Saturday, 16 April 2011

Royal Sands Development, Pleasurama Site Ramsgate Cliff Safety Response From Thanet District Council.

I have received a response from the council which they have asked me to publish on this blog relating to my concerns about the foundations that support the cliff façade, the base of which has recently been partly exposed by the contractor.

I have also received a response from the contractor via Laura Sandys MP, who is the MP for this constituency.

First an explanation for anyone who either hasn’t been following this issue or hasn’t understood it properly.    

The two pictures above show the bottom of the concrete cliff façade support pillar marked with red dots and what appears to be virgin (undug) chalk below it. 


The picture should get bigger if you click on it and even bigger if you click on it again. 
This picture shows you where this is and I have drawn a red line around the area shown in the two first pictures.  
This is a detail from the original design plans for the pillar supplied to me under foi legislation from the HSE, it is a side on view of the pillar.

I have added coloured lines to it to help explain what is where. The red line shows where the front of the pillar should be. The green line the ground level before the contractor started excavating. The blue line is roughly where I think they have dug down to. The purple line roughly where the virgin chalk has been cut back to.

As I can’t work out how the foundation was put beneath the virgin chalk, without digging it up and the front of the pillar doesn’t follow the line shown in the design drawing I have concerns about the integrity of this structure.

I discovered this situation last Saturday and asked Kent Fire and Rescue if they would examine it and close the footpath above it while more detailed investigations were made.

Kent Fire and Rescue investigated the area, confirmed that they couldn’t find and sign of foundations but told me that as the council had told them that the cliff was safe, they were not able to close the footpath.

Below is the response I have received by email from the council’s engineer Mike Humber signed by the council’s Director of Regeneration services Brian White which they have asked me to publish here.   

"REGENERATION SERVICES

Michael.child@aol.com
15 April 2011
Our ref: BJW/BH
Your ref:
Dear Mr. Child
‘PLEASURAMA’ CLIFFSIDE, RAMSGATE
I am writing in response to your interest regarding the cliff wall to the rear of the Royal Sands
(formerly ‘Pleasurama’ site at Ramsgate. Your concern being that the cliff wall has no proper
foundations, and is therefore at risk. A site visit was made on Monday 11 April by Mr. Mike Humber,
the Council’s Engineer and myself. The ground has been excavated adjacent to the cliff wall in
recent weeks to enable work on the foundations to the Royal Sands development to proceed.
Consequently chalk is visible in places at a level beneath the cliff wall façade, and this has led you to
believe that there may be no foundations supporting the cliff wall itself.
However the point that you have missed on your inspections is that there are substantial concrete
foundations, to a minimum depth of two metres, beneath each of the main supporting columns to the
cliff wall. This was verified during our site inspection.
Records exist of the design of the original cliff wall dating from the early part of the 20th century in the
form of a construction drawing and I believe you already have a copy of this. The observations made
on site this week confirm that the foundation provision appears to be as described on the drawing. It
can be seen that the foundations and columns were both cast insitu with the columns exhibiting a
regular finish from timber formwork whilst the foundations were cast against the hand excavated face
of bare virgin chalk. I suggest that it is this interface between these two very different concrete
finishes that you have misinterpreted as the base of the concrete structure. Although recessed a
little, the foundation does continue well below this elevation as confirmed above.
I do trust that this letter draws your concern to a satisfactory conclusion. Thank you for your interest
in the subject. Perhaps you might post a copy of this letter on your blog.
Whilst writing, because of your interest also in the engineering history of Ramsgate Harbour I thought
I would draw your attention to the pending completion of a new floating concrete breakwater in the
Outer Harbour area. This is the single biggest investment the Council has made in the Harbour for
some 20 or so years. The new floating breakwater will not only protect the Eastern Marina, it will also
provide satisfactory berthing for work boats used in the construction and ongoing operation of the
London Array offshore windfarm. The Council is very pleased with the new structure, a large portion
of the funding was provided through European Union grant.
Yours sincerely
B White
Director of Regeneration Services
Tel: 01843 577007
cc. Cheryl Pendry
Mike Humber"

Below is my response to them 

"Dear Brian and Mike.

I have to admit the saga of this cliff wall is a bit of a difficult one, but as the wretched thing doesn’t conform to the design drawings I feel it best to err on the safe side. Most particularly as the previous two problems I reported to the council, the bulging panel and the 1860s balustrade both resulted in council action to repair the problem.

God alone knows how that 1860s balustrade is supposed to work, if it has foundations and how much water is getting in from behind. Did you know that when the railway extension from Herne Bay to Ramsgate was put in, in the 1860s the government inspector, Captain Rich condemned much of the civil engineering work including several of the bridges, which had to be rebuilt?

