RSSB looking at possible extension of 3rd rail electrification

[Roast Veg]

Additionally as is often repeated, there isn't capacity in the existing infrastructure to tack on the last 5%. If you have to add new connections to the grid, why not do it the vastly more efficient way?

 

[AM9]

But we have DV units.

By my quick totting-up, excluding the new fleets of 345/700 707 and 717, there are about 220 post privatisation EMUs running around that are either ac/DC as I speak or would be with simple depot refitment of shoes. There are another 3-400 DC-only units that have provision for ac fitment, all of which are currently deployed on 3rd rail duties.

 

[yorksrob]

But we have DV units. And 3rd rail is clearly many times less safe as well as far less efficient.
It is mental to keep building it.

Well 'many times' less safe is disputed by some very knowledgable comentators.

 

[corfield]

Well 'many times' less safe is disputed by some very knowledgable comentators.

But very strongly agreed with by more knowledgeable ones and evidenced in a plethora of statistics.

As an Engineer for whom risk is my professional life, it seems quite clear 3rd rail is not something we should be seriously considering further installation.

 

[Taunton]

But very strongly agreed with by more knowledgeable ones and evidenced in a plethora of statistics.

As an Engineer for whom risk is my professional life, it seems quite clear 3rd rail is not something we should be seriously considering further installation.

OK, so what are the stats then. If we electrify Oxted to Uckfield 3rd rail compared to overhead, what are the additional incidents which are statistically probable. We know the mileage, that it is rural, etc.

 

[A0wen]

So can OHLE if not treated with respect.

The difference though is 25kv is 10 feet up in the air - to "accidentally" come into contact with it you have to be doing something you probably ought not be doing i.e. dangling from a bridge, climbing on a train or walking around in close proximity with something long that can conduct electricity.

Whilst I concede people shouldn't be walking around the railway lines, the fact is trespass is (and always has been) an issue - but the railways need to take reasonable and sensible precautions to minimise the risk to others. As has been pointed out there are no shortage of railwaymen who have inadvertently come into contact with the con-rail with occasionally fatal consequences.

I came across a vid on Youtube the other day of Waterloo in the 80s or 90s with the locos being hooked up for Exeter services - and one of those was on a snowy day. One slip from the guy doing the connecting and it could have been fatal.

 

[corfield]

OK, so what are the stats then. If we electrify Oxted to Uckfield 3rd rail compared to overhead, what are the additional incidents which are statistically probable. We know the mileage, that it is rural, etc.

More than if we use diesals or battery trains.

More than if we put AC in.

Since we can do those, it falls within ALARP to do so.


I don’t think yours is really the right question however.

 

[Philip Phlopp]

Additionally as is often repeated, there isn't capacity in the existing infrastructure to tack on the last 5%. If you have to add new connections to the grid, why not do it the vastly more efficient way?

It's only more efficient if the infill of the missing 5% is the start of a rolling program of 750V DC to 25kV AC conversion work.

The provision of 25kV AC OLE cannot be provided on the Hurst Green to Uckfield section of the Oxted Line affordably in isolation - the provision of a feeder is the key issue here, you either need to provide a small dedicated 25kV feeder for that route (a smaller unit, maybe 8MVA) or you provide something larger (40MVA or greater). The small feeder is inefficient on its own and not terribly useful as part of a conversion program, the larger feeder is more efficient but costly and wasteful if there is no conversion program.

There's also the perennial 'please avoid' of dual-voltage infrastructure. Modern track circuitry doesn't have the same unpredictable behaviour that the earlier electronic signalling systems did, and almost everything now is immunised for both electrification systems out of the box or with minor works. That said, stray electrical currents from all of the traction and signalling equipment can cause issues which need to be monitored, such as corrosion problems, so changing voltages should only be undertaken if there's no option.

If RSSB and ORR will permit infill with third-rail, I would endorse the 'hold your nose' and do it approach.

 

[contrex]

Thought it might be, can't even remember where I saw it.

