Operation of EMUs in Preservation

[luckymucklebackit]

We all know that it is pretty much improbable that there will ever be a preserved line with 25kVA overhead electrification,  the cost of installation and maintenance are obviously prohibitive and safety would always be a massive concern.  However the tramway museums at Crich and Beamish have fully functional tramwires and seems to be capable of  keeping them safe and in good working order.  This led me to pose possibly a daft question, could a BR EMU have its transformers etc altered to work off a low tramway voltage of 550V DC even at low speed and on the level?   Or do they just need to much amperage to get moving?

 

Jim

[Wickham Green too]

A transformer - by definition - requires AC current in order to transform one voltage to another ......... but it 'should' be possible to bypass the transformer & rectifier on older units ( most things preserved at present ) to run on DC. As you hypothesise, the currents to be handled between the catenary and existing DC circuitry would be far greater than the existing gear is designed for so heavier cabling etc would be required.

[rodent279]

11 minutes ago, Wickham Green too said:

A transformer - by definition - requires AC current in order to transform one voltage to another ......... but it 'should' be possible to bypass the transformer & rectifier on older units ( most things preserved at present ) to run on DC. As you hypothesise, the currents to be handled between the catenary and existing DC circuitry would be far greater than the existing gear is designed for so heavier cabling etc would be required.

It would have to have resistance control, and as most AC emu's use a transformer with a tapchanger, if you bypass the transformer, this literally wouldn't be going anywhere!

The only AC emu's that have resistance control that i know of are the class 313.

Edited February 1, 2021 by rodent279

[Pete the Elaner]

Why would you want to use DC?

If you leave it as AC you could step it up or down as required after transmission to the train.

But as mentioned earlier, lower voltage means higher current so the OLE would need to be heavier & therefore more expensive to maintain.

 

3rd rail is right out. I know it is rather silly to step on it, but if it can be done, someone will do it. Today's society will hold whoever installed it responsible for making the problem possible, so on that basis, Health & safety would not allow it. Extending existing railways is an exception.

Even the DLR got upside down shielded 3rd rail & that opened in 1987.

[DY444]

12 minutes ago, rodent279 said:

It would have to have resistance control, and as most AC emu's use a transformer with a tapchanger, if you bypass the transformer, this literally wouldn't be found anywhere!

The only AC emu's that have resistance control that i know of are the class 313.

 

What about the GE DC units that were converted to AC?  I don't know if they retained resistance control after conversion but feeding the DC traction equipment with DC obtained from the onboard transformer/rectifier (which is what 313s did) would have been the cheapest and easiest way to do it.

 

I reckon any BR era AC emu fitted with tapchanger or thyrister control (which covers most of them) is a none starter really.

 

Even if you could figure it out the other problem of course is getting enough current through a tram wire system.

Edited February 1, 2021 by DY444

[phil-b259]

47 minutes ago, luckymucklebackit said:

We all know that it is pretty much improbable that there will ever be a preserved line with 25kVA overhead electrification,  the cost of installation and maintenance are obviously prohibitive and safety would always be a massive concern. 

 

 

 

In theory 25KV is actually not a big problem from a regulatory perspective in preservation terms - it complies with the electricity at work act by being generally inaccessible to trespassers or the public (unlike conductor rail systems) and in any case 750VDc is perfectly able to kill you as well.

 

Put it this way, the ORR are far more likley to accept a 25KV preservation project than a 750V conductor rail one!

 

 

 

 

[phil-b259]

5 minutes ago, Pete the Elaner said:

Why would you want to use DC?

If you leave it as AC you could step it up or down as required after transmission to the train.

But as mentioned earlier, lower voltage means higher current so the OLE would need to be heavier & therefore more expensive to maintain.

 

 

Only to maintain the same power output ability!

 

If you are willing to accept typical Heritage line perimeters (e.g. 25mph max and a load of around 7 Mk1s) then there is simply no need for high power levels and the voltage / current can be limited accordingly.

 

Its worth remembering that BR was an expert at this - electrification schemes in the 1980s were notorious for being done with significant power restrictions - e.g. Only a single 5WES unit west of Poole to Weymouth, Only a single 4 car EMU to Kings Lyn, no AC locos between Hitch and Cambridge, etc.

[dave750t]

Might be a bit of a tough sell to visitors though. It's bad enough being fobbed off with a clapped out rattling DMU when the steam service isn't running.

[Wickham Green too]

12 minutes ago, Pete the Elaner said:

..... 3rd rail is right out. I know it is rather silly to step on it, but if it can be done, someone will do it. ........

Seems oddly fatal to humans - but I've seen foxes trot across the juice rail many a time without coming to any harm ..... weird !

[andyman7]

16 minutes ago, Wickham Green too said:

Seems oddly fatal to humans - but I've seen foxes trot across the juice rail many a time without coming to any harm ..... weird !

