban trunk lines in Europe are already electrified. There are many outer-suburban/regional routes that are, for example, 50 miles along an electrified trunk line then 25 miles on an un-electrified branch line. Currently that means whole route needs to be operated by diesel trains. But a battery train only needs to be capable of doing (eg) 50 miles on battery, then it can recharge when it's running under the wires.
  - dredmorbius 4y ago
    Do you have any references for serious studies or proposals for such systems?
    - Reason077 4y ago
      Not just proposals: orders have been placed and trains should be in passenger service this year. Google "FLIRT Akku" which is the name of Stadler's battery-electric train. https://www.urban-transport-magazine.com/en/schleswig-holstein-orders-55-battery-electric-trains-with-stadler/ https://www.urban-transport-magazine.com/en/schleswig-holste... "The longest non-electrified section on the diesel network is 80 km. Under optimal conditions, however, a battery range of 150 km should be possible."

fennecfoxen 4y ago

For NYC diesel trains, you're talking about stretches like the one from Croton-Harmon to Poughkeepsie (by car, it's about 40 miles). I'm not sure whether this counts as "short." https://www.reddit.com/r/nycrail/comments/l57nw2/map_of_the_electrified_sections_of_the_greater/ https://www.reddit.com/r/nycrail/comments/l57nw2/map_of_the_... (LIRR Montauk branch is longer, but I'm less familiar with it.)

dredmorbius 4y ago

It's not the length of the line. It's the duty cycle of the rolling stock. Running a trainset four times along a 100 mile route, or 40 times along a 10 mile route, you're still travelling 400 miles. And the stop frequency is likely far higher on the urban route. It's the acceleration that costs, and batteries only save you so much there, even with regenerative braking. Add in heating/cooling loads, air handling, etc., and there's a lot to consider. About the only place batteries make sense on rail is where you're moving a heavy load one-way down-grade. There are operating quarry and logging operations which effectively work as battery storage. Laden cars (or trucks) run downhill, whilst regenerative braking charges the batteries. Empties return uphill, slowly, on that charge. Other than a Soylent Green operation from a mountain resort, few commute rail systems have a suitably matching travel pattern.

7952 4y ago
Could make sense for short distance, low frequency. I know of a few services on branch lines that have long linger times at stations. They will do a 10 minute journey twice an hour and stay in the station between trips.
Reason077 4y ago
> "Running a trainset four times along a 100 mile route, or 40 times along a 10 mile route, you're still travelling 400 miles." We're not talking about 100 miles on battery power here - although there are already battery electric transits that are capable of that and more. For the most part, inter-urban trunk lines in Europe are already electrified. There are many outer-suburban/regional routes that are, for example, 50 miles along an electrified trunk line then 25 miles on an un-electrified branch line. Currently that means whole route needs to be operated by diesel trains. But a battery train only needs to be capable of doing (eg) 50 miles on battery, then it can recharge when it's running under the wires.
- dredmorbius 4y ago
  Do you have any references for serious studies or proposals for such systems?
  - Reason077 4y ago
    Not just proposals: orders have been placed and trains should be in passenger service this year. Google "FLIRT Akku" which is the name of Stadler's battery-electric train. https://www.urban-transport-magazine.com/en/schleswig-holstein-orders-55-battery-electric-trains-with-stadler/ https://www.urban-transport-magazine.com/en/schleswig-holste... "The longest non-electrified section on the diesel network is 80 km. Under optimal conditions, however, a battery range of 150 km should be possible."