Atomic Systems

Hmm, I'm still against the multiple unit principle. I don't think talking about going over 125mph is going to be fruitful - besides, locomotive haulage can achieve this speed and more. Samd22 is right - the locomotive + carraiges + driving trailer is usable on both HSLs and 'regular' lines, as proven in Germany.

Nick

alexnick wrote:Hmm, I'm still against the multiple unit principle. I don't think talking about going over 125mph is going to be fruitful - besides, locomotive haulage can achieve this speed and more. Samd22 is right - the locomotive + carraiges + driving trailer is usable on both HSLs and 'regular' lines, as proven in Germany.

Nick

I wouldn't really want to see loco hauled trains on an HSL - that would lower the available capacity. But if we have an HSL they would be great for serving the areas not warranting a regular HSL service.

For example, an HSL service would run directly from Manchester to London over new track. And a loco hauled train would run the route from Manchester-Crewe-Birmingham-Oxford-London.

Also as for speeds, in Germany loco hauled trains run at 230km/h on the section between Koln and Duren so travelling times shouldn't be a problem.

I believe we really need a mass electrification programme and then we need a new multi-prupose locomotive that runs on electric power.

Sorry, I misunderstood you there. I can see the logic of your principle, though. I'm sceptical that we will ever get a DB-NBS/SNCF-LGV style HSL built (apart from the CTRL).

To be pedantic, I'm not sure about the 230km/h claim. DB's 101s are limited to 220km/h - though the 182s might be capable of 230. I think SBB may run its Re460s at their maximum permitted 235km/h - certainly 200. Actually I was thinking of the Hannover-Wuerzburg NBS line, which sees similar loco-haulage.

You're certainly right about the mass-electrification programme - I believe it holds our railways back enormously.

Nick

My idea is to simply build dual cabbed loco's and stick one on each end of a rake of Mk3's, or new Mk3 replacement coaches.

The real problem with loco-haulage is track forces - most 'high-speed' locomotives (Class 91s, BR101s, Re460s, etc) weigh in at about 84 tonnes (21 tonnes per axle). Class 67s weigh 90t (22.5t/axle). Class 43s are superior to all this at 17.5t/axle. HST2 will be inferior if its powercars have anything more than 17.5t/axle - besides, the track peeps like stuff to be low in track forces, as it makes their life easier - which is also why I want the leading bogie to be unpowered, as this helps bring the train into the curve (instrumented up to provide data for Dan's active suspension). Weight (or lack of) is the order of the day - anything that can be moved to another vehicle must be, in order to meet the 70 tonne weight restriction - although I'd suggest a 'desirable' figure be around 64-66t. The marginal increase in the weight of the coaches would not be significant.

IIRC, using only four powered axles, held down by 80-ish tonnes, could lead to traction problems in that you're putting all your faith in the slippery rails under four motors. A 2+8 multiple-unit formation could theoretically have up to 18 motors (one per bogie, with leading/trailing bogies unpowered), so the chances of wheelslip significantly disrupting forward motion are reduced. If a motor or inverter set goes, you've still got 17 others - rather than three (or even two if the loco has only got one inverter per-bogie as opposed to one-per-motor).

Articulation would be nice - but I'm not sure if an articulated powered bogie has been successfully implimented into high-speed service - I think 'Elisa' was testing the concept for Alstom, but I don't think it's been tried elsewhere. It would be nice, and we do have about 10 years to develop it.

We haven't mentioned Coach Length - 26m conventional, 23m articulated.

Sleepie - we have Discount Book-Ahead fares already - commonly branded as 'Value' fares, other products also exist.

Time to think Quad-arts? if you do introduce articulated stock however, fixed length trains would be required unless there could be a way of fitting spare bogies into the locking point for recieveing the artic bogie so that you can jump a car out if there areproblems and it would be alrite to run without HST 2 or specially dsigned powercars/locomotives.

mattvince wrote:

BR7MT wrote:Over to Matt Vince

"Elvis has entered the building"

The Shopping List:

.......

