LBSCR electrification from an ASLEF point of view

[roythebus]

motormen-on-the-brighton-railway.php

 

A fascinating account of the early LBSCR electrification, this history is from the Brighton Branch of ASLEF and details the negotiations of ASLEF to gain the same rate of pay for motor-men and steam drivers. There's some fascinating pictures of the early AC electrics and the change-over to 3rd rail DC electrics.

 

Thanks to my friends on the Facebook Lost Boys group for the link.

 

I've also copied this to the Southern Electric page on here.

[Griffin Road]

As you say " a fascinating account " . Thanks for sharing .

 

Mike

[russ p]

Very interesting, I noticed the bit about the Midland taking over the LTS and says that it has to electrify within seven years....

Must have been very expensive for the SR to convert from AC to DC which also seems a retrograde step, although I could be argued that the DC system was cheaper and easier to expand

[Zomboid]

I think the decision to go DC was in no small part because the LSWR had greater influence in the SR at the time.

AC would have been a better choice technically, cost wise they're about the same (con rail is cheaper than OLE, but you have to have many, many more substations with low voltage dc systems)

[russ p]

One other massive saving with third rail is that structures don't need altering to the extent of OHL systems

[Mike Storey]

Absolutely fascinating - many thanks

[roythebus]

I haven't had time to red through the entire article yet, but yes, it does throw up a lot of fascinating facts from the other side, things that the "history books" tend to leave out too.

[Nearholmer]

Cracking stuff!

 

As to why the single phase system was removed in favour of dc, that is a topic that, as both a Brighton fan, and a railway electrical engineer by profession, I've long been intrigued by, and have attempted to delve into.

 

The short story is that the SR desperately needed to electrify the suburban lines to control operating costs, and had two systems in front of it, between which to choose (it was nearly three). The third rail dc system was the one that could be pushed forward quickest, and the SR went on to deal with the whole of suburbia in very short order. The main 'slow down' with the ac system was the erection of masts and OHLE. Ruthless efficiency then demanded that the non-standard system be got rid of, although the speed with which that was done involved writing off kit that was 'fresh out of the box'. I've tried to understand how they got this to stack in accounting terms, and can't claim to be to the bottom of that question.

 

Did personalities play a part? Probably some, given who the GM and Chief Electrical were, but I don't read vindictiveness into it, just the stunning ability to make tough decisions quickly, and then to put them into affect with great energy.

 

There are many points of detail that I've glossed over here, both technical and financial. And, without wishing to be unkind to Zomboid, I dont agree at all that the cost of substations would have outweighed the cost of OHLE in this case - it definitely would not have, taking all factors into account.

 

Kevin

[The Stationmaster]

One thing of course was that the overhead portal structures (or not all of them) weren't thrown away - they kept on reappearing all over the Southern in different guises in later years.

 

Incidentally thanks to the excellent, copiously illustrated, book by Stephen Grant covering the installation of the overhead it looks as if the clearances used were quite tight by later high voltage ac overhead standards although obviously the structures needed to carry the catenary would have been far more extensive than simply adding a third rail.

[Mike Storey]

Whilst no expert, by any means, I have read up a lot on this over the years, and a key issue for an OLE solution (low or high voltage) would have been the tunnels and bridges of the miserly SER and LCDR, especially at Sevenoaks, Strood and Chatham, and to a lesser extent the south end of the SW, particularly the tunnel outside Southampton. These would have almost certainly required half a coach in each set formation to be lost to low slung pantograph housings, and a possible corresponding reduction in all vehicles height (including non-electrified stock) come the day that HV was introduced. Or a many multi-million pound rebuild of the offending obstacles. Or the non-electrification of substantial parts of the SR (as indeed happened with the Hastings, Oxted and other routes, despite the use of third rail). Did they manage to wire up the tunnels and long under bridges along the SLL, for the brief period OLE existed? Did they use neutral sections for that system?

[Nearholmer]

At the time that the decision to junk the single-phase system was arrived at, nobody had their eye on longer-term main-line electrification; it was all about suburbia, and how quickly operating costs could be driven down, and capacity increased. You can see from the ASLEF material that the LBSCR was on the case to cut operating costs in 1909/11, and the SR was even more keen, because wage costs had shot-up by 1923.

