Third Rail or OHLE freeze

[RobShipway]

Earlier this evening I popped to the local Tesco store which is next to Martins Heron station.

In walking over the bridge over the Waterloo Reading line, I noticed a class 458 pulling out on it's way to go to Bracknell. As it pulled out theer was quite a few sparks from the 3rd rail conductor which I am presuming is down to the show gear of the train, hitting the frozen conductor?

Now, I have seen something similar I am sure happen with OHLE lines on the WCML & ECML, when it has been cold weather as we have at the moment.

Which got me wondering when the OHLE cabling is done for the GWML will the same occur?

 

[455driver]

Yes, if there is something between the pick-up and the con-rail/ catenary then you get sparks.

 

[table38]

[youtube]Ve1exJ_nTA8[/youtube]

 

[RobShipway]

Okay, thanks guys that is what I thought was the case.

The reason for my question, was that a colleague at work seem to think that if we changed all 3rd rail lines to OHLE, then you would not get the spark as shown in the video above when temperatures are below 0, to which I said yes you would but the flashes of sparks as shown in the video would not be as much as you get with 3rd rail.

 

[ainsworth74]

to which I said yes you would but the flashes of sparks as shown in the video would not be as much as you get with 3rd rail.

I wouldn't be so sure about that

[youtube]eIXlLIL3oZo[/youtube]

(It gets good from 44 seconds)

 

[Goldfish62]

Earlier this evening I popped to the local Tesco store which is next to Martins Heron station.

In walking over the bridge over the Waterloo Reading line, I noticed a class 458 pulling out on it's way to go to Bracknell. As it pulled out theer was quite a few sparks from the 3rd rail conductor which I am presuming is down to the show gear of the train, hitting the frozen conductor?

Now, I have seen something similar I am sure happen with OHLE lines on the WCML & ECML, when it has been cold weather as we have at the moment.

Which got me wondering when the OHLE cabling is done for the GWML will the same occur?

The train I got off there this evening gave quite an impressive firework display pulling out of the station!

 

[RobShipway]

The train I got off there this evening gave quite an impressive firework display pulling out of the station!

If the train was around 5pm, then it was the same train that I saw, giving a fantastic light display.

 

[O L Leigh]

OLE still gives sparks, but frost and ice doesn't affect the power transmission to the same extent as it does on 3rd rail.

O L Leigh

 

[jopsuk]

Thursday morning (the coldest this week) as I was cycling alongside the railway the trains passing were giving quite the light show from their pantographs. I was a little surprised (having never paid attention before) that the second and even third pantograph on a formation gave as much sparks; I'd have thought the passage would have de-iced to certain extent, and indeed that the mainlines run light locos for this purpose?

How much damage to the pan heads does the sparking cause?

 

[D365]

Thursday morning (the coldest this week) as I was cycling alongside the railway the trains passing were giving quite the light show from their pantographs. I was a little surprised (having never paid attention before) that the second and even third pantograph on a formation gave as much sparks; I'd have thought the passage would have de-iced to certain extent, and indeed that the mainlines run light locos for this purpose?

How much damage to the pan heads does the sparking cause?

No more damage than to third-rail shoes I would imagine. How would a light engine help catenary? There aren't any electric being used for this... Or am I missing something?

 

[captainbigun]

LNW use ice breaking locos north of Preston.

Better to lose a carbon on a light loco than on one of the following service trains.

Carbon damage is a big issue and is something that the carbon manafactures are actively looking at. EC suffers far more than WC. GE is also a hot spot.

 

[1018509]

How much damage to the pan heads does the sparking cause?

Pick up shoes - cast iron. Pantograph heads - carbon strip insert. Quite a lot of replacements needed on the pantograph head I would presume.

 

[D365]

That makes sense, which locos are used for this 'ice-breaking'?

 

[Lrd]

No more damage than to third-rail shoes I would imagine. How would a light engine help catenary? There aren't any electric being used for this... Or am I missing something?

Running light engine means just running the loco around without it pulling anything, it still uses power to run.

 

[ainsworth74]

That makes sense, which locos are used for this 'ice-breaking'?

86s and 87s regularly feature.

 

[D365]

No more damage than to third-rail shoes I would imagine. How would a light engine help catenary? There aren't any electric being used for this... Or am I missing something?

Running light engine means just running the loco around without it pulling anything, it still uses power to run.

How does this help clear the catenary of ice and wintery stuff? I've only read of diesels being used..
--- old post above --- --- new post below ---

That makes sense, which locos are used for this 'ice-breaking'?

86s and 87s regularly feature.

That makes sense now, but isn't 87002 (ACLG) the only mainline operational 87 in Britain? At least it's getting use, I guess. Their 86s have been hired too IIRC - please correct me if I'm wrong!

 

[captainbigun]

That makes sense now, but isn't 87002 (ACLG) the only mainline operational 87 in Britain? At least it's getting use, I guess. Their 86s have been hired too IIRC - please correct me if I'm wrong!

Yes. 87002 and 86101 both in use with NR until next Saturday.

Neither are GSM-R fitted, and there are no plans to fit currently, so the future is unclear.