With the disclaimer that none of what I write here is intended to override the 11th commandment 'don't touch the Third Rail' - you can step on it without ill effect as long as you do not create a route to earth. Unlike the (invariably fatal) contact with 25kv AC, many rail staff have over the years survived contact with effects ranging from nothing to a hefty kick to hospitalisation, depending on what footwear they were wearing, the weather and the exact nature of both their contact with the third rail and where the rest of their body was at the time. 

[rodent279]

1 hour ago, DY444 said:

 

What about the GE DC units that were converted to AC?  I don't know if they retained resistance control after conversion but feeding the DC traction equipment with DC obtained from the onboard transformer/rectifier (which is what 313s did) would have been the cheapest and easiest way to do it.

 

I reckon any BR era AC emu fitted with tapchanger or thyrister control (which covers most of them) is a none starter really.

 

Even if you could figure it out the other problem of course is getting enough current through a tram wire system.

Yes, of course, I forgot about them, and what later became the class 302's, which were also 1500v D.C. at first. I don't know for certain, I'd imagine they were resistance control, and retained that when converted to AC. Theoretically & technically, it's possible, but whether it's realisable in practice is a different matter.

 

On similar lines, if a 1500v DC line could be connected between the output of the rectifiers on a class 86 and an EM2, it could run on the mainline in the UK again. Of course, it's not that simple, but power bus lines have been fitted between vehicles on  emu's. The class 501's that used to work on the 630v DC between Euston & Watford also had 630v bus lines between sets as well, at least according to a 1957 driver's handbook. I'd imagine getting a safety case and permission from the powers that be would be rather unlikely though.

 

Then again, if it's possible to restore 71000 when most of it's vital components were missing, and if it's possible to build an A1 from scratch, then who am I to say it can't be done?

Edited February 1, 2021 by rodent279

[rodent279]

1 hour ago, Wickham Green too said:

Seems oddly fatal to humans - but I've seen foxes trot across the juice rail many a time without coming to any harm ..... weird !

I remember reading that when the Hastings line was being electrified, special gaps had to be inserted in the conductor rail, because badgers were being electrocuted in large numbers (or was it the Weymouth extension?)

[luckymucklebackit]

I was thinking more of the type of installation the SR used in Goods yards in the early days, those were big locos working off a DC trolley wire at low speed.

 

Jim

[TravisM]

The AC locomotive group got their Class 81 up and running at Barrow Hill awhile back, albeit not able to move but the internals became alive and it “roared” again.

[Wickham Green too]

1 hour ago, andyman7 said:

With the disclaimer that none of what I write here is intended to override the 11th commandment 'don't touch the Third Rail' - you can step on it without ill effect as long as you do not create a route to earth. Unlike the (invariably fatal) contact with 25kv AC, many rail staff have over the years survived contact with effects ranging from nothing to a hefty kick to hospitalisation, depending on what footwear they were wearing, the weather and the exact nature of both their contact with the third rail and where the rest of their body was at the time. 

Well, I don't know what type of invisible rubber galoshes those foxes were wearing   -  but one foot on the juice rail and at least one on the ballast or sleeper without going out with a bang doesn't seem to make sense ................ though it might be different if ballast or sleepers were wet, of course.

[TravisM]

17 minutes ago, rodent279 said:

I remember reading that when the Hastings line was being electrified, special gaps had to be inserted in the conductor rail, because badgers were being electrocuted in large numbers (or was it the Weymouth extension?)

Possibly the Weymouth extension but when I worked for Southeast Trains in the train planning office and the Hastings electrification was done, the CME couldn’t understand why the pickup shoes on their Class 375’s got damaged by overheating but didn’t affect older EMU’s?

 

It suddenly dawned on them that the 3rd rail between Tonbridge and Hastings was not swopping sides of the running line often enough to stop the shoes overheating.  The shoes of the Mk1 EMU’s were unaffected as they more “sturdy” but the shoes on a Class 375’s were lighter and with the current draw over the long sections lead to them melting or getting heat damaged.

 

Over a weekend, gaps and some of the 3rd rail sections were swopped sides and the problem went away.

[009 micro modeller]

2 hours ago, phil-b259 said:

Put it this way, the ORR are far more likley to accept a 25KV preservation project than a 750V conductor rail one!

 

But presumably the same applies to any overhead installation, including DC, either at 1500V (potentially relevant for preservation purposes) or lower-voltage DC (as used by trams already preserved with overhead wire and also used for electrified industrial lines). I wonder whether SR dual-equipped locos could run.

 

There are several narrow gauge lines which may be relevant, but circumstances are slightly different. The Volk’s Electric Railway uses a third rail but that is both very low voltage and has been continually operating. It also has the live rail in the centre rather than on the outside.

 

Hythe Pier Railway uses a live rail, but that is a commercial operation run only by paid staff (the ferry company own it) and also in continuous operation for more than a century.

 

Seaton Tramway is a tram, presumably having a similar safety case to the standard gauge trams at Crich etc.

