New RSSB standards for speed signs

[midland1]

I saw the A boards at Bristol Temple Meads last year 2023

 

[Scotrail88]

Is there any other new A board locations?

Would benefit loads of routes especially now with longer trains since speeds were originally installed

 

[Railsigns]

One was recently put in at St. Albans City (exit of centre siding).

 

[Scotrail88]

Not aware of any in Scotland but would like to stand corrected

 

[MalaiseForever]

What do the new A boards mean?

 

[swt_passenger]

What do the new A boards mean?

The explanation is in the first post of this thread. A (for accelerate) at the sign rather than when the rear of the train reaches the sign.

 

[Chris125]

Is there any other new A board locations?

Would benefit loads of routes especially now with longer trains since speeds were originally installed

Island Line briefly used one for a speed limit over a foot crossing, but it wasn't obvious drivers were taking any notice of it.

 

[zwk500]

Is there any other new A board locations?

Would benefit loads of routes especially now with longer trains since speeds were originally installed

the track still has to be suitable for the new speed further back so on e.g. points or sharp curves the opportunity to place a board may not exist. That still leaves plenty of locations where they would be useful.

 

[edwin_m]

the track still has to be suitable for the new speed further back so on e.g. points or sharp curves the opportunity to place a board may not exist. That still leaves plenty of locations where they would be useful.

Restrictions due to track geometry are unlikely to get A boards for this very reason - the whole train has to be clear of whatever is restricting the speed before it can accelerate. These are going to be used for things like level crossings and signal sighting issues where the restriction is no longer relevant once the front of the train has passed it.

 

[zwk500]

Restrictions due to track geometry are unlikely to get A boards for this very reason - the whole train has to be clear of whatever is restricting the speed before it can accelerate. These are going to be used for things like level crossings and signal sighting issues where the restriction is no longer relevant once the front of the train has passed it.

Absolutely, that was the point I was trying to make!

 

[MalaiseForever]

The explanation is in the first post of this thread. A (for accelerate) at the sign rather than when the rear of the train reaches the sign.

Totally missed that - thanks!

 

[MarkyT]

These are going to be used for things like level crossings and signal sighting issues where the restriction is no longer relevant once the front of the train has passed it.

Also for the previously mentioned departure movements from terminal platforms. The risks approaching a buffer stop typically imposes a more severe restriction than usually determined by geometry and signal spacing alone. While technically still applying after reversal without the A boards, such a speed has no relevance on departure, when the speed of the throat turnouts is the important factor.