white light on pantograph/catenary

[Wickham Green]

1 hour ago, The Stationmaster said:

.......  It always used to be very amusing to watch dual voltage EMUs on the West London Line stopping just south of Mitre Bridge to changeover to 3rd rail from 25kv overhead - very strange when you knew that Class 373 Eurostars were doing the same changeover elsewhere at 100mph.

Could it be that the Mitre Bridge overhead was - shall we say - built to a price and not designed with the resilience for changeover at 100mph on the move. 

[number6]

I'm sure I read in Modern Railways back in the 70s of an up WCML train losing power at speed somewhere around Watford and managing to coast all the way to Euston. The driver lowering and raising the pantograph at speed to test. I can't quite remember but I seem to think he made the wise decision to stop at the bottom of Camden Bank before the station throat instead of running out of momentum and coming to a halt across the whole thing. Cue 'Those were the days' comments.

[jim.snowdon]

6 hours ago, Wickham Green said:

Could it be that the Mitre Bridge overhead was - shall we say - built to a price and not designed with the resilience for changeover at 100mph on the move. 

At the moment, I believe the curious situation exists where Southern trains stop to do the changeover, but TfL's trains do it on the move. To me, that would point to an over restrictive approach by someone, either Southern Railway or Network Rail.

 

Jim

[jim.snowdon]

5 hours ago, number6 said:

I'm sure I read in Modern Railways back in the 70s of an up WCML train losing power at speed somewhere around Watford and managing to coast all the way to Euston. The driver lowering and raising the pantograph at speed to test. I can't quite remember but I seem to think he made the wise decision to stop at the bottom of Camden Bank before the station throat instead of running out of momentum and coming to a halt across the whole thing. Cue 'Those were the days' comments.

Given that I have heard the same story from someone who was in BR at the time, there is quite possibly more than a grain of truth in it.

 

Jim

[russ p]

Class 88s raise and lower pans on the move , I think these are the only traction unit in the UK authorised to do it at present.  Those new Anglia units were originally intended to do it but I believe that option has now been dropped 

[jim.snowdon]

21 minutes ago, russ p said:

Class 88s raise and lower pans on the move , I think these are the only traction unit in the UK authorised to do it at present.  Those new Anglia units were originally intended to do it but I believe that option has now been dropped 

Unless there is something unusual or special about their pantographs, it seems typically British that they should be uniquely authorised. As far as the overhead is concerned, all it sees is the arrival or departure of a pantograph head; it doesn't matter what the vehicle supporting the pantograph happens to be.. 

 

Jim

[royaloak]

22 hours ago, Erixtar1992 said:

if that was true the railway would come to a grinding halt when trains go through a neutral section lol

 

you regularly hear the 25kv drop out if you sit in a train under the pantograph, aswell as aircon switching off ect for a few moments

What you are hearing is the Vacuum Circuit Breaker (VCB) opening, the pantograph remains in contact with the OHLE.

[royaloak]

56 minutes ago, russ p said:

Class 88s raise and lower pans on the move , I think these are the only traction unit in the UK authorised to do it at present.  Those new Anglia units were originally intended to do it but I believe that option has now been dropped 

We do it with the IETs when swapping power mode, either London side of Chippenham or London side of Newbury Racecourse.

 

At speed we can drop the pan anywhere but can only raise it in a few locations otherwise speed has to be reduced to 20mph and we can then raise the pan anywhere.

[Erixtar1992]

1 hour ago, royaloak said:

What you are hearing is the Vacuum Circuit Breaker (VCB) opening, the pantograph remains in contact with the OHLE.

Right you are

[jim.snowdon]

13 hours ago, The Border Reiver said:

The new class 397 have very bright pantograph lights

The brighter the light, the better the on board camera can get a sharp picture. In analysing the cause of a dewirement, and therefore who is responsible for the delay minutes, getting a clear picture of an event lasting milliseconds is of fundamental importance to the train operator.

 

Jim

[royaloak]

5 minutes ago, jim.snowdon said:

The brighter the light, the better the on board camera can get a sharp picture. In analysing the cause of a dewirement, and therefore who is responsible for the delay minutes, getting a clear picture of an event lasting milliseconds is of fundamental importance to the train operator.

 

Jim

And the train maintainer, and The Network operator, there is a lot of money involved.

[Davexoc]

2 hours ago, royaloak said:

We do it with the IETs when swapping power mode, either London side of Chippenham or London side of Newbury Racecourse.

 

At speed we can drop the pan anywhere but can only raise it in a few locations otherwise speed has to be reduced to 20mph and we can then raise the pan anywhere.

I take it that came about when the high speed trial ended up badly around West Ealing was it?

The resultant dewirement caused chaos for the morning rush into Padd. The section involved was headspan rather than the rugged steelwork holding up the knitting further west.

[royaloak]

1 hour ago, Davexoc said:

I take it that came about when the high speed trial ended up badly around West Ealing was it?

The resultant dewirement caused chaos for the morning rush into Padd. The section involved was headspan rather than the rugged steelwork holding up the knitting further west.

As far as I know its always been like that, I dont think that dewirement had anything to do with raising the pan and everything to with the  'state' of the pan at the time the button was pressed., lets just say the pan head didnt contact the OHLE at any stage in that incident.

The headspans did account for the complete meltdown in the service afterwards although breakdowns like this usually result in a complete meltdown of service, OHLE or no OHLE involvement.

