Signal failures

[harlesden]

Has centralized control succeeded or failed in reducing the number and frequency of signal failures - in comparison to the days when a guy in a small signal cabin sited beside the track itself was controlling trains he could actually see.

[Colin]

Errmm...how do arrive at the conclusion that signal failures are connected to signal cabins and control rooms?

Quite frankly it doesn't make a jot of difference either way!

A signal failure can be down to a blown bulb, blown track circuit fuse, scaling over a block joint (metal bridging a block joint in the rail), metal across both running rails, positive earth on positive traction current rail (ie, a fallen collector shoe touching both the positive traction current rail and the nearest running rail), broken wire, failed points, failed signal main, etc. I'm sure I could add more.

[paterson00]

Aug 14, 2010 9:54:45 GMT @harlesden said:

Has centralized control succeeded or failed in reducing the number and frequency of signal failures - in comparison to the days when a guy in a small signal cabin sited beside the track itself was controlling trains he could actually see.

Are you asking if response tines to failure has improved?

[harlesden]

I had assumed that some signal failures might be due to a breakdown in communication between the controller/signal person and the actual signal

[Colin]

I'm not sure I see where you're going with this

Cabins and control room signallers only have control over signals in areas where there are points (in the simplest of terms) - the vast majority of signals on LU are actually fully automatic and therefore work all on their own with no control by either a cabin or control room.

Signals that are controlled by a signaller are done so by the use of buttons or levers. Some of this is automated via computers or programme machines, but can always be overridden by buttons.

It's a bit like pressing the buttons on your TV remote control - you push a button and the channel changes, or the volume changes, etc.

If I'm teaching you to "suck eggs", I apologise, but you haven't made yourself all that clear.

[harlesden]

Your responses have been an education - perhaps for a few others in addition to myself.
Your input is much appreciated.

[Colin]

So we're heading in the right direction then?

[Deleted]

There is a lot more equipment between a control room and the actual equipment rather than a signalman in a signal cabin.

You can think something isn't working, but it is.

Like Scanning causing all the track circuits to light up, lack of comms between sites, modern equipment doing allsorts of strange things

[citysig]

As has been touched on, centralised control brought with it a new era in failures (and also a new era of more people being able to see the failure and consequences to the service.)

The failure of computers or programme machines that operate the signalling at a particular site is the equivalent to the old signaller falling asleep and needing to be woken up (which of course never happened ;D ).

Sometimes the link between the control room and this remote equipment is lost - which normally results in 2 possible outcomes: the site continues to operate on it's own with the timetable it has, or the site fails as well until the link is fixed.

When centralised control projects are planned, the "reliability" aspect (which is what I think the OP may be referring to) is normally angled towards the fact that with whole line being visible within one control room, operation and regulation of the service is achieved better than when you have several separate cabins and "blank spaces" between them where trains are "lost" until they reach the next controlled area.

[smudge76]

As both a signalman and control room operative at Coburg Street. I have dealt with a number of such failures. At Finchley Central I had a points failure approaching the station NB (20 points). It was a Sunday and I was alone. With just a scotch block, I rammed it into the open point blades gave the driver the okay. When tripped I re set it and the train proceeded. I kicked the block out of the points and returned to the box. The East Finchley Linesman arrived on the following train. The delay 3 minutes.
Health & Safety regulations would have had a field day with this.
Common sence and commitment to doing your job to your best initative was how we operated then. But then our bosses were people who worked up through the grades and appreciated our efforts.

[Deleted]

Absolutely, Smudge76. Couldn't agree with you more !!!

[citysig]

I second that - having started service in what became one of the last years of operating under common sense.

Had a failure at Amersham yesterday, and to get the train underway it took almost 30 minutes. Back then (if the failure had happened, which I doubt) we would have been moving much much sooner.

[Deleted]

Please advise.

Recently I read that a "scotch" was different that a "scotch block"."Scotch" was a wooden timber wedge to separate rails. "Scotch block" was more like a wheel chock to keep a train wheel from moving.