I am still concerned that I haven’t got any evidence that there is sound concrete all the way between the bottom of the visible concrete pier and the rough cast concrete that you have discovered at the at the bottom of the recent excavation.

Have you either exposed continuous concrete between the bottom of the pier and the bottom of the excavation, carried out a driven rod or bore test this in this area?

The reason I ask this is that the chalk at the bottom of the pillar doesn’t have the appearance of made ground and I can’t see how the back of a load spreading foundation or the bottom of the pillar could have been constructed without disturbing the chalk.

As we have discussed before the façade isn’t a load bearing structure and I am particularly concerned that heavy vehicles are accessing the cliff edge while below excavations are being made of foundations that don’t conform to exactly the design drawings i.e a uniformly cast liner pillar extending down to the foundations.

After the arched part of the façade (visibly the most sound and professionally constructed part) the contractor will presumably excavate in front the less linier portal part of the façade where both the pinning took place and the contractor has already discovered and documented one pillar with inadequate foundations sitting on made ground.

In short the risks of a normal building site appear to have been adequately addressed apart from the added problem of the proximity of the public footpath to the edge of the cliff.

I am not asking that this be permanently closed while the building work is in progress, something would I think be unnecessary and damaging to the town’s economy.

Just that the parts above excavation of any part of the base of the façade that doesn’t conform precisely to the design drawings is closed while investigations are made and of course some emergency signage warning people not to drive anywhere near the cliff edge.

Best regards Michael"
I have also had a response from Laura Sandys informing me that the contractor, Cardy Construction will “further expose a section of the foundation and provide Michael with photographic evidence of the existing foundation,”


I have added a link to a series of linked webpages showing some of the various technical reports on the cliff façade structure http://www.thanetonline.com/cliff 

27 comments:

  1. Michael did the council provide photographic evidence ? surely this is easy enough to prove I used to often provide inspection pits for footings when I was building and they were aalways for the building inspector to prove what was there was capable and wouldn't collapse when we did our work.

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  2. Don I don’t really see how they can until the contractor has further exposed them, I think they have found some concrete at the bottom of where thy have dug down to, but the bit under the pillar is still all what looks like virgin chalk.

    I think it possible too that my point about how you could get the concrete pillar in and the back of the load spreading foundation in, without disturbing the chalk in front of the pillar or above the foundation was more difficult to get across to them than I expected.

    As they have described it as virgin chalk in their letter, they appear to think like me that it hasn’t been disturbed.

    Perhaps there is some method of doing this that was used in the 1930s that I don’t know about.

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  3. I must admit that Michael's photos don't show any sign of concrete foundations. However, I wonder if everyone is talking at cross purposes here. The man from the Council talked about that "main supporting pillars" - rahrter an odd way of describing the sides of the arches. I wonder if he meant the large brick structures at either end of this wall. Only a thought

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  4. Andrew I have added a link to the bottom of the post for you to a series of linked pages of related documents, which may help you understand the structure in more detail.

    The brick pillar at one end is the lift and at the other an 1860 support for pedestrian bridge.

    It is important to understand that none of the cliff façade structure was designed to support the cliff, essentially it leans against the cliff. Build a flat Lego wall and you will see that the amount of force to the side of it at the top required to knock it over is relatively small.

    In this instance they definitely do mean the pillars at the sides of the arches and what the support is the hundreds of tons of concrete that form the façade apron above them and of course themselves.

    The arches have been filled in with concrete blockwork that only supports itself.

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  5. From what you say, and a quick read through the attached documents, it would seem to be better to knock the facade down and start again!

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  6. If you start knocking down existing concrete fascades in front of chalk you really are asking for trouble.

    The contractor and the council engeers have provided an answer and are going to expose more of the foundations for Michael to take more photos. What else do you folk want, councillors chained to the uprights whilst members of the public jump up and down on the footpath above.

    Talk about flogging a dead horse.

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  7. Michael, the confusion arises from the fact that you are using a drawing of the foundation for the infill wall to illustrate your point, but your photos are at the base of a supporting pillar.

    You have previously published the drawing of the foundations to the main pillars, it shows a large inverted "T" foundation set well down into the ground.

    For this inverted "T to exist a large area of chalk would have been previously excavated and the "virgin chalk" could not exist.
    The vertical leg of the inverted "T" should continue up as the main pillar.

    I am willing to visit the site and make a series of simple tests which will establish beyond doubt the structural stability of the main columns, if you can arrange a meeting with TDC or Cardys

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  8. Now Ken is talking sense and proposing a positive step to allay fears. Well done, that man.

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  9. Andy this is the case with the faulty panel I reported to them at the end of 2009 after the £1m repair, they have already had to knock it down and rebuild it.

