Another land slip

[Davexoc]

Yet another one....

 

https://www.bbc.co.uk/news/uk-england-beds-bucks-herts-68433405

 

RTT has bustitution at the weekend...

Edited February 29 by Davexoc

[MidlandRed]

South Eastern trains have also been suspended for the last week by a landslide near Newington also. Planned to be repaired by tomorrow but given the volume of rain in the last week that will remain to be seen - bus substitution was still in operation this evening - interestingly the A2 road which the buses use has been subject to severe congestion also owing to the southbound A249 beyond the M2 being closed for five weeks also - so the buses have encountered significant delays en route. 
 

https://www.kentonline.co.uk/sittingbourne/news/landslip-images-show-fallen-embankment-causing-travel-chaos-302605/

Edited March 1 by MidlandRed

[john new]

Given the amount of rain and resultant groundwater levels these landslips, and locally to me cliff falls, seem to be increasing in frequency. Cliff erosion is nothing new, that is true, but not with this regularity.
 

The other issue round here is the abundance of newly emergent small springs where the ground water is finding any small crack in road and footway surfaces; drains are working in reverse too in many places.

[Michael Hodgson]

 

 

4 minutes ago, john new said:

Given the amount of rain and resultant groundwater levels these landslips, and locally to me cliff falls, seem to be increasing in frequency. Cliff erosion is nothing new, that is true, but not with this regularity.

 

Yeah, we're just not used to rain in this country.

[john new]

Just now, Michael Hodgson said:

 

 

Yeah, we're just not used to rain in this country.

We are used to it at level n, what we seem to be getting is many more concentrated storm cells and therefore what was designed to be able to cope with level n is failing at both the new background n+x level and short bursts of 2 or 3 times n. Add into that other man-made contributory factors and problems occur. Up round where my mum lives on the Vale of York one of the man-made contributions is agricultural machine weights, the Victorian land drains were pottery pipes, the modern heavy stuff has crushed much of it so the fields now have massive puddles where before it ran to ditches. Not digging out ditches is another factor too.

[Oldddudders]

5 minutes ago, john new said:

We are used to it at level n, what we seem to be getting is many more concentrated storm cells and therefore what was designed to be able to cope with level n is failing at both the new background n+x level and short bursts of 2 or 3 times n. Add into that other man-made contributory factors and problems occur. Up round where my mum lives on the Vale of York one of the man-made contributions is agricultural machine weights, the Victorian land drains were pottery pipes, the modern heavy stuff has crushed much of it so the fields now have massive puddles where before it ran to ditches. Not digging out ditches is another factor too.

Not to mention missing hedgerows, which cheerfully absorbed water to help them grow, but hindered easy access to every square inch of land for increasingly bigger machines. Interestingly, EU farmers, having done exactly the same over the years, are now being offered premiums to plant them, having regard to green issues and windbreaks. 

[woodenhead]

There is also the issue of land that used to absorb the water now being concreted over and the run off drains go directly to the rivers concentrating further the water into narrow channels which then overflow.

[KingEdwardII]

1 hour ago, john new said:

Given the amount of rain and resultant groundwater levels

Curiously, for England, there has only been a very modest increase in rainfall over the past century or so, especially in Winter, as can be found on the Met Office site here:

 

https://www.metoffice.gov.uk/research/climate/maps-and-data/uk-temperature-rainfall-and-sunshine-time-series

 

 

Yours, Mike.

[Titan]

The Oxford canal has also suffered a landslip, fortunately in a cutting so the canal is blocked rather than breached  as some have reported. Unfortunately it is in remote section so getting in heavy machinery to dig it out is problematic.

[john new]

3 minutes ago, KingEdwardII said:

Curiously, for England, there has only been a very modest increase in rainfall over the past century or so, especially in Winter, as can be found on the Met Office site here:

 

https://www.metoffice.gov.uk/research/climate/maps-and-data/uk-temperature-rainfall-and-sunshine-time-series

 

 

Yours, Mike.

The problem, as I understand it, isn’t the overall long-term average it is twofold (1) the concentration into storms, localisation of those storms and (2) periods of a consecutive year or two of extra above average rain. Here in Dorset there was the Martinstown freak, and record, rainstorm. Further afield Lynton/Lynmouth , Boscastle and other recent one’s in Devon and Cornwall (Dawlish, but from inland not the sea is one). The worry is that climate change is drifting us towards the UK climate becoming warmer, the warmer air holds more moisture, and both (1) & (2) become more frequent.