Obviously I am no way qualified to say - so I am just asking.
Was the definition I read too nitpicky?
Are the two terms interchangeable?
Do the definitions vary by railway, country, etc.?

[Deleted]

The definition is spot on. with no being to your last two questions.

[railtechnician]

Oct 12, 2010 19:45:06 GMT @kentuckytony said:

Please advise.

Recently I read that a "scotch" was different that a "scotch block"."Scotch" was a wooden timber wedge to separate rails. "Scotch block" was more like a wheel chock to keep a train wheel from moving.

Obviously I am no way qualified to say - so I am just asking.
Was the definition I read too nitpicky?
Are the two terms interchangeable?
Do the definitions vary by railway, country, etc.?

Scotch is a useful word! It has so many meanings, Scotch and Scotch block are just as you have heard as Justnebbing attests.

Scotch is obviously an alcoholic tipple and also a description of some things Scottish such as Scotch beef but it is also a brand of electrical insulating tape used in signalling and communications and it is another word for cancel too!

So if something is 'scotched' it could be prevented from moving but it could also be insulated or cancelled! The clues as to the exact meaning are usually elsewhere rather than in the word itself!

Examples:
The points were clipped and scotched. (to lock them normal or reverse)

The trolley was scotched. (to stop it running away - not used so much since track trolleys were fitted with failsafe handbrakes)

The cabledrum was scotched. (usually with battens to stop it rolling)

The joint was scotched. (a temporary cable repair)

The job was scotched. (it was cancelled)

[Deleted]

What about in cab signalling? That would at least eliminate the broken bulb mode of failure.

[Deleted]

Oct 13, 2010 5:56:46 GMT railtechnician said:

Oct 12, 2010 19:45:06 GMT @kentuckytony said:

Please advise.

Recently I read that a "scotch" was different that a "scotch block"."Scotch" was a wooden timber wedge to separate rails. "Scotch block" was more like a wheel chock to keep a train wheel from moving.

Obviously I am no way qualified to say - so I am just asking.
Was the definition I read too nitpicky?
Are the two terms interchangeable?
Do the definitions vary by railway, country, etc.?

Scotch is a useful word! It has so many meanings, Scotch and Scotch block are just as you have heard as Justnebbing attests.

Scotch is obviously an alcoholic tipple and also a description of some things Scottish such as Scotch beef but it is also a brand of electrical insulating tape used in signalling and communications and it is another word for cancel too!

So if something is 'scotched' it could be prevented from moving but it could also be insulated or cancelled! The clues as to the exact meaning are usually elsewhere rather than in the word itself!

Examples:
The points were clipped and scotched. (to lock them normal or reverse)

The trolley was scotched. (to stop it running away - not used so much since track trolleys were fitted with failsafe handbrakes)

The cabledrum was scotched. (usually with battens to stop it rolling)

The joint was scotched. (a temporary cable repair)

The job was scotched. (it was cancelled)

Botched you mean ;D ;D ;D

[railtechnician]

Oct 14, 2010 16:56:27 GMT @aetearlscourt said:

Oct 13, 2010 5:56:46 GMT railtechnician said:

Scotch is a useful word! It has so many meanings, Scotch and Scotch block are just as you have heard as Justnebbing attests.

Scotch is obviously an alcoholic tipple and also a description of some things Scottish such as Scotch beef but it is also a brand of electrical insulating tape used in signalling and communications and it is another word for cancel too!

So if something is 'scotched' it could be prevented from moving but it could also be insulated or cancelled! The clues as to the exact meaning are usually elsewhere rather than in the word itself!

Examples:
The points were clipped and scotched. (to lock them normal or reverse)

The trolley was scotched. (to stop it running away - not used so much since track trolleys were fitted with failsafe handbrakes)

The cabledrum was scotched. (usually with battens to stop it rolling)

The joint was scotched. (a temporary cable repair)

The job was scotched. (it was cancelled)

Botched you mean ;D ;D ;D

Obviously you know just as I do that it all depends who was doing the scotching! I certainly came across a few botchers in my 28 years on the combine.