Main aspect with position light signal

[Gooner18]

Do you have to always get authority from the signaller to progress past a Red signal in circumstances where you have a main aspect signal showing Red and a position light signal showing two white lights at 45 degrees or has two white flashing lights at 45 degrees ( proceed on sight authority ) , the way I am understanding it’s only required when progressing on PoSA , however this don’t sit right , surely the right and safe thing to do Would be to stop and check / gain authority from the signaller in Both situations?

 

[Highlandspring]

The illumination of the PoSA is a movement authority in itself. See the first paragraph of clause 2.1 of Rule Book module PoSA.

 

[Gooner18]

The illumination of the POSA is a movement authority in itself.

So you would not contact to signaller to double check ?

 

[Highlandspring]

No, I’d follow the requirements of the relevant rule.

 

[dk1]

So you would not contact to signaller to double check ?

Hell no. It's permission to continue into a permissive platform or until you can see the line to be clear. Dread to think of the delay & disruption you'd cause by contacting the signaller. He/she would question your sanity.

 

[LowLevel]

You don't have to get the authority of signaller to pass a red signal with a position light illuminated. That's the whole point of the signal. You pass it and proceed cautiously preparing to stop short of any obstruction. It's usually used to give access to things like permissive lines (the one that immediately comes to mind is the Melton Mowbray platform starter on the up which has a position light to access the up goods).

 

[Mag_seven]

Do you have to always get authority from the signaller to progress past a Red signal in circumstances where you have a main aspect signal showing Red and a position light signal showing two white lights at 45 degrees or has two white flashing lights at 45 degrees ( proceed on sight authority ) , the way I am understanding it’s only required when progressing on PoSA , however this don’t sit right , surely the right and safe thing to do Would be to stop and check / gain authority from the signaller in Both situations?

It is for all intents and purposes a proceed aspect isn't it?

 

[Highlandspring]

Looking back it’s not clear from the question whether you’re specifically asking about the illumination of a PoSA aspect (two flashing lunar white lights at 45 degrees) or an associated position light (two steady lunar white lights at 45 degrees). Either way both of them convey a movement authority without any need to contact the signaller before proceeding.

 

[Gooner18]

Sorry , prob not very clear , when you have authority to proceed with two flashing white lights (PoSA) it says you may get instructions from the signaller that you must stick to, got me thinking whether best policy is to contact the signaller in both situations , both steady and flashing lights from the position signal

 

[Gooner18]

Oh and association with main aspect

 

[Highlandspring]

You ‘may’ get instructions from the signaller before the PoSA is cleared. If you get instructions then you carry them out once the signal has cleared. If the signaller doesn’t contact you before the PoSA clears, or if it is already displayed when you first sight it then you proceed. There is no need for a driver to seek authority from the signaller before proceeding under a PoSA aspect, the whole point of it is to minimise the need for communication during degraded working.

As for associated postion lights, again these convey a movement authority in themselves and there is no need to contact the signaller before proceeding. The rules around bother PoSA and associated position light signals are very clear (no pun intended).

 

[Mag_seven]

two flashing lunar white lights at 45 degrees

I must confess in all my extensive travels on the UK rail network I've never seen this - is there any location where it is a regular occurrence?

 

[Highlandspring]

Thameslink Core has them but I have no idea how often they’re used.

 

[FGW_DID]

 

[Gooner18]

You ‘may’ get instructions from the signaller before the PoSA is cleared. If you get instructions then you carry them out once the signal has cleared. If the signaller doesn’t contact you before the PoSA clears, or if it is already displayed when you first sight it then you proceed. There is no need for a driver to seek authority from the signaller before proceeding under a PoSA aspect, the whole point of it is to minimise the need for communication during degraded working.

As for associated postion lights, again these convey a movement authority in themselves and there is no need to contact the signaller before proceeding. The rules around bother PoSA and associated position light signals are very clear (no pun intended).

Fair enough, so just proceed under caution, prepare to stop short etc

 

[Highlandspring]

For completeness...

 

[Gooner18]

View attachment 55614

Cheers , it was the part where you have two flashing giving authority to proceed as per PoSA with possible instructions from the signaller that made me think lol

 

[swt_passenger]

Thameslink Core has them but I have no idea how often they’re used.

...and the East London line core section.

 

[Highlandspring]

You might be going wrong by thinking that PoSA aspects and associated position lights are the same thing; they are used for different classes of route within the signalling principles and have subtly different meanings and implications for drivers.

 

[Gooner18]

You might be going wrong by thinking that PoSA aspects and associated position lights are the same thing; they are used for different classes of route within the signalling principles and have subtly different meanings and implications for drivers.

Yes you’re correct I think I am getting myself confused with PoSA associated and a PoSA aspect position light signal

 

[Highlandspring]

You are getting confused. A (main aspect colour light) signal may have an associated position light which, when displayed at the same time as a red aspect, gives authority for a train to proceed onto a line which may be occupied by another train or vehicle. This is called an ‘associated position light’. That’s as opposed to an ‘independent position light’ which conveys the same message but is not associated with another signal.

A Proceed-on-Sight Authority signal looks identical to an associated or independent position light signal when it is unlit but when illuminated displays a flashing aspect to differentiate it from the other types of position light signals. The illumination of a PoSA signal gives authority for a train to proceed even though an associated signal (if there is one) may be displaying a red aspect or no aspect at all. PoSA signals are only used under very specific circumstances during degraded working. The term Proceed-on-sight or PoSA only refers to this type of signal.

There are five classes of route in the signalling principles - Main, Warning, Call-on, Shunt and PoSA. An associated position light could used for call-on and shunt class routes, while PoSA signals are only used for PoSA class routes. Main aspect signals are used for main and warning class routes.

 

[sw1ller]

This is why you don’t read the rule book before you start in the classroom.

 

[ComUtoR]

This is why you don’t read the rule book before you start in the classroom.

They were warned but people keep insisting on posting links to revision revision material

Context is everything.

 

[sw1ller]

The rule book doesn’t even make sense when you’re in the classroom, so what chance people think they have when you haven’t started yet is beyond me. It doesn’t start properly falling into place until you’re out with an instructor. Even then it can take time.

 

[ComUtoR]

...and the East London line core section.

..and through London Bridge

 

[ComUtoR]

Fair enough, so just proceed under caution, prepare to stop short etc

As I'm in a little bit of a cheeky mood...

How fast will you be proceeding 'under caution' ? (There have been a few incidents recently due to to this being misinterpreted.)
If the PoSA was flashing, what aspect will the next signal show ?
What about route indication ?
What about a 'running' ground position light (as found at Stewarts Lane) ?

So many potential pitfalls from reading ahead

 

[Gooner18]

Hellooo all ,

I took on the previous advice not to read ahead , this all come about by watching a video about it , I had the semi bright idea to double check in the rule book , But it ended up making even less sense , hence my post here. No more videos as well now lol.

 

[Surreytraveller]

So you would not contact to signaller to double check ?

No. The position light signal IS the authority from the signaller. There would be no point having the signal if the driver had to speak to the signaller to confirm the signal!

 

[Surreytraveller]

Hell no. It's permission to continue into a permissive platform or until you can see the line to be clear. Dread to think of the delay & disruption you'd cause by contacting the signaller. He/she would question your sanity.

Indeed. The driver would possibly be taken off-track for not following the rules.

 

[DanDaDriver]

Indeed. The driver would possibly be taken off-track for not following the rules.

Depends, there’s quite a few occasions where you would query a subsidiary signal, particularly on passenger work.