    18.57 trouble absolutely, as I said to Andy they already have and it was a lot of trouble, the panel they had to knock down was about 8 metres high, so they had to use a long armed JCB, type of thingy, with the cab 8 metres away because of the falling lumps of concrete. Hopefully there won’t be a recurrence as the back of the Royal Sands will soon be 4 metres away.

    I don’t recommend the footpath above until after the contractor has made their investigation next week, I think it is probably quite safe, but as there are miles of cliff top to stand on in Thanet I would avoid this short stretch until after the middle of next week.

    Readit, I think you will find that this is the right drawing for the foundations of the support pillars of the arched part of the façade, the inverted T foundations are used for the support pillars of the portal part of the façade, to the south of the arches. I have only got written details about the foundations for a short length of the block work panels, this was from the senior engineer of the firm that supervised the main contract and confirms in writing that the only bit they have investigated doesn’t have foundations and is built directly onto made ground.

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  10. Michael, the drawing you are publishing at the moment is a section between columns and gives no clue to the column foundation.
    The furry hatching denotes the junction between manmade structures and natural strata.

    The published letter from TDC states "Although recessed a little, the foundation does continue well below this elevation as confirmed above."

    If this is in fact the case it should be possible for Cardys to clean that face and photograph it

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  11. Michael , can you direct me to the post which shows the inverted "T" foundations?

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  12. Ken here is the drawing that I take to be from the “new line of cliff” marked of the arched section before the blockwork was added, at this time I believe there was a short concrete facing on the bottom six feet of the chalk between the arches with bare chalk between the arches above it.

    http://www.michaelsbookshop.com/laptopol311/id7.htm

    I think the arches were built in the 1930s

    The block infill added in the 1940s although I am not certain I am in the right decade for this, it could have been later.

    The block infill covered with steel mesh and rendered in the 1970s

    The drawing underneath shows the portal pillars with the T foundations.

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  13. Ken Readit all of the documents apart from the ones I emailed to you are at aeries of linked pages you find if you follow the link at the bottom of this post.

    I have written rather a lot of posts about Pleasurama and three websites so it was easier just to republish the sheet than look through several years of internet publishing, you have to appreciate that this sheet forms only one of the hundred thousand or so that I have published onto the internet in the last ten years.

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  14. Michael, I think we can go on conjecturing about this one until the cliff fall down.

    The best solution is a rod penetration test at each column. The whole lot could be tested in an hour and all the uncertainty dispelled.

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  15. To anonymous 16 April 18:57,

    You say, "What else do you folk want, councillors chained to the uprights whilst members of the public jump up and down on the footpath above."

    Yes please. I would like to volunteer for the jumping up and down, sir.

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  16. Then, Mr. John Holyer, you obviously have great confidence in the cliff and path being able to take your jumping up and down weight. Point proved, I think.

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  17. Not a rod penetration test no less! I wondered when sex would have to come into the debate. Mind you, it is an area that will have seen much before in its prime, particularly back in Coronation Ballroom days.

    Think I will join the guy who went off to watch paint dry for this is getting seriously boring. Mind you, what can you expect when a council candidate is prolonging the debate.

    Incredible how politicians see so much mileage in negativity. Perhaps that is why so little gets done when they are elected.

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  18. No, Mr anonymous (presumably you have a name) what I really want is for the councillors to be chained to the uprights, or anywhere for that matter.

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  19. Readit, up to a point the problem though is that first one has to establish what should be there from the plans, which I think I have. The next stage with this one was establishing that what exists in reality differs from the plans, it doesn’t much matter how you look at this, all of the plans show all of the pillars extending down the same shape as they are above the ground until they spread out, I think we have established that this doesn’t happen. So obviously there are areas where if you hammered in a rod where it should hit concrete it would meet no resistance.

    10.55 I have been having this sort of debate with Ken Readit for years, I don’t think it has anything to do with his politics. I think you are barking up the wrong tree here, but let us suppose the worst case scenario politically, for a moment, which would be that a dodgy elected member sold the cement that was supposed to be used for the bottom of the pillar. Well it was built in the 1930s so that has to make it a least 72 years ago, you would have to have been at least 21 to stand as a councillor then so that would make the offender at least 93 years of age and then to cap it all he or she could have been an independent, which using your logic could damage Ken’s chance of getting elected.

    What all of them John, there are only 31 pillars and there are 52 councillors.

    The real point here is though, does anyone think that the footpath should remain open while the examination to see what is actually at the bottom of the pillar hasn’t been completed.

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  20. Michael, another real possibility is that the concrete steps back slightly and continues down,just as the two senior council officers state in their published letter.

    Otherwise they are committing professional suicide.

    Two senior council officers would have the authority to close the footway above the cliff if they felt something was not right.

