Landslip near entrance to Harbury Tunnel

[whole diary]

[ChrisB]

http://www.railwaygazette.com/news/infrastructure/single-view/view/siemens-starts-work-on-banbury-resignalling.html

I'm being told that the layout on those screens in the photo in this article is the finished layout of the project....does it look like Banbury? I'm not sure.....

HOWEVER.....the project has already caused problems....

Chiltern Railways (@chilternrailway)

31/01/2015 17:31

We are experiencing disruption between Leamington Spa and Banbury due to a landslip. Here's what that looks like: ow.ly/i/8sPpx

That link is this photo -

Landslip where they were working - note the barriers - ooops. No trains today between Leamington/Banbury. Unlikely tomorrow too....

[ChrisB]

No trains between Banbury/Leamington until at least Tuesday.

It's at the entrance to Harbury Tunnel, exactly the same place as a slip not a year ago. Not only does NR^» (Network Rail - home page) not do any preventative maintenance, seems they've stopped completing jobs properly too!

[paul7575]

The photo that's just appeared on NR^» (Network Rail - home page)'s website suggests that work was still in progress.  I'd suggest that they were actually doing preventative maintenance, and it wasn't complete:

http://www.networkrailmediacentre.co.uk/News-Releases/Media-statement-Harbury-tunnel-landslip-update-1-Feb-2263.aspx

Paul

[ellendune]

Is this another case of decades of BR^▸ (British Rail(ways))'s low cost low maintenance approach to earthworks coming home to roost?  NR^» (Network Rail - home page) certainly seems to be doing far more planned earthworks maintenance than I can recall ever in my lifetime.

[IndustryInsider]

Is this another case of decades of BR^▸ (British Rail(ways))'s low cost low maintenance approach to earthworks coming home to roost?  NR^» (Network Rail - home page) certainly seems to be doing far more planned earthworks maintenance than I can recall ever in my lifetime.

Changing weather patterns (milder but wetter winters) has been part of the problem according to NR.  The Banbury to Leamington section of railway has always had quite challenging geology to deal with - the area around Fenny Compton causing numerous flooding and stabilisation issues as well as the cutting and tunnel at Harbury.

[ChrisB]

The photo that's just appeared on NR^» (Network Rail - home page)'s website suggests that work was still in progress.  I'd suggest that they were actually doing preventative maintenance, and it wasn't complete:

http://www.networkrailmediacentre.co.uk/News-Releases/Media-statement-Harbury-tunnel-landslip-update-1-Feb-2263.aspx

Since February last year?....why so long?

A week.....and that's just "to allow for an investigation to determine the scale of  the problem." Not fix it.

[ellendune]

The photo that's just appeared on NR^» (Network Rail - home page)'s website suggests that work was still in progress.  I'd suggest that they were actually doing preventative maintenance, and it wasn't complete:

http://www.networkrailmediacentre.co.uk/News-Releases/Media-statement-Harbury-tunnel-landslip-update-1-Feb-2263.aspx

Since February last year?....why so long?

A week.....and that's just "to allow for an investigation to determine the scale of  the problem." Not fix it.

Soil mechanics is a difficult technology.  After fixing the immediate problem last February, they would have commissioned a detailed geotechnical survey before reviewing the options.  Getting it right takes time. 

Once you have a landslip you cannot just go digging around in case you make it worse.  IF you do make it worse you could endanger the people working to put it right. 

[ChrisB]

Or do nothing/not a lot & watch it slip again so 350,000 tons of soil threaten to take trains off the track?...hmmm

[ellendune]

Dig in the wrong place and you only bring more down.  The one thing we know about the ground beneath our feet is we don't know what is there. It always contains the unexpected.  A major earth slip (and this looks like a major slip from NR^» (Network Rail - home page)'s photo) will therefore take time. 

When the GWR^▸ (Great Western Railway) was built through Wiltshire the whole project was delayed for 18 months because they could not get the earthworks to stay up. The terminus was at Faringdon Road (later called Challow Station). Later they encountered the same problem on the Swindon end of the line to Gloucester. Part of the reason for the cost of the redoubling of the Swindon to Kemble line and the Chiltern line through Bicester was having to do a 50 year backlog of earthworks maintenance.   

If you think you can do better then just remember one cubic metre of soil weighs over 1.5 tons - get that on you and most people do not survive.  Unfortunately there are plenty of accident reports to prove it. 

[ChrisB]

It'll be interesting to see what happens on 14/15 & 21/22 Feb when the WCML^▸ (West Coast Main Line) is closed again at Watford...Chiltern route being the diversion. This won't be finished by the former dates....will they canx the WCML works? They're pretty major & will be part of the bigger, timtabled picture

[IndustryInsider]

Could the mods give consideration to splitting this topic as the land slip at Harbury has little connection with the resignalling of Banbury station?

[grahame]

Could the mods give consideration to splitting this topic as the land slip at Harbury has little connection with the resignalling of Banbury station?

Good idea.   I am on an intermittent connection until this evening, though, so will leave it up to another moderator as I don't want to drop the split halfway through.

[Chris from Nailsea]

Topics now split, as suggested.  CfN. 

[Chris from Nailsea]

An update, from the BBC^» (British Broadcasting Corporation - home page):

Landslip stops Chiltern Line trains at Harbury Tunnel


The cutting is an "unusually steep embankment" originally intended to be built as a tunnel

Passengers are experiencing a third day of travel disruption after a major landslip closed a railway line between Banbury and Leamington Spa.

Chiltern Railways said no direct trains could run between London and the West Midlands for "at least a week".

The landslip occurred near Harbury Tunnel in Warwickshire on Saturday, the scene of a similar incident last year.

Engineers were not able to access the site because the land was still moving, Network Rail said.

A replacement bus service is running between Leamington and Banbury, adding about 90 minutes to journey times.

Chiltern Railways is also running revised services between London Marylebone and Banbury and between Leamington and Birmingham Moor Street.

Virgin Trains and London Midland are accepting Chiltern Railways tickets, the firm said.

Thomas Ableman, spokesman for Chiltern Railways, said the line would be open next Monday at the earliest, but advised anyone with travel plans for next week to prepare for the line remaining closed.

"At no point was there a risk, but in terms of timescale of opening the line there is now 300,000 tonnes of earth and rock which is very unstable and could fall on to the track at any time," he said.

Stabilisation work was carried out after a smaller landslide at the site on 14 February 2014.


Network Rail say the land is still moving and "extremely dangerous"


Network Rail say the cutting is "unusually deep" with steep sides


Network Rail said the embankment had been a problem since the track was laid

Dan Donovan, Network Rail spokesman, said engineers had been able to repair the damage over one weekend last February but this landslip was "much worse".

"The land is still moving, it is extremely dangerous. We can't begin carrying out detailed assessments at the site," he said.

Mr Ableman said the embankment had been a problem since the track was laid 150 years ago.

Isambard Kingdom Brunel's decision not to build a tunnel meant the cutting was unusually deep with steep sides, he said.

So there you have it: it's all Isambard Kingdom Brunel's fault. 

[IndustryInsider]

Yes, it always seemed a strange decision to build it like they did.  Harbury Tunnel itself is very short at a mere 70 yards, with long stretches of cutting either side.  The location of this latest slip has often had work done on it over the years.