86701 and 86702 are both stopped now.

 

[TDK]

Pick up shoes - cast iron. Pantograph heads - carbon strip insert. Quite a lot of replacements needed on the pantograph head I would presume.

Yes indeed, in 2010 VT pendo's and 350's had major problems with the pantographs having to be replaced. If a show is in contact with a conductor rail and there is significant icing it can actually weld itself to the conductor rail, this happend back in 2001 on a few occasions, we were told to keep the train moving so completely had to change our driving technique. It got to the stage where there was a job to take an 8 car 456 up the branchlines during the night to try and assist the morning peak by clearing snow and ice off the conductor rail and I never had a line light in the leading cab except where the ice had melted.

 

[sarahj]

One issue is that locos such as a 91 has one pantograph, so if the carbon strip wares down, there is nothing you can do. There is a plan to add another pan to a 91, so when one goes, you drop it and lift up the other one.

But what you have seen is ice forming on the wire, this causes the sparks. Its more common on the third rail due to temps, size and the fact that snow etc lies on it. More advanced systems, such as the DLR has the rail facing down and the shoe up which helps a lot, and has the bonus of making it next to impossible to stand on and go bang.

SJ

 

[captainbigun]

First duplex pan already fitted to a 91 (14 I think).

 

[D365]

The duplex was installed for testing but I'm not sure if 91114 has retained it in service.

 

[455driver]

The duplex was installed for testing but I'm not sure if 91114 has retained it in service.

It has, not sure if it is signed off for use though.
--- old post above --- --- new post below ---

How does this help clear the catenary of ice and wintery stuff? I've only read of diesels being used..

They use electric locos.
The point of running them is to prevent a large build up of ice plus the fact the fact they are not hauling a train means they dont draw huge amounts of current minimising damage to the carbon strips.

Some companies use electric units instead of locos.

 

[ainsworth74]

It has, not sure if it is signed off for use though.

Last I heard it wasn't yet being used in service but there are plans to do so in the near future.

 

[apk55]

3rd rail is a top contact system where snow will accumualate on the surface, so shoes could end sking up on top of the snow. OH lines are bottom contact so that that snow can not accumulate on them. The problem is probably freeze-thaw cycles where snow melts then refreezes forming hard ice. This could happen on overhead although the higher voltage could probably blast a way through.
Our climate is bad for freeze thaw cycles, were as a lot of other countries it just goes cold and stays cold. This is also a big problem for road engineers as freeze thaw cycles break up road surfaces rater than just cols.

 

[RobShipway]

3rd rail is a top contact system where snow will accumualate on the surface, so shoes could end sking up on top of the snow. OH lines are bottom contact so that that snow can not accumulate on them. The problem is probably freeze-thaw cycles where snow melts then refreezes forming hard ice. This could happen on overhead although the higher voltage could probably blast a way through.
Our climate is bad for freeze thaw cycles, were as a lot of other countries it just goes cold and stays cold. This is also a big problem for road engineers as freeze thaw cycles break up road surfaces rater than just cols.

The break of the road surface also means that there are lose chippings even in snowy winter conditions as I have recently found out as I found yesterday that the glass for the nearside fog light on my car is cracked, which I presume is from a chipping.

The above brings me to another question that I want to ask, which is as the snow hardens to ice, if there are large mounds of it on the 3rd rail lines could this not do damage to the trains shoe gear on the conductor rails? Or as mentioned before does Network rail/TOC's use Class 73's as much as they can to make sure the routes are clear prior to the passenger trains using them?

 

[sarahj]

It can cause massive damage to the contact shoe. What we run are ghost trains through the night and the MPV comes on out which squirts de-icer at the third rail. The only time the 73 has been out round ours is to tow away a stuck 377 near falmer on friday night.

SJ

 

[TGV]

Problems with ole and pantograps in cold and snowy weather do exist to the extent that carbons have a shorter life expectancy and despite the low ambient temperatures, the arcing causes overheating locally on the pan head.

These, for us at least, are less of an issue than ballast damage to the trains in similar conditions. In other words, the overheads are not the limiting factor in restrictions to service.

On the high speed lignes, the overheads can be pulsed with over-current before first service of the day to heat them enough to melt frost. I don't know if this is done in the uk?

 

[cyclebytrain]

Problems with ole and pantograps in cold and snowy weather do exist to the extent that carbons have a shorter life expectancy and despite the low ambient temperatures, the arcing causes overheating locally on the pan head.

These, for us at least, are less of an issue than ballast damage to the trains in similar conditions. In other words, the overheads are not the limiting factor in restrictions to service.

On the high speed lignes, the overheads can be pulsed with over-current before first service of the day to heat them enough to melt frost. I don't know if this is done in the uk?

If I can ask, how is the current sinked when you do that?

 

[TGV]

If I can ask, how is the current sinked when you do that?

Good question. I assume it is loaded somewhere on the network. It is all taken care of by RFF. I would have to refer to them to be sure.

 

[cyclebytrain]

Thinking about it; assuming you could sink it practically, you could do something very similar with third rail?