Discussion on EMU's from the Cig 3 thread.

Bit off topic, but all new 750v DC EMUs have to have the capability for 25kv AC overhead supply, was this forced upon by the regulators or was it an option to then operate on other lines that don't have 3rd rail.

 

It wasn't forced on anyone, but as trains are owned by private companies it makes economic sense to make them future proof in the sense that they can be moved around the Network if necessary in search of better leasing deals. Also the extra costs of making a train dual voltage are tiny in comparison to the costs of building it in the first place as there is hardly any difference between the two these days particularly as a single design of bodyshell and a single type of traction 'package' can be used for both*). This is because unlike previous BR ordered electric stock which was ordered for a specific need and no need to consider alternative uses for it.

*ALL modern electric trains take their supply (regardless of whether it is DC or AC) and turn it into a nice 'clean' DC feed (the 750 received from the conrail is too 'noisy' and full of voltage spikes to be used as is) before turning that into a form of AC for the computer controlled AC traction motors.

 

The NRM had a Class 50 - 50033 - it got rid of it.
Ironically the Class 84 must rank as the most unsuccessful 25kV locomotive design, highlighting the fact that the NRM doesn't just preserve successful designs.

The NRM also has examples of classes 02, 03, 08, 20, 33, 40, 55, 87, the APT-E, a prototype HST power car, the prototype Deltic, etc and has at least 58050 and 73142 designated for preservation. So a little more comprehensive than you imply!

 

And, just to build the picture, took 50033 on despite being a relatively minor footnote in locomotive history and a significant proportion of the class already being preserved.

 

Didn't they end up with that one by default because they just had it on loan from BR for a long time? And presumably BR initially lent them something that wasn't very good because all the decent stuff was still in use.

 

True, but it doesn't fit your definition of new sidings, platforms etc. at places where it already exists. It's still a brand new railway line.

All of those mitigating factors could be true of our hypothetical electrified heritage line, too, potentially.

And as for the project being uneconomic if the new S-stock were unable to run over it - not necessarily, because it would be perfectly feasible to run a DMU service to Aylesbury instead, with London passengers changing at Croxley or Rickmansworth, if that was the only way of making it work. But they don't want to do that. My bet is that nobody has tested the economics of the alternatives, because neither the ORR nor anybody else has asked them to.

So desirable that they've been talking about it for at least 20 years without so much as turning a sod.

As for this argument about VAT exemption, it's a fallacy. I remember talking to a senior manager of a heritage railway about this some 10-15 years ago and he pointed out that passengers on cruise liners aren't on journeys that fulfil a public transport need either - that doesn't mean that they are any less important as passengers, they still want to go somewhere, even if they never leave their cabin.

Thus clearly demonstrating my point that it is not a blanket ban, it is a case of looking at what is proposed, what the risks and mitigations are, and taking a view. Clearly, building new lines with exposed conductor rails is not something to be undertaken lightly, and anyone proposiong it would have to jump through many hoops, but to suggest that the ORR won't allow it, period, is just not true. As the above example proves.

The definition of risk is a product of the probability of a hazard occurring and the consequence of that hazard. So by your own admission if a Sussex resident is more aware that there are dangerous voltages in the rails, the probability of that person being daft enough to climb over the fence is reduced, thus the risk is lower. The consequence is of course the same, though if we're lucky that might just mean severe burns.
On 25kV lines, the probability of coming into contact is much reduced but the consequence is devastating - basically certain death. One could argue that in windy parts of the country (like, say, Scotland) where people are more likely to fly kites, we would be better off putting the conductors on the ground. Yes, this is a spurious argument but my point is that it is not black or white, but various shades of grey in-between which we are trying to quantify.

I do take your point though.

So do I, actually. And I remain convinced that a d.c. electrified heritage line is at least a theoretical possibility. So we shall have to agree to differ, at least until it happens whereupon I can say "I told you so". (A 25kV a.c. one, on the other hand, I can't imagine ever happening.)

PS: Mail Rail?

