Class 320/4 (Scotrail, formerly of London Midland)

[Scotrail12]

3 times in a week that I've been on these trains and they are always really darn slow. They are also a much more uncomfortable ride than the regular 320's and the interiors aren't nice either.

Does anyone know if there are any problems with these trains? I'm curious as to how they are always so slow.

 

[hexagon789]

3 times in a week that I've been on these trains and they are always really darn slow. They are also a much more uncomfortable ride than the regular 320's and the interiors aren't nice either.

Does anyone know if there are any problems with these trains? I'm curious as to how they are always so slow.

Other than having been 4-car, I don't think there's much difference - they have the same traction motors outputs.

The only thing would be perhaps the gearing, the original 320 were 75mph, later increased to 90, while the 320/4 were 100mph when they were 321s.

The question is whether the gearing is any different or if an normal 320 has the same gearing.

 

[61653 HTAFC]

When the original 320s were upped to 90mph they had yaw dampers fitted to give a smoother/more stable ride at higher speeds. This resulted in a firmer ride at lower speeds but shouldn't have affected anything else (acceleration etc.). The later conversions already had yaw dampers fitted, so shouldn't be any different to their earlier lives apart from being shorter.

 

[hexagon789]

When the original 320s were upped to 90mph they had yaw dampers fitted to give a smoother/more stable ride at higher speeds. This resulted in a firmer ride at lower speeds but shouldn't have affected anything else (acceleration etc.). The later conversions already had yaw dampers fitted, so shouldn't be any different to their earlier lives apart from being shorter.

So an original 320 could do 100mph?

 

[61653 HTAFC]

So an original 320 could do 100mph?

Not sure how you've got that from the post you've quoted...

Originally 320s were 75mph units as mentioned upthread. Not sure if the motors and gearing would be capable of much more, but in any case the lack of yaw dampers meant that if they did significantly overspeed the bodyshell wouldn't necessarily stay within gauge... which is obviously a big problem.

The fitting of the dampers to the bogies prevented this and allowed the increase in max. speed to 90mph. 100mph may well have been possible but wasn't required for the routes they operate.

 

[hexagon789]

Not sure how you've got that from the post you've quoted...

Originally 320s were 75mph units as mentioned upthread. Not sure if the motors and gearing would be capable of much more, but in any case the lack of yaw dampers meant that if they did significantly overspeed the bodyshell wouldn't necessarily stay within gauge... which is obviously a big problem.

The fitting of the dampers to the bogies prevented this and allowed the increase in max. speed to 90mph. 100mph may well have been possible but wasn't required for the routes they operate.

I mean an original 320 in the sense not a 321 conversion, not one pre-yaw dampers

 

[61653 HTAFC]

I mean an original 320 in the sense not a 321 conversion, not one pre-yaw dampers

Then no. They were 75mph max. They might well have been technically capable of more, but wouldn't be safe doing so.

 

[Chris125]

Do they try and keep the 320/4s together? I can't imagine there's much if any performance difference if they don't.

 

[Scotrail12]

Do they try and keep the 320/4s together? I can't imagine there's much if any performance difference if they don't.

It varies. The train I was on this morning from Coatbridge Ctl to Argyle St was a 320/4 in the front and a regular 320 in the back. The one on the return leg is a 318 at the front and a 320/4 at the back. Just left Motherwell where I saw two 320/4's coupled together.

 

[hexagon789]

Then no. They were 75mph max. They might well have been technically capable of more, but wouldn't be safe doing so.

I think perhaps I'm still not being clear.

If there are no technical differences now between either the original build 320s abd those converted from 321s then do they both have 100mph gearing or only the ex-321s?

On other words is the running gear exactly identical on both types of 320.

 

[Peter0124]

Also noticed the PA tends to fault a lot on 320/4s. I've heard of a few times when the PA makes a horrible noise pitched noise almost equivalent to a fire alarm.

 

[61653 HTAFC]

I think perhaps I'm still not being clear.

If there are no technical differences now between either the original build 320s abd those converted from 321s then do they both have 100mph gearing or only the ex-321s?

On other words is the running gear exactly identical on both types of 320.

As far as I can determine, the yaw dampers were the differential factor (apart from length of sets) rather than motors or gearing, so in theory all sets could run at 100mph (providing they could gain a safety-case for running at the higher speeds) if there was an operational requirement to do so.

But I'll have to bow to the knowledge of others on this one. I think we have one or two front-line Scotrail staff as regular contributors to RailUK, so if they're able to answer this query that might be the best option.

 

[hexagon789]

As far as I can determine, the yaw dampers were the differential factor (apart from length of sets) rather than motors or gearing, so in theory all sets could run at 100mph (providing they could gain a safety-case for running at the higher speeds) if there was an operational requirement to do so.

That's exactly what I was meaning. That there's nothing in theory that makes either type any less capable of 100. Though I'm not sure whether the ex-321s are still stencilled for '100'.

But I'll have to bow to the knowledge of others on this one. I think we have one or two front-line Scotrail staff as regular contributors to RailUK, so if they're able to answer this query that might be the best option.

No problem