ScotRail HST Introduction - Updates & Discussion

[gsnedders]

If I remember my high-school physics, high power AC motors are significantly lighter than their DC equivalents.

And smaller.

 

[swaldman]

If I remember my high-school physics, high power AC motors are significantly lighter than their DC equivalents.

And they don't need the brushes replacing periodically because there aren't any.

Ahhh. Thanks

 

[edwin_m]

What's the benefit of AC motors on diesels? Presumably for overhead electric power it avoids an AC->DC conversion stage, with associated losses, but that can't be the case with HSTs?

At the risk of going off-topic, the use of AC motors has nothing to do with the power supply of an electric train being AC or DC. The motors need AC at a specific frequency depending on speed, so the AC supply is turned into DC and then "inverted" to produce AC at the correct frequency for the motor.

This also means that the speed of an AC motor is more controllable than that of a DC motor, which is another reason to use them on diesels (as well as electrics) as it reduces wheel slipping when adhesion is poor. Also an AC motor can provide more torque, and therefore more acceleration, at the higher end of the speed range but on a diesel this is only useful if the engine itself has enough power.

 

[InOban]

And while the OHLE is 25kv single phase, the motors use 3 phase. So 25kv is first transformed to a lower voltage ? ca 300v? then rectified, then converted using fancy thyristors into 3 phase AC. Modern DC trains also use AC motors, which is why we have AC/DC trains.

 

[NotATrainspott]

If you replaced the HST drive motors there really wouldn't be much of the original train left!

It would be lovely to have even more bits of the HSTs made new. I would love for Hitachi to resurrect the Hayabusa concept and for the ScotRail HSTs to become hybrids. I doubt anything that major is going to happen though since I can't see the investment every really being repaid. The other major fleet refurbishments have been in and around London where there's a need to eke out every last bit of efficiency. In ScotRail-land the HSTs are already going to be a significant improvement over the 170s without any further work being done. There seems to be no problem finding depot and stabling space, so in the worst case scenario ScotRail could just pick up some more power cars as they become surplus to requirements. That seems to be the plan for the Mk3 EMUs, given the ever-increasing number of 321 conversions heading up here.

 

[Northhighland]

Think the sanding gear is a must. On VTEC Inverness train just leaving Pitlochry and struggling to get traction. Weather not bad at all just drizzle. Worse than any other time have been on this train and I use it every other week.

 

[jingsmonty]

Think the sanding gear is a must. On VTEC Inverness train just leaving Pitlochry and struggling to get traction. Weather not bad at all just drizzle. Worse than any other time have been on this train and I use it every other week.

Totally agree with that, Pitlochry can be very slippy. Leaving Inverness heading South is tricky too - lots of other blackspots. I will be sorely disappointed if our HST doesn't have sanding gear...better order a good few replacement nosecones too...!

 

[Highlandspring]

The powercars aren't getting sanders. A new driver's seat, forward facing CCTV camera and modifications to incorporate a traction interlock circuit (for the power doors) are the only modifications. We've been told that sanders won't be necessary because the short sets won't weigh as much as the VTEC 2+9s so adhesion "won't be an issue"...

 

[Paul Kerr]

I sure do, it's located in the village of "any thing's possible", on a serious note, it would have been better for XC if they had ordered more Voyagers in the long haul, which are fully DDA compliant, crash worthy, stylish, enviromentally friendly and can be formed of 10 coaches. (2 x 5 Coach Voyagers)

Stylish? You must be joking surely. Voyagers are (in my opinion) one of the worst design of trains ever foisted on the unfortunate traveling public in the UK. Ugly, cramped and smelly, not to mention the constant drone and vibration from those Cummins underfloor engines which is enough to drive you to distraction. The Voyager is a glorified Class 170 by all accounts and doesn't seat many more passengers than a 170 either. If you want to travel on those glorified rail buses be my guest; the rest of us are looking forward to travelling on a proper train without the noise of those awful underfloor engines and which was designed by engineers, not bean counters

 

[Paul Kerr]

HSTs are quite expensive to operate, in terms of leasing and ,maintenance.

More expensive to maintain, yes. But the HSTs are cheaper to lease because of their age. Still, it's like comparing a 40 year old Mercedes SEL to a 15 year old Ford Focus. The HST is a vastly superior train to what they are replacing, hands down. Better designed and far more comfortable. As for those Voyagers, don't get me started on their flaws again; we could be here all day!

 

[380101]

The powercars aren't getting sanders. A new driver's seat, forward facing CCTV camera and modifications to incorporate a traction interlock circuit (for the power doors) are the only modifications. We've been told that sanders won't be necessary because the short sets won't weigh as much as the VTEC 2+9s so adhesion "won't be an issue"...

One of the Driver Trainers (nice shiny shoes) showed us a picture of the HST "sander" at a safety brief last week in Glasgow. All I'll say is good luck with it in a howling wet day and that the penny pinching attitude of Abellio will come back to bite them big style over their new trains introduction. Glad i only have a wee 156 and "Rolls Royce" 380 to drive!

 

[AndrewE]

Voyagers... enviromentally friendly

Really? Someone said in another thread that they are very fuel-inefficient, and if you are talking about controlled emission toilets, then (apart from cosmetic and track and under-train worker issues) the old-fashioned system is effectively a linear sewage works, with lots of ballast for bugs to live on which eat up the nutrients.

