Has the sea got waves

February 2008 | home thanetonline.com michaelsbookshop.com Click here for books about The Isle of Thanet Dangerous cliff ?

this link takes you to the rest of my Pleasurama site this link takes you to my previous correspondence

My attempts learn about the Pleasurama project have lead me into a dialogue with Thanet District Council about their website and the way they pass on correspondence to councillors. Click on the links above to read the correspondence.

Pleasurama update 26/9/2007 Click here to see video of the spring tide in Ramsgate 2007

The council and developers have now admitted that the building will be liable to occasional flooding during tidal surges, see the account of the ERA meeting at http://www.michaelsbookshop.com/tdc/id46.htm as tidal surges are accompanied by storms it would seem that the next step is to get the council and developers to admit that the sea has waves.

Current research

My research into the safety of the Pleasurama building, which has become an ongoing interest, has produced some interesting information that may have some useful applications for other projects including the Sandwich costal defence project.

The historical data used to produce the tidal surge related figures for this area come from the old Margate tide gauge the 200 year predicted was calculated for Margate and the Margate figure is used for this whole area.

The problem being here that Margate is in the North Sea but Broadstairs Ramsgate Pegwell bay and Sandwich are in the English Channel and situated at the point where both tidal systems meet.

The current tide gauges in use each side of Ramsgate are at Harwich and Dover, obviously the relationship between the Harwich and Dover tide measurements would be useful when compared to the Ramsgate and Margate tide gauge measurements for 1953 unfortunately the Harwich records were destroyed in the 1953 surge and the Dover records appear to be missing although I haven’t managed to find out why.

I haven’t managed to find anything out about the Margate records the British Oceanographic Data Centre that supply the Environment Agency with the data to predict tidal surges didn’t use the Ramsgate tide gauge measurements as it was an admiralty gauge and they either didn’t know about it or didn’t have access to it