Neutral Sections

[IrishDave]

Not really. In DC land gaps are freaking everywhere and there are regular gapping incidents. On AC I've never heard of a unit being gapped in a neutral section. I'm sure its happened I just can't recall any.

Neutral sections are usually well placed and not at places where you bring your unit to a stand and they are usually placed on a gradient so you can gravitate out. Its our first instruction for neutral sections.

On DC I worry about gapping, on AC I rarely, if at all, think about it.

There was a 4-car class 350 gapped near Berkswell a couple of years ago (either Jan or Feb of 2014 or 2015, I think). The train had started from a stand at Berkswell heading up towards Coventry / London - the gentle climb up from Berkswell towards Beechwood tunnel didn't help, as rolling out of the neutral section would have entailed rolling backwards.

I vaguely recall (not sure on the details) there being some kind of temporary speed restriction, which meant the driver wouldn't have been carrying enough speed and got caught out. In the end another 350 had to come and rescue it.

To be honest with the neutral section so close to Berkswell station I'm surprised it doesn't happen there more often.

 

[MisterT]

Astonishing the pantograph isn't lowered for the transit of the bridge.

That's not necessary for many of the air gaps in the Netherlands.
Only a few requires us to lower the pantograph.
Exception in passenger service is the Traxx locomotive: even though it should work, we are instructed to lower the pantograph on every air gap.
Other units and locomotives in passenger service in the Netherlands simply raise the pantograph to their maximum height, so they are physically unable to reach any further.
For Traxx locomotives, on the other hand, we are able to change the maximum height by changing some 'settings'. As it is theoretically in really rare cases possible to do that by accident, the Traxx is not deemed to be 'save' or 'reliable' enough for using the air gaps like intended.

Fortunately, there are not many problems with the air gaps. I guess it happens once or twice a year I guess.
And then we have to push

 

[Mojo]

Not really. In DC land gaps are freaking everywhere and there are regular gapping incidents.

Indeed, and trains can (and do) get their shoes ripped off by errant infrastructure and other trackside obstructions, and that the train simply carries on as normal with the driver not being aware; until they get gapped!

 

[PermitToTravel]

Though a train could have software that detects if one shoe seemingly isn't drawing current when the rest are, allowing greater care to be taken / the issue to be seen to promptly

 

[Mulberry2016]

Harker, Ecclefechan, Murphat, Elvanfoot, Strawfrank (Carstairs South) and Carstairs East.
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You can take power once the VCB has closed but on the units I work there is a 20 second delay while the computers check everything is OK before giving traction back to the Driver. The neutral section at Upperby you mention is a pain as well as the two at Carstairs.
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VCB on 350s.
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Black background sign marks the approach of an OHNS and a white background sign marks the site.

Neutral sections always seem to be situated in the most inappropriate points, particularly very low speed areas such as the one just south of Carlisle Station and the one on the curve at Golbourne junction. There is one just north of Penrith station on the up gradient which must have been a right royal pain for the 86/87 locos pulling away from the station back then.Must be quite nerve wrecking for a trainee or novice

 

[QueensCurve]

Neutral sections always seem to be situated in the most inappropriate points, particularly very low speed areas such as the one just south of Carlisle Station and the one on the curve at Golbourne junction. There is one just north of Penrith station on the up gradient which must have been a right royal pain for the 86/87 locos pulling away from the station back then.Must be quite nerve wrecking for a trainee or novice

I don't ever recall any problems at those neutral sections even when traveling on trains hauled by Class 86/87 locos. Likewise Class 81/82/83/84/85 which alas were sometimes used.

 

[The Planner]

As I have mentioned before, they can and do cost time when near stations.

 

[GRALISTAIR]

I don't ever recall any problems at those neutral sections even when traveling on trains hauled by Class 86/87 locos. Likewise Class 81/82/83/84/85 which alas were sometimes used.

Wow -we sure have different tastes. I loved those old beasts - I clocked some mileage behind them in the 1970s especially after Weaver- Glasgow was electrified. So much rarer than 86/87s so I always preferred them. I have a fantastic shot of an 84 at Carstairs waiting to leave.

 

[wimbledonpete]

The thunk of the pantograph dropping on a 395 is very noticeable - but the other day I was on a 12 car, sitting in the front coach of the rear unit, and it still thunked, even though it didn't look as though (from the shadow of the train) that the pan was actually up after the section. So do all the pantographs go through some sort of process even if down?

 

[QueensCurve]

Wow -we sure have different tastes. I loved those old beasts - I clocked some mileage behind them in the 1970s especially after Weaver- Glasgow was electrified. So much rarer than 86/87s so I always preferred them. I have a fantastic shot of an 84 at Carstairs waiting to leave.

The concern I had was with the power. In my experience the older locos never managed to keep the train to time.

They lost it at TSRs, not neutral sections.

 

[GazK]

The thunk of the pantograph dropping on a 395 is very noticeable - but the other day I was on a 12 car, sitting in the front coach of the rear unit, and it still thunked, even though it didn't look as though (from the shadow of the train) that the pan was actually up after the section. So do all the pantographs go through some sort of process even if down?

The paragraph doesn't drop on any train. The thunk is the main 25kV circuit breaker on the train dropping out (and then back in again). Pan stays up.

Sent from my HTC One_M8 using Tapatalk

 

[HowardGWR]

I've noticed a similar gap on a lifting bridge near Den Holder, also in Netherlands.

