Electrifying Mainlines for Battery Train operation (using Class 897 as an example

[Elecman]

Even better, the train could be programmed to normally use AC, but switch to battery when the line voltage drops below a certain threshold, say 23kV.

I think you would need to drop that voltage level to around 19kV rather than 23kV as that voltage level is too often reached in normal service

 

[GraphitProjekt]

Much better go to west from Hull to Gilberdyke as @zwk500 says and the OHLE can take the hotel and aux loads during the long layovers in Hull and charge at low-ish C rate that is kind to batteries and avoid the Selby headache.

yes hence zwk500 and I suggesting doing the far (Hull) side of Selby rather than the short ECML - Selby section. (This also make the TP Hull services and some Northern Service easy to BEMU...)

Yeah, I do see in retrospect how much more strategic wiring at the Hull end would be - I didn't actually know there was a swing bridge at Selby.

The only wrinkle is that this wiring would need to be N-2 contingent lest a battery 897 could be stranded. This means Hull-Gilberdyke would need to have 2 feeder stations with at least 3 grid connections between them. If the system was contiguous with the ECML, you may only need 1 extra grid connection. It was said that Hambleton Jnc SFC was designed to support a theoretical Hull scheme. And is backed up by the surrounding feeder stations (Potteric Carr, Ravensthorpe) also using SFC technology and so should all be quite a bit more capable than classic connections in the area (York and Kirkstall)

 

[zwk500]

Yeah, I do see in retrospect how much more strategic wiring at the Hull end would be - I didn't actually know there was a swing bridge at Selby.

The only wrinkle is that this wiring would need to be N-2 contingent lest a battery 897 could be stranded. This means Hull-Gilberdyke would need to have 2 feeder stations with at least 3 grid connections between them. If the system was contiguous with the ECML, you may only need 1 extra grid connection. It was said that Hambleton Jnc SFC was designed to support a theoretical Hull scheme. And is backed up by the surrounding feeder stations (Potteric Carr, Ravensthorpe) also using SFC technology and so should all be quite a bit more capable than classic connections in the area (York and Kirkstall)

The N-2 contingent could be provided by a 'giant extension lead' if really needed, although surely Hull-Gilberdyke would only need 1 Feeder station with 2 incoming supplies given the amount of power it would actually need to supply?

There's a 400KV line crossing the railway not too far east of Gilberdyke (https://openinframap.org/#12.09/53.73897/-0.62457) which would be the obvious point for a feeder station, does N-2 need to come from independent supplies or could you use 2 separate sets of equipment?
Equally, you could just decide that in the unlikely event of the Feeder Station going offline, Short-term operational measures will be taken to reduce the risk of a train getting stranded (cancellations and RRBs, load-shedding, slow speed, etc).

 

[GraphitProjekt]

The N-2 contingent could be provided by a 'giant extension lead' if really needed, although surely Hull-Gilberdyke would only need 1 Feeder station with 2 incoming supplies given the amount of power it would actually need to supply?

Indeed, you probably only need 1 grid supply for the actual requisite power, 1 fs 2gsp is for N-1 contingency. But as you say, the supplies need to be independent, exactly what the level of independence is on the grid side I'm not sure. Probably adjacent feeder stations need to be in different transmission grid areas especially if taken from the 132kV network directly. I'm not sure exactly how the requirement of separation changes where feeds are drawn from lower-down networks.

I did once try to chart out the interdependencies between the upstream infrastructure for Tyne & Wear metro substations (which all draw from local secondary distribution lines (11kV)). And I found that all of them corresponded to a different Primary substation, but those Primaries were often themselves connected to similar Transmission substations. This is somewhat complicated by the fact that, in the Newcastle area, it's common for transmission voltage is stepped down straight to the Primary distribution level of 33kV or 66kV skipping over sub-transmission layer (132kV).

There's a 400KV line crossing the railway not too far east of Gilberdyke (https://openinframap.org/#12.09/53.73897/-0.62457) which would be the obvious point for a feeder station, does N-2 need to come from independent supplies or could you use 2 separate sets of equipment?
Equally, you could just decide that in the unlikely event of the Feeder Station going offline, Short-term operational measures will be taken to reduce the risk of a train getting stranded (cancellations and RRBs, load-shedding, slow speed, etc).