 

The LBSCR, on the other hand, very definitely had their sights on the sea when they selected the system in the first place, and were overt about it. It was actually an ideal system for what the LBSCR had in mind, but less than ideal for suburban electrification, especially in a "needs must when the devil drives" hurry.

 

When it came to decision time, there was a bit of a problem about who should fight the single-phase corner at the technical level, because the LBSCR didnt actually have a really heavy-hitter on the staff to beqeath to the SR. They had been reliant on a very good consultant, and by 1923 he was involved in broader work about national electrification policy. When asked to give a view on the SR suburban electrification question, the national committee gave a pretty pathetic, mealy-mouthed response, because the members were busy trying not to fall out with one another.

 

Feeding diagram for the initial section below. I've never looked hard at photos to see exactly how OHLE was arranged at section boundaries.

 

On clearances, worth remembering that this was initially 6.6kV, later 11kV, not 25kV.

 

On "technically superiority": yes, no, and maybe! At the dates concerned, mercury arc rectifiers were a very new idea indeed, and certainly not robust enough to be rattled about in trains, and solid-state power-electronics were only a theory, which meant that motor-control was quite a challenge on systems with HV supply, whether it be single or three phase. Single phase systems were operated at relatively low frequencies, to permit use of motor and control-gear that was very little modified from that used on d.c. traction. It was a very inelegant solution, although it was applied successfully in numerous places, and it wasn't until the French proved the use of mercury-arc rectifiers on board locos, in the early 1950s, that HV single phase electrification really took off "big time".

 

Er ........ possibly I'm off on my hobbyhorse; sorry!

 

Kevin

[Zomboid]

That looks more like a DC system than an AC one (not a million miles from how I believe the German 16.67Hz system is set up, though).

With that many substations you're right, the plant costs aren't going to be much different from a 750V DC system.

[roythebus]

The ASLEF viewpoint does give an insight into problems and reasons that have possibly not been mentioned in the existing books on the subject.

[The Stationmaster]

Whilst no expert, by any means, I have read up a lot on this over the years, and a key issue for an OLE solution (low or high voltage) would have been the tunnels and bridges of the miserly SER and LCDR, especially at Sevenoaks, Strood and Chatham, and to a lesser extent the south end of the SW, particularly the tunnel outside Southampton. These would have almost certainly required half a coach in each set formation to be lost to low slung pantograph housings, and a possible corresponding reduction in all vehicles height (including non-electrified stock) come the day that HV was introduced. Or a many multi-million pound rebuild of the offending obstacles. Or the non-electrification of substantial parts of the SR (as indeed happened with the Hastings, Oxted and other routes, despite the use of third rail). Did they manage to wire up the tunnels and long under bridges along the SLL, for the brief period OLE existed? Did they use neutral sections for that system?

 

Stephen Grant's book clearly shows that there was wiring under brick arch overbridges that had not been altered and he states that 'very few overbridges had to be altered'.  In at least one case the catenary was not carried under a station footbridge but just teh contact wire in order to avoid altering the bridge.  The tunnel at Crystal Palace also appears not to have been altered.

[Nearholmer]

Zomboid

 

Nearly all of those sites are little sectioning-cabins, very modest affairs compared with great big cathedral-type rotary-convertor substations, and they weren't staffed, whereas substations had to be. So, on that basis single-phase looks cheaper.

 

The feeding configuration was partly dictated by the fact that there was no national grid, so the LBSCR had to pay for new capacity to be built at Deptford (IIRC, the alternators for the LBSCR were totally distinct from the rest of the station, which operated at either dc or a different frequency; I'd need to consult my notes to be sure of the detail), which is partly why there was so much cabling). The distributors from Deptford were as 6.6kV, rather than anything higher, because of the limits on cable insulation technology that applied at the time.

 

But, the real decider when it came to the SR was, I am fairly sure, speed, rather than the finer points of electrical engineering. Every day of steam operation was vast amounts of money down the drain, so the fact that conductor rail could be dropped out in short possession, and cabled-up very quickly, whereas OHLE needed foundations for the structures, cranes to erect many of them, plus "knitting possessions", counted against the latter.

