ScotRail HST Introduction - Updates & Discussion

[jingsmonty]

At Kings Cross, Paddington & St Pancras HST Power cars that are on the blocks are always shut down. Unless the service going back out is late and has a right turn around.

The proper procedure is to shut down the power car nearest the buffer stops & leave the other one running (as it's the rear power car upon arrival, the ETS would normally be supplied from here anyway). This is to prevent the station filling up with diesel exhaust fumes (& potential to set off the station fire alarm!).
Then, when mobilising the HST for departure, you'll go to the (shut down) power car, start it, release the parking brake & switch the ETS to run from what, now, will be the rear power car.

The power car outside the station roof (far end of the platform) is left running, as it maintains the air, as the ETS will provide power to the air compressor in the buffer end power car that's shut down on arrival. Saves a lot of hassle!

 

[jingsmonty]

The general impression of the classics is positive, very positive. To the point where people moan about a 170. Scotrail just need to get on top of the reliability and staffing and we are on a winner.

A bit of work though to get reliability up where it needs to be. I am sure though this is very achievable.

Pretty spot on comments. The HST is a big learning curve for us all (maintenance & train crew alike) & there's probably been issues crop up that were never envisaged. A lot of investment (probably not anticipated) has been necessary too (such as extending the stabling roads at Inverness).

But - once we get used to them (& give them a bit of TLC), they'll be great!

I get a bit sick of the 'old trains' comments from some of my more cynical colleagues - to me, an 'old' train (which has aged poorly, in comparison to an HST) that needs replacing, are the 158s...

It's a privilege to actually get to work these 'real' trains....

 

[chuff chuff]

There's a 5 car classic at top end of Haymarket out the road just sitting there been there past 4 days doing nothing baby reason why that is

Don’t know why it’s sitting up the head shunt other than keeping out of the road but it must be going through the fuel somewhat.

 

[Journeyman]

The general impression of the classics is positive, very positive. To the point where people moan about a 170. Scotrail just need to get on top of the reliability and staffing and we are on a winner.

I don't think this is anything to do with them specifically being HSTs, though. It's just the extra capacity, which could have been provided in many different ways.

A bit of work though to get reliability up where it needs to be. I am sure though this is very achievable.

Good luck with that. On average GWR HSTs fail twice as often as all the rest, so ScotRail have their work cut out.

 

[najaB]

Good luck with that. On average GWR HSTs fail twice as often as all the rest, so ScotRail have their work cut out.

Which is largely down to GWR's usage patterns and GWR's maintenance regime - there's nothing to say that the experience will be the same with ScotRail.

 

[Journeyman]

Which is largely down to GWR's usage patterns and GWR's maintenance regime - there's nothing to say that the experience will be the same with ScotRail.

But (a) the wear and tear is already there, and (b) the power cars are not getting the electronics upgrades which all the more reliable fleets have.

 

[najaB]

True on both counts, but that doesn't mean that ScotRail will necessarily have the same experience as GWR. Old and reliable aren't mutually exclusive.

 

[Northhighland]

True on both counts, but that doesn't mean that ScotRail will necessarily have the same experience as GWR. Old and reliable aren't mutually exclusive.

This so very true. If Scotrail get on top of the fleet and understand them and maintain them as effectively as a 170 then I see no reason why they cannot be successful.

The maintenance teams do a pretty good job breakdowns are thankfully rare on the 170 fleet. I say this having Used the HML fortnightly for the last 10 years.


Old does not equal unreliable.

 

[Railperf]

Hmm, you just have to watch old videos of HSTs to hear the abuse!

Now I imagine the MTUs get much gentler treatment. Certainly from what I've read in this thread there just isn't the need to thrash the living daylights out of them

What do you mean by abuse and thrash? The engines only run at a maximum of 1500 rpm and they are designed to be used in notch 5 at 1500 rpm. You cannot rev these engines any higher. And in marine applications the engines are run at a constant 1500 RPM hour after hour. If I remember correctly the early issues were to do with the heating and Cooling cycle generated by periods of full power followed by periods of idling.

 

[hexagon789]

What do you mean by abuse and thrash? The engines only rang have a maximum of 1500 rpm and they are designed to be used in notch 5 at 1500 rpm. You cannot rev these engines any higher. And in marine applications the engines are run at a constant 1500 RPM hour after hour. If I remember correctly the early issues were to do with the heating and Cooling cycle generated by periods of full power followed by periods of idling.

I mean abuse as in going straight to Notch 5 rather than notching up or into Notch 5 at lower speeds and very quickly shutting off again.

