Flashing yellows

[Tomnick]

Just a quick question follwing a discussion yesterday. Does anyone know whether these are permitted on an Absolute Block line (single flashing yellow in the distant, more specifically), and whether there are any examples on the network? The things that come up in conversation on a quiet Sunday .

 

[156441]

No not allowed under AB and therefor no examples.
Hope that helps.

 

[Tomnick]

Thanks - I couldn't think of any reason really why they shouldn't be used on AB, but haven't had anything like chance to find the relevant standard and check.

 

[156441]

One would assume they wouldn't be used on AB as the colour light signals used in this type of signalling directly replace semaphores which wouldn't be able to show a 'flashing yellow aspect'

Another train of thought would be that your unlikely to have a high speed turnout on a AB line?
--- old post above --- --- new post below ---
That said I do only sign AB routes within a 60 mile radius of Manchester so others may have examples.

 

[Tomnick]

Hmm, I don't know - although a two-aspect (Y/G) distant is indeed equivalent to (and probably directly replaced, in most cases) a semaphore distant, there are examples of further indications being provided - three-aspect distant signals (Y/YY/G) being the first that comes to mind, with one (excepting preservation, the only one on an AB line that I can think of at the moment!) at Blea Moor on the Up. The location we were discussing is a bit of a bottleneck, with a 20mph crossover (approach control from red on the protecting signal) forming part of the long and slow crossing move onto the Up Branch, and I was wondering what effect a higher speed crossover (and flashing yellows) would have.

 

[FLHH East Anglia]

Another train of thought would be that your unlikely to have a high speed turnout on a AB line?
--- old post above --- --- new post below ---
That said I do only sign AB routes within a 60 mile radius of Manchester so others may have examples.

They do'nt have to be high-speed,theres a 15,yes 15mph one at Hackney Downs coming from Clapton if you are heading onto the Surburban line.Its onl 30 on the approach.

 

[Railsigns]

There's no reason at all why flashing yellow aspects can't exist on an Absolute Block line. It's less likely to occur than on a TCB line but, providing all the criteria for flashing yellows are met, it's acceptable to have them and the method of working the line isn't a factor.

Examples? Well, there's Brocklesby Junction, where the distant signal that can display a flashing yellow aspect is in the AB section from Barnetby, albeit with the lines beyond the junction being worked by TCB.

The opposite scenario once existed at Carmuirs West Junction: Flashing aspects on the TCB approach to the junction, then AB on both routes beyond.

 

[455driver]

the colour light signals used in this type of signalling directly replace semaphores which wouldn't be able to show a 'flashing yellow aspect'

Why have I got this picture in my head of a signalman pushing and pulling the lever in and out of the frame, sweat pouring from his forhead, swearing for the <bleep>ing driver to get a move on!

 

[Tomnick]

Examples? Well, there's Brocklesby Junction, where the distant signal that can display a flashing yellow aspect is in the AB section from Barnetby, albeit with the lines beyond the junction being worked by TCB.

Ah, thanks for confirming that it is allowed (albeit rather rare?) - I suppose I should have remembered Brocklesby, as I've been there and seen it!

 

[Scottw]

Not knowing much about this,but the signal at brandon outside durham,is always double amber and starts flashing double amber when a train is approaching durham station.if it turns to green it's going straight through on the centre line.
You can see it in my avatar lol

 

[Tomnick]

I'm sure it's flashing double yellow really .

 

[Boothby97]

I am still confused to this day about what a Double Amber shows but when I was at Tamworth one day the Royal Train came through on DA
Thanks, Sam

 

[Cherry_Picker]

Double amber? Don't say that out loud in front a signaller or a driver or you will get a clip around the ear. It's never amber, it's yellow!

 

[The Planner]

Only 3 aspect as far as i recall at Tamuff, so it wouldnt have been a double.

 

[Tomnick]

It's four aspect downstairs on the Trent Valley at Tamworth, isn't it? Either way, flashing double yellow (please!) indicates that the second signal has been cleared for the highest speed diverging route, the next showing flashing single yellow.

 

[DarloRich]

I am still confused to this day about what a Double Amber shows but when I was at Tamworth one day the Royal Train came through on DA
Thanks, Sam

Not knowing much about this,but the signal at brandon outside durham,is always double amber and starts flashing double amber when a train is approaching durham station.if it turns to green it's going straight through on the centre line.
You can see it in my avatar lol

IT IS YELLOW!!!!!!!!!!! You have amber on the roads

 

[Tomnick]

I am still confused to this day...

Now that I'm not trying to type on the little screen on my phone, I can provide a link to a more thorough answer than my very brief comment above! Have a good read through this to learn all about flashing yellows and other forms of junction signalling...

 

[wilsontown]

It might also be worth a look at what happened at Colwich Junction. The driver misunderstood what the flashing yellow signals were telling him, with tragic results.

 

[The Planner]

It's four aspect downstairs on the Trent Valley at Tamworth, isn't it?

Good point, forgot about the branch line on the bottom.

 

[ainsworth74]

Double amber? Don't say that out loud in front a signaller or a driver or you will get a clip around the ear. It's never amber, it's yellow!

Either way, flashing double yellow (please!)

IT IS YELLOW!!!!!!!!!!! You have amber on the roads

Do rail staff twitch when they see people refer to double amber?

 

[DarloRich]

Do rail staff twitch when they see people refer to double amber?

Only because I once misspoke myself and described an amber signal to a colleague who was once a signalling manager. He subjected me to a long lecture as the error of my ways! I believe his next task would have been to send me for a bucket of steam!

 

[Tomnick]

Do rail staff twitch when they see people refer to double amber?

Yes, it's almost as bad as 'train station' .

 

[PaulLothian]

Not the silliest thing I have seen today - try today's Herald - http://www.heraldscotland.com/news/transport/victorian-rail-signals-replaced.20112493

ONE of the last of Scotland's sets of Victorian railway signals, which have controlled trains on the main line between Edinburgh and Perth for more than 100 years, are to be replaced by electric "traffic lights".

 

[ChiefPlanner]

It might also be worth a look at what happened at Colwich Junction. The driver misunderstood what the flashing yellow signals were telling him, with tragic results.

Very good point and a study of "misunderstanding" - there was a similar sort of error in semaphore (just after nationalisation) days at Bourne End - but that was to do with "splitting distants"...a nasty wreck with multiple casualties.

 

[455driver]

Good point, forgot about the branch line on the bottom.

You naughty naughty person.

 

[dk1]

IT IS YELLOW!!!!!!!!!!! You have amber on the roads

Thank you. Amber REALLY winds me up.

 

[Tomnick]

Join the club!