NAAR Signals

[BTU]

Can anyone explain what NAAR signals are?

 

[godfreycomplex]

Can anyone explain what NAAR signals are?

Have you any context by any chance please?

 

[rower40]

Suggest it’s “Not Approachable At Red”. Effectively “double block “ operation.

 

[NSEWonderer]

Pretty much above, its pretty much a distant signal that can show a Red, making the actual Signal thats truly set at danger, un approachable. Thats how I've always understood them.

 

[Supercoss]

A few of these in London on Thameslink route
“ mid platform signals” non approachable at red to avoid train being stopped at location where it will not be fully accommodated in platform, looks just like a regular signal

 

[BTU]

That makes perfect sense it's the distant signal that can show a red. I was missing that I kept thinking distant signal that cant show a red as in 2 aspect signalling here making the double block and Not Approachable at Red.
Thank you everyone.

 

[Sunset route]

We’ve got distant signals on some of our bi directional signalled running lines where in the normal direction of traffic of flow the distant signals for the wrong direction bi-di will show red and can not be approached whilst showing red. But as soon as the bi directional signalling is used will trains now travelling counter to normal flow and to approach them the, they behave like normal distant signals with the red aspect disengaged. The reason for this was during normal working was to reduce the risk of driver reading across errors.

 

[Tester]

We’ve got distant signals on some of our bi directional signalled running lines where in the normal direction of traffic of flow the distant signals for the wrong direction bi-di will show red and can not be approached whilst showing red. But as soon as the bi directional signalling is used will trains now travelling counter to normal flow and to approach them the, they behave like normal distant signals with the red aspect disengaged. The reason for this was during normal working was to reduce the risk of driver reading across errors.

I can follow the logic of that.

For context, where is this, please.

 

[Supercoss]

Down Moorgate
TWH3007 TWH3011 TWH3015 TWH3019
Up Moorgate
TWH3008 TWH3014 TWH3018
so all underground in Thameslink Core
All these are NOT signals controlling the

entrance to a track circuit block section.

 

[Tomnick]

Down Moorgate
TWH3007 TWH3011 TWH3015 TWH3019
Up Moorgate
TWH3008 TWH3014 TWH3018
so all underground in Thameslink Core
All these are NOT signals controlling the View attachment 191076

entrance to a track circuit block section.

What's the point of them, then?

 

[Supercoss]

Consider them as distant signals on a Bi Directional line But due to signal sighting issues , so they are not mistaken or read through risk ,they show red when Bi Di working not in use
This is all well and good until someone decided to do a bit of parallel running through the core , two northbound trains running next to each other …….!

 

[Port Road]

Consider them as distant signals on a Bi Directional line But due to signal sighting issues , so they are not mistaken or read through risk ,they show red when Bi Di working not in use
This is all well and good until someone decided to do a bit of parallel running through the core , two northbound trains running next to each other …….!

Interesting. But the signal in the photo is plated as an automatic [stop] signal?

 

[NSEWonderer]

Interesting. But the signal in the photo is plated as an automatic [stop] signal?

Yes but a train "rarely rarely" ever "stops" at it when red. Making it non approachable at red.

 

[Sunset route]

I can follow the logic of that.

For context, where is this, please.

The section of line between Balcombe Tunnel Junction and Copyhold Junction on the Brighton Main Line.

 

[Tester]

The section of line between Balcombe Tunnel Junction and Copyhold Junction on the Brighton Main Line.

Many thanks

 

[milooo]

Doesn't this kind of signal also exist in the Trent valley especially on the approach to junctions and rugby?