That's all I can think of for the moment.

Matt - your love affair with all things technical seems routed in common sense. There any chance you could get a job with the SRA? Sounds like you know more about rolling stock than their bloody bean counters.

But anyway: Additions from the Footplate.

Braking - amen to anything that makes it pull up quick, although I am concerned that no mention was made of tread brakes. Nothing wrong with them; very handy for conditioning the wheel/rail interface (real speak: it cleans the wheels up when there's gunk around), and they also are much better than discs for low-speed control. When you're shunting half-sets of anything, treads are the thing to be using.

Control Systems. - Save us drivers from one-handle controllers. We want seperate power and brake controllers, please. It makes us feel like we're driving a train rather than a Playstation and it makes for a better driving position; when you have to be in the chair for four or five hours then you want to be comfortable. RSI will become an issue in years to come; mark my words. And while I think about it, can we have a cab that looks like it was a primary consideration rather than a tiresome add-on? Quiet, comfortable and with air-conditioning that not only works but doesn't drown out the AWS?!

Distributed Power - Unpowered leading bogies is a fine idea, but I would like to see as many seperate axles powered as possible with lighter, less powerful individual motors. Track force is kept down, adhesion is improved and under regen, braking would become markedly more efficient. No one wants to use 15% g. braking under normal conditions, but it's handy to have up your sleeve if required. Look at Ufton Nervet and Selby...
25 years ago APT sets using all braking systems were going from 125 to a stand in a quarter of a mile. We need to better that.

Multiple Unit versus Fixed Formation - never discount the "glamour" factor. HST is a loco+fixed rake+loco formation. There might be rumbles, but they are locos and carriages and as such the ambience is better than that of a unit. Units aren't sexy, they don't fire the imagination - despite Virgins best efforts. TGV does, but it's bigger, fast and more powerful than anything we're talking about here. The look is everything; todays railway is at least as much about marketing as it is about operations. In whatever form it arrives, it absolutely has to look the busniess.

Multiple Unit versus Fixed Formation - never discount the "glamour" factor. HST is a loco+fixed rake+loco formation. There might be rumbles, but they are locos and carriages and as such the ambience is better than that of a unit. Units aren't sexy, they don't fire the imagination - despite Virgins best efforts. TGV does, but it's bigger, fast and more powerful than anything we're talking about here. The look is everything; todays railway is at least as much about marketing as it is about operations. In whatever form it arrives, it absolutely has to look the busniess.

Can I also say that, as a passenger, locomotive-hauled coaches are better than multile units, especially DMUs. DMUs are horrible because they shake nastily with engine vibrations (EMUs not so bad) - HSTs are so much more comfortable to ride in than Voyagers and the like. Multiple units also tend to be more cramped than coaches - think Pendolinos (fortunately, we have Desiros down my way, so I'm quite lucky with this!) - one of the nicest things about rail travel is that you don't feel like you're being squeezed into a coffin (I get this sensation in cars and planes).

As for looking the part - please just paint them in sensible liveries! We have some of the most disgusting liveries in this country that I've ever seen! However, multiple units aren't characterless - I love old EMUs (and some newer ones - 455s) - but that's more charm than anything else - hardly marketable. To be honest, I think people would respond positively to something which was given a sensible livery, and looked relatively plain - industrial design should be kept simple.

Nick

Nick - the blame for Pendolino being so small probably lies at the door (or gravestone) of Joseph Locke, who was by comparison with some of his contemporaries, a bit of a cheapskate. Not only did he invent bullhead rail, but decided to build the West Coast to match the lay of the land, consequently the only way to go at a reasonable speed (like 125mph) is to tilt, and the only way to tilt at reasonable cost is to make the trains fit. Voyager - or SuperVoyager, to be precise - is in the same boat, the economies of scale of building 220s and 221s to be near-identical above bogie level meant it was more cost-effective for everyone - that Meridians/Pioneers also use similar components as it makes vehicle acceptance easier. The other problem with 220/222 units is apparently because of the rubber suspension on the B5000 bogies. Personally the paragon of excellence as regards DMUs is the Turbostar.

