Push-pull operation of suburban trains

[hexagon789]

As others said, is very common in North America for push pull. Been on a few including Toronto and main observation is they feel slow compared to UK getting to line speed between stations. Think some of this is the crash worthiness requirements so increased carriage weight and think a few sets use converted freight engines.

The Bombardier deckers GO Transit use are about 61-65 tonnes I believe, which is quite heavy compared to, for instance, the French V2N, which weigh in about 47-48 tonnes.

 

[ac6000cw]

As others said, is very common in North America for push pull. Been on a few including Toronto and main observation is they feel slow compared to UK getting to line speed between stations. Think some of this is the crash worthiness requirements so increased carriage weight and think a few sets use converted freight engines.

The slowness is a combination of the heavy double-deck passenger cars, long consists, only four powered axles and a relatively low power-weight ratio (typically a 4000hp DC-drive diesel plus ten to twelve 60+ tonne cars, so around 4.7 to 5.5 hp/tonne. A modern UK DMU is at least twice that...

GO Transit do have sixteen 5400hp diesels (out of a total fleet of about 90 locos) which helps a bit, but they've started to electrify the system as the long-term solution.

 

[OVS Flatbottom]

I can't think of any British examples of suburban push-pull using diesel or electric locomotives. (Inter-city push-pull is clearly a different story.)

Not British as such, but NIR definitely ran some Belfast suburban services (Portadown-Bangor corridor) with push-pull stock (101 class Hunslet diesels and the 1970 Enterprise Mk2s) in the late 1980s, alongside the DEMU fleet. I believe they even considered rebuilding the 104 class (Metrovicks, ex-CIÉ C class) to replace the Hunslets on this operation, but nothing came of it.

Of course, Dublin had push-pull suburban trains for considerably longer, first with the converted AEC railcars, then the Mk3s.

 

[StephenHunter]

Some countries in Europe had full-length push-pull suburban trains worked by steam power, many years before BR tried it with diesel and electric.

Not full length, what the now Liberty Line was known in my area as "the push-pull" due to historical use of steam in this way.

There were also some GWR examples, pre-Grouping.

 

[hexagon789]

Not full length, what the now Liberty Line was known in my area as "the push-pull" due to historical use of steam in this way.

There were also some GWR examples, pre-Grouping.

Well indeed, the GWR made great use of them even on mainlines running stopping services where they might run two trailers either side of a loco.

But I don't think use on lengths of say 8-12 coaches as a norm appeared until the BR era with the 4REPs, 4TCS and push-pull 33s etc

 

[Taunton]

Steam push-pull was quite expensive compared to normal trains, for the fireman had to be a higher paid senior Passed Fireman, one who has passed their driving exams and is waiting for a vacancy, as when on their own with the loco propelling they had to do a range of the drivers' tasks in addition to their own, such as operating the vacuum ejector or the cut-off. The guard meantime was often, on these less-used services, given a ticket machine to handle passengers joining at Halts, for which again an additional payment was made. Given such trains were only one or two coaches and often sparsely patronised, it was a high cost.

On the GWR/WR trains scheduled as push-pull were often run conventionally by the crew, running round at the termini, as they preferred this and it overcame the sometimes challenging connecting of the push-pull controls. The two trailers either side of the loco was a feature of the Plymouth-Saltash shuttle, a busy service before the road bridge opened, with no space at cramped Saltash station for running round.

Once diesels came along further issues were steam heating when the loco was propelling, as there were very few diesels with ETH and it was long only available on express stock. The Edinburgh-Glasgow 2 x Class 27 push pull showed a further range of issues with an unattended loco at the back, steam heating was eventually replaced by a separate ETH diesel generator in one loco but this brought its own unreliability which had no supervision when at the trailing end, soon needing further automatic fire protection, which of course itself delighted in spontaneously filling the engine room with CO2 at the most awkward moments. Nothing is simple!

 

[LickeyIncliner]

But I don't think use on lengths of say 8-12 coaches as a norm appeared until the BR era with the 4REPs, 4TCS and push-pull 33s etc

Presumably because of the Board of Trade restriction mentioned by @Taunton in post #06 above

 

[hexagon789]

Presumably because of the Board of Trade restriction mentioned by @Taunton in post #06 above

Yes, I forget what exactly was done to legally change that but it is mentioned somewhere in relation to the Bournemouth electrification project

 

[LickeyIncliner]

Once diesels came along further issues were steam heating when the loco was propelling

Was that a technical problem, or a staffing issue in that the second man who was responsible for operating the steam heating boiler was required to be with the driver in the leading cab when not actually attending to the boiler?

 

[Iskra]

Lots of push-pull locomotive operation on Flordia Tri Rail including a one carriage example in Miami: