Excessive barrier down time at Liss?

[Colin1501]

This afternoon I caught the 16.39 service from Liss to Petersfield. This is the 15.30 Waterloo to Portsmouth Harbour, which calls at all stations south of Guildford. The full barrier crossing at Liss, controlled from Petersfield signal box, was closed at 16.31 - there was no up train anywhere in the area. At the time, both Real Time Trains and Open Train Times showed the 16.39 at the platform at Liphook, the previous station, where it was not due to depart until 16.33. It arrived and departed Liss on time, by which time the barriers had been closed for eight minutes.

I cannot understand why the barriers were closed so early. I could perhaps understand it for a fast service, to ensure that the driver did not sight an adverse signal - there are three signal sections between Liphook and Liss, and the signals are 3-aspect. But for a stopping service, especially one that has not even left the previous station, this seems excessive. The down 'starting' signal at Liss (PF231) is some way back from the crossing, and I always thought the point of such positioning was to allow a train to enter the platform with the barriers open, thus reducing delays to road traffic.

 

[godfreycomplex]

This afternoon I caught the 16.39 service from Liss to Petersfield. This is the 15.30 Waterloo to Portsmouth Harbour, which calls at all stations south of Guildford. The full barrier crossing at Liss, controlled from Petersfield signal box, was closed at 16.31 - there was no up train anywhere in the area. At the time, both Real Time Trains and Open Train Times showed the 16.39 at the platform at Liphook, the previous station, where it was not due to depart until 16.33. It arrived and departed Liss on time, by which time the barriers had been closed for eight minutes.

I cannot understand why the barriers were closed so early. I could perhaps understand it for a fast service, to ensure that the driver did not sight an adverse signal - there are three signal sections between Liphook and Liss, and the signals are 3-aspect. But for a stopping service, especially one that has not even left the previous station, this seems excessive. The down 'starting' signal at Liss (PF231) is some way back from the crossing, and I always thought the point of such positioning was to allow a train to enter the platform with the barriers open, thus reducing delays to road traffic.

It’s autumn, low rail head adhesion means that lowering the crossing early is a prudent safety measure undertaken by the signaller using their professional knowledge and experience.

If the train were to lose braking contact at the crucial moment, even slightly, with the barriers raised the train would proceed straight into the open road, and also into anyone and anything on it at the time. Better a marginal wait than that.

 

[DerekC]

It’s autumn, low rail head adhesion means that lowering the crossing early is a prudent safety measure undertaken by the signaller using their professional knowledge and experience.

If the train were to lose braking contact at the crucial moment, even slightly, with the barriers raised the train would proceed straight into the open road, and also into anyone and anything on it at the time. Better a marginal wait than that.

Agreed, but it does sound as though the signaller may have overdone it a bit. Actual running time from Liphook to Liss is about four minutes, I think, so lowering the Liss barriers when the train left Liphook would allow plenty of margin and save two or three minutes delay to road traffic. Regular very long closed times are a risk too, because local road vehicle drivers are more likely to cross when the barriers are coming down.

 

[Colin1501]

It’s autumn, low rail head adhesion means that lowering the crossing early is a prudent safety measure undertaken by the signaller using their professional knowledge and experience.

If the train were to lose braking contact at the crucial moment, even slightly, with the barriers raised the train would proceed straight into the open road, and also into anyone and anything on it at the time. Better a marginal wait than that.

Agreed, but it does sound as though the signaller may have overdone it a bit. Actual running time from Liphook to Liss is about four minutes, I think, so lowering the Liss barriers when the train left Liphook would allow plenty of margin and save two or three minutes delay to road traffic. Regular very long closed times are a risk too, because local road vehicle drivers are more likely to cross when the barriers are coming down.

Thanks for both helpful replies. I'd be grateful for clarification on one point, though. Notwithstanding additional precautions during leaf-fall season etc, am I correct in my belief that it is normally permissible for a train to approach a level crossing with the barriers up, providing the protecting signal is a certain distance in rear of the crossing, or have the rules changed? I know there was an accident at Milford (further up the same line) in 1978, when a train failed to stop at the signal protecting the crossing (which was a ahb, set to 'stopping' mode), and struck a road vehicle. However, in his report, the inspecting officer made no recommendations that procedures should be changed.

 

[zwk500]

Thanks for both helpful replies. I'd be grateful for clarification on one point, though. Notwithstanding additional precautions during leaf-fall season etc, am I correct in my belief that it is normally permissible for a train to approach a level crossing with the barriers up, providing the protecting signal is a certain distance in rear of the crossing, or have the rules changed? I know there was an accident at Milford (further up the same line) in 1978, when a train failed to stop at the signal protecting the crossing (which was a ahb, set to 'stopping' mode), and struck a road vehicle. However, in his report, the inspecting officer made no recommendations that procedures should be changed.

At lots of level crossings that are within the overlap of a signal there are 2 overlaps - a 'full' overlap which requires the barriers to be closed but permits the usual signal aspect sequence and a 'restricted overlap' which will permit the barriers to be open but requires the signal in rear (i.e. 2 before the crossing) to be held at Red until the train has slowed down to a safe speed. Use of the restricted overlap obviously has an impact on the runtimes of the stopping train, as it approaches the station much slower. During leaf fall season, there may well be a local instruction not to use the ROL as they are usually c.40m, and even a small amount of leaf mulch could easily lead to a train overrunning by more than that.

 

[WestRiding]

Maybe the Signaller just wanted the toilet so did it a bit earlier to make sure nothing would come to a stand.....

 

[Stigy]

Does Liss have OSS+ (formerly TPWS+)? This would mitigate against SPAD’ing the signal and entering the crossing with the barriers raised as it would put the brakes in if travelling at (roughly) over 10mph at the grids. This is used at a lot of higher risk crossings. If it isn’t fitted with it, this may be why the barriers were lowered so early. It still seems a bit excessive though.

