"Black" signals (for want of a better description)

[Deleted]

What is the procedure on arriving at a signal at "black" - i.e. with no light lit?

I gather that it has to be assumed that it should be on, but what happens? If it is in fact off, the train will not be tripped on going through. Does the procedure involve visual checking of the trainstop?

On a similar note, what is the procedure when a signal is showing dual aspect? Obviously it can only do this if it is really off, but if the trainstop is up, it will trip the train.

[abe]

As I understand it, a signal with no aspect illuminated must be treated as if it was at danger. The same applies if it shows two aspects (e.g., red and green), or if it is bobbing (i.e., aspects changing back and forth between red and green). I'm sure that I read somewhere that low air main pressure can cause bobbing signals, due to the trainstop going up and down - can someone confirm?

[Deleted]

abe said:

As I understand it, a signal with no aspect illuminated must be treated as if it was at danger. The same applies if it shows two aspects (e.g., red and green), or if it is bobbing (i.e., aspects changing back and forth between red and green). I'm sure that I read somewhere that low air main pressure can cause bobbing signals, due to the trainstop going up and down - can someone confirm?

I think low air pressure is more likely to cause a dual aspect rather than a bobbing signal, as the trainstop fails to lower.

A signal with no aspect, dual aspect or that is bobbing should be treated as a signal at danger.

[chrish]

tfc said:

abe said:

As I understand it, a signal with no aspect illuminated must be treated as if it was at danger. The same applies if it shows two aspects (e.g., red and green), or if it is bobbing (i.e., aspects changing back and forth between red and green). I'm sure that I read somewhere that low air main pressure can cause bobbing signals, due to the trainstop going up and down - can someone confirm?

I think low air pressure is more likely to cause a dual aspect rather than a bobbing signal, as the trainstop fails to lower.

A signal with no aspect, dual aspect or that is bobbing should be treated as a signal at danger.

"Should" being the main word there... not always possible to do so! I have passed a signal with no aspect at almost line speed before, solely as it was the green aspect out, so the repeater was fine! As i came round the corner, nothing showing, but it was far too late to stop! Obviously if the signal in question was at danger though, the repeater would be on, so no excuses for hitting it really!

[Colin]

You should have still treated it as being at danger. The fact remains that there was no aspect showing on a stop signal - and as said already, no aspect is a danger signal! It would have been treated as a category B SPAD - and that's fine cos it don't go on yer record (equipment failure)

There is one exception to the no aspect situation - suppressed signals. An example off the top of me 'ead is FG22 at Dagenham East, the home signal for the eastbound through platform. If a train is routed into the bay platform, there is potential for confusion as FG22 would correctly show a red aspect. To ensure a train op doesn't confuse the meaning of the signal, the aspect is suppressed (not lit) when the route is set up & cleared for the bay platform.

On the point of 'applying the procedure' but not getting tripped (say a green aspect has failed & the train stop has correctly lowered), the train operator is still expected to apply the rule - that is to proceed at a speed at which they can stop short of an obstruction until they have passed two consecutive stop signals. They may well be instructed otherwise, but that is the official rule as I understand it and I'd be very careful about the possibility of risking my job.

It's always, always, always better safe than sorry

[Deleted]

colin said:

On the point of 'applying the procedure' but not getting tripped (say a green aspect has failed & the train stop has correctly lowered), the train operator is still expected to apply the rule - that is to proceed at a speed at which they can stop short of an obstruction until they have passed two consecutive stop signals. They may well be instructed otherwise, but that is the official rule as I understand it and I'd be very careful about the possibility of risking my job.

It's always, always, always better safe than sorry

I completely agree there. What, if anything, is (or should be) announced in that situation?

I have as yet only ever been on one train that passed a signal at danger under rule.

[Colin]

I'd probably say something along these lines, if I knew for a fact I wasn't gonna get tripped:

"Ladies & Gentleman, we are currently experiencing signalling problems in this area. To ensure we can pass through the area safely, we will be carrying out a routine procedure which means we'll be traveling slowly for a while before resuming a faster speed. Once again I'm sorry for the delays you are currently experiencing."

If it's the full procedure proper, there's well rehearsed script to follow about holding tight etc - the refurb D stock even has it as an option! ;D ;D

[Deleted]

colin said:

If it's the full procedure proper, there's well rehearsed script to follow about holding tight etc - the refurb D stock even has it as an option! ;D ;D

As does the 95TS.

[Deleted]

colin said:

You should have still treated it as being at danger. The fact remains that there was no aspect showing on a stop signal - and as said already, no aspect is a danger signal! It would have been treated as a category B SPAD - and that's fine cos it don't go on yer record (equipment failure)

If you do cat. B SPAD, do you stop and call before continuing at caution?

[Tom]

pmrnorthern said:

colin said:

You should have still treated it as being at danger. The fact remains that there was no aspect showing on a stop signal - and as said already, no aspect is a danger signal! It would have been treated as a category B SPAD - and that's fine cos it don't go on yer record (equipment failure)

If you do cat. B SPAD, do you stop and call before continuing at caution?

