Great Western Coffee Shop

We pulled into Westbury at 16:00 from Melksham ... and the train idled in platform 1 until 16:25 when it headed back towards Swindon.  Another train pulled into platform 2 from Gloucester a few minutes later - around 16:32 and was left idling there - still idling when I left on another train at around 16:55; it was shown as the 17:12 departure to Warminster.

With rising fuel prices, and with concerns at the amount of fossil fuel we burn, is it really climate friendly to leave engines running on such long layovers? 

This used to be very common in Reading where the NDL turbos were often left running with no crew on board for quite long periods of time. Recently however I've noticed that the NDL trains now wait with doors open and the engines off, until the crew turn up about 10 minutes before departure and the driver restarts the engines. On one occasion the driver then wound the engines up to full power for about half a minute, which was extremely noisy inside with the doors still open!

Reasons to leave engines running.
Fear that if stopped, that they might not start when called upon.
To provide air for brakes, air suspension, door operation and perhaps other purposes.
To provide electricity for lighting and sometimes other purposes.

Reasons to not leave engines running.
Fuel costs.
Climate change.
Noise nuisance.
Local air pollution.

How to reduce engine running.
Improve maintenance so as to ensure reliable re-starting.
Fit larger main air reservoirs, and mend some of the air leaks to reduce air consumption.
Better batteries so as supply half lights without engine running.

In the longer term electrify.
On longer DMUs, consider design alterations so that only one engine need be run, rather than several.

There’s no doubt drivers could shut their engines down more often.  Some only do it where local instructions mandate that they do.  

Depending on the type of train the heating/air conditioning and lighting will soon start to drop off, so in extreme temps it’s best to keep running, but in all other occasions I think a general 15 minute layover rule should apply as doors will usually be ok for getting on for an hour.  With IET’s that should mean into the ‘turnaround’ mode where 1 or 2 engines are kept running on 5 and 9/10 car trains respectively.  It would be good if a similar system could be developed for older trains.

When the engines are revved to max on Turbos it means the compressor speed up has been activated which helps to build the air up quickly - you need about 7 bars in the brake cylinders before the brakes can be released.

In extreme cold weather, below zero, I would support leaving engines running in the interests of reliability and passenger comfort.
In extreme hot weather, over about 28 degrees, I would support leaving the engines running if required to supply air conditioning.

In less extreme conditions, engines should be shut down whenever possible.

With older buses on layover, they were left running all day from the start for fear of never starting again out on the road, and perhaps this is the case with older multiple units. Many older buses would come with a large note in the cab with instructions not to switch off. There were also huge air leaks so it would take several minutes to build pressure back up meaning many drivers would rev the damn things hard till pressure built up. However, times should have moved on and more modern buses and rolling stock should be more than capable of being built and maintained to a level where they can be turned off during layover, thus saving from pollution, fuel waste and, often overlooked, noise.

It's not just passenger trains on layovers at Reading (and indeed when being assembled into longer combinations of two or three being assembled to go to the depot,  which in a northwesterly wind results in the over bridge canopy filling with noxious fumes)  it is also the Windhof (?) Railhead cleaning trains that sit at the inner ends of platforms 5 or 6 adding a loud unpleasant racket to the fumes.

Switch the d.........d things off!

Over the last couple of days I have travelled on a number of the Valley Lines out of Cardiff.

On a couple of occasions while the 150 has been waiting at a crossing point for a train coming the other way the engines have shut down.  I suspect it was automatic as on both occasions just after the engines shut down the doors were closed and the engines re-started.  I can't see the driver shutting them down just ahead of departure.