 

Historically even railways owe their origins to a period of severe above average rain over a prolonged period - back in the early 1600s the ground around Nottingham was too sodden for coal carts and wains, Huntingdon Beaumont built the wooden waggonway at Woolaton to overcome the problem. That was recorded in 1604, the rest is history.

[Oldddudders]

https://www.bbc.co.uk/news/science-environment-68435197

 

[geoffers]

My rainfall figures for this winter (Dec, Jan, Feb) is 150.8% of normal (247.7mm as opposed to the mean of 164.3mm - the mean being RAF Coltishall just 7 miles away as the crow flies). Much of this is in Feb (113.3mm as opposed to the mean of 45.2mm) but both Dec and Jan were above average  74.1 mm against 64.0mm, and  60.0mm against 55.1mm respectively.  It also follows a wet 2023 with 876.9mm recorded against the mean of 683.9mm, or 128.2% of normal. My readings are not official as it is a non-standard exposure, but gives a good idea. John new is quite correct - warmer air has the capacity to hold more moisture per cubic metre and the increase is exponential.

Edited March 1 by geoffers

[KingEdwardII]

My understanding is that landslips and cliff falls are mostly to do with the buildup of groundwater in soil and rocks, providing both lubrication and pressure.

 

Groundwater levels are mostly a long-term tale of rainfall over weeks and months, rather than caused by individual storms. Individual storms are more associated with riverine flooding than with groundwater levels. Around here in central southern England, Jan/Feb 2014 was probably the worst recent period we've had for high groundwater, with widespread destructive groundwater flooding across a wide area as well as landslips.

 

Yours, Mike.

[MidlandRed]

(BBC link didn’t work from the forum for some reason - just toggled to the earlier post with a BBC link!!)

 

Network Rail has stated the Newington land slip is caused by climate change. It has created quite a large rectification work which is now not expected to be completed until Monday - it’s interesting also that there is large new housing development on the other side of the embankment which, from observation from the train, during construction, appeared to take some effort to dewater.

 

My understanding of the recent periods of rainfall deluge in the south and south east have been generated by the position of the jet stream being across the middle of the country so every front coming from the Atlantic has hit that area with heavy and sometimes concentrated rainfall. There have been land slips in coastal areas of Folkestone and elsewhere recently along with significant cliff falls on the south coast. 
 

It is also notable that the daily amounts of rain in many instances have been multiples of inches (certainly over an inch) where in the past that would have been absolutely exceptional except perhaps locations such as the Welsh mountains for instance. 
 

Latest info from Met Office:- 

 

Wettest February since 1836 in the south of England. 

Temperature has increased on average by one degree over the last 60 years.

Warmest February on record. 

Edited March 1 by MidlandRed

[Siberian Snooper]

Single line working, was introduced between Newton Abbot and Totnes, Sunday afternoon/evening, due to a landslip. The up line was in use, I was on the wrong side of the train to see the exact location and the extent of the slip, it did however add nearly 70 minutes to the already 10 minute late train.

 

 

[Northmoor]

8 hours ago, KingEdwardII said:

Curiously, for England, there has only been a very modest increase in rainfall over the past century or so, especially in Winter, as can be found on the Met Office site here:

 

https://www.metoffice.gov.uk/research/climate/maps-and-data/uk-temperature-rainfall-and-sunshine-time-series

 

 

Yours, Mike.

That "very modest increase" is perhaps about 50% in 180 years, or over 20% in the last 50 years.  Neither of those is modest and the latter figure is what the historic record suggests we might have seen in 200 years, not 50.

 

However, the impact of the extra rainfall, increasingly falling in severe events, is exacerbated by what humans have done to the land as described by others above.

Edited March 1 by Northmoor

[Winnie]

There is a slip at Oakengates which occured yesterday on the Wolverhampton to Shrewsbury line .

https://www.shropshirestar.com/news/local-hubs/shrewsbury/2024/03/09/train-line-could-face-disruption-for-the-rest-of-the-month-after-landslip/

[Southernman46]

I keep banging on about this. The amount of rain etc . doesn't matter ....................

 

Railway drainage is designed to cope with "one in XYZ year" events BUT NOT if it is not maintained satisfactorily and THAT IS WHERE is issue quite clearly lies .........................................

[phil-b259]

10 hours ago, Southernman46 said:

I keep banging on about this. The amount of rain etc . doesn't matter ....................

 

 

Actually it does!

