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ScotRail HST Introduction - Updates & Discussion

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Railperf

Railperf

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chuff chuff said:
Which route?
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The full monty. So Edinburgh to Aberdeen and back. Edinburgh to Inverness return, Glasgow to Inverness and return, and Glasgow to Aberdeen and return. Looks like i will be chopping and changing at Perth quite a bit to get the best itinerary in order to cover the 3 major routes. Plus a blast from Edinburgh to Glasgow and back aboard the 385's.
 
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chuff chuff

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I've managed a few 0-100 runs your looking at 2 1/4 miles and two 1/2 miles or other way round,did post it on lner azuma thread.
 
Railperf

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jingsmonty said:
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...
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That's no surprise. a 158/170 can't even match an 8 coach HST, and a 6-car is light years ahead. So your Scotrail 4-coach versions are going to accelerate faster than Class 385 EMU's - well almost!
 
jingsmonty

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Railperf said:
which stations were those from?
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Railperf said:
do you suffer much trouble with wheels slipping?
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Not really - same as any train, early morning mist can induce wheelslip, as can light drizzly rain. I've not driven an HST during the autumn, though..
Whenever I've had wheelslip, I've found out that you can gain reasonable acceleration in notch 3 or 4 (stiil better than a DMU flat out) until more speed is built up. Again, though, I've no experience with an HST during leaf fall season!

There's a 'bothy rumour' doing the rounds just now about Scotrail power cars being retrofitted with sanding equipment - how true this is, I don't know....
 
jingsmonty

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Railperf said:
That's no surprise. a 158/170 can't even match an 8 coach HST, and a 6-car is light years ahead. So your Scotrail 4-coach versions are going to accelerate faster than Class 385 EMU's - well almost!
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As a 'real world' comparison between a 4 coach HST & a 170 or 158, when leaving Inverness & climbing up to Culloden viaduct & Moy loop, you'll be on full power in a DMU the whole way (about 16/17 mins), doing about 55 mph (170) or 50ish (158) up to Culloden, maybe briefly touching 70 on Culloden viaduct, then down to 50/55 climbing to Moy.

An HST will easily do 80 mph (line speed) to Culloden viaduct (notching back on the way UP the hill) & 75 mph from Culloden to Moy (line speed), with notching back required here too.

It's quite a machine...!
 
Railperf

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jingsmonty said:
As a 'real world' comparison between a 4 coach HST & a 170 or 158, when leaving Inverness & climbing up to Culloden viaduct & Moy loop, you'll be on full power in a DMU the whole way (about 16/17 mins), doing about 55 mph (170) or 50ish (158) up to Culloden, maybe briefly touching 70 on Culloden viaduct, then down to 50/55 climbing to Moy.

An HST will easily do 80 mph (line speed) to Culloden viaduct (notching back on the way UP the hill) & 75 mph from Culloden to Moy (line speed), with notching back required here too.

It's quite a machine...!
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In terms of station to station performance - how much of a potential improvement is this over the other traction? Have you had a chance to assess this?
 
Railperf

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chuff chuff said:
Carnoustie heading south would be another good one for it.You really need to pick your day for it if you're going for it.
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probably i will have to book an advance ticket - so i will have to take whatever weather comes on the day!!Lol.
 
jingsmonty

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Railperf said:
In terms of station to station performance - how much of a potential improvement is this over the other traction? Have you had a chance to assess this?
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It's a bit hit & miss just now, mainly due to the horrendous station dwell times with the 'classic' slam door stock. The 'SP' differential speeds on the HML don't help either.

The potential is definetly there, but some in-depth review of line speeds & the refurbished sets will be needed to fully realise it
 
Railperf

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chuff chuff said:
Carnoustie heading south would be another good one for it.You really need to pick your day for it if you're going for it.
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Checked the WTT, and not many HSTs stop at Carnoustie. So Arbroath looking the best bet for a decent 0-100.
 
BRX

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jingsmonty said:
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...
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Are they higher revving than a DMU engine though? (A very quick google suggests around 2000rpm for a class 158 engine)

I can see that in frontline use an HST is going to be going between high revs and idle quite a bit, the high revs being used to get moving with the maximum acceleration, but isn't the same true of a DMU especially on a line like the HML? My subjective passenger experience of 170s and 158s on the HML is that the engines are frequently being hammered at full tilt to make it up gradients etc.
 