 

The 15” gauge tram at Conwy Valley Railway Museum is an interesting one. Not only is the overhead line (110V DC) slightly lower because of the smaller size of the tram but it’s also hard up against the Network Rail boundary for the Blaenau Ffestiniog branch, which you might think would cause some issues. However, in practice this seems to have no problems although I understand it isn’t able to run at present due to storm damage a couple of years ago. There is a similar 18” gauge operation in Cardiff.

Edited February 1, 2021 by 009 micro modeller

[Dava]

The Melton RIDC test track is available for hire, ideal for a 125 mph bash with 89001 or rather slower for an 81-87, costs close  to £20k a day for track, power, VAT & other costs.

 

3rd & 4th rail cheaper for your EMUs. Maybe they could be persuaded to do an open weekend with the ACLG someday after COVID? 
 

https://www.networkrail.co.uk/industry-and-commercial/research-development-and-technology/rail-innovation-development-centres/melton-rail-innovation-development-centre/

 

Dava

[009 micro modeller]

4 hours ago, Dava said:

The Melton RIDC test track is available for hire, ideal for a 125 mph bash with 89001 or rather slower for an 81-87, costs close  to £20k a day for track, power, VAT & other costs.

 

3rd & 4th rail cheaper for your EMUs. Maybe they could be persuaded to do an open weekend with the ACLG someday after COVID? 
 

https://www.networkrail.co.uk/industry-and-commercial/research-development-and-technology/rail-innovation-development-centres/melton-rail-innovation-development-centre/

 

Dava

 

If the parallel third/fourth rail and 25kV AC section is still in place you could even recreate old scenes from the WCML where it parallels the Watford local lines. Not sure you would make enough money back to justify the £20k cost though...

Edited February 1, 2021 by 009 micro modeller

[Dava]

The RIDC has two separate test sections on the line, the 3&4 rail is used for testing new LUL stock. Separate charge for that so an expensive day out. I’d like to see the Badger exploring the tunnels though....

 

[adb968008]

14 hours ago, Dava said:

The Melton RIDC test track is available for hire, ideal for a 125 mph bash with 89001 or rather slower for an 81-87, costs close  to £20k a day for track, power, VAT & other costs.

 

3rd & 4th rail cheaper for your EMUs. Maybe they could be persuaded to do an open weekend with the ACLG someday after COVID? 
 

https://www.networkrail.co.uk/industry-and-commercial/research-development-and-technology/rail-innovation-development-centres/melton-rail-innovation-development-centre/

 

Dava

14 miles at 125mph is going to be a very short ride.

 

The MLVs are a resource yet to be tapped, rigged up with modern batteries they could provide power for a reasonable run off grid.

 

I think the future of AC or DC operation is on the mainline or a feed from it myself.

outside that Battery technology exists. Its a pity Wareham to Norden or Haywards Heath to Horsted Keynes couldnt be 3rd rail set up.

 

That said barriers to EMUs on the mainline aren't that great, it can be done and some groups are pursuing it... VEP, BEL, CIG.. the only problem is money as can be seen here..

https://www.justgiving.com/crowdfunding/1753mailline

theres not a lot of it... just £400 raised towards the £100k needed.

Edited February 2, 2021 by adb968008

[ClikC]

It always occurred to me, that potentially the Old Dalby Test Track could enter the sphere of 'preservation', providing 25kV OLHE suitable for running preserved AC Electric Locomotives. If one was smart about it, you could maintain weekday functionality for modern day testing, museums for British Rail's R&D history a functionality as a preserved railway with a 'not so modern image' slant.

 

Regards

 

Matt

[Zomboid]

11 hours ago, 009 micro modeller said:

Not sure you would make enough money back to justify the £20k cost though..

You'd need a lot of people at sensible ticket costs (1000 at £20 a go). It would probably need someone with deep pockets who wants to see the ACLG locos run again to bankroll it. Which isn't impossible, but you'd probably be looking more in the order of 100k once you've got the locos there and sourced some carriages and a platform.

 

A proper electric train museum on the site with a few running days a year might be viable, at least once it's been built.

[009 micro modeller]

26 minutes ago, Zomboid said:

You'd need a lot of people at sensible ticket costs (1000 at £20 a go).

 

I suppose you might get that many - some people would probably go for the chance to ride on the test track even if they weren’t really into electric traction. Some of the ACLG locos run on the main line already.

 

26 minutes ago, Zomboid said:

A proper electric train museum on the site with a few running days a year might be viable, at least once it's been built.

 

Especially if it was still able to be open on non-running days (as a static museum) and generate additional income.

 

The issue that I see is with preserved electric stock that runs on electrification systems that are no longer used.

Edited February 2, 2021 by 009 micro modeller

[Michael Hodgson]

https://www.islandecho.co.uk/the-only-way-is-essex-group-set-up-to-preserve-island-line-train/