Talk past or route around?

Steamer in post 103608 said:

Chromatix in post 103607 said:

Which behaviour is more realistic for UK operations? Should this be considered a bug in SimSig?

The behaviour is correct for UK practice- I suspect it would have been altered a long time ago if it wasn't!

I remember reading that on some of the earlier 50s/60s MAS schemes (southern WCML), a signal would show Y onto an unlit signal that would otherwise be showing proceed. Additionally, it was very rare for the top yellow on four aspect signals to be proved, so if the top lamp failed the driver would get the sequence G-> Y-> Y-> R. I don't know if the top lamp is now proved on modern software interlockings.

There are still locations that have this today. Yes today the top yellow is proved, it was also proved in some schemes in the 1970s.

if the green aspect was missing in a signal, the Signaller would ensure that this signal only showed a double yellow at the most by a signal held at danger ahead

Not working in the UK, but here in Sweden we are instructed to avoid taking trains past a signal at danger as far as practical for safety reasons. However, of course, sometimes that's not possible without causing major delays.

Bonan in post 103605 said:

Not working in the UK, but here in Sweden we are instructed to avoid taking trains past a signal at danger as far as practical for safety reasons. However, of course, sometimes that's not possible without causing major delays.

Passing signals at danger does not affect safety. A Signaller in the UK has very strict rules they must carry out before authorising trains passed signals at Danger. It is perfectly safe and is carried out often.

Giantray in post 103616 said:

Bonan in post 103605 said:

Not working in the UK, but here in Sweden we are instructed to avoid taking trains past a signal at danger as far as practical for safety reasons. However, of course, sometimes that's not possible without causing major delays.

Passing signals at danger does not affect safety. A Signaller in the UK has very strict rules they must carry out before authorising trains passed signals at Danger. It is perfectly safe and is carried out often.

I'm afraid I hugely disagree with that statement!

https://www.gov.uk/raib-reports/derailment-at-knaresborough

Talking a train passed a signal at danger resulted in a derailment. The moment you talk a train past you have lost the vital safety that the interlocking usually provides.

Quote:

if the green aspect was missing in a signal, the Signaller would ensure that this signal only showed a double yellow at the most by a signal held at danger ahead

That's all well and good if there are controlled signals in the right places to do so. What about when it's a long stretch of automatics on plain line? Not every automatic signal has an emergency replacement switch on the panel.

Chromatix in post 103615 said:

Quote:

if the green aspect was missing in a signal, the Signaller would ensure that this signal only showed a double yellow at the most by a signal held at danger ahead

That's all well and good if there are controlled signals in the right places to do so. What about when it's a long stretch of automatics on plain line? Not every automatic signal has an emergency replacement switch on the panel.

For a long time it's been a requirement that at least every 4th (or is it a maximum of 4 signals in sequence without ERS?) be fitted with an ERS. However since CBIs came about there is virtually no cost to fitting every automatic signal with an ERS.

So while it's not perfect for older installations, it's not as bad as you imply.

Chromatix in post 103615 said:

Quote:

if the green aspect was missing in a signal, the Signaller would ensure that this signal only showed a double yellow at the most by a signal held at danger ahead

That's all well and good if there are controlled signals in the right places to do so. What about when it's a long stretch of automatics on plain line? Not every automatic signal has an emergency replacement switch on the panel.

For a long time it's been a requirement that at least every 4th (or is it a maximum of 4 signals in sequence without ERS?) be fitted with an ERS. However since CBIs came about there is virtually no cost to fitting every automatic signal with an ERS.

So while it's not perfect for older installations, it's not as bad as you imply.

I vaguely remember that at Bristol Panel we had one ERS each way betwen Bristol and Bath and they weren't the reliable sort.

KymriskaDraken in post 103664 said:

I vaguely remember that at Bristol Panel we had one ERS each way betwen Bristol and Bath and they weren't the reliable sort.

7 autos so that's about right.

General question: can you use a non-reliable one to limit aspect reversions - ie we're not stopping trains at it, just trying to prevent a driver getting a black or adverse change of aspect?

KymriskaDraken in post 103664 said:

I vaguely remember that at Bristol Panel we had one ERS each way betwen Bristol and Bath and they weren't the reliable sort.

7 autos so that's about right.

General question: can you use a non-reliable one to limit aspect reversions - ie we're not stopping trains at it, just trying to prevent a driver getting a black or adverse change of aspect?