I'd guess that transmission grid source for such a line would be overkill, and so unnecessarily expensive. The entire MML from Farringdon to Sheffield was planned to be fed off 10x TNO connections amongst 5x feeder stations. Hull - Gilberdike is 17 miles and Gilberdike - Hambleton Jnc is about another 17 miles (interesting coincidence).

17 miles of feeder cable between Hambleton and Gilberdike is definitely do-able, it's about 5km longer than longest 25kV feeder cable currently around (Thingley Jnc - Wooton Basset Jnc). But it's not exactly cheap and easy (even though Southern Region have been doing such things for years without any complaint).

I would probably go for a 2x SFC feeder drawn off the 33kV switchboard of a nearby 132/33kV substation, similar to Potteric Carr in Doncaster: perhaps the 132kV sites at Hull South or Hull East.

Another way would be not to have an extension lead, and instead do 2 fs with 4 gsp but from the local 11kV grid with the Siemens equipment.

But this is all random guesswork tbh.

 

[zwk500]

17 miles of feeder cable between Hambleton and Gilberdike is definitely do-able, it's about 5km longer than longest 25kV feeder cable currently around (Thingley Jnc - Wooton Basset Jnc). But it's not exactly cheap and easy (even though Southern Region have been doing such things for years without any complaint).

I would probably go for a 2x SFC feeder drawn off the 33kV switchboard of a nearby 132/33kV substation, similar to Potteric Carr in Doncaster: perhaps the 132kV sites at Hull South or Hull East.

In that case, Osgodby is a 132/33kV substation just east of Selby, which reduces the need for the 'extension lead' (if not removing it altogether), and then you could potentially have a secondary feeder at either Hull South substation (also 132/33kV), or where the 33kV line runs under the triangle just outside Hull Paragon (useful for sectioning if the coast is ever electrified!).

As you say, all rather speculative/academic/crayoning at this point though.

It does, however, highlight a very relevant problem with the growing rise of batteries as part of the traction provision - creating significant inefficiencies in the OLE Power Supply Network because contingency and resilience is required but the area isn't big enough to provide the normal setup.

 

[GraphitProjekt]

Thinking about the fact Gilberdike is pretty much 17 miles from both Hull and Hambleton. It does make me think that the plan was to put a midpoint substation at that junction and feed eastwards from a new feeder somewhere in Hull. (Hull South 132kV near to Paragon seems like a good spot to me). 17 miles is pretty ideal for a classically fed system, an SFC system can do a lot more from a lower voltage, but is quite expensive if a classic option is available (impossible for us to know that though).

What about wiring all the way through with a short discontinuity through Selby with cables for each OLE circuit around the swing bridge?

 

[Zomboid]

What about wiring all the way through with a short discontinuity through Selby with cables for each OLE circuit around the swing bridge?

That's what we'd do if we had any sense. In fact we'd have done it in about 1976.

The technology exists now to have live wires on the bridge if we want, and whilst that would be relatively expensive and non-standard it would mean that a lot of the trains running that way (ECML and TPE, plus at least a good chunk of the northern services) could be straight electric with all the weight and removal of complexity benefits that would bring.

Though to be honest I can see a case for doing wires to the bridge abutments and fitting most electric trains with a few miles worth of traction batteries. Selby station may be a bit too close to the bridge for coasting, but with modern train acceleration it might be possible with a permanently earthed beam to guide the pantograph over.

 

[zwk500]

What about wiring all the way through with a short discontinuity through Selby with cables for each OLE circuit around the swing bridge?

It's what the dutch would do

That's what we'd do if we had any sense. In fact we'd have done it in about 1976.

Well, it'd have been 'phase 2' of the ECML electrification through the area at least.

The technology exists now to have live wires on the bridge if we want, and whilst that would be relatively expensive and non-standard it would mean that a lot of the trains running that way (ECML and TPE, plus at least a good chunk of the northern services) could be straight electric with all the weight and removal of complexity benefits that would bring.

Wiring Selby-Hull on it's own would only allow the ex-King's Cross services to move to EMU operation. Without Micklefield-Selby the Northern and TPE would still need an independent mode.

I suspect that going forward we will see most, if not all, EMUs be ordered as BEMUs to allow services to continue in the event of disruption to the power supply (see the 555s), the main distinction will then be between EMUs with a short range or restricted speed on battery, and BEMUs designed to use them in regular service. In this context, there will be limited saving of weight and complexity reduction.

