Heart of Wales stations which are request stops in one direction only

[SouthEastBuses]

So I've noticed that some stations (Llanwrda for example) on the Heart of Wales line are request stops only in a certain direction (in the case of Llanwrda towards Swansea), with the stop being mandatory for the opposite direction (in the case of Llanwrda being Shrewsbury), so that the crew can activate the level crossing on the platform.

Using the Llanwrda example, why are Swansea trains not required to stop unlike Shrewsbury trains, and how would the level crossing be activated in this instance?

 

[craigybagel]

Treadles. The train passes over the treadle, which activates the crossing. Similar to how AHB crossings work on busier routes, although the speed limits are a lot lower and the driver needs to ensure the crossing has operated correctly (as shown by a flashing white light) before proceeding over the crossing and into the station

 

[SouthEastBuses]

Treadles. The train passes over the treadle, which activates the crossing. Similar to how AHB crossings work on busier routes, although the speed limits are a lot lower and the driver needs to ensure the crossing has operated correctly (as shown by a flashing white light) before proceeding over the crossing and into the station

Ok this makes sense thank you. Using the Llanwrda example, why would a treadle not be workable towards Shrewsbury, therefore requiring trains to stop at Llanwrda and operating the level crossing from the platform?

 

[Railsigns]

Is Llanwrda LC not still an "Open" crossing without road traffic lights, and therefore without treadles and track circuits since there's nothing there to be activated?

 

[SuspectUsual]

Ok this makes sense thank you. Using the Llanwrda example, why would a treadle not be workable towards Shrewsbury, therefore requiring trains to stop at Llanwrda and operating the level crossing from the platform?

Is it because the station means there's no way of knowing how long it'll be before the train reaches the crossing if a treadle was activated prior to the station, and therefore its less disruptive for road users if the crossing is activated only when the driver knows he's ready to proceed?

 

[Llanigraham]

Is Llanwrda LC not still an "Open" crossing without road traffic lights, and therefore without treadles and track circuits since there's nothing there to be activated?

According to Google Streetview, yes it is an open crossing with no wigwags or sirens, so I can't see any reason for any treadles and I can't see any in the 4' looking in the Shrewsbury direction
Rail sightlines northbound don't look to be that good so that could be the reason.

 

[craigybagel]

Ok this makes sense thank you. Using the Llanwrda example, why would a treadle not be workable towards Shrewsbury, therefore requiring trains to stop at Llanwrda and operating the level crossing from the platform?

I'm open to correction, but I always assumed it was ensure the level crossing wasn't operated until the train was ready to leave the station. If the train activated a treadle before the platform, and then got delayed at the station, it would activate the crossing for an undesirably long time.

Is Llanwrda LC not still an "Open" crossing without road traffic lights, and therefore without treadles and track circuits since there's nothing there to be activated?

Google maps suggest that is the case. I only ever signed the other Northern half of the HOWL so I had assumed Llanwrda was AOCL(+B) like the crossings further up the line I'm more familiar with.

 

[Llanigraham]

EDIT
I doubt road traffic is going to be a problem as the road only goes to a few houses and a farm.

 

[SouthEastBuses]

I'm open to correction, but I always assumed it was ensure the level crossing wasn't operated until the train was ready to leave the station. If the train activated a treadle before the platform, and then got delayed at the station, it would activate the crossing for an undesirably long time.

Google maps suggest that is the case. I only ever signed the other Northern half of the HOWL so I had assumed Llanwrda was AOCL(+B) like the crossings further up the line I'm more familiar with.

Ahh makes sense now. Down here in West Sussex, road users often have to wait for 5 minutes at a level crossing, which even includes trains that depart at stations before a level crossing (Littlehaven going towards London and further north, and Crawley going towards Horsham and further south are examples of this). The level crossings are activated before the train that is about to cross the level crossing has even stopped at the station!

 

[louis97]

Ahh makes sense now. Down here in West Sussex, road users often have to wait for 5 minutes at a level crossing, which even includes trains that depart at stations before a level crossing (Littlehaven going towards London and further north, and Crawley going towards Horsham and further south are examples of this). The level crossings are activated before the train that is about to cross the level crossing has even stopped at the station!

Those two crossings are full barriers, typically those type of crossings will be lowered so trains don't receive restrictive aspects. Although this isn't the case everywhere. The difference with automatic crossings is most are raised by treadles, if these treadles are not activated within so long the crossing will fail. So a lowering treadle before a platform of where you could have an unknown dwell time has the risk of causing the crossing to fail. Therefore you get the crossing lowered by train crew to mitigate against this risk.

 

[AlbertBeale]

Those two crossings are full barriers, typically those type of crossings will be lowered so trains don't receive restrictive aspects. Although this isn't the case everywhere. The difference with automatic crossings is most are raised by treadles, if these treadles are not activated within so long the crossing will fail. So a lowering treadle before a platform of where you could have an unknown dwell time has the risk of causing the crossing to fail. Therefore you get the crossing lowered by train crew to mitigate against this risk.

At the new-ish Mitcham Eastfields station, the platforms are staggered, with both following the train's crossing of a level crossing. I don't know whether this was because of constriats on the site when the staton was added, in a built-up area, of whether part at least of the reason was to avoid the need to have the barriers down while a train in either direction was in the station. It's not a layout I remember seeing anywhere else.

 

[30907]

At the new-ish Mitcham Eastfields station, the platforms are staggered, with both following the train's crossing of a level crossing. I don't know whether this was because of constriats on the site when the staton was added, in a built-up area, of whether part at least of the reason was to avoid the need to have the barriers down while a train in either direction was in the station. It's not a layout I remember seeing anywhere else.

It was common enough in the C19, but more to allow passengers to cross the line safely without having to provide a footbridge. The SER was known for it, and Rye is a survivor (it has a bridge now, and there was never a road crossing mid platform).

 

[Bletchleyite]

At the new-ish Mitcham Eastfields station, the platforms are staggered, with both following the train's crossing of a level crossing. I don't know whether this was because of constriats on the site when the staton was added, in a built-up area, of whether part at least of the reason was to avoid the need to have the barriers down while a train in either direction was in the station. It's not a layout I remember seeing anywhere else.

Several Marston Vale stations are like that, including a couple converted to that recently, indeed to reduce the time the barriers were closed for.

 

[zwk500]

At the new-ish Mitcham Eastfields station, the platforms are staggered, with both following the train's crossing of a level crossing. I don't know whether this was because of constriats on the site when the staton was added, in a built-up area, of whether part at least of the reason was to avoid the need to have the barriers down while a train in either direction was in the station. It's not a layout I remember seeing anywhere else.

Staggered platforms were quite popular in the early days of railway building as they enabled passengers to cross between platforms behind trains, as well as for the gates (as they were then) to be opened quicker. Sometimes staggered platforms have been eliminated as lengthening schemes have taken place and bridges provided, or platforms have been moved around etc.

Ahh makes sense now. Down here in West Sussex, road users often have to wait for 5 minutes at a level crossing, which even includes trains that depart at stations before a level crossing (Littlehaven going towards London and further north, and Crawley going towards Horsham and further south are examples of this). The level crossings are activated before the train that is about to cross the level crossing has even stopped at the station!

IIRC those crossings are within the signal overlap, and therefore need to be closed to signal a train into the platform. More frustrating was Plumpton Level Crossing, which has 7 coach platforms but usually 8- or 12-car trains calling, with the station being north of the line the rear of an Up train obstructs the crossing. The reason why Plumpton is especially galling is that there's a massive unused length of Up platform for race-day specials that could easily have been brought into use to allow a 12-car train to clear the crossing.

 

[louis97]

IIRC those crossings are within the signal overlap, and therefore need to be closed to signal a train into the platform.

As long as the signal protecting the crossing is a set distance back from it (25 metres I think), there is no requirement to lower the crossing to signal a train into the platform where the overlap goes over the crossing. The situation with those crossings is as it is because it avoids a slower approach to a platform because of the red protecting the crossing.

 

[61653 HTAFC]

EDIT
I doubt road traffic is going to be a problem as the road only goes to a few houses and a farm.

There's been a fair few incidents in recent years at crossings of minor roads, and overfamiliarity can lead to complacency, especially on a line as lightly used as the HOWL.

 

[Nottingham59]

It's not a layout I remember seeing anywhere else.

Elsenham is like that. It was a factor when those two girls got hit running for the train when there was only one ticket machine - on the other platform

 

[norbitonflyer]

At the new-ish Mitcham Eastfields station, the platforms are staggered, with both following the train's crossing of a level crossing. I don't know whether this was because of constriats on the site when the staton was added, in a built-up area, of whether part at least of the reason was to avoid the need to have the barriers down while a train in either direction was in the station. It's not a layout I remember seeing anywhere else.

There are a number. I noticed recently, when passing through, that Hykeham was converted to that arrangment some time since I last used it 50 years ago (!)