 

[Railperf]

I mean abuse as in going straight to Notch 5 rather than notching up or into Notch 5 at lower speeds and very quickly shutting off again.

based on what has been explained on this forum in the past I understood it made no sense to go into notch 5 as it was the electronics that didn't agree with a full load demand at lower speeds - and not any issue to do with the engine not mechanically being able to cope.

 

[Railperf]

I am planning a trip Scotland shortly so could someone please update the diagrams for these?

 

[hexagon789]

based on what has been explained on this forum in the past I understood it made no sense to go into notch 5 as it was the electronics that didn't agree with a full load demand at lower speeds - and not any issue to do with the engine not mechanically being able to cope.

I still wouldn't have thought it did much good for the engine going full speed, idle, full speed etc.

 

[najaB]

I still wouldn't have thought it did much good for the engine going full speed, idle, full speed etc.

I'm not a mechanic, but something in the back of my mind is telling me this is less of a problem for diesel engines than petrol.

 

[anamyd]

Pretty spot on comments. The HST is a big learning curve for us all (maintenance & train crew alike) & there's probably been issues crop up that were never envisaged. A lot of investment (probably not anticipated) has been necessary too (such as extending the stabling roads at Inverness).

But - once we get used to them (& give them a bit of TLC), they'll be great!

I get a bit sick of the 'old trains' comments from some of my more cynical colleagues - to me, an 'old' train (which has aged poorly, in comparison to an HST) that needs replacing, are the 158s...

It's a privilege to actually get to work these 'real' trains....

Speaking generally (National Rail), 158s are considered refurbishable to a modern standard and some have been; 158s (and 159s) will remain in service on the network alongside the refurbished and made reliable HSTs and mini-HSTs that will stay, after 150/153/155/156s come off...

 

[hexagon789]

I'm not a mechanic, but something in the back of my mind is telling me this is less of a problem for diesel engines than petrol.

Because of the nature of how diesel fuel uses compression-ignition while petrol is generally spark-ignited ?

 

[anamyd]

Because of the nature of how diesel fuel uses compression-ignition while petrol is generally spark-ignited ?

Diesel engines are also built from stronger materials than petrol engines. Not that there are really any petrol locomotives left

 

[hexagon789]

Diesel engines are also built from stronger materials than petrol engines. Not that there are really any petrol locomotives left

Well I think this shows my knowledge on the matter. I thought rapid low-high-low revs on an engine too often and too rapidly would increase wear-and-tear on it, but seemingly it's not as much of an issue?

 

[anamyd]

Well I think this shows my knowledge on the matter. I thought rapid low-high-low revs on an engine too often and too rapidly would increase wear-and-tear on it, but seemingly it's not as much of an issue?

Just look at train/lorry/boat etc big Diesel engines in general. They're designed to be way more than durable enough for the job. Take their capacity and cylinder count and then compare that with their relatively low horsepower and, to a lesser extent torque, figures.

 

[hexagon789]

Just look at train/lorry/boat etc big Diesel engines in general. They're designed to be way more than durable enough for the job. Take their capacity and cylinder count and then compare that with their relatively low horsepower and, to a lesser extent torque, figures.

Regarding durability then, do you know if the MTUs any better or worse in that respect?

 

[43096]

Regarding durability then, do you know if the MTUs any better or worse in that respect?

As I think I made the original comment misused and abused comment about the Valenta, I’ll make these points:
- the MTU is a 25-30 years newer design with all the improvements in materials and manufacturing techniques since then
- the HST duty cycle is uniquely demanding in terms of thermal cycling. When an engine is at full power it heats up and expands, the opposite when it is idling. Then think of all the idle - full power - idle - full power cycles an HST goes through every day and the resultant stress on the engine
- the Valenta never had the same TLC that the MTU does in terms of planned maintenance (oil change every 1,000hrs for example) and never had pre-heat (although 41001 does have it now). Engine wear is greatest at start-up and even more so on a cold start.

 

[hexagon789]

As I think I made the original comment misused and abused comment about the Valenta, I’ll make these points:
- the MTU is a 25-30 years newer design with all the improvements in materials and manufacturing techniques since then
- the HST duty cycle is uniquely demanding in terms of thermal cycling. When an engine is at full power it heats up and expands, the opposite when it is idling. Then think of all the idle - full power - idle - full power cycles an HST goes through every day and the resultant stress on the engine
- the Valenta never had the same TLC that the MTU does in terms of planned maintenance (oil change every 1,000hrs for example) and never had pre-heat (although 41001 does have it now). Engine wear is greatest at start-up and even more so on a cold start.

Thank you for the detail, that pretty much answers my questions, thanks.