 

[43096]

Stylish? You must be joking surely. Voyagers are (in my opinion) one of the worst design of trains ever foisted on the unfortunate traveling public in the UK. Ugly, cramped and smelly, not to mention the constant drone and vibration from those Cummins underfloor engines which is enough to drive you to distraction. The Voyager is a glorified Class 170 by all accounts and doesn't seat many more passengers than a 170 either. If you want to travel on those glorified rail buses be my guest; the rest of us are looking forward to travelling on a proper train without the noise of those awful underfloor engines and which was designed by engineers, not bean counters

You were doing well until the end.....

Bean counters don’t design trains. It’s a pretty dumb and ignorant comment.

 

[AndrewE]

You were doing well until the end.....

Bean counters don’t design trains. It’s a pretty dumb and ignorant comment.

Better to have sad "Designed to appease the bean-counters!" The problem is with making a business case for a private-sector investment, which demands as quick a return as possible, against a public-sector infrastructure investment, which wants the best value-for-money over the long term. Witness the quality and reliability of Mk3 stock (and even the Sprinter DMUs) after all these years compared with some of the stuff built since.

 

[najaB]

The problem is with making a business case for a private-sector investment, which demands as quick a return as possible...

All depends on what type of investment you are talking about. Many private sector projects have 30+ year return periods.

 

[AndrewE]

All depends on what type of investment you are talking about. Many private sector projects have 30+ year return periods.

Examples? I'll bet most of your "private sector" projects running over that period are PPI or infrastructure-related. Either that or they pay for themselves pretty quickly, leaving a hefty profit over the longer term.

 

[najaB]

Examples? I'll bet most of your "private sector" projects running over that period are PPI or infrastructure-related. Either that or they pay for themselves pretty quickly, leaving a hefty profit over the longer term.

Way to go there creating an unlevel playing field removing infrastructure from the private side but leaving it on the public side.

 

[AndrewE]

Way to go there creating an unlevel playing field removing infrastructure from the private side but leaving it on the public side.

No, my point is that your "private sector" schemes with a long payback are really public funded in some way or other (with an absolutely guaranteed long-term income stream), whereas you haven't yet pointed out any purely private speculative venture that would depend on a long-term return.

 

[MG11]

Really? Someone said in another thread that they are very fuel-inefficient, and if you are talking about controlled emission toilets, then (apart from cosmetic and track and under-train worker issues) the old-fashioned system is effectively a linear sewage works, with lots of ballast for bugs to live on which eat up the nutrients.

I meant with them being Diesel ELECTRIC Multiple Units, the electric generators reduce carbon gases.

 

[AndrewE]

I meant with them being Diesel ELECTRIC Multiple Units, the electric generators reduce carbon gases.

Oh dear... can't you see that it's still a fossil-fuel powered train? It might even be the case that more fuel is used with an intermediate transmission stage than a simple diesel mechanical would use, although probably not.

 

[cactustwirly]

I meant with them being Diesel ELECTRIC Multiple Units, the electric generators reduce carbon gases.

You clearly do not know what you're talking about...
Voyagers will produce the same amount of CO2 as other DMUs, its just that the transmission is the electric motor, instead of a hydraulic transmission.

 

[43096]

I meant with them being Diesel ELECTRIC Multiple Units, the electric generators reduce carbon gases.

 

[deltic08]

Better to have sad "Designed to appease the bean-counters!" The problem is with making a business case for a private-sector investment, which demands as quick a return as possible, against a public-sector infrastructure investment, which wants the best value-for-money over the long term. Witness the quality and reliability of Mk3 stock (and even the Sprinter DMUs) after all these years compared with some of the stuff built since.

You can't say that about Mk3s. Privatisation has been a complete success due to noisier, smellier, more cramped, claustrophobic DMUs/EMUs and extortionate, eye-watering fare increases to travel on them. That is the only reason for 120% growth since 1995.

 

[snakeeyes]

Does anyone have any pictures of the HST getting converted at all please?

 

[Bletchleyite]

Does anyone have any pictures of the HST getting converted at all please?

There are a few upthread if you scroll back I think.

 

[IanXC]

Can I remind members that this thread is entitled:

ScotRail HST Introduction - Updates & Discussion

Discussion of Voyagers, Airliners, Nuclear Power Stations etc, is off topic!!

 

[Highland37]

Thank you.

Scotrail are still in patronising mode regarding cycle spaces. I think they are trying to avoid telling the public that the spaces they had promised will not be appearing.

 

[Paul Kerr]

You were doing well until the end.....

Bean counters don’t design trains. It’s a pretty dumb and ignorant comment.

Apologies; I was being facetious. No offense intended. Saying designed to appease accountants (not bean counters) would have been a better and more respectful coin of phrase, but would you not agree that accountants do drive most of the design decisions on today's railway? Regardless, I think the HST with its well designed MK3 saloons is vastly superior to either a Voyager or the existing 170's. I remember very well travelling on the MK3 push pull sets on Scotland's inter-city network in the 80's which in my opinion were the peak of intercity rail travel in Scotland. I also remember ScotRail investigating running short formed HST sets cascaded from the ECML to replace the 47/7's as their reliability started to suffer. How ironic we have come full circle nearly 30 years on! I think the HSTs will be a roaring success; I do think they will need to be strengthened to 2+5 and 2+6 though. Time will tell.

 

[InOban]

The phrase 'the cost of everything and the value of nothing' comes to mind.

 

[Marklund]

The phrase 'the cost of everything and the value of nothing' comes to mind.

With regard to not fitting sanders? Yes.

Have the mini-HSTs been tested on the Inverness route yet?
Would have been interesting in the leaf-fall season, and a perfect time to test to justify the decision not to fit them if it was entirely successful...