 

And, any resemblance to low frequency single-phase practise on the continent is no coincidence, because that was exactly what it was! Dawson's 1909 textbook on railway electrification, which focuses very heavily on the knowledge he applied for the benefit of the LBSCR, is chock-full of continental case examples (and some from the US).

 

The post WW1 notional electrification committee, which, sort of, eventually, came down in favour of 660V and 1500V dc, possibly also had an eye to British-based manufacturing capability, in that both of the real biggies, the ex-US-owned plants at Rugby and Trafford Park, were heavily into supplying the kit needed for US-style dc electrification. There was no really developed knowledge or skill base around single-phase railway electrification in GB (there was the experience of the Midland Railway at Heysham, which was meant to transfer to the LT&SR, but didn't, and that drew on German and US knowledge-base), but there was a symbiotic relationship between the two factories and electrification of railways in the London area, which dated back to US capital being used to bankroll the electrification of the District, and a great deal of the construction of the Tube railways. Westinghouse and GE had made a very solid attack on the British market c1899-1905, seeing-off the vestiges of Siemens influence (although that is complicated, because, very briefly, Siemens-influenced money owned GE), and making sure that the Ganz three-phase system got no toehold (well, one little toe on the PB&SSR), although the latter was the first choice of the Metropolitan.

 

The LBSCR installation was a serious irritant to US/British industry!

 

Kevin

[Zomboid]

Most of those substations seem to have "Booster Transformers", which were clearly not what such things are these days, but look much more analogous to a Rectifier set.

The architecture is very much like a DC system, with a higher voltage network of cables linking the incoming supplies to various substations where local transformers (and rectifiers for dc) feed the tracks.

Presumably a simple transformer didn't need attention in the same way that a rotary converter did, but back in those days I don't think any form of automated remote control had been invented, so if a feeder tripped then someone would have had to attend to put it back in.

[Nearholmer]

Zomboid

 

The booster transformers are doing exactly the same job as now, although I'm not totally sure I understand the connection.

 

The way I read it, there is only one voltage in the system, 6.6kV; I agree that the parallel cables are being used to 'hold up' voltage, but by the simple expedient of providing a lower impedance parallel path, not through any transformer arrangement.

 

I'm not to the bottom of the remote control question. But, some of the "switches" (circuit breakers) were remotely controlled (and indicated presumably), so my guess is that this was simple direct-wire control, but it might have been something more interesting. Even direct-wire could be made sort-of economical on wires by using polarised coils.

 

Kevin

[Nick Holliday]

Whilst no expert, by any means, I have read up a lot on this over the years, and a key issue for an OLE solution (low or high voltage) would have been the tunnels and bridges of the miserly SER and LCDR, especially at Sevenoaks, Strood and Chatham, and to a lesser extent the south end of the SW, particularly the tunnel outside Southampton. These would have almost certainly required half a coach in each set formation to be lost to low slung pantograph housings, and a possible corresponding reduction in all vehicles height (including non-electrified stock) come the day that HV was introduced. Or a many multi-million pound rebuild of the offending obstacles. Or the non-electrification of substantial parts of the SR (as indeed happened with the Hastings, Oxted and other routes, despite the use of third rail). Did they manage to wire up the tunnels and long under bridges along the SLL, for the brief period OLE existed? Did they use neutral sections for that system?

According to C Hamiton Ellis:

Under low bridges, of which Victoria had three, there had to be dead lengths of contact line. In Victoria and London Bridge Stations too, the Board of Trade insisted that live wires should be 6 ft 6 in. higher than the tops of the largest carriages, e.g. The clerestory and balloon types, including Pullman cars. (This height also applied in a number of places, such as depots and other termini)

At Victoria there was a major operation, lasting many weeks - the complete renewal of points and crossings. During Sunday occupancy the current was turned off over a stretch of several hundred yards... The trains coasted the gap with ease.

Another major op was the renewal of the brick lining to Crystal Palace tunnel, lasting some months. The line was temporarily singled to make room for the staging. For five days, while it was being erected, the electric trains coasted with bows down. Hereafter a special wire was suspended over the single line, with a dead section of 200 ft under the staging. Over this the trains ran without having to retract their bows.