 

Ironically, I think a 50 in completely original condition would have been a worthy candidate for preservation because it was rather ahead of its time - the first mainline diesel to be full of electrical gubbins... and the first mainline diesel to be full of electrical gubbins that was so chronically unreliable it was all stripped out upon refurbishment. So in it's original form, I think there are two reasons (or is it lessons?) that 50033 would have been a worthy candidate for the National Collection.

However, as you rightly say, in its refurbished state it wasn't a particularly innovative or worthy design and there were already a whole bunch preserved... I think leaving the likes of the Class 50 Alliance to specialise in those locos was ultimately a wise idea.

Although let us not forget that it took a hell of a lot of persuasion (and a campaign led by RAIL magazine) in the mid-1980s to get D200 claimed by the NRM and, before that, restored back to mainline use by BR. Initially the NRM was adamant that it wasn't needed, despite its significant historical status as the doyen of Britain's first class of mainline diesel locos.

Yes, I know here was some unusual story behind the fact that the 84 ended up preserved by the NRM. Is it significant because it was built by NBL? Anyone?

 

The solution to the "third rail" problem at some of the US museums (eg IRM, Seashore, Branford) is to mount a simple tram-style trolleypole on the roof of the cars so that they can be run off tramway style overhead. Not exactly prototypical, but it does work, and that is for fairly "heavyweight" subway/rapid transit rolling stock !

 

I'm not sure Crich'll want'em, and I think most heritage lines will be sceptical about installing oh wiring… Diesel shoving and maybe some sort of generator/battery lash up might work, but otherwise it's never going anywhere.

Sorry.

Simon

 

I more than likely won't fit through tunnels and bridges due to gauging issues. Have you seen the amount of tunnels / bridges rebored for the northern link program.

 

EMUs at Crich-ha, no!

The track layout is for single cars, not big long multiple units. The curves are too tight. The loops and stubs are too short. The rail is completely the wrong profile, and not meant for the axle loadings of an EMU. Crossings and points are completely wrong for railway stuff too. Oh, and running through the street-No!*

The power supply won't take the load. It struggled with Halle 902, the PCC derived car. I daresay you could get the wires nice and toasty too. All of this assumes you can fit a pantograph to the roof, which isn't as easy as you think. You need a strong enough roof, and the whole thing designed so if the pan gets snagged, it only rips the arm off and not half the roof. OHL on an existing railway would be a good, well understood engineering solution, but would look utterly wrong and cost a fair bit.

About the only thing Crich has got going for it for EMUs is the sodding great empty quarry next to it where you could store them.


*It has been suggested, not very seriously, that we recreate Weymouth tramway. Mere mention of a Class 33+4TC can now cause riots.

 

You are mixing up the physical situation on the ground and the legal state of affairs. For example consider the 'Leamside Line" in County Durham - a line which was "mothballed" by BR in the early 90s, then had most of its track stolen by scrap metal theaves over subsiquent decades (with the remainder lifted by network Rail a couple of years ago). In strictly legal terms it is still an 'existing railway' and as such NR could put the track back with virtually no consultation if they wished and nobody living nearby would have any right to stop them. Similarly when residents in Kincardine tried to stop heavy coal trains running over the rebuilt railway - because it had never officially been shut NR was legally entitled to run what they wanted whenever they wanted.

Thus with the Watford scheme the quantity of 'new' track is, in legal terms tiny - and whats more most of it will be on a brand new viaduct well away from the public. That all means the element of additional risk posed having exposed conductor rail on the 'new bit' is equally tiny. Yes the section from Croxley onwards to Watford Junction requires serious work to make it secure - but that falls under the 'upgrade any existing installation 'rather than 'new heading

Its all rather different from a rural line with only post and rail fencing to stop folk wandering onto it or the Uckfield / Marshlink / North Downs lines or any heritage setup I can think of.

Potentially yes. Realistically No.

The cash turnover of an organisation like LU is way more than even the best performing Heritage body which means they can have more people in the right places with the right skills to convince the ORR they can manage the situation. They have also been around as a organisation for a considerable quantity of time and as such have a well established track record which they can use as evidence that they are competent in all aspects of exposed conductor rails.

