Thames Valley infrastructure problems causing disruption elsewhere - 2014

[whole diary]

[Oxonhutch]

Due to signalling problems between Swindon and Didcot Parkway:
Impact:
Train services running through these stations may be delayed. An estimate for the resumption of normal services will be provided as soon as the problem has been fully assessed.

Next up are Didcot Parkway and Swindon as the works head West I guess? Either that or the rain 

Overrunning over-night engineering works according to the dispatcher at Didcot.  The first up Bristol (1L01) was held 45 minutes at Swindon and was 55 down entering PAD^» (Paddington (London) - next trains).

[ChrisB]

Next up overnight - ex-Hurricane Gonzalo......good luck in the morning, folks!

[Chris from Nailsea]

And a third now - the initial thoery of the cause of the recent coal train derailment in the Vale of Glamorgan is a rail defect...poor, very poor - were no lessons actually learnt from Potters Bar, Grayrigg...?!

http://www.bbc.co.uk/news/uk-wales-south-east-wales-29661936

There is a link on the above BBC^» (British Broadcasting Corporation - home page) page to the initial RAIB^▸ (Rail Accident Investigation Branch) report

Also discussed on the Coffee Shop forum, at http://www.firstgreatwestern.info/coffeeshop/index.php?topic=14668.msg163572#msg163572 

[stebbo]

Just like the freight train derailment at Gloucester back last year.

[tomL]

Kind of relevant and a bit belated.

But it seems the network held up relatively well with the weather/'hurricane'.

[IndustryInsider]

Yes, it was fairly tame down south.  The biggest problem with strong winds is the risk of large trees being brought down, and as such there's an element of luck involved as to just how many fall, what time and where.  This time the railway network was fairly 'lucky'.  Mind you, another problem in Autumn is strong winds bringing down a lot of leaves and rain then making them incredibly slippery, so the skills of a driver are often truly tested at such times.

[JayMac]

Evidence of the slipping and sliding, following the leaf fall brought about by the high winds, can be heard when on board.

Many trains I've taken in the past few days have noticeable wheel flats.

[TaplowGreen]

Evidence of the slipping and sliding, following the leaf fall brought about by the high winds, can be heard when on board.

Many trains I've taken in the past few days have noticeable wheel flats.

I am still baffled as to why in our benign climate such a minor feature of nature which has been occurring since the dawn of time has the potential to bring chaos to the railways (along with almost every other form of weather to be fair!)

Surely there must be a way of addressing it? (other than felling every tree within a 5 mile radius of the line?)

[chrisr_75]

I am still baffled as to why in our benign climate such a minor feature of nature which has been occurring since the dawn of time has the potential to bring chaos to the railways (along with almost every other form of weather to be fair!)

Surely there must be a way of addressing it? (other than felling every tree within a 5 mile radius of the line?)

There are certain species (as I recall the dreaded sycamore is a particular offender) who's leaves produce a more slippery rail head which are specifically targetted and are removed. Equally, species prone to dropping large limbs or suffering other wind damage should also be targetted for removal.

This is also something which has arisen since the demise of steam traction. When everything was steam powered the trackside areas & embankments were religiously cleared of virtually all vegetation to reduce the incidences of lineside fires. Obviously that was no longer such an issue with diesel & electric trains, so the lineside vegetation was allowed to flourish from the late 1960's onwards. Considerable effort over the past 10-15 years has been put in to manage trackside vegetation from a point of view of improving rail head conditions and visibility from level crossings & the lineside.

There is also the issue that many trains are now disc braked, which means that the wheel treads are no longer cleared each time the brakes are applied and brake performance is massively superior with disc brakes (equally as is acceleration) which in itself raises the likelihood of a slip.

So, in other words, the problem has existed forever, just more of an issue in the past 50 years or so since the advent of diesel & electric traction and is an evolving problem as other technologies change.

We now also have the situation that these areas have become important wildlife corridors and habitats, so need to be carefully managed.