 

The laws of physics apply just as much to railway infrastructure as elsewhere and if a drainage pipe is of a certain diameter there is a physical limit to how much water can flow through it.

 

Granted a poorly maintained drainage system will be compromised in its ability top pass liquid but even the most expertly maintained system won't cope if the quantity of liquid presented to it exceeds its capacity.

 

Thats why we have so many raw sewage discharges - its not so much that the existing sewer system is intrinsically badly maintained - it more the case that population growth, changes in land use and the increasingly large volumes of water dumped by weather systems in short periods of time* is simply too much for the inherited network to cope with! Fixing that requires money to be spent on NEW drainage / sewers (which is of course the reason why it hasn't happened on anything like the scale needed).

 

*The statistics are quite clear - although the quantity of rain over a year or the number of 'rainy days' may not have changed much the volume of water being dumped at any given time increasing.

 

10 hours ago, Southernman46 said:

 

Railway drainage is designed to cope with "one in XYZ year" events BUT NOT if it is not maintained satisfactorily and THAT IS WHERE is issue quite clearly lies .........................................

 

I very much doubt that is the case historically - designing for 'one in XXXX years wasn't something the Victorians did. They simply accepted that things would flood occasionally.

 

They simply built drainage systems to cope with what they perceived as average rainfall and never expected it to cope with prolonged downpours. There was certainly no need to produce the in depth environmental reports and studies where such things are duly considered by the modern planning process before they started building things. Certainly I have yet to be shown a Victorian 'balancing pond' or land set aside to deliberately flood at times of heavy rain - both features which are seen alongside many developments / roads built over the past 40 years.

 

[Michael Hodgson]

5 hours ago, phil-b259 said:

I very much doubt that is the case historically - designing for 'one in XXXX years wasn't something the Victorians did. They simply accepted that things would flood occasionally.

 

They simply built drainage systems to cope with what they perceived as average rainfall and never expected it to cope with prolonged downpours. There was certainly no need to produce the in depth environmental reports and studies where such things are duly considered by the modern planning process before they started building things. Certainly I have yet to be shown a Victorian 'balancing pond' or land set aside to deliberately flood at times of heavy rain - both features which are seen alongside many developments / roads built over the past 40 years.

 

 

Sewers weren't built for drainage.  They were well thought-out and built to overcome the health problems like the Great Stink of 1858.  Rain remained something that the British were just expected to accept with a stiff upper lip, although cholera had become a different matter. 

 

However they were realistic enough to understand that sewerage would have to cope with a lot more than mere human waste so Victorian engineers made allowance both for water run-off and a reasonable growth in population.  The discharge outlets were merely the plumbing equivalent of the steam engine's safety valve, the need for both no doubt being learned from bitter experience.

 

Subsequent maintenance fell to local authorities run by politicians with no interest in the subject and who invariably had higher priorities for the use of limited public funds.  Would you rather build a new pumping station or spend the ratepayers' money on a bandstand in the park?  There's an old saying in local politics that there's no votes in sewers - until they are overflowing.  The centuries of neglect are the inevitable result of our system of local government.

 

[Northmoor]

17 hours ago, Southernman46 said:

I keep banging on about this. The amount of rain etc . doesn't matter ....................

 

Railway drainage is designed to cope with "one in XYZ year" events BUT NOT if it is not maintained satisfactorily and THAT IS WHERE is issue quite clearly lies .........................................

The amount of rain matters a great deal if that 1 in XYZ year storm happens after a prolonged period of unseasonably high rainfall (like getting a typical January rainfall in June).  If the ground is already saturated and the drains are running fairly high, they will not cope with that 1 in XYZ year storm in addition.  Which is now happening in 1 in XYZ/5 years, due to the change in weather patterns.

 

30-40 years ago my Dad was designing storm water and sewerage schemes; even then it was being acknowledged that what was previously a 1 in 1000 year storm was now probably a 1 in 200 year event.  There was an amusing event where a local MP complained after some properties were flooded, that he'd been told the drains were designed for 1 in 100 year storms, which he insisted was ridiculous as he'd only been MP for less than 5 years and it had happened already....

[Southernman46]

6 hours ago, phil-b259 said:

 

Actually it does!

 

The laws of physics apply just as much to railway infrastructure as elsewhere and if a drainage pipe is of a certain diameter there is a physical limit to how much water can flow through it.

 

Granted a poorly maintained drainage system will be compromised in its ability top pass liquid but even the most expertly maintained system won't cope if the quantity of liquid presented to it exceeds its capacity.