Also I have yet to see a Heritage railway successfully establish itself as a public transport operator anywhere in the country. Yes some people make use of a Heritage railway for public transport because it happens to be convenient for them - but that is not why the Heritage railway exists in the first place. Public Transport is by contrast the sole reason for LUs existence - yes they may do Heritage things from time to time (station restorations, the Steam on the Met specials etc) but that is not heir prime function.

VAT is 20% is it not. Take the cost of a train tickets to travel on the Severn Valley, North York Moors, the Bluebell, etc is not exactly the cheapest of things, particularly as far as families, etc are concerned (even with the various types of 'family' tickets out there) As such visitor numbers would be hit if VAT were applied to such lines - which is why even the tiny East Somerset railway and the infant Swanage Railway went between two publicly accessible station as soon as possible.Now that doesn't mean to say that said railways are 'public transport' as you or I might understand the term, but from an accounting point of view it doesn't matter whether the passengers are just out for a nice ride or not. If both stations are publicly accessible then it is a public transport service under law and any railway would be a fool to not take advantage.

I suggest you think a bit more about what you have just written - public bodies don't go round spending large quantities of taxpayers money without lots of research, feasibility studies, etc to back up their decisions and being a recently approved scheme there is lots of information on the web. To summarise however...

Firstly the mere fact that the link between the two lines has to be on a long viaduct crossing two roads and the Grand union canal means the infrastructure costs are large (you don't save much by making it single track) and their construction costs need to be paid back somehow. Studies show a frequent Metropolitan service is far more likely to attract users than a relatively infrequent diesel service. Secondly it has long been recognised (even by the LNER & LPTB when they built the Watford branch) that the station in Watford is badly sited (it was originally planned to be in the main shopping street but the railway companies were continually refused cross Cassiobury Park to get there). Thirdly the current scheme makes efficient use of resources - the ticket gates from the current met station will be re-used at the new stations on the extension and it only requires 2 extra S stock train to be procured. Fourthly various combinations of a service along a Aylesbury - Rickmansworth - Watford axis WERE tested as part of drawing up the current scheme but all failed the BCR analysis and as such no public body (the DfT, LU, local councils) felt they could justify spending funds on such a service.

Also the ORR are a regulator, not a scheme promoter. It is up to others such as the DfT or TfL to decide whether to promote any particular scheme and work out the details. The ORR will examine the scheme not to question whether its good value for money - they are concerned whether it meets their requirements of a safe railway (which includes the safety of the staff running it) and that any new exposed conductor rail has significant justification for the deviation from the standard - which says that it presents too many risks to be allowed for new work.

Talk to anyone at the ORR off the record and they will tell you its never going to be allowed. Officially the position is simply that exposed conductor rail will not be permitted for new work unless it can be demonstrated that no other means is suitable / effective and that all reasonable precautions are taken to protect staff, passengers and the public at large. Also the definition of the terms 'new' and 'existing are not defined
However....

There are lots of things that are not officially banned in this country, but other H&S rules, Insurance considerations or legal liabilities make it practically impossible for any person or organisation to get round them. This is why the ORR talk of 'new' and 'existing' installations but do not define them and leave the proposer to make that choice.

To take you example of a hypothetical heritage railway with exposed conductor rail - that needs public liability insurance from the private sector to operate. Given the ORR advise against it what are the chances of obtaining a affordable policy for your railway - without which it cannot operate. In such a situation the ORR have not 'banned' you from doing anything but they have achieved the same end through alternative means.

It is important to note however that Network Rail have taken the official ORR stance / been given advice that electrification of the Uckfield / Marshlink North Downs / Bidston - Wrexham, etc cannot be done with exposed conductor rail - but that the laying of extra electrified sidings at Brighton and Horsham for the Thameslink project, plus the 'new' Borough market viaduct (not that different from the situation at Croxley in length and being a viaduct) and platforms at London Bridge are permissible.

