TL Core signal problems (again)

[asylumxl]

This seems to be a pretty regular occurence and always seems to be when I am travelling to London.

I thought they recently installed signals to allow drivers to proceed on sight, are they not in use yet?

What caused it his time? Recently it seems to always be the recently installed signals failing.

I think someone at NR needs to be hit with a blunt heavy object.

Thanks for any replies

 

[Mike395]

On an EMT service now, just past West Hampstead Thameslink (thankfully our only delay was waiting to cross onto the St Pancras high-level lines a second ago), and it would appear that Southbound services are now stacking all the way back to there from City Thameslink - feel sorry for commuters on FCC this morning!

 

[tsr]

Delays are now up to 60 minutes (officially - NRE). It started as about 25 minute delays, so that's not what I call a good service recovery - I imagine the problem is the congestion within the backlog of TL Core services. LDBs at BFR are quite bad. Luckily, I have no need to use FCC's currently utterly miserable service today!

EDIT: FCC is now in chaos with a PHBT at Royston on the other segment of their network, and the delays on the TL Core are expected until between 1700hrs and 1800hrs. The incident on NRE was created at 0743hrs. Since the problem has been fixed for a while, that sounds like an estimate for a moderate level of complete incompetence.

 

[asylumxl]

On an EMT service now, just past West Hampstead Thameslink (thankfully our only delay was waiting to cross onto the St Pancras high-level lines a second ago), and it would appear that Southbound services are now stacking all the way back to there from City Thameslink - feel sorry for commuters on FCC this morning!

I will probably make use of the EMT services this evening to avoid the joke which is Thameslink.

that sounds like an estimate for a moderate level of complete incompetence.

 

[Bald Rick]

Yep the Proceed on Sight Aspects were in employed in anger for the first time today. And they worked as designed. Problem was a track circuit failure at City Thameslink.

Main reason for the delays was that the driver of the first train through (allegedly) took quite a while to contact the signaller, which caused a queue to develop. Delays were in the region of 30-40 mins per train, but compared to a very similar incident in November that had delays up to 3 hours per train, it was somewhat better. Still, I'd rather it hadn't happened.

 

[tsr]

Problem was a track circuit failure at City Thameslink.

You know, I pretty much took an educated guess and thought that had happened, and it's a pity I didn't put that on here earlier, but I suppose I was limiting any potential embarrassment by being wrong!

 

[b0b]

anyone take pictures of the POSA in action?

 

[Bald Rick]

anyone take pictures of the POSA in action?

I think you'd rather have a video!

It did feel vaguely French to be sailing past two red signals with the cats eyes blinking away...

 

[Class377/5]

Yep the Proceed on Sight Aspects were in employed in anger for the first time today. And they worked as designed. Problem was a track circuit failure at City Thameslink.

Main reason for the delays was that the driver of the first train through (allegedly) took quite a while to contact the signaller, which caused a queue to develop. Delays were in the region of 30-40 mins per train, but compared to a very similar incident in November that had delays up to 3 hours per train, it was somewhat better. Still, I'd rather it hadn't happened.

Wasn't the driver that delayed but once the PoSA signals were used to anger and once they started, they seemed to work ok with smaller delays especially compared to Nov. fixing it caused even more problems but got it sorted!

 

[asylumxl]

Am I right in thinking that axle counters are more reliable? I remember reading on here that NR didn't want to replace the track circuits in the TL core but don't remember why.

 

[Class377/5]

Am I right in thinking that axle counters are more reliable? I remember reading on here that NR didn't want to replace the track circuits in the TL core but don't remember why.

I believe one reason given is the amount of then as there are some very short signalling sections and with all the bi directional working meant there would be a lot of them.

Plus the tunnels tend to flood a fair bit (which buggers the signalling up every now and then).

 

[tsr]

Plus the tunnels tend to flood a fair bit (which buggers the signalling up every now and then).

I presume this is largely due to corrosion, given the fact that it's not too hard to waterproof electronics, even if they are temporarily deluged (as we can quite clearly see when the trains carry on running elsewhere when it rains pretty hard)?

 

[Class377/5]

I presume this is largely due to corrosion, given the fact that it's not too hard to waterproof electronics, even if they are temporarily deluged (as we can quite clearly see when the trains carry on running elsewhere when it rains pretty hard)?

It's not a case of getting wet but there very little places for the water to go so just sits there. However as you say it's not hard to make electronics waterproof but sure there's a good reason for it (and I don't know why).

 

[ole man]

That's a understatement, Clerkenwell tunnels are prone to massive puddles, especially just after KX Thameslink, also there some weird green stuff growing in the four foot

 

[Bald Rick]

Having looked into the subject a bit, the reason why TCs were chosen over axle counters was for three main reasons:
1) This type of TC was more reliable than axle counters at the time it was specified many years ago. Not sure I buy that.
2) The short sections can induce mis-counts with axle counters, because there is a greater chance of a wheel stopping exactly on the head. This is particularly so with mid-platform signals.
3) Any mechanised track maintenance requires all axle counter heads to be removed in advance and then replaced, and proved after work is done. The core section will require rail grinding every 6 months at least, and with the quantity involed it would add considerably to the possession duration (and thus cost) of the maintenance.

Hope this makes sense