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  21. Ken I think possibility is the key word in your comment. What these two officers say is that “the foundations were cast against the hand excavated face of bare virgin chalk”. Since the thing is shaped like an inverted L, or an inverted T and the drawing I put the link to in my 21.26 post has a scale on it showing the hole is 3 feet across that goes down 6 feet four inches with the bottom extending out to one side about three feet. I think the original thing could have been dug by hand this way and then the concrete poured in. my main worry though is the one that has already been excavated at the other end of the site that proved to have no foundation. But it still comes back to it isn’t so important if there is a foundation there or not, but is it an acceptable risk to take in view of the proved uncertain state of the structure?

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  22. And STILL I see no "evidence" that a concrete foundation exists. The Council's argument seems to be that the concrete was cast in a chalk mould and so it looks like chalk. Easy to tell the difference. If it's chalk you can scrape it away with your penknife. If it's concrete you can't. Another site incursion?

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  23. Michael

    Yesterday I saw the contractor has hidden the arches nearest to the eastern entrance to the site with wooden planks, as illustrated in your photo.

    Why would they do that if there was nothing to hide?

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  24. Confused in ThanetApril 18, 2011 10:59 am

    Michael, regardless of what you say this issue has been hijacked for blatant electioneering. Snide anonymous comments, suggestions of things to hide and anonymous contributors waiting to see the evidence.

    Whilst on the one hand we have good news coming out of Margate with the TC, this issue is providing a wonderful opportunity for the Labour activists to smear the present administration.

    One does reach a point where one starts to wonder how many answers are needed to ally fears. You have already had council officers and our local MP responding. Perhps the PM should also check it out!

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  25. 8.23 I am pretty certain now that the foundations under the pillar were dug out by hand and filled with concrete and I have been promised photographs showing evidence of the later this week.

    9.45 I don’t think this is any sort of conspiracy, just a handy wall to lean the shuttering they are using to cast the upright for the building they are building 17 feet away from the cliff face.

    Confused it is now looking pretty certain that the foundations do in fact exist, where I asked the council to check they existed under the pillars, as soon as I have the pictures and some sort of notion about what is holding up the block panels between the pillars, the panels are not such a problem as if one collapses it would be unlikely to bring down the footpath above with the people on top of it, just land on the building workers below.

    The council have already replaced one of these block panels because I found that it was bulging and had a big crack down the middle, also they are not very expensive to replace, I did publish the cost of replacing the bulging one and think it was in the order of £20,000 but would have to check to be certain. Of course the ones between the arches are much bigger than the one they replaced but I would think £50,000 would be about the right amount.

    I genuinely don’t think the have a clue if they have cut away the chalk about one or two feet away from them to a depth that is below the blockwork foundations.

    I would say anyone who engages in speculations on this blog with me has a good chance of being wrong about things to do with the cliff façade structure, it seems to vary in age between 150 years and 18 months, the council seems to have very little in the way of original design drawings for it and those they do have are not exactly like the structure as built.

    You have to appreciate that I have plenty of other things to do apart form worrying about the cliff façade structure, but the history of how these public structures were constructed here in Thanet is of considerable interest to me.

    You can no doubt see how very small the hole would be to work in with a pickaxe and a shovel, I would say that this arched structure is pretty typical on the older concrete cliff facades in Thanet.

    Ken’s comments are helpful to me when trying to understand this aspect of our local civil engineering, something I have published several books about, the aside here is that this is a seventy foot high concrete structure where people are digging away at its foundations. My message here can be summed up as, be careful, ken’s seems to be poke a stick in and make sure there is concrete before you dig next to it.

    I hope you thought my coverage of the Turner Contemporary was OK and didn’t have weird political undertones.

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  26. Confused in ThanetApril 18, 2011 2:14 pm

    It is not your weird political undertones, Michael, it is the people who jump on the bandwagon with their anonymous 'things to hide' comments.

    On the TC, good cover and great to see people enjoying something for a change. That could be contagious and maybe a bit of joy will spread in our little corner. Sure hope so.

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  27. Confused, with the Royal Sands, it has a bit of a history of things hidden, which for something so big about there times the size of the TC is a bit problematic.

    Anonymity operates for a lot of candidates including yourself, I know there are often justifiable reasons for this, I would say that you, for instance are leaving yourself wide open to people pretending to be you, as you haven’t registered a blogger identity, something that wouldn’t compromise your anonymity but would stop people maliciously pretending to be you, I suspect this is something that will end in tears.

    On the brighter note of the TC I am glad that local people seem to be happy with my coverage as a lot of people worldwide seem to be looking at it, this si the breakdown so far today.

    United Kingdom 551

    United States 61

    Denmark 28

    Germany 16

    Italy 15


    France 14

    Russia 7

    Iran 5

    Japan 4

    Ukraine 4

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