I think it mainly arose from an article in a railway magazine or book in the early 1970s and got quoted and passed on. The voltage on the Bournemouth electrification was always nominally 750 volts but for timing purposes, 90 percent of that (675 volts) is assumed. Of course, the voltage at the substation busbars might rise above 750 when there is no train taking load in the section. Trains will experience voltages from 830V (light load next to a lightly loaded substation) down to about 580V in the middle of a heavily loaded section between a substation and a TPH or another substation. I believe experience and measurements have shown that 675V is the most appropriate figure to use for timing purposes. I should think that was what Roger Ford calls "modern lard-butt" EMUs with around 1 megawatt hotel loads will drag the voltage down in a section more than (say) a couple of stationary VEPs with no heating on.

 

[paul1609]

Does it make a difference when you already own a railway line through the middle of it ?

Why would you want an extension from Dungeness? The power station hasn't generated since 2018. The 400kv grid crosses the old Uckfield to Lewes line 2 miles south of Uckfield Station.

 

[philthetube]

It seems to me that if you cannot justify third rail on safety grounds you cannot justify overhead either, diesel is much safer.

 

[James90012]

There's also the perennial 'please avoid' of dual-voltage infrastructure.

Indeed and I'd like to understand the engineering / electrical viability of 4 AC/DC change overs on the North Downs for example, and frankly the idea of a rolling AC/DC changeover point as you incrementally extend AC is ludicrous. In theory, yes replace DC with AC but we are years away from that being a) a priority, b) affordable against other schemes and, c) deliverable without severe and extensive disruption. We don't have unlimited resource nor funds.

I also think it's a misnomer to take the view that 'if it's going to be converted you should start somewhere' - the reality is the cost of laying DC to Uckfield and then ripping it up to replace with AC will be peanuts in the context of AC conversion of the BML.

 

[Taunton]

I don’t think yours is really the right question however.

I'm always a little askance when I'm told my question is, somehow, the "wrong" question. I'd actually like to see these figures worked through for the Uckfield line. I would say I expect them to be readily available because this is what RSSB do for a living, but after the recent exposition by Ian Walmsley and others of their figures quoted having been just made up, I don't have that confidence any longer.

 

[Dr Hoo]

I'm always a little askance when I'm told my question is, somehow, the "wrong" question. I'd actually like to see these figures worked through for the Uckfield line. I would say I expect them to be readily available because this is what RSSB do for a living, but after the recent exposition by Ian Walmsley and others of their figures quoted having been just made up, I don't have that confidence any longer.

Well; if you introduce a completely new 'hazard' there is the scope for an accident.

Very simply the two electrocutions that I had to deal with both occurred on the Basingstoke-Bournemouth line. Obviously these just wouldn't have happened if the route hadn't been electrified with third rails in 1967.

There was a well-known tragic case when a young member of naval personnel was electrocuted at Fareham around 2000, I believe. So it is clearly possible to link 'infill' with the potential for serious harm.

 

[corfield]

I'm always a little askance when I'm told my question is, somehow, the "wrong" question. I'd actually like to see these figures worked through for the Uckfield line. I would say I expect them to be readily available because this is what RSSB do for a living, but after the recent exposition by Ian Walmsley and others of their figures quoted having been just made up, I don't have that confidence any longer.

Because you are asking something (a) in isolation (b) it is a loaded question in the sense you are not approaching it head on and (c) you’ve already decided what the answer is anyway. In short - what you mean is “prove my answer wrong”.

Demanding someone go and do a load of work to get you the answer when in fact it is a rhetorical device which you intend to further your pretermined argument with - is in essence, dishonest and so I would suggest, it is the “wrong” question.

From another perspective the pertinent question would be “should we do anything?”

The answer given DV for such islands does seem pointless and complex, is I feel, no. Keep using diesel and or move to battery trains as and when.

 

[edwin_m]

More than if we use diesals or battery trains.

More than if we put AC in.

Since we can do those, it falls within ALARP to do so.


I don’t think yours is really the right question however.

The RP in ALARP stands for Reasonably Practicable. Excessive cost may be cited (with appropriate justification) as a reason for a particular course of action not being reasonably practicable.

 

[corfield]

The RP in ALARP stands for Reasonably Practicable. Excessive cost may be cited (with appropriate justification) as a reason for a particular course of action not being reasonably practicable.

Yes - those two words in what is supposed to be clear guidance are in fact massively grey!

Always thus still subjective, and indeed my professional life is about making that very judgement (aircraft). In this case we aren’t however talking about massive changes in cost, but a significant impact on safety (sorry but even the most charitable interpretation shows there is).