 

Thats why we have so many raw sewage discharges - its not so much that the existing sewer system is intrinsically badly maintained - it more the case that population growth, changes in land use and the increasingly large volumes of water dumped by weather systems in short periods of time* is simply too much for the inherited network to cope with! Fixing that requires money to be spent on NEW drainage / sewers (which is of course the reason why it hasn't happened on anything like the scale needed).

 

*The statistics are quite clear - although the quantity of rain over a year or the number of 'rainy days' may not have changed much the volume of water being dumped at any given time increasing.

 

 

I very much doubt that is the case historically - designing for 'one in XXXX years wasn't something the Victorians did. They simply accepted that things would flood occasionally.

 

They simply built drainage systems to cope with what they perceived as average rainfall and never expected it to cope with prolonged downpours. There was certainly no need to produce the in depth environmental reports and studies where such things are duly considered by the modern planning process before they started building things. Certainly I have yet to be shown a Victorian 'balancing pond' or land set aside to deliberately flood at times of heavy rain - both features which are seen alongside many developments / roads built over the past 40 years.

 

I will simply say that I have been there - done it - all the calcs etc for the many many railway drainage systems I have been in contact with - the Victorians (thankfully) did over engineer but those have been reassessed in the light of modern information / records etc. I CAN make the statements I make because I KNOW what I am talking about - new systems for renewals are also designed to cope with 1 in XYZ monsoon events etc ..................... BUT NOT if they aren't subsequently maintained properly or damaged by hair-brained project work ................................................ 

[Southernman46]

4 minutes ago, Northmoor said:

The amount of rain matters a great deal if that 1 in XYZ year storm happens after a prolonged period of unseasonably high rainfall (like getting a typical January rainfall in June).  If the ground is already saturated and the drains are running fairly high, they will not cope with that 1 in XYZ year storm in addition.  Which is now happening in 1 in XYZ/5 years, due to the change in weather patterns.

 

30-40 years ago my Dad was designing storm water and sewerage schemes; even then it was being acknowledged that what was previously a 1 in 1000 year storm was now probably a 1 in 200 year event.  There was an amusing event where a local MP complained after some properties were flooded, that he'd been told the drains were designed for 1 in 100 year storms, which he insisted was ridiculous as he'd only been MP for less than 5 years and it had happened already....

Yes but the point is they've still been designed for it and also rely on adequate maintainance whereas NR are shifting their many failings on the overwhelming volume of water already - THAT bow-wave is yet to hit - it will happen if our planetary manipulation goes on.

[Michael Hodgson]

21 minutes ago, Southernman46 said:

Yes but the point is they've still been designed for it and also rely on adequate maintainance whereas NR are shifting their many failings on the overwhelming volume of water already - THAT bow-wave is yet to hit - it will happen if our planetary manipulation goes on.

If the sltuation continues to get significantly worse, disruption of rail services will be the least of our worries ... flooding like East Anglia in 1947 and 1953, and more recently in Carlisle, Sheffield and elsewhere, the risk of the Thames barrier being overtopped

[Rivercider]

Network Rail will have control about what happens inside the railway fence. and no doubt in places will have influence

about what happens outside the railway fence.

Along the South Devon sea wall section it has been mentioned before that it is not just storm damage from the sea that is the problem, the red sandstone cliffs inland of the railway have been a continual problem too. There is currently work taking place on the cliff above Kennaway Tunnel at Dawlish, Parsons Tunnel rock shelter has been extended, and in recent years a lot of work has taken place on the sea wall section from Parsons Tunnel to Teignmouth. There is a combination of walling, fencing, and detection equipment in use. 

Last week we were walking along the coast at Shaldon which has similar geology to the railway sea wall section, particularly the section between Teignmouth and Sprey Point. On the Ness Beach we saw some recent falls close up. In several places small waterfalls were dropping onto the beach, and in places were there had been a recent slip the liquid red clay was still oozing onto the beach. 

 

This is Ness Beach looking east, Parsons Tunnel passes through Hole Head which is the headland in the distance. 3/3/2024

 

A close up of the recent slip on Ness Beach, the muddy water, or liquid clay, was running down in a couple of places. 3/3/2024

Mud running out onto Ness Beach 6/3/2024.

 

Obviously the section of cliffs behind the railway is better managed than this, but it is not cheap, or 100% successful, so I think calls for a real long term solution there will not go away.

 

cheers

 

 

Edited March 10 by Rivercider
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