 

[BRX]

- the HST duty cycle is uniquely demanding in terms of thermal cycling. When an engine is at full power it heats up and expands, the opposite when it is idling. Then think of all the idle - full power - idle - full power cycles an HST goes through every day and the resultant stress on the engine

In what way is this unique to the HST?

 

[route101]

Took the 1725 from Inverness to Glasgow , only Glasgow HML HST service i think . One mk3 lost power , so was out of action. overheard some moans about the franchise and HSTs from staff.

 

[jingsmonty]

In what way is this unique to the HST?

The performance required of an HST & the fact that the HST engines are 'high revving' engines, as far as rail use goes (although 1500 rpm isn't particularly high, it's higher than most) - I think a standard loco engine tops out at around 850/950 rpm? I may be wrong...

It's a fair point that Scotrail will likely be a lot gentler on the MTU units - moving an 8 coach train at 125mph, as opposed to pootling along at 60mph on the A2I line with 4 coaches is a different sort of operating environment. We're taught when notching back to hold it in notch 1 until the amps drop below 500. Also little need to maintain notch 5 for long periods (you'd be way over line speed if you did.....)!

 

[Railperf]

The performance required of an HST & the fact that the HST engines are 'high revving' engines, as far as rail use goes (although 1500 rpm isn't particularly high, it's higher than most) - I think a standard loco engine tops out at around 850/950 rpm? I may be wrong...

It's a fair point that Scotrail will likely be a lot gentler on the MTU units - moving an 8 coach train at 125mph, as opposed to pootling along at 60mph on the A2I line with 4 coaches is a different sort of operating environment. We're taught when notching back to hold it in notch 1 until the amps drop below 500. Also little need to maintain notch 5 for long periods (you'd be way over line speed if you did.....)!

I am planning a trip up in the next month. Which are the best stations to record a fast acceleration to 60 and 100mph?

 

[chuff chuff]

I am planning a trip up in the next month. Which are the best stations to record a fast acceleration to 60 and 100mph?

Which route?

 

[jingsmonty]

I am planning a trip up in the next month. Which are the best stations to record a fast acceleration to 60 and 100mph?

I can't speak for the Aberdeen-Dundee/Edinburgh/Glasgow trains, but heading out of Perth (towards Dunkeld), leaving Blair Atholl (North), leaving Carrbridge (both directions) spring to mind. Sustained acceleration when departing Inverness as well, as sustained power needed, due to the steep climb out - 80mph, which actually IS achievable with an HST! There's a stretch of 100mph on the HML, between Aviemore & Kingussie (South of Kincraig loop).

Sure there are others, but this is just off the top of my head... Aberdeen - Inverness is fairly pedestrian by comparison - quite flat & slower speeds (a mix of mostly 60, with a few bits of 65/70 as far as Elgin, then mainly 75 towards Inverness.

 

[Railperf]

The performance required of an HST & the fact that the HST engines are 'high revving' engines, as far as rail use goes (although 1500 rpm isn't particularly high, it's higher than most) - I think a standard loco engine tops out at around 850/950 rpm? I may be wrong...

It's a fair point that Scotrail will likely be a lot gentler on the MTU units - moving an 8 coach train at 125mph, as opposed to pootling along at 60mph on the A2I line with 4 coaches is a different sort of operating environment. We're taught when notching back to hold it in notch 1 until the amps drop below 500. Also little need to maintain notch 5 for long periods (you'd be way over line speed if you did.....)!

Yes, a GWR or LNER HST has to accelerate for at least 8 to 10 minutes to reach 125mph. Imagine the heat build up in that time. A short-rake Scotrail HST is not going to need more than 2 to 3 minutes worth of full power to reach the 100mph limits on the fastest sections of track. And the same applies to the steep gradients such as Schlod summit, where the shorter set will need less time on full power to hit the maximum linespeed. So i guess the heat build up will be significantly lower - along with the associated thermal stresses.

 

[jingsmonty]

Yes, a GWR or LNER HST has to accelerate for at least 8 to 10 minutes to reach 125mph. Imagine the heat build up in that time. A short-rake Scotrail HST is not going to need more than 2 to 3 minutes worth of full power to reach the 100mph limits on the fastest sections of track. And the same applies to the steep gradients such as Schrod summit, where the shorter set will need less time on full power to hit the maximum linespeed. So i guess the heat build up will be significantly lower - along with the associated thermal stresses.

Pretty much the case - only sustained Notch 5 we need is leaving Inverness & Carrbridge. Even then, line speed is still easily achievable fairly quickly. It's night & day compared to a 170/158...