Though to be honest I can see a case for doing wires to the bridge abutments and fitting most electric trains with a few miles worth of traction batteries. Selby station may be a bit too close to the bridge for coasting, but with modern train acceleration it might be possible with a permanently earthed beam to guide the pantograph over.

If you're wiring to the bridge itself then the obvious thing to do is have APCO beacons west/south of Selby station (but the wires as far as the platforms) and east of the swing bridge. If traction batteries fail to engage, then coasting as far as Selby station should be possible and then can manually pan up to continue/reverse as required.

 

[Zomboid]

Wiring Selby-Hull on it's own would only allow the ex-King's Cross services to move to EMU operation. Without Micklefield-Selby the Northern and TPE would still need an independent mode.

I failed to explain my full crayon sandwich there, but I had included Mickelfield to Selby and Church Fenton to Gascoigne Wood.

It's scope creep, but enabling the full Leeds to Hull (including the Manchesters) service to go over to straight electric operations seems a worthwhile benefit, and provides a load more charging infrastructure for the battery services that'll operate in the south east of Leeds area.

 

[zwk500]

I failed to explain my full crayon sandwich there, but I had included Mickelfield to Selby and Church Fenton to Gascoigne Wood.

It's scope creep, but enabling the full Leeds to Hull (including the Manchesters) service to go over to straight electric operations seems a worthwhile benefit, and provides a load more charging infrastructure for the battery services that'll operate in the south east of Leeds area.

Ah, fair enough. We're both of the same page. Shame the treasury aren't likely to be!

 

[Zomboid]

Ah, fair enough. We're both of the same page. Shame the treasury aren't likely to be!

Yeah, I doubt it'll go how I'd choose, but I would definitely look to do complete routes where possible so that as many trains as possible can just be straight electrics - which will be cheaper to buy, lighter (so use less energy moving and do less damage to the track), won't incur charging and discharging losses (so more energy efficient again) and simpler to maintain, whilst not having expensive components that are unlikely to last the life of the train.

Doing 10 miles here and there will be expensive to provide resilience, less energy efficient, harder on the tracks and fast charging batteries frequently is a great way to ensure they have a short life.

Many service groups will have to be battery operated, and for short sections like swing bridges or AC/ DC changeovers having a small battery makes the infrastructure much simpler and can also provide hotel power and a limp home mode during disruption, so is probably worthwhile.

 

[GraphitProjekt]

It's what the dutch would do

It's what they did in Norwich too! As well as attempting to build an electrified swing bridge, there are also 2 cables across the riverbed. I think the Dutch way is to coast over but I presume this isn't an option for Selby. Are there any other fully wired swing bridges out there?

Yeah, I doubt it'll go how I'd choose, but I would definitely look to do complete routes where possible so that as many trains as possible can just be straight electrics - which will be cheaper to buy, lighter (so use less energy moving and do less damage to the track), won't incur charging and discharging losses (so more energy efficient again) and simpler to maintain, whilst not having expensive components that are unlikely to last the life of the train.

Doing 10 miles here and there will be expensive to provide resilience, less energy efficient, harder on the tracks and fast charging batteries frequently is a great way to ensure they have a short life.

Many service groups will have to be battery operated, and for short sections like swing bridges or AC/ DC changeovers having a small battery makes the infrastructure much simpler and can also provide hotel power and a limp home mode during disruption, so is probably worthwhile.

I very much agree
I wonder if there's any way for NT and TPE fleets that run in this area to also deployed somewhere where their batteries might be used more often. Perhaps for Northern there are some relevant routes like through Goole to Doncaster and Knottingley.

 

[zwk500]

It's what they did in Norwich too! As well as attempting to build an electrified swing bridge, there are also 2 cables across the riverbed. I think the Dutch way is to coast over but I presume this isn't an option for Selby. Are there any other fully wired swing bridges out there?

Technically Trowse is a solid bar, not a wire The US has had at least one fully wired swing bridge on the Northeast Corridor (the Portal bridge https://en.wikipedia.org/wiki/Portal_Bridge#Rail_service), but it probably has (or had) others. There are also electrified moving bridges in Germany, but they're rolling or lifting bridges rather than swing bridges I think (such as the Huntebruecke in Oldenburg https://www.ndr.de/nachrichten/nied...r-ohne-einschraenkungen,huntebruecke-118.html).