Short circuit bar

[jc1]

Is there ever any circumstances when a short circuit bar can't be used?

 

[PaxVobiscum]

On a non-electrified line?

 

[ComUtoR]

Sounds suspiciously like a 'rules' question. Look at those yellow kickboards; they might give you a clue

 

[tsr]

Areas with a fourth rail (mostly...)

Areas with conductor rail guard boards / yellow guard plates (these are actually printed with “Do Not Use Short-Circuit Bar” on them)

 

[jc1]

I'm told there are four different circumstances

 

[alxndr]

I'm told there are four different circumstances

Are you perhaps getting confused with the four circumstances where you should apply one?

 

[jc1]

Are you perhaps getting confused with the four circumstances where you should apply one?

I've got the four when they can be used but not the four when they can't

 

[bb21]

Are you perhaps getting confused with the four circumstances where you should apply one?

There are four where SCB may be used, and four where they should not be used.

I've got the four when they can be used but not the four when they can't

What have you got so far?

 

[jc1]

There are four where SCB may be used, and four where they should not be used.



What have you got so far?

When there is a guard board
When there is a yellow plastic shroud

 

[bb21]

Someone above has already given you the answer to the third. (Hint: Gunnersbury, Kew Gardens, etc)

The last one is where dangerous goods are involved. (Just consider what applying SCBs would produce.)

 

[jc1]

Someone above has already given you the answer to the third. (Hint: Gunnersbury, Kew Gardens, etc)

The last one is where dangerous goods are involved. (Just consider what applying SCBs would produce.)

Do you mean a non electrified line?

 

[bb21]

No, they are fourth-rail land. The official answer is "on London Underground lines except East Putney to Wimbledon".

 

[jc1]

No, they are fourth-rail land. The official answer is "on London Underground lines except East Putney to Wimbledon".

Ok thanks but why is East Putney to Wimbledon different?

 

[robbeech]

*guess alert*

Is this where it is not 4th rail?

 

[swt_passenger]

*guess alert*

Is this where it is not 4th rail?

It is fourth rail, but the overall installation along there including substations follows normal Network Rail design standards and rules, despite the ownership change at privatisation. Elsewhere the mainline stock is running on a “system” that follows LU engineering standards and their rules.

 

[baz962]

Also if there is a conductor rail section gap

 

[Bigfoot]

It is fourth rail, but the overall installation along there including substations follows normal Network Rail design standards and rules, despite the ownership change at privatisation. Elsewhere the mainline stock is running on a “system” that follows LU engineering standards and their rules.

But it's not really 4th rail. As its bonded to the running rails. Which is why it's safe to use track circuit operating clips.

 

[swt_passenger]

But it's not really 4th rail. As its bonded to the running rails. Which is why it's safe to use track circuit operating clips.

Yes, it’s a pity it doesn’t have a more accurate name...

 

[robbeech]

But it's not really 4th rail. As its bonded to the running rails. Which is why it's safe to use track circuit operating clips.

Ah. Yes this is what I meant but worded it badly. 630v and 0v

 

[theageofthetra]

What about in a very wet conditions or partial flooding?

 

[choochoochoo]

I'm told there are four different circumstances

over high ballast

over point work

 

[t_star2001uk]

4th rail has its own specific short circuit bar

 

[Matt Taylor]

In flooding and laying snow I believe.

 

[Dstock7080]

But it's not really 4th rail. As its bonded to the running rails. Which is why it's safe to use track circuit operating clips.

LU staff are told not to use track circuit operating clips on any 4-rail system, including East Putney-Wimbledon

 

[t_star2001uk]

LU staff are told not to use track circuit operating clips on any 4-rail system, including East Putney-Wimbledon

Same on Chiltern when operating on the Met...

 

[nuts & bolts]

Do no deploy SCB near track circuit installations!