Class 170 question

[BaffieHalt]

Hi - I wonder if anyone can help
me?
I’m currently in correspondence with ScotRail regarding their use of Class 170’s 3 car sets for journeys between Edinburgh/Glasgow and Aberdeen.
Before the pandemic I must confess to being quite a fan of the Class 170’s but in these current times I can’t see how a three car set could ever be considered suitable for journeys lasting approximately two an a half hours (Aberdeen to Kintore perhaps!).

As a mere passenger - dare I say customer? - I’m struggling to find the correct technical language to express my concerns about the efficiency of the on-board air conditioning - as sadly the units in question are the later version without windows that open.

Does anyone know what system of air conditioning is deployed on a Class 170, how it’s calibrated and how efficient or otherwise it is?

Perhaps I’m being over critical but having sat on several trains that had “standing room only” from Perth onwards I feel ScotRail’s strategy for selecting suitable rolling stock needs to be interrogated

Baffie Halt

 

[WideRanger]

If there are windows that open in the main saloon of the train, then surely that is a much older train without air conditioning at all. I think that Class 170s are the most recently constructed Diesel trains that Scotrail has.

 

[BaffieHalt]

If there are windows that open in the main saloon of the train, then surely that is a much older train without air conditioning at all. I think that Class 170s are the most recently constructed Diesel trains that Scotrail has.

There were definitely a few with top windows that could be opened - by the guard I seem to recall.

 

[Neptune]

There were definitely a few with top windows that could be opened - by the guard I seem to recall.

Not on any 170’s. 158’s have 4 opening hoppers on each coach.

 

[BaffieHalt]

Not on any 170’s. 158’s have 4 opening hoppers on each coach.

I bow to your expertise and must have been mistaken. Are you able to answer any of the questions regarding the air conditioning provided on a 170?

 

[Neptune]

I’m afraid not. There will be someone on here for sure to help you though.

 

[scotraildriver]

What is your concern with the air conditioning? It generally works well although there can be hotspots and cold spots. What I do find happens is that crew set it to winter mode on cold mornings but it then gets too warm as the heating runs almost continually. It's best left on the "normal" setting. Crew can choose between Summer, normal or winter. Compared to 158s it's pretty reliable and there have never been any opening windows on 170s.

 

[Efini92]

There were definitely a few with top windows that could be opened - by the guard I seem to recall.

Are you sure it was a 170? That sounds like a 158 that you’re describing.


The air conditioning System is electrically driven off the alternators.

Carriage cooling is driven by two air conditioning modules for each car to give redundancy if one fails.

Carriage heating is by means of a water circuit.

A water pump in the diesel fired auxiliary heater will circulate heated

water around the circuit until the engine coolant reaches 70°C, this

then shuts down and the engine driven coolant pump circulates water

through a heat exchanger taking heat out of the engine coolant circuit

and passing it to the carriage heating elements.

 

[Ex-controller]

Hi - I wonder if anyone can help
me?
I’m currently in correspondence with ScotRail regarding their use of Class 170’s 3 car sets for journeys between Edinburgh/Glasgow and Aberdeen.
Before the pandemic I must confess to being quite a fan of the Class 170’s but in these current times I can’t see how a three car set could ever be considered suitable for journeys lasting approximately two an a half hours (Aberdeen to Kintore perhaps!).

As a mere passenger - dare I say customer? - I’m struggling to find the correct technical language to express my concerns about the efficiency of the on-board air conditioning - as sadly the units in question are the later version without windows that open.

Does anyone know what system of air conditioning is deployed on a Class 170, how it’s calibrated and how efficient or otherwise it is?

Perhaps I’m being over critical but having sat on several trains that had “standing room only” from Perth onwards I feel ScotRail’s strategy for selecting suitable rolling stock needs to be interrogated

Baffie Halt

Hi there

None of the class 170 units have windows that open. I’m not sure the air conditioning on those units would be any less effective than any others, although the mid saloon doors would allow for the passage of air through the carriage, but that’s only for limited periods as you know.

Im not sure that you’d be at any greater risk on a class 170 units v any other type, aside from potential overcrowding issues caused by them having more limited space as opposed to a HST. However a HST could also potentially be overcrowded under certain, albeit unlucky, circumstances. The reduced timetable on many of the long distance routes also wouldn’t help I imagine.

As for decisions on whether a class 170 operates on a longer distance route, there are two aspects to this. First is train planning, who create the original schedule and the intended rolling stock resource (ie the type of train planned to operate).

ScotRail should have enough HST stock to operate all their long distance routes but even with that, it is likely that some services will have to be operated by class 170 or 158 units. Otherwise, there would be no means of transferring them to different parts of the country to cover other services there (eg Montrose to Inverurie). Ideally this transfer of stock would be scheduled for quieter services, such as late night or early morning).

The other aspect is last minute changes caused by train failures or other sources of disruption, meaning if the booked or diagrammed rolling stock is no longer available, and another of the same type can’t be found, the next most appropriate will require to be used. This will usually result in a class 170 unit being used where a HST is no longer available for use. These decisions are taken at short notice and have a number of factors impacting on the decision, including reduction of delays, wider impact of the stock change, rolling stock fuel and maintenance requirements. I’m afraid it’s not something that the general public, or even elected representatives can really interrogate very easily unless you have sn in depth knowledge of railway operations and rolling stock specifications.

It sounds like the biggest issue you may have here is overcrowding, which is unfortunate but should hopefully be alleviated somewhat by use of face coverings. I doubt the air conditioning quality varies by a huge amount on any train, although someone may correct me.

 

[Spaceship323]

Is the air continually recirculated (as this would be the most efficient way of keeping a constant temperature), or can it be set to provide fresh air to the cabin?

 

[BaffieHalt]

Thanks everyone for the feedback and information - very informative and useful.

 

[Tynwald]

Aircon is at recirculative at hightest, or lowest tempretures. but always allows a percentage of fresh air. 158 aircon is dreadfull. driven by hydrostatic motors.