Styling - as I said earlier, a long, pointy nose (low in drag, high in speed...) - possibly taking some styling hints from Shinkansen sets. Then adapt whoever's livery to suit it (banning FirstGroup at the same time). The thing which really inspires is when the design looks like it's going 125mph standing still.

Perhaps, rather than investing in new trains, we need to be investing in our track. It seems that our track isn't in good condition - and we should try an electrify more of our network. Of course, we really should have been doing this a few years ago, but that's privatisation for you. I also still want to see how we could ever get the HST2 we want, seeing as the ROSCOs have so much control, and have no obligation to deliver good quality stock. We could also get more life out of the same stock if ROSCOs would let us cascade stock around the country from franchise to franchise more - perhaps we woldn't need an HST2 just yet then. I also don't see why we have to put up with trains built on the cheap.

Nick

The engineer's in the ROSCO's want a decent train, the bean counter's at the Treasury will be the ones who cut the price.

I think it will be taken as read that HST2 will have distributed traction motors throughout a fixed rake. If a diesel engine is to be used (I personally don't think it is necessary but I suspect the luddites at DfT Rail will insist on it...) then it must be in the end vehicles - the lesson's in passenger comfort experienced with the 220, 221, 222 families need to be learnt.

I am dubious about tread brakes purely because they lead to local heating on the wheel tread and therefore have a significant effect on the wheel/rail interface in terms of wear. It will be either wheel mounted disc's or axle mounted disc's, I suspect the former will be chosen if it is a Bombardier design whilst a foreign designer will probably go for axle mounted.

I seriously doubt that the bodyshell's will be designed for tilting, the Siemen's Venturio is certainly not a tilting bodyshell from what I have seen (yet they offer a tilting version - interesting...).

Separate power and brake controller's - again, I doubt that separate one's will ever be fitted again on main line stock, purely on the grounds of cost. But if the Union's were to make more of an issue of it; who knows?


The key thing's for track wear is the weight of the vehicles, design of the suspension and the speed. We need light-weight vehicle's with a suspension arrangement that minimises wheel/rail interface wear. The former is the domain of structural engineer's and material scientists, it is not impossible to achieve but cost is a factor. The latter exists mostly in theory with a few practical systems being developed (the Bombardier Mechatronic Bogie for instance) but again, adds complication and risk.

The design has to be carried out in a sensible and manner with a view to creating a design that will last at least 30 years.

Regards,

Dan

I am reading a lot of good points - Electrification is a must, progressivly over the next few years the GWML and MML should be done. All new track (including replacements) on main lines should allow for tilt.

I think I'm alone in finding Voyagers quiet and smooth - probably because I'm used to 150's - ok they are noiser then an HST (the Mark 3 always has been exceptionally quiet) but unless you are really listening for the engine you don't notice it. Most of their problems are due to length and interior layout

True - my anti-DMU somments could have something to do with having grwon up riding on EMUs. However, I don't see why we shouldn't expect a superior ride-quality from our trains. Maybe Voyagers are worst in first class, ironically.

Nick

enotayokel wrote:I think I'm alone in finding Voyagers quiet and smooth - probably because I'm used to 150's - ok they are noiser then an HST (the Mark 3 always has been exceptionally quiet) but unless you are really listening for the engine you don't notice it. Most of their problems are due to length and interior layout

I took one the other day that was vibrating so much the plastic panels inside were vibrating.

I agree with matt - the turbostars are the best riding, though I've yet to sample a desiro.

The 444s and 450s have great riding qualities - I don't know about the diesel versions. I'm afraid I don't like the 170s, however - they are very cramped inside - I'm just too tall for their seats! The 165/6s are much better if you ask me.

Nick