Can be seen here:
https://goo.gl/maps/UYQevBmEmVk

Interesting to see a classic Dutch bridge used on a railine

It's Den Helder, not Den Holder. 'Helder' means 'clear' in Dutch and I have always assumed, given the location, that it was the equivalent of Land's End.
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Fortunately, there are not many problems with the air gaps. I guess it happens once or twice a year I guess.
And then we have to push

Great to hear from Dutch colleagues. I shall be travelling back soon and shall keep my eyes open, as a result of this thread, thanks.

 

[MisterT]

It's Den Helder, not Den Holder. 'Helder' means 'clear' in Dutch and I have always assumed, given the location, that it was the equivalent of Land's End.

Completely off-topic, but the name Den Helder is probably derived from the old Middle Dutch word for a dune: Helle/Helre/Hille (writing depends on the source).
The word hill in English is also derived from those words, although with a little different meaning.

 

[najaB]

The thunk of the pantograph dropping on a 395 is very noticeable...

It's not always the pantograph making the noise. There's a very noted 'thunk' from the HVAC on Pendolinos for example.

 

[edwin_m]

The thunk of the pantograph dropping on a 395 is very noticeable - but the other day I was on a 12 car, sitting in the front coach of the rear unit, and it still thunked, even though it didn't look as though (from the shadow of the train) that the pan was actually up after the section. So do all the pantographs go through some sort of process even if down?

There is a "Thunk" when the air conditioning inlets are shut on the approach to a tunnel, to reduce pressure pulses inside the train. This sounds very much like the sort of noise a circuit breaker makes.

 

[HowardGWR]

Completely off-topic, but the name Den Helder is probably derived from the old Middle Dutch word for a dune: Helle/Helre/Hille (writing depends on the source).
The word hill in English is also derived from those words, although with a little different meaning.

Thanks for that (although I liked my fanciful 'looking out into the clear ocean' idea; yours sounds a better etymological explanation). Just one more OT then, do people realise the original Dutch influence extending into northern France with such as 'Dunkirk'? Literally Dune Church'.

Back to topic (a bit) where does pantograph come from? French?

 

[MisterT]

Pantograph is a French word indeed.
According to Wiktionary the French word is originated in the Ancient Greek language:

From*French*pantographe, from*panto-*(fromAncient Greek*παντός*‎(pantós), genitive singular of*πᾶν*‎(pân,*“all”)) and*-graphe*(fromγράφειν*‎(gráphein,*“to write”))

https://en.wiktionary.org/wiki/pantograph

 

[Domh245]

A train's pantograph is named because of it's similarity to the pantograph device used for copying things at a different scale.

 

[ComUtoR]

The paragraph doesn't drop on any train. (...) Pan stays up.

On the Dual voltage units I drive the pan goes up and down. Are there units where the pantograph always stays up ? Do they have a "pan over height" safety system like ours do and how would they deal with missing wires ?

Cheers in advance.

 

[GazK]

On the Dual voltage units I drive the pan goes up and down. Are there units where the pantograph always stays up ? Do they have a "pan over height" safety system like ours do and how would they deal with missing wires ?

Cheers in advance.

the discussion is about neutral sections, and that was the context of my statement about pans dropping. Yes, all UK pans can be dropped - apart from anything else electric trains sometimes need to be dragged off the wires through non-electrified low bridges.

But when passing through a neutral section, the pan isnt dropped. The train breaker is taken out and that prevents an arc being drawn across the neutral section.

Hope that clears things up.

Sent from my Pixel C using Tapatalk

 

[driver9000]

On the Dual voltage units I drive the pan goes up and down. Are there units where the pantograph always stays up ? Do they have a "pan over height" safety system like ours do and how would they deal with missing wires ?

Cheers in advance.

A pantograph going over height would suffer an ADD activation.

 

[ComUtoR]

Hope that clears things up.

Completely thanks.

 

[GRALISTAIR]

I am adding this thread to the "WIKI"

 

[Mordac]

I am adding this thread to the "WIKI"

There's a wiki?

 

[GRALISTAIR]

I am adding this thread to the "WIKI"

There's a wiki?

See post 4 - so that is why I put "wiki" in inverted commas. It is not truly a wiki but I am hoping the mods may see fit to make a sticky. So - wiki-sticky
Basically a summary of electrification threads that are extant.

http://www.railforums.co.uk/showthread.php?t=136891

 

[Strat-tastic]

Not a sticky wiki? Or is that something I don't want to get onto?

 

[SpacePhoenix]

Not a sticky wiki? Or is that something I don't want to get onto?

Are you possibly thinking of a now discontinued cabaret act in Benidorm?

 

[leomartin125]

Do modern units like the Class 390 Pendolino and Class 800 IEP both still have to power down at Neutral sections and then power up again afterwards, or is this done automatically by the onboard computer?

Also how do they do it on HS1? Are the 373's and 374's the same procedure?

 

[Joseph_Locke]

Do modern units like the Class 390 Pendolino and Class 800 IEP both still have to power down at Neutral sections and then power up again afterwards, or is this done automatically by the onboard computer?

Also how do they do it on HS1? Are the 373's and 374's the same procedure?

I'm not a rolling stock expert but I have a science background - the point of neutral sections is to isolate two AC feeds that may or may not be on different electrical phases; I have no idea what "software" would do for you.

Its a lot simpler just to isolate the train as it goes through the neutral section to remove any possibility that the AC-DC rectifiers (or step-down transformers suddenly see (effectively) minus 25kV. The traction system has to have a line circuit breaker anyway, so why wouldn't you use that?

 

[rebmcr]

Do modern units like the Class 390 Pendolino and Class 800 IEP both still have to power down at Neutral sections and then power up again afterwards, or is this done automatically by the onboard computer?

There is indeed a balise on the side of the track that does tell the train to cut power and then reapply it afterwards, without the driver having to operate any controls.