[Electric train]

I am still baffled as to why in our benign climate such a minor feature of nature which has been occurring since the dawn of time has the potential to bring chaos to the railways (along with almost every other form of weather to be fair!)

Surely there must be a way of addressing it? (other than felling every tree within a 5 mile radius of the line?)

There are certain species (as I recall the dreaded sycamore is a particular offender) who's leaves produce a more slippery rail head which are specifically targetted and are removed. Equally, species prone to dropping large limbs or suffering other wind damage should also be targetted for removal.

This is also something which has arisen since the demise of steam traction. When everything was steam powered the trackside areas & embankments were religiously cleared of virtually all vegetation to reduce the incidences of lineside fires. Obviously that was no longer such an issue with diesel & electric trains, so the lineside vegetation was allowed to flourish from the late 1960's onwards. Considerable effort over the past 10-15 years has been put in to manage trackside vegetation from a point of view of improving rail head conditions and visibility from level crossings & the lineside.

There is also the issue that many trains are now disc braked, which means that the wheel treads are no longer cleared each time the brakes are applied and brake performance is massively superior with disc brakes (equally as is acceleration) which in itself raises the likelihood of a slip.

So, in other words, the problem has existed forever, just more of an issue in the past 50 years or so since the advent of diesel & electric traction and is an evolving problem as other technologies change.

We now also have the situation that these areas have become important wildlife corridors and habitats, so need to be carefully managed.

It is also the case that traction units are much lighter, the heavier 100 tonne locomotives had far better adhesion however their power to weight ratio was poor, modern multiple unit traction with distributed traction along the train (or at least a couple of coaches) are more energy efficient, lower rolling resistance etc however a little bit of "grease" (ie leaves and moisture) and they don't have the mass to displace the "grease"

[Western Enterprise]

Many trains I've taken in the past few days have noticeable wheel flats.

I was waiting at Slough last night when a High Speed Train (HST^▸ (High Speed Train)) ECS^▸ (Empty Coaching Stock) came through on the up relief.
The last power car's wheels were making a hell of a noise, it sounded oval shaped. Possibly going for repair / lift ?
There was that brilliant tv programme recently where they showed them changing a bogie overnight, but that my have been Laira.

Edit: VickiS - Clarifying Acronyms

[chrisr_75]

It is also the case that traction units are much lighter, the heavier 100 tonne locomotives had far better adhesion however their power to weight ratio was poor, modern multiple unit traction with distributed traction along the train (or at least a couple of coaches) are more energy efficient, lower rolling resistance etc however a little bit of "grease" (ie leaves and moisture) and they don't have the mass to displace the "grease"

Not forgetting a massive reduction in driving wheel circumference which will alter the dynamics considerably.

Also of note for anyone who hasn't had the joy of working on a railway in wet weather, is that if you step (strictly against the rules!) on a wet but otherwise clean rail, you pretty quickly discover that a rubber boot sole slips as if it was on smooth ice, so it gives a bit of an appreciation of what happens to a steel wheel when you stick a bit of wet, slippery, partially decomposed leaf matter in between it and the rail!

[JayMac]

A major problem with leaf fall after high winds in early autumn is that the leaves are still quite green and thus full of moisture.

Last year I learnt this at personal cost. Moist leaves on the steps outside my flat led to an A over T moment and a broken coccyx. Still gives me occasional gyp.

Credit to the train drivers out there though. Takes some skill to drive a train when rail head conditions are poor. Better to have a few 50p shaped wheels than a SPAD^▸ (Signal Passed At Danger) or unintended meeting with a buffer stop.

[Jason]

Today's treat is a broken down freight train at Langley, with 20 minute delays into Paddington. I've been stop/start since before Slough.
Edit : I'm already 40 mins late, still nr Southall

[BBM]

I'm guessing that the broken down freight is the one in the RTT^» (Real Time Trains - website) link below, the GBRf 0203 from Moreton-on-Lugg to Harlow Mill:

http://www.realtimetrains.co.uk/train/R02683/2014/10/24/advanced