I never said it was an impossibility from a theoretical point of view - but a theory is pretty useless until it can be put into practice in some manor or is proved correct / wrong by having a go.

Thus far the only Heritage style operation using exposed conductor rail is Volks Electric Railway on Brighton seafront - which is owned and run by Brighton and Hove City Council (with the active help of a voluntary supporting group).

Yes the 'Mail Rail' will join it in a couple of years or so, but this is underground (so difficult for the public to gain access to where they shouldn't be) plus the Trust operating it was until 2004 an integral part of Royal mail and it still has a strong relationship with its former parent.

So to surmise, while you may desperately desire the chance to experience 3rd rail EMUs working away under their own traction motors, the realities if the world we live in including such things as the ORRs guidance, HSE requirements, Insurance costs, the way even NR realise 3rd rail is a bad idea, etc means its extremely unlikely to happen. Pretending otherwise does nobody any favours, but as even then, I do acknowledge the theoretical possibility is there if someone feels brave enough to try.

 

Not quite sure how Crich even got brought into this, given that it is a tramway museum, not a rail museum.
At least in North America the tramway/interurban/heavy rail definitions are sufficiently blurred for the likes of the IRM at Union to electrify their entire 5 mile (?) main running line so that it can cater for steam, diesel and electric trains. They didn't have any overbridges to worry about, but I'm sure something could be arranged at a UK preservation site, even in the form of a "demonstration line" given the will and the finance. Personally, I can't see it happening though.

Its a shame the Low Moor preservation scheme floundered, as they intended to have an electrified operation to run both tramway and main-line stock, from memory.

 

Because it is fundamentally irrational to think that any other railway in the uk will ever have overhead wires. Not because I thought we'd see slam door emus at Crich.

Simon

 

It's not the only place running heritage trams with overhead wires. There are trolleybus museums with overhead wires too. A 25kV electric line though - isn't going to happen.

Phil-d259, you make some good points but you also agree with me that a 3rd rail heritage line, however unlikely in a practical sense, remains a theoretical possibility. So we have nothing further to discuss really. It "would be nice" if someone would have a try, and if someone was serious about it and had the right people involved I'm sure they would get pretty close to achieving it - you're obviously less sure, which is fine - it's a hypothetical discussion at present anyway. To pick up on one point in your message above, clearly fencing (and in a more general sense, keeping people out) would be one of the issues and traditional post-and-rail wouldn't cut the mustard, that much is obvious.

Meanwhile, I'm off to design an electrification system based on induction loops on the back of an envelope.

 

The Volks line is electrified at 110V like the Seaton Tramway so not the sort of risks you would get with 750V

Could an EMU run on those sort of voltages at 25mph?

 

power in Watts = Amps x Volts.High power is used at starting so at reduced voltage the current will rise to produce the same power. The EE 507 is rated at 250HP. I suspect that the current draw will be excessive at starting.. A 4 car unit has 4 EE507s total rating 1000HP. Interestingly a 12 car train had 3000HP, compareable with the first 25k AC locos

You could retrofit 110V motors and control gear but you would no longer have a clasic 3rd rail unit

 

If you really want to go off the deep end regards third rail...

A fully enclosed in plastic rail, with plastic lips covering the top and a wedge shape shoe to open them smoothly. Best analogy I can think of is the seals on car windows that wind up and down. Rail broken into short sections, maybe two car lengths, only energised when a unit is over them using some kind of sensor (magnetic or radio, perhaps). Think of a version of the tramway stud contact system, but with modern electronics that fail safe. Decent fences, and switch the lot off when not in use, you'd surely be about there for safety.
Bit of a pricey solution if you want to electrify for miles, but would do for a couple of miles of demo line. I am fully aware that this is pointless waffle, I find these problems interesting though.

 

Isn't this exactly the same principle that Brunel's Atmospheric Railway worked - or rather didn't work - on?

 

I think Brunel forgot to add the electric third rail in the pipe. Mind you, vacuum powered EMUs-that would definately avoid the dangers of 750V DC.

Unfortunately, EU laws prevent us building a big enough hoover to power it.