Cornwall Landslip Today

[edcayton]

Just heard on the radio that there are no trains in or out of Cornwall this morning due to a land slip. Can't find any more about it, does anyone here know any more?

 

Ed

[St. Simon]

Hi,

 

There's a landslip near St. Austell, there's no trains throughout the county.

 

It's all because of floods, people are trapped in their house near St. Blazey with 2 helicopters from the Royal Navy and 1 from the RAF attending

 

Simon

[Kris]

As Simon said, this is due to heavy rain over night. You really don't want to be trying to move long distance in Cornwall at the moment as the major roads (A30, A38, A390) are also suffering.

[Penlan]

Oh, just got in from problems in the village, don't seem so bad now if there's people trapped in their houses, but that's going to be another rise in our insurance rates, a double flood area for us.....

 

Most problems here are due to gratings over culverts blocked, the diverted routes are not happy routes.

 

So, today, allocated to pack up the layout ready for the journey up through Cornwall towards Warley NEC tomorrow, looks to be thwarted, hopefully the roads will be clear when I eventually set off.

 

Simon states heavy rain, the wind/gale was something to behold too, set us back about two weeek's with the damage to our Harbour Christmas lights displays - 2 weeks we haven't got.

[Raffles]

It would appear that there are multiple landslips with the Newquay branch currently completely blocked. There has also been a rock fall at Teignmouth. Must have been some pretty grim weather down there last night.

[10800]

Wasn't aware of the rock fall here - if the wind drops and it's safe I might venture down later.

[Glorious NSE]

Definately grim weather in Exeter last night....

[Penlan]

... - if the wind drops and it's safe I might venture down later.

Well it's a bright sunny morning with hardly a whiff of wind, a complete contrast to yesterday evening when we were trapped in 'The Legion'.

Mind you having had about 8 phone calls this morning starting around 6.15 re. problems, I'm just grateful it's passed over,

although checking the charts here (Magicseaweed surf charts) there's another low coming in, I think last nights low was down around 955 millebars.

(Click on Charts along top menu bar, then you can select, pressure, wind, surf etc.,).

[Raffles]

Wasn't aware of the rock fall here - if the wind drops and it's safe I might venture down later.

 

There is apparently some debris on the up line at Shaldon. Services running at extreme caution.

[Captain Kernow]

OK, brief update, ('cos, guess what, I'm busy!! )...

 

Cornish main line - landslip at Brownqueen - between Liskeard and Lostwithiel. Shuttle rail services between Plymouth and Liskeard and between Penzance and Par, with buses being arranged in between. No estimate for resumption, although initial indications from our man on site are more hopeful than previously - check with the usual sources if you are travelling.

 

Newquay branch - at least 2 landslips in Luxulyan area - unit trapped back at Newquay - no realistic prospect for rest of day for clearing this - local roads also treacherous, not helping matters. Buses also having problems, apparently (so I've heard) - recommendation - don't travel Newquay to Par/St Austell today if you can help it!

 

Teignmouth - this is a small retaining wall at Shaldon, to the west of Teignmouth station - trains on caution and it is being inspected at the moment.

[Raffles]

Rock fall at Teignmouth now cleared.

 

General advice is for people not to travel. Tickets for travel today will be valid for tomorrow. There are some bus servcies but as you can imagine, the roads are suffering as well, hence the advice for people to defer their travel plans.

[Gwiwer]

Shuttle rail services between Plymouth and Liskeard and between Penzance and Par, with buses being arranged in between.

 

Photos posted in various places including Pirate FM's Facebook page. These show a small amount of flooding in St. Blazey, apparently less than a foot deep. Other areas reported to be somewhat wet but passable. People have been reported "trapped in homes" and calling for rescue helicopters yet they only seem to have water up their garden paths.

 

Ironically "Buses arranged" between Par and Liskeard conflicts with First and Western Greyhound (the two major operators) who both advise no service on some routes including 593 between Bodmin and Liskeard and the 26 / 526 beyond Pentewan to Mevagissey and Gorran Haven. It strikes me as odd that the low-lying section of route to Pentewan can be served but up and over the hill (and it's a big hill) to Meva is "flooded". Doesn't water flow downhill or has there been a landslip up there?

