3 ms·

No engines have an internal combustion engine connected directly to the wheels. You can't get anywhere near enough torque. Steam engines have incredible torque.

No engines have an internal combustion engine connected directly to the wheels. You can't get anywhere near enough torque. Steam engines have incredible torque. What you're describing is a diesel-electric and is essentially synonymous with saying diesel engine on the railway. There are also electro-diesels which can shut off their diesel engine and take electricity directly from an overhead line or third rail by raising a pantograph or lowering a boot. This used to happen at Faringdon in London (maybe still does).

tunareter 8y ago
You're completely wrong. Most diesel locomotives are in fact diesel electrics. I.e. diesel engine, generator, electric motors. Most of those cannot use external power sources (although a few can, e.g. class 73 in the UK). Certainly in the UK: the most common locomotives such as class 66, 60, 58, 67, 47 - they're all diesel electric. In the US, same story: for passengers the GE Genesis is pretty big, things like SD90MAC and AC6000CW are big for freight.
- cup-of-tea 8y ago
  I think you misread my comment.
pmyteh 8y ago
There are non-trivial numbers of diesel-mechanical (IC to wheels via a gearbox) and diesel-hydraulic (IC to wheels via a fluid coupling) trains out there. The British class 172 Turbostar is an example of the former, most other class 1xx DMUs the latter. Diesel electric transmission does happen on smaller multiple units sometimes, but really shines on larger and faster trains, or on electro-diesels (where you need the electric final drive anyway).
isostatic 8y ago
Doubt Farringdon switched from diesel to overhead - overhead to third rail. Some trains have to stop to raise the pantograph, some do it on the fly (I think the 395s can switch 3rd rail to ohel at 60mph when coming on/off hs1) Some trains are hybrid - will use electricity while under wires, and switch to diesel when there's no wires, the new class 800 in the UK as an example.
- cup-of-tea 8y ago
  It was diesel to overhead. It was the Thameslink train and I think it used diesel south of London (to Brighton).
  - isostatic 8y ago
    When the snow hill tunnel re-opened in 1988, and trains started from Farringdon to Blackfriars, they were operated by class 319s, which were dual voltage from the very start. While I'm sure some diesel engineering trains have been through the tunnels, and perhaps some diesel goods trains in the 60s before the closure, I'm not aware of any diesel passenger trains through them (as there were no passenger trains since 1916) Some 319s are being converted to partial diesel and becoming class 769s, but not on this route.
    - cup-of-tea 8y ago
      Oh it could have been switching from overhead to third rail... I never actually went on the train to Brighton, I just remember the pantograph coming down.
      - isostatic 8y ago
        Still does it now, there's a similar switchover north of Shepherds Bush. The Southern 350s used to stop when I got that train, I think the overground trains can raise/lower on the fly. I assume there's a similar changeover in East London. Before 2009 and HS1 to St Pancras, Eurostar also switched from overhead to third rail, on the fly I think, somewhere near Ashford.

tunareter 8y ago

You're completely wrong. Most diesel locomotives are in fact diesel electrics. I.e. diesel engine, generator, electric motors. Most of those cannot use external power sources (although a few can, e.g. class 73 in the UK). Certainly in the UK: the most common locomotives such as class 66, 60, 58, 67, 47 - they're all diesel electric. In the US, same story: for passengers the GE Genesis is pretty big, things like SD90MAC and AC6000CW are big for freight.

cup-of-tea 8y ago
I think you misread my comment.

pmyteh 8y ago

There are non-trivial numbers of diesel-mechanical (IC to wheels via a gearbox) and diesel-hydraulic (IC to wheels via a fluid coupling) trains out there. The British class 172 Turbostar is an example of the former, most other class 1xx DMUs the latter. Diesel electric transmission does happen on smaller multiple units sometimes, but really shines on larger and faster trains, or on electro-diesels (where you need the electric final drive anyway).

isostatic 8y ago

Doubt Farringdon switched from diesel to overhead - overhead to third rail. Some trains have to stop to raise the pantograph, some do it on the fly (I think the 395s can switch 3rd rail to ohel at 60mph when coming on/off hs1) Some trains are hybrid - will use electricity while under wires, and switch to diesel when there's no wires, the new class 800 in the UK as an example.

cup-of-tea 8y ago
It was diesel to overhead. It was the Thameslink train and I think it used diesel south of London (to Brighton).
- isostatic 8y ago
  When the snow hill tunnel re-opened in 1988, and trains started from Farringdon to Blackfriars, they were operated by class 319s, which were dual voltage from the very start. While I'm sure some diesel engineering trains have been through the tunnels, and perhaps some diesel goods trains in the 60s before the closure, I'm not aware of any diesel passenger trains through them (as there were no passenger trains since 1916) Some 319s are being converted to partial diesel and becoming class 769s, but not on this route.
  - cup-of-tea 8y ago
    Oh it could have been switching from overhead to third rail... I never actually went on the train to Brighton, I just remember the pantograph coming down.
    - isostatic 8y ago
      Still does it now, there's a similar switchover north of Shepherds Bush. The Southern 350s used to stop when I got that train, I think the overground trains can raise/lower on the fly. I assume there's a similar changeover in East London. Before 2009 and HS1 to St Pancras, Eurostar also switched from overhead to third rail, on the fly I think, somewhere near Ashford.