As we see it, could we stand in Court looking at the family of a dead person and be happy we had made the right call.

I don’t think this is a case where you could “hold your nose” and do that.

Hence why even though I generally avoid the “do nothing” approach, it seems the sensible one for the SR islands, and AC the right one for Basingstoke etc.

 

[HSTEd]

Always thus still subjective, and indeed my professional life is about making that very judgement (aircraft). In this case we aren’t however talking about massive changes in cost, but a significant impact on safety (sorry but even the most charitable interpretation shows there is).

Even Network Rail puts the cost of 25kV installations drastically higher.

 

[GRALISTAIR]

Whatever happened to BATNEEC ? Best Available Technology Not Entailing Excessive Cost ? Is that used anymore?

 

[Bald Rick]

Why would you want an extension from Dungeness? The power station hasn't generated since 2018. The 400kv grid crosses the old Uckfield to Lewes line 2 miles south of Uckfield Station.

@yorksrob is not guilty here; he was referring to a comment I made about “an extension lead from Dungeness” which I was making in jest.

It seems to me that if you cannot justify third rail on safety grounds you cannot justify overhead either, diesel is much safer.

I think you misunderstand the regulations. The issue with third rail is that it is an unprotected bare conductor in a location where it is possible (within the grounds of reasonable practicality) for people working on the track, or members of the public, to come into contact with it. In the latter case, it could be something as simple as falling off a platform, or walking off the platfrom ramp, or trespassing.

This isn’t the case with OLE, as it is protected to a reasonable extent, and always isolated whenever there is work taking place within a given distance of it.

 

[yorksrob]

But very strongly agreed with by more knowledgeable ones and evidenced in a plethora of statistics.

As an Engineer for whom risk is my professional life, it seems quite clear 3rd rail is not something we should be seriously considering further installation.

I refer to my earlier post. Third rail is somewhat more dangerous than OLE, but not to the multiples as often quoted.

Why would you want an extension from Dungeness? The power station hasn't generated since 2018. The 400kv grid crosses the old Uckfield to Lewes line 2 miles south of Uckfield Station.

A previous poster mentioned Dungeness and I was just pointing out that it was linked to the network by railway owned land, so you'll have to ask them.

 

[yorksrob]

@yorksrob is not guilty here; he was referring to a comment I made about “an extension lead from Dungeness” which I was making in jest.



I think you misunderstand the regulations. The issue with third rail is that it is an unprotected bare conductor in a location where it is possible (within the grounds of reasonable practicality) for people working on the track, or members of the public, to come into contact with it. In the latter case, it could be something as simple as falling off a platform, or walking off the platfrom ramp, or trespassing.

This isn’t the case with OLE, as it is protected to a reasonable extent, and always isolated whenever there is work taking place within a given distance of it.

Ah cheers. My knowledge of which bits of the grid are current is limited.

 

[philthetube]

@yorksrob is not guilty here; he was referring to a comment I made about “an extension lead from Dungeness” which I was making in jest.



I think you misunderstand the regulations. The issue with third rail is that it is an unprotected bare conductor in a location where it is possible (within the grounds of reasonable practicality) for people working on the track, or members of the public, to come into contact with it. In the latter case, it could be something as simple as falling off a platform, or walking off the platfrom ramp, or trespassing.

This isn’t the case with OLE, as it is protected to a reasonable extent,

​

Unfortunately, nothing like well enough , relevant to the point you are making.

I can think of three incidents of stupidity around OLE, and I don't work with it.

The kids in the freight yard climbing on an engine.

The video, often used in training of the guy walking along the platform with a metal ladder, and he was staff.

and the guy taking pics of a kettle, with a mobile on a selfie stick held up towards the OLE.

Fortunately the last two were lucky and got away with it.

My point is that Diesel is indisputably safer than OLE and OLE is insisputqbly safer than Third rail, where do you draw the line.

If you put a value on each life lost then third rail probably wins

 

[ForTheLoveOf]

Unfortunately, nothing like well enough , relevant to the point you are making.

I can think of three incidents of stupidity around OLE, and I don't work with it.

The kids in the freight yard climbing on an engine.

The video, often used in training of the guy walking along the platform with a metal ladder, and he was staff.

and the guy taking pics of a kettle, with a mobile on a selfie stick held up towards the OLE.