 

A message arrived from friends on the spot saying they were stopped by Police and told they could not go through despite the flood water not being even kerb depth. They promptly went through when the officer spoke to the car behind and had no problem at all.

 

It's been a wild night but Cornwall seems to have forgotten how to cope. If the flooding is due to blocked drains and gratings then the Highways Agency or Cornwall Council has some serious questions to answer. To close roads for just a few inches of water seems excessively cautious and actually creates bad feeling.

 

Apart from the Newquay line I'd hazard a guess that everything on rails will be clear - albeit delayed and cautioned - later today.

[trisonic]

If leaves are not cleared they can quickly block up storm drains.

I'm surprised, though, at the number of landslips - are these at natural formations or what?

 

Another storm is currently passing over our area around NYC. As is usual with American weather systems the rains come but the wind usually follows on after the rain (not with Nor'easters or Tropical Systems though).

We're expecting high winds later (until 1:00am tonight).

 

Best, Pete.

[Captain Kernow]

Apart from the Newquay line I'd hazard a guess that everything on rails will be clear - albeit delayed and cautioned - later today.

Correct estimation. Currently waiting engineers reports from Brown Queen, but worst of mud is now cleared.

 

Shaldon (Teignmouth) now running normally as well.

[Oldddudders]

It's been a wild night but Cornwall seems to have forgotten how to cope. If the flooding is due to blocked drains and gratings then the Highways Agency or Cornwall Council has some serious questions to answer.

Perhaps the winds brought all the remaining leaves down in one go, blocking the drains? Even the best-equipped and -funded County (we suspect Cornwall suffers from being neither) might not be able to cope everywhere in such circs.

[Clay Country]

Despite reports of floods in Falmouth on the national news this morning everything appears to be normal down here. Trains are running as normal from Truro.

[Captain Kernow]

Cornwall main line now reopened at Brown Queen, albeit with a caution speed past the site.

[Fat Controller]

If leaves are not cleared they can quickly block up storm drains.

I'm surprised, though, at the number of landslips - are these at natural formations or what?

 

Another storm is currently passing over our area around NYC. As is usual with American weather systems the rains come but the wind usually follows on after the rain (not with Nor'easters or Tropical Systems though).

We're expecting high winds later (until 1:00am tonight).

 

Best, Pete.

A lot of landslips on cutting sides are due to problems outside the railway boundary- most often to field drains on adjacent agricultural land becoming blocked, or even completely broken during ploughing.

Here's a link to a recent accident report on the RAIB web-site, illustrating the problem:-

http://www.raib.gov.uk/latest_news/101028_pn_gillingham_tunnel.cfm

There was another one near Kemble, with similar causes, but I couldn't find the report; there have certainly been others.

What seems to have been happening in recent years is that the UK (and parts of mainland Europe) have had periods of much more concentrated rainfall (sometimes as much as 1"/25mm, possibly more) in an hour. When this happens, normal storm drains and culverts become overwhelmed, leading to soil becoming saturated, producing either slips (because of the lubricating effect of the water on clay, for example) or causing pressure to build up behind walls at the foot of cuttings, causing catastrophic failures. The problem is that such changes in the nature of rainfall can be very difficult to monitor- if you're looking at a rain-gauge once a day, 25mm shows as 25mm, whether it's fallen in an hour-long cloudburst or more gently over a longer period.

There haven't just been failures of cuttings- there have been several major embankment failures or near-misses due to saturated ground. On parts of the former GWR, the problem is accentuated by embankment sides being steeper than the norm - to reduce land-take, Brunel devised a system of constructing a core of logs, bound together by chains. In the ensuing 150+ years, both logs and chains have degraded, reducing the integrity of the structure.

[trisonic]

Thank you Fat Controller for a brilliant explanation. I've learnt something new about Brunels' way of working. I'm not a GWR expert.

 

 

Best, Pete.

[Fat Controller]

Thank you Fat Controller for a brilliant explanation. I've learnt something new about Brunels' way of working. I'm not a GWR expert.

 

 

Best, Pete.

