5 ms·

Yard service is a perfect application for these types of locomotives. Diesel fired locomotives tend to sit around idling and burning fuel many more hours than t

by donarb 5y ago

Yard service is a perfect application for these types of locomotives. Diesel fired locomotives tend to sit around idling and burning fuel many more hours than they are being used every day. Diesel locos also tend to not be very fuel efficient when constantly stopping/starting around the yard.

zeusk 5y ago
AFAIK, most "diesel locos" are really diesel electric, with the diesel engine feeding a generator. Hybridization of locomotives seems like a no brainer since they can recover so much more energy with regenerative braking and can plan for braking to be recovery efficient.
- dogsgobork 5y ago
  As I understand, braking occurs across the entire train, not just via the drive axles, so the hybrid regeneration method would be a considerable departure from normal operations.
  - throwawayboise 5y ago
    Yes, but diesel-electric locomotives have a brake mode where the "regenerative" current is shunted through big air-cooled resistors and exhausted as heat. Often used on downgrades to control speed without burning up the brake shoes. Recovering this into battery charge would be an easy win, though you might still need the resistors after the batteries are fully charged or if they can't absorb the charge fast enough.
    - wiredfool 5y ago
      This is where overhead electric is great, and why the Pennsylvania railroad ran full electric over the mountains back in the steam era. A coal train going down the mountain could mostly power the one going up.
  - NickNameNick 5y ago
    I have the impression that engaging the airbrakes is a little bit all-or-nothing. They're great for stopping (relatively) quickly on level ground. But not so grest for controlling your speed. Big diesel-electric locomotives have large, actively cooled resistor banks, usually on top of the engine. When rolling down hill they run the electric motors as generators, and dumping the energy into the resistor banks. The mechanical brakes can't absorb that much energy - they'd wear out after a few minutes.
    - s1artibartfast 5y ago
      resistors or capacitor banks? It seams like a resistor on a generator would just be a breaking load, and not actually capture any power.
      - Gare 5y ago
        The end result is waste heat. Capturing it would be great, but a battery is needed for that. Capacitors are still not up to the task for that amount of energy.
      - bluGill 5y ago
        I'm not aware of any locomotives that captures power from braking.
Animats 5y ago
These new locomotives are from Progress Rail, division of Caterpillar, and from Wabtec, which is Westinghouse Air Brake Technologies, 150 years old. They're just Diesel-electric platforms with batteries replacing the Diesel. "Replacing" may be just that. Few locomotives are built for yard work today. Most US switchers are old road locomotives, often half a century old. Sometimes they have a new power package. Progress Rail started as a locomotive rebuilder, changing out power packages for new ones, usually Caterpillar Diesels. Their electric seems to be a repower job of a classic General Motors Electro-Motive Division GT. Here's a video of their standard new Diesel repower job.[1] Lithium iron phosphate batteries, at least in the Progress Rail version. The heavier weight of lithium iron phosphate is a feature, not a bug, in a locomotive. Locomotives are built heavy to improve traction. The end result is not just a yard locomotive. Some of these are in test elsewhere for short-haul lines. Range maybe 300 miles. Another boring, but useful, technology, from old-line industrial companies. This is what makes the world go. [1] https://www.youtube.com/watch?v=6Kth3i2PGE0 https://www.youtube.com/watch?v=6Kth3i2PGE0
- jacquesm 5y ago
  How is the reliability on those? The diesel-electrics are incredibly reliable.
- hakfoo 5y ago
  For context, Progress Rail is what became of Electro-Motive Division when GM split them off, and Wabtec bought the locomotive division of GE a few years ago.
- algo_trader 5y ago
  Is the "electric" part of the diesel electric a commoditized technology? Is it a single motor or one per axis? How expensive is a 10MW electric motor? Asking for a friend Edit: for context - Tesla Semi is just 4x 250kw motors
  - olivermarks 5y ago
    The Tesla semi doesn't exist, those are theoretical specs https://www.inverse.com/innovation/tesla-semi-price-specs https://www.inverse.com/innovation/tesla-semi-price-specs

by donarb 5y ago

zeusk 5y ago

AFAIK, most "diesel locos" are really diesel electric, with the diesel engine feeding a generator. Hybridization of locomotives seems like a no brainer since they can recover so much more energy with regenerative braking and can plan for braking to be recovery efficient.

dogsgobork 5y ago
As I understand, braking occurs across the entire train, not just via the drive axles, so the hybrid regeneration method would be a considerable departure from normal operations.
- throwawayboise 5y ago
  Yes, but diesel-electric locomotives have a brake mode where the "regenerative" current is shunted through big air-cooled resistors and exhausted as heat. Often used on downgrades to control speed without burning up the brake shoes. Recovering this into battery charge would be an easy win, though you might still need the resistors after the batteries are fully charged or if they can't absorb the charge fast enough.
  - wiredfool 5y ago
    This is where overhead electric is great, and why the Pennsylvania railroad ran full electric over the mountains back in the steam era. A coal train going down the mountain could mostly power the one going up.
- NickNameNick 5y ago
  I have the impression that engaging the airbrakes is a little bit all-or-nothing. They're great for stopping (relatively) quickly on level ground. But not so grest for controlling your speed. Big diesel-electric locomotives have large, actively cooled resistor banks, usually on top of the engine. When rolling down hill they run the electric motors as generators, and dumping the energy into the resistor banks. The mechanical brakes can't absorb that much energy - they'd wear out after a few minutes.
  - s1artibartfast 5y ago
    resistors or capacitor banks? It seams like a resistor on a generator would just be a breaking load, and not actually capture any power.
    - Gare 5y ago
      The end result is waste heat. Capturing it would be great, but a battery is needed for that. Capacitors are still not up to the task for that amount of energy.
    - bluGill 5y ago
      I'm not aware of any locomotives that captures power from braking.

Animats 5y ago

These new locomotives are from Progress Rail, division of Caterpillar, and from Wabtec, which is Westinghouse Air Brake Technologies, 150 years old. They're just Diesel-electric platforms with batteries replacing the Diesel. "Replacing" may be just that. Few locomotives are built for yard work today. Most US switchers are old road locomotives, often half a century old. Sometimes they have a new power package. Progress Rail started as a locomotive rebuilder, changing out power packages for new ones, usually Caterpillar Diesels. Their electric seems to be a repower job of a classic General Motors Electro-Motive Division GT. Here's a video of their standard new Diesel repower job.[1] Lithium iron phosphate batteries, at least in the Progress Rail version. The heavier weight of lithium iron phosphate is a feature, not a bug, in a locomotive. Locomotives are built heavy to improve traction. The end result is not just a yard locomotive. Some of these are in test elsewhere for short-haul lines. Range maybe 300 miles. Another boring, but useful, technology, from old-line industrial companies. This is what makes the world go. [1] https://www.youtube.com/watch?v=6Kth3i2PGE0 https://www.youtube.com/watch?v=6Kth3i2PGE0

jacquesm 5y ago
How is the reliability on those? The diesel-electrics are incredibly reliable.
hakfoo 5y ago
For context, Progress Rail is what became of Electro-Motive Division when GM split them off, and Wabtec bought the locomotive division of GE a few years ago.
algo_trader 5y ago
Is the "electric" part of the diesel electric a commoditized technology? Is it a single motor or one per axis? How expensive is a 10MW electric motor? Asking for a friend Edit: for context - Tesla Semi is just 4x 250kw motors
- olivermarks 5y ago
  The Tesla semi doesn't exist, those are theoretical specs https://www.inverse.com/innovation/tesla-semi-price-specs https://www.inverse.com/innovation/tesla-semi-price-specs