 

[GB]

Can be any number of reasons why the barriers were down for 8 minutes, some have already been said but is the calling point for starting the lowering sequence the same whether the train stops at Liphook or not?

 

[Gloster]

I worked at one box where there was an AHB a couple of hundred yards off the end of a station platform, for which we had a selector switch in the box. When selected for a non-stop train the barriers just operated normally as the train hit the track circuits or treadles. If a train was due to stop in the station we would select Stopping: when station work was complete the guard would operate a Train Ready to Start button on the platform, after which the barriers would lower and the signal on the end of the platform would clear.

 

[louis97]

At lots of level crossings that are within the overlap of a signal there are 2 overlaps - a 'full' overlap which requires the barriers to be closed but permits the usual signal aspect sequence and a 'restricted overlap' which will permit the barriers to be open but requires the signal in rear (i.e. 2 before the crossing) to be held at Red until the train has slowed down to a safe speed. Use of the restricted overlap obviously has an impact on the runtimes of the stopping train, as it approaches the station much slower. During leaf fall season, there may well be a local instruction not to use the ROL as they are usually c.40m, and even a small amount of leaf mulch could easily lead to a train overrunning by more than that.

If I recall (I'm sure someone can correct me if I'm wrong) a signal can be 25 metres back from a level crossing on a station platform and there is no requirement for a separate overlap or for the crossing to be lowered/lowering for the trains arrival. Not sure if it is a requirement but in recent cases on schemes there are wheel sensors for detecting train speed on approach and fast acting triggers at the signal in case of a SPAD.

In the case of Liss there is no separate overlap, just a 400 metres one over the crossing. There is TPWS on the approach to the platform associated with the signal.

 

[edwin_m]

Does Liss have OSS+ (formerly TPWS+)? This would mitigate against SPAD’ing the signal and entering the crossing with the barriers raised as it would put the brakes in if travelling at (roughly) over 10mph at the grids. This is used at a lot of higher risk crossings. If it isn’t fitted with it, this may be why the barriers were lowered so early. It still seems a bit excessive though.

That wouldn't help if the SPAD was caused by poor adhesion, which was suggested above to be the likely reason for closing the barriers early.

 

[D6130]

I know there was an accident at Milford (further up the same line) in 1978, when a train failed to stop at the signal protecting the crossing (which was a ahb, set to 'stopping' mode), and struck a road vehicle.

There was also a serious "near-miss" at Liss in 1978, when the signaller at Petersfield failed to lower the barriers at Liss in time and the driver of a Waterloo-Portsmouth Harbour fast - on which I was a passenger - received a single yellow at the previous signal (PF229), cancelled the AWS and then totally forgot about it. The mile-and-a-half from that signal to Liss station is the fastest section of the Portsmouth Direct line - on a 1 in 80 falling gradient - and the train entered Liss station at between 85 and 90 mph with signal PF231 at danger and the barriers raised. On sighting the banner repeater signal on the platform in the 'on' position, the driver realised his mistake, made an emergency brake application and sounded the horn continuously. The front of the train passed over the level crossing at something like 75-80 mph, missing by inches a taxi which had just picked up passengers who had alighted a few minutes earlier from an up stopper, and came to a stand at Princes Bridge AHB crossing - about three quarters of a mile further on. While not strictly relevant to the situation with a down stopper, I believe that several changes were made to the working instructions for Liss crossing as a result of that incident.

 

[Stigy]

That wouldn't help if the SPAD was caused by poor adhesion, which was suggested above to be the likely reason for closing the barriers early.

It was a suggestion as to a possible reason. If OSS+ is fitted a distance from the stop signal, it would reduce the likelihood of a SPAD occurring. I appreciate that speed isn’t necessarily a factor with low rail adhesion, but to force drivers to travel at a crawl on approach to the end of the platform, may be enough to warrant not bringing the barriers down any earlier than normal.

 

[Colin1501]

There was also a serious "near-miss" at Liss in 1978, when the signaller at Petersfield failed to lower the barriers at Liss in time and the driver of a Waterloo-Portsmouth Harbour fast - on which I was a passenger - received a single yellow at the previous signal (PF229), cancelled the AWS and then totally forgot about it. The mile-and-a-half from that signal to Liss station is the fastest section of the Portsmouth Direct line - on a 1 in 80 falling gradient - and the train entered Liss station at between 85 and 90 mph with signal PF231 at danger and the barriers raised. On sighting the banner repeater signal on the platform in the 'on' position, the driver realised his mistake, made an emergency brake application and sounded the horn continuously. The front of the train passed over the level crossing at something like 75-80 mph, missing by inches a taxi which had just picked up passengers who had alighted a few minutes earlier from an up stopper, and came to a stand at Princes Bridge AHB crossing - about three quarters of a mile further on. While not strictly relevant to the situation with a down stopper, I believe that several changes were made to the working instructions for Liss crossing as a result of that incident.

Ouch!

 

[Llanigraham]

If I recall (I'm sure someone can correct me if I'm wrong) a signal can be 25 metres back from a level crossing on a station platform and there is no requirement for a separate overlap or for the crossing to be lowered/lowering for the trains arrival. Not sure if it is a requirement but in recent cases on schemes there are wheel sensors for detecting train speed on approach and fast acting triggers at the signal in case of a SPAD.

In the case of Liss there is no separate overlap, just a 400 metres one over the crossing. There is TPWS on the approach to the platform associated with the signal.

Not at a station but the UP Home at Bromfield SB was about 25mts from the barriers.
And the DOWN Inner Home a little bit more.