Both my brother-in-law and sister are geotechnical engineers... Before he retired, one of Gary's projects was advising on the stability of earthworks on Railtrack's Western Zone in the Wiltshire/Gloucestershire/Somerset area, so I got to hear a lot about such things.

One of the most dramatic examples of an embankment failure that I can think of caused the flood that trashed the centre of Vaison-la-Romaine in September 1992:-

http://www.eumetcal.org.uk/euromet/courses/english/satmet/s9220/s9220005.htm

The rain built up in the area behind the long-disused embankment of the line to Nyons; when it failed, the town was devastated. We were at the fringes of that storm, doing our vendanges in Beaujolais (about 150 miles north)- there was a lot of wash-out damage there, whilst the thunder was strong enough to break windows.

I just checked the RAIB web-page for something else, and found some more references to cutting/embankment/retaining wall failures due to heavy rain:-

http://www.raib.gov.uk/publications/investigation_reports/reports_2008/report072008.cfm

http://www.raib.gov.uk/publications/investigation_reports/reports_2008/report052008.cfm

It's noticeable that on recent construction, notably CTRL/HS1, embankment and cutting slopes have been a lot less steep, and that cutting sides often have a concrete retaining wall at the base.

[The Stationmaster]

The BBC news this evening painted a rather different picture with some areas flooded to thigh depth and roads flooded with several feet of water and large amounts of rock/soil debris visible etc. The river at Lostwithiel was almost up to the top of the bridge arches but then in some respects such flooding is not surprising as 50mm of rain fell during the night on Bodmin Moor and several places in Cornwall recorded falls in excess of 40 mm during the night.

The main line bank slip didn't look too serious on the tv news but there was a considerable volume of water coming down the bank which is presumably what caused the slip in the first place.

Brian's comment about Brunellian construction methods is interesting but most of the worst places for slips on Western main routes were/are on sections built long after Brunel had gone to the great broad gauge railway in the sky. On his original route the only truly serious problem - for many years - was on Dauntsey Bank and it was finally recognised (only about 20 years ago) that the continuing problem was largely because a diverted water course had re-established its old route over the years with hefty impact on part of the embankment every time there was heavy rain. Because of the problems, and persistent slips, when the embankment was being constructed this was where Brunel used the chained piles in an effort to stabilise the bank but this was only succesful as a constructional aid; slips continued to occur thereafter, for over a century. Problems have also occurred over the years in several places between Swindon and Didcot but these, again, have been mainly due to water and not the angle of the slope, indeed one of the worse spots for many years was where the embankment was very gradually sloped and had been extended a long time after Brunel had gone.

A lot of embankment and cutting stabilisation work has been carried out on the Western over the last decade or so but very little of it has been on sections built by Brunel.

[Gwiwer]

More pictures now received from friends in Lostwithiel. Being at the foot of a steep hill the rain which fell on higher ground cascaded down the main road and washed the emergency lane kitty-litter out and down into the town's drains. That appears to be what has caused the main part of the flooding, not the actual volume of water itself.

 

Eden Project is closed until further notice owing to flooding of some of their visitor facilities and are reporting that while none of the plants, domes or land has been damaged a fair amount of craft work being done in their centre has been lost. They could have cleared the site faster but it might have caused more flooding to surrounding areas by doing so.

 

No further delays are reported by local bus operators.

 

A few homes will need some repair work, there is mud and debris to be cleared from streets (mostly done from reports received) and underground services need to be checked over but all in all not a very large event in the scale of things.

[Kris]

The Newquay line is still closed and apparently is likely to remain so until mid December.

[Kenton]

all in all not a very large event in the scale of things.

As always for most of these things - unless, of course, it directly effects you, then it can seem like the end of the world.

[Captain Kernow]

The Newquay line is still closed and apparently is likely to remain so until mid December.

NR is working hard to get the line opened asap, what was thought to be the worst slip up near Rockmill Viaduct has turned out to be an easier job to deal with from a civil engineering point of view. The more challenging site is that at Pontsmill Cottages, where the near-vertical side of the bank has to have rock bolts, netting and other reinforcement measures undertaken:

 

 

 

Specialist contractors are getting well into the work required here and I understand that further announcements regarding the likely reopening of the branch will be made soon.