Yes, as otherwise it becomes an aggravated SPAD (and that's not something you want to be involved in).

[Colin]

A SPAD is a SPAD.

The category is an indication of how it's dealt with and recorded afterwards.

[c5]

And then there is "tripped in vicinity"!!!!!

[Deleted]

c5 said:

And then there is "tripped in vicinity"!!!!!

Been trying to work out what that means - is it anything to do with being tripped on something other than a trainstop? (Tripcock tester, squirrel or pigeon?)

[c5]

pmrnorthern said:

c5 said:

And then there is "tripped in vicinity"!!!!!

Been trying to work out what that means - is it anything to do with being tripped on something other than a trainstop? (Tripcock tester, squirrel or pigeon?)

Not a tripcock tester (no worries on getting tripped on a tester, so long as the light goes out!).

Its getting tripped and not believing it to be a signal. It (some say ) has to be treated from a SPAD point of view, until confirmed otherwise.

Plastic bags, high ballast, footballs or lumps of wood are the usual suspects ;D ;D

[Deleted]

I remember being told a tale about a driver who had been tripped on a pigeon and then picked up said pigeon and took it to the line controller to prove it!!
Whether this was just an urban myth or really happened, I have no idea! I can't for the life of me remember who told me, but I'm sure it was one of the ECT drivers.

[railtechnician]

It is possible to be tripped on a tripcock tester if it is out of alignment but it would need to have sustained an impact for that to happen as they are routinely gauged and tested! It happened several times at Wood Green E/B a few years ago and I changed the tripcock tester on that road twice within a matter of weeks because of it even though the TT was in gauge. I believe we suspected a fault with the tripcocks being out of alignment on some sets at the time but the sets in question weren't being tripped on the TTs at Acton.

'Tripped in vicinity' can be the result of all sorts of things left on the track or lobbed there by vandals or indeed such things as pickup shoes knocked off earlier trains and yes high ballast is a culprit. Ballast is notorious for causing trainstop failures to first trains following rerailing too, where it gets caught preventing the arm coming to the fully 'on' position.

Other causes of 'trips' are such things as tin cans blown into the trainstop can guard (one type known as a 'Roman helmet') by the passage of trains and preventing the trainstop arm being fully lowered. Can guards are fitted to trainstops in tube tunnel areas but seem to attract rubbish rather than deflect it.

Suppressed Reds can be a nightmare for the new lineman, I reckon every lineman gets caught once somewhere! The one not to get caught on is the one in the T4 loop. It is suppressed because of the extremely long and very straight approach which might cause the driver to slow from normal line speed from too far away and thus delay the service unnecessarily. If you think it's failed it's a long walk back to check the bulb only to find there's no circuit until a train is on the approach track circuit!

Bobbing is caused most often by the section rail (which is the feed side of a track circuit) of one of the tracks in the signal selection being intermittently earthed. Causes of such earthing are scaling of railheads contacting earth, or discarded drinks tins bridging the rail to an earth etc or the breaking down of a blockjoint by the building up of magnetised iron filings around the insulating 'T' piece which keeps the rails of two track circuits apart. Obviously there are other possibilities associated with wire and equipment failure which I won't go into.

[Deleted]

railtechnician said:

Suppressed Reds can be a nightmare for the new lineman, I reckon every lineman gets caught once somewhere!

They seem to be a favourite of DMTs and T/Ops reporting them as having no aspect too, along with RGIs that are fed over a set of points.

[Chris M]

alanl said:

I remember being told a tale about a driver who had been tripped on a pigeon and then picked up said pigeon and took it to the line controller to prove it!!
Whether this was just an urban myth or really happened, I have no idea! I can't for the life of me remember who told me, but I'm sure it was one of the ECT drivers.

From Picadilly Pilot's tales of the past on DD's main site:
A DR train got tripped and caused a bit of delay (take the comments such as "how would anyone notice" etc. as read). (Readers - please note: - It's been Standard Practice for many years for there to be more than a degree of 'banter' between Piccadilly and District Line Train Crew. One overworked joke is that the Picc has a timetable - the District just works to a calendar! District Dave)
When the Motorman explained the cause to the Regulator he was disbelieved. A few hours later the door of Earl's Court Regulating Room flew open, the Motorman standing there asked who the Regulator was he'd spoken to earlier. He then went over to the Regulator's desk, slapped down the dead pigeon he'd been tripped on and said, "Don't call me a liar".

[railtechnician]

randomnumber said:

railtechnician said:

Suppressed Reds can be a nightmare for the new lineman, I reckon every lineman gets caught once somewhere!

They seem to be a favourite of DMTs and T/Ops reporting them as having no aspect too, along with RGIs that are fed over a set of points.

Yes indeed, some were jobsworth's and that was all they were good at! Most of the ones I dealt with were okay but I used to have to curb their enthusiasm when I was dealing with a failure. The last thing you need is a uniform asking for a report while you're still dealing with the problem!