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Railperf

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jingsmonty said:
It's a bit hit & miss just now, mainly due to the horrendous station dwell times with the 'classic' slam door stock. The 'SP' differential speeds on the HML don't help either.

The potential is definetly there, but some in-depth review of line speeds & the refurbished sets will be needed to fully realise it
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Yes...just checking the sectional appendix and on average the sprinter limits are 10mph above HST permitted speeds!
 
jingsmonty

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BRX said:
Are they higher revving than a DMU engine though? (A very quick google suggests around 2000rpm for a class 158 engine)

I can see that in frontline use an HST is going to be going between high revs and idle quite a bit, the high revs being used to get moving with the maximum acceleration, but isn't the same true of a DMU especially on a line like the HML? My subjective passenger experience of 170s and 158s on the HML is that the engines are frequently being hammered at full tilt to make it up gradients etc.
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I"m not sure about the max revs of DMU engines, but I can certainly attest to fact that they spend far, far longer at full throttle than an HST on the HML!

An HST only needs notch 5 (normally) to reach line speed, an intermediate notch is usually enough to hold line speed, once you reach it (evrn on a rising gradient). Wheras a DMU is pretty much on full power from, for example, Blair Atholl to Drumochter summit.

I've heard of a Scotrail HST running on one power car maintaining line speed on this part of the HML, which, if true, is truly impressive
 
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jingsmonty said:
I"m not sure about the max revs of DMU engines, but I can certainly attest to fact that they spend far, far longer at full throttle than an HST on the HML!

An HST only needs notch 5 (normally) to reach line speed, an intermediate notch is usually enough to hold line speed, once you reach it (evrn on a rising gradient). Whereas a DMU is pretty much on full power from, for example, Blair Atholl to Drumochter summit.

I've heard of a Scotrail HST running on one power car maintaining line speed on this part of the HML, which, if true, is truly impressive
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Notch 5 is set at 1500rpm, 350rpm below the max for the engine - any more power and the traction motors will melt trying to use it!
Typical underfloor DMU engines are 2.1-2.4L per cylinder but the MTU HST engine is 4.77l/cylinder

As regards circa 900rpm max you are thinking of older low speed engines such as EMD's 710 2 stroke engine (11.63L/ cylinder) most modern locomotive engines are medium speed designs with lower displacements e.g. CATs C175 in the 68s 5.3l/cylinder (max 1800rpm) or the MTU 4000s.
The original Valenta engines were very ahead of their time.
 
hexagon789

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BRX said:
Are they higher revving than a DMU engine though? (A very quick google suggests around 2000rpm for a class 158 engine)
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1500rpm for an HST
1900rpm for a 170
2100rpm for a 158 (all ScotRail's ones being 350hp examples)
 
hexagon789

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jingsmonty said:
Cheers - every day's a schoolday! I was thinking of the sort of power units fitted to older locos, such as Class 47s
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I think 47s are 750rpm IIRC. Generally older Diesel-Electric locos tend to have slower-speed engines, multiple units and modern locos are typically higher-speed from what I gather.
 
Railperf

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There are 10 Scotrail diagrams showing in the 125 group website. Are all of these active.? How many refurbed and classic sets do Scotrail now have?
 
hexagon789

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Railperf said:
There are 10 Scotrail diagrams showing in the 125 group website. Are all of these active.? How many refurbed and classic sets do Scotrail now have?
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Not sure about diagrams, it seems to vary a lot. I believe there are 10 Classic (to be increased to 13) and 3 Refurbed sets. Only two of the latter in passenger service.
 
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I thought only the original refurb set was in use with the other 2 being used for training?
 
Highlandspring

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HA25 and HA26 have both been out in passenger traffic at the same time. HA24 is yet to see revenue service though.
 
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hexagon789 said:
Not sure about diagrams, it seems to vary a lot. I believe there are 10 Classic (to be increased to 13) and 3 Refurbed sets. Only two of the latter in passenger service.
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Given the final plan is for 27 sets, are there not more classic sets available until the refurbs are complete to free up 170s and 158s? It would surely be possible to send 5 sets to Scotland then as one refurb is complete send a Classic set south?
 
jingsmonty

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Class83 said:
Given the final plan is for 27 sets, are there not more classic sets available until the refurbs are complete to free up 170s and 158s? It would surely be possible to send 5 sets to Scotland then as one refurb is complete send a Classic set south?
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I've heard there's a shortage of TGS vehicles, not sure if that's accurate or not?

Although refurbished sets don't use TGS coaches, the Classic sets do
 
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