Edited November 20, 2019 by royaloak

[newbryford]

15 hours ago, Pete the Elaner said:

There were just 2 of them (104 & 010). I don't think they would have been there from new & I have not noticed them on any others, so I think it is still just the 2.

 

I think the first two were fitted with cameras/lights when used for testing the new section through Bolton and Chorley.

Don't know about the lights, but most, if not all, Pendos now have pan-monitoring cameras fitted. Look for a painted number near the pan -it is quite visible and is the vehicle number.

The story I've heard is that if there is an instance of a pan/knitting interface problem that results in OLE damage, then the camera footage can be used to determine if it was the pan, or the OLE that has caused the issue (and therefore who to attribute blame to........)

 

 

 

[melmerby]

5 hours ago, jim.snowdon said:

At the moment, I believe the curious situation exists where Southern trains stop to do the changeover, but TfL's trains do it on the move. To me, that would point to an over restrictive approach by someone, either Southern Railway or Network Rail.

 

Jim

Surely TfL's trains are running under NR rules on NR lines?

[jim.snowdon]

2 minutes ago, melmerby said:

Surely TfL's trains are running under NR rules on NR lines?

More correctly, TfL's trains will running in accordance with the Rule Book, which is published by the RSSB, and both services will be being operated in accordance with their particular TOC's rules.

 

Jim

[DY444]

12 hours ago, russ p said:

Class 88s raise and lower pans on the move , I think these are the only traction unit in the UK authorised to do it at present.  Those new Anglia units were originally intended to do it but I believe that option has now been dropped 

 

As mentioned IETs are authorised as are Class 378s on the WLL between Shepherds Bush and Willesden Jn.

[caradoc]

20 hours ago, newbryford said:

 

The story I've heard is that if there is an instance of a pan/knitting interface problem that results in OLE damage, then the camera footage can be used to determine if it was the pan, or the OLE that has caused the issue (and therefore who to attribute blame to........)

 

 

True of course, but such footage would also be invaluable, by establishing the exact cause and sequence of events, in preventing further incidents. And also very useful in finding an OLE defect causing damage to pantographs, but not sufficient to wreck the pan or bring the wires down. I know from Control experience how difficult and time-consuming that can be !

 

[roythebus]

On 20/11/2019 at 18:43, jim.snowdon said:

Given that I have heard the same story from someone who was in BR at the time, there is quite possibly more than a grain of truth in it.

 

Jim

It was possibly me who mentioned it. I was 2nd man to a Rugby driver, 1975, working an up express. He shut off for the neutral section at Kings Langley, opened up but got no power. The line light was still on and the compressors were running, air kept up. We were doing <ahem) 100 at the time. I asked him if we were going to stop at Watford for assistance, he said no, we'll try for Euston. We got there without assistance albeit a bit slowly towards the end of the journey. I suspect the panel box must have realised we had a problem and gave us a clear run in. It's down hill all the way. "Modern" stock rolls quite nicely. 

[roythebus]

In Europe the DB trains from Germany lower the pan running in to the NS station at Eindhoven. A KoF shunter takes the DB loco off into a siding and places it ready for the next run to Germany. Similarly the NS loco will drop the pan to be towed out. The station sections are switchable from 1500vDC to 16.6kvAC.

 

There's also a lot of swing or lifting bridges in Holland without catenary.

Edited November 22, 2019 by roythebus

[The Stationmaster]

On 22/11/2019 at 23:16, roythebus said:

In Europe the DB trains from Germany lower the pan running in to the NS station at Eindhoven. A KoF shunter takes the DB loco off into a siding and places it ready for the next run to Germany. Similarly the NS loco will drop the pan to be towed out. The station sections are switchable from 1500vDC to 16.6kvAC.

 

 

That sort of thing used to be common at non-commutable (= switchable current/voltage) border stations in mainland Europe where loco changes took place.  And of course it also happens at commutable stations in some situations. (perhaps the ultimate example of which is a Eurostar UK owned 373 set running into Aachen under its own power and then being hauled forwrad to Köln by a DB electric loco which shunted onto  it after the current/voltage had been changed.  Coming back from Köln the oppositre took place.

 

The discussions which took place in various languages were even more unusual a, English member traincrew - who had driven the train to Aachen with a Belgian Conductor  - translating the German Traction Inspector's words into French for the benefit of the SNCB Traction Inspector.  But that sort of linguistic mélange often used to happen in things involving Eurostar   (although very few Eurostar UK Drivers or Traction Inspectors spoke German).

[AberdeenBill]

To add an irrelevant aside...    Didn't some (West) German restaurant cars have their own pantograph?    I recall seeing a train leaving Koln (or was it Munich??) and the restaurant car pan raised as the train was pulling out of the platform. 

 

Bill

 

[griffgriff]

Never say never.

 

.... this from a few years back

 

Griff

 

[The Stationmaster]

1 hour ago, AberdeenBill said:

To add an irrelevant aside...    Didn't some (West) German restaurant cars have their own pantograph?    I recall seeing a train leaving Koln (or was it Munich??) and the restaurant car pan raised as the train was pulling out of the platform. 

 

Bill

 

And some SBB dining cars.

[Titan]

From what I understood there was an axle driven generator to provide electricity for cooking.  The pantograph was only raised when stopped, or at least very low speed to enable cooking to continue when the generator was not providing sufficient output.  The pantographs used were not really suitable for use at any significant speed.