Fortunately the last two were lucky and got away with it.

My point is that Diesel is indisputably safer than OLE and OLE is insisputqbly safer than Third rail, where do you draw the line.

If you put a value on each life lost then third rail probably wins

Diesel doesn't instantaneously kill anyone but I would be surprised if the societal effects of the emissions, let alone the production of the fuel, don't massively outweigh any "benefit" of not needing AC/DC.

 

[hwl]

Why would you want an extension from Dungeness? The power station hasn't generated since 2018. The 400kv grid crosses the old Uckfield to Lewes line 2 miles south of Uckfield Station.

The later bit has been pointed out several time by myself typically about once every other page on this thread, but there is more to it than that...
The Uckfield branch only needs about 5% of the the typical capacity of a small GSP, hence it would be a DNO supply or a new GSP address DNO supply issues too. In the later case where the grid crosses the old Lewes-Uckfield line isn't a most probable GSP location for reinforcement of DNO network purposes, connection to DNO 132kV would be the key for location purposes.

 

[Belperpete]

Indeed and I'd like to understand the engineering / electrical viability of 4 AC/DC change overs on the North Downs for example,

I agree. For lines like the Uckfield line, where there would be a single changeover point, I can understand the logic of doing it with AC. But for the North Downs line, where the trains would be constantly swapping from one system to another, it makes no sense.

I seem to recall back in BR days a proposal to provide battery sub-stations on such infill schemes. The batteries would charge through the third rail when there was no train in section. Nothing came of it, I suspect because the battery technology of the day wasn't up to it. The idea of a 650 volt lead acid battery capable of supplying the kind of power needed is frightening.

 

[Bald Rick]

Unfortunately, nothing like well enough , relevant to the point you are making.

I can think of three incidents of stupidity around OLE, and I don't work with it.

The kids in the freight yard climbing on an engine.

The video, often used in training of the guy walking along the platform with a metal ladder, and he was staff.

and the guy taking pics of a kettle, with a mobile on a selfie stick held up towards the OLE.

Fortunately the last two were lucky and got away with it.

My point is that Diesel is indisputably safer than OLE and OLE is insisputqbly safer than Third rail, where do you draw the line.

If you put a value on each life lost then third rail probably wins

I am perhaps in a fortunate position of having access to some of the data and risk assessments on this. I, too, can think of several incidents where the OLE has caused safety issues. I can think of hundreds more where the third rail has caused safety issues, on a network that is rather smaller.

The principle of risk assessment is to identify what could happen (precursors), the consequences, and the probability. Be under no doubt: there are significantly more precursors of an incident with the third rail than with OLE, which leads to a higher probability of an incident, and a higher risk.

 

[30907]

DNO? GSP?
Could someone translate for non-electricians please?

 

[ForTheLoveOf]

DNO? GSP?
Could someone translate for non-electricians please?

Distribution Network Operators are the companies responsible for the non-National Grid side of the electricity network (lower voltage stuff below 132kV iirc).

 

[Fincra5]

Curious to know if the anti-DC brigade, opr others, are able to share some data which compares fatal injuries from DC 3rd Rail to that of AC OHLE.

One safety flaw with AC is that it can jump, especially in wet weather. All be it the chance of it coming into contact with someone holding an umbrella is low, doesn't mean it hasn't happened.

3rd Rail, as its "Bottom Contact" isn't the safest admittedly but then there are X-amount of miles with it across the South East, Merseyside and 3/4th Rails on LuL. To me AC islands in a DC land make as much sense as having diesel islands. Yes there are DV units but they're all accounted for as it stands, although new stock is likely to be around by the time electrification has been posted.

I can't say I've heard of that many electrocutions on the SN/SE network in the years i've been on it.

Batteries just aren't good enough atm for real use on Heavy Rail. And just creates another microfleet.

One option is to explore the system used for Trams, that use (or Ground-Level Power)..

APS uses a third rail placed between the running rails, divided electrically into ten-metre rail segments with three-metre neutral sections between. Each tram has two power collection shoes, next to which are antennas that send radio signals to energise the power rail segments as the tram passes over them. At any one time, two consecutive segments under the tram will be live.

The "new" 3rd Rail could be broken into sections that are only live when the train is on/ near it.