[Nick Holliday]

Just to add to the above, this extract from SR Instructions June 1926

Under Ecclestone and Elizabeth Bridges at Victoria Station the high pressure overhead wires are "dead" that is to say, at any point below a heigh of 19 ft 9 ins. above rail level the wires are not charged with electricity, except whilst an electric train is passing under them.

 

I wonder how that worked - mechanical switching by someone, a detector arrangement or an early Frog Juicer?

[Zomboid]

Zomboid

 

The booster transformers are doing exactly the same job as now, although I'm not totally sure I understand the connection.

 

The way I read it, there is only one voltage in the system, 6.6kV; I agree that the parallel cables are being used to 'hold up' voltage, but by the simple expedient of providing a lower impedance parallel path, not through any transformer arrangement.

 

I'm not to the bottom of the remote control question. But, some of the "switches" (circuit breakers) were remotely controlled (and indicated presumably), so my guess is that this was simple direct-wire control, but it might have been something more interesting. Even direct-wire could be made sort-of economical on wires by using polarised coils.

 

Kevin

They're more like autotransformers then. Booster transformers are not found at substations (other than by coincidence), and are only used for immunisation. In terms of distribution of power they're a hindrance as they are just a lump of impedance in the OLE.

[bécasse]

Just to add to the above, this extract from SR Instructions June 1926

Under Ecclestone and Elizabeth Bridges at Victoria Station the high pressure overhead wires are "dead" that is to say, at any point below a heigh of 19 ft 9 ins. above rail level the wires are not charged with electricity, except whilst an electric train is passing under them.

 

I wonder how that worked - mechanical switching by someone, a detector arrangement or an early Frog Juicer?

 

 

I rather suspect that there wasn't any normal switched electrical supply to these sections but that the instructions were worded in this way because the sections became momentarily charged as collectors entered and left them. There may possibly have been a manually-switched supply that could be energised to enable a stalled train to move, although on the third-rail there were many places on the network where gapping was possible but rarely happened - and if it did a second train was brought up to give the stalled train a "nudge".

 

On the third-rail network it was possible to gap 16-SUB coming down from Victoria(E), through the down loop at Herne Hill and then going round towards Tulse Hill - they found out the hard way one day!

[Nearholmer]

I don't think they are acting as ATs. They seem to have one winding in series with the 'line', by being connected across an otherwise open section in the bus at the TSC, and the other winding connected in series with the neutral, which is earthed at various locations, and presumably also connected to the running rails. To me, they seem to be booster transformers as we would now know them, not ATs used for boosting the line voltage.

 

This has made me decide to borrow Dawson's book again, to double-check; copies tend to be out of my buying price range, although I do have Dover's book, which may cover the point.

 

Kevin

[Nearholmer]

Dover does have it, in a much clearer diagram.

 

K

[Zomboid]

Fair enough, that does look very much like a BT circuit.

It doesn't say why they did that, does it? I guess it would work for immunisation in the same way it does today, but were induced voltages considered as important then?

[Nearholmer]

There was (still is?) a BoT regulation limiting voltage on running rails, to help control earth leakage currents that could interfere with telegraph and telephone circuits, so that may have been the main driver. There was also hyper-sensitivity in the area, because of fears about disturbing observations at Greenwich Observatory ( I guess they measured the earth's magnetic field there), but that isn't mentioned in the books I have.

 

They might also have been concerned about volt-drop in the neutral side of the circuit, and/or damage to bonding being caused by high current flows. I'm not sure whether or nottheLBSCR had much track circuiting at this stage - I would guess it was limited to circuits to indicate trains held at home signals in busy areas, probably dc; those circuits might have been sensitive to currents set up by differential neutral current flows in the two running rails due to damaged bonds, causing potential differences, and/or to induction affects.

 

My gut feeling is that intereference/immunisation mechanisms weren't fully understood at that date, because some of the understanding arose through investigations of wrong-side failures over the years, added to which the signalling relays used were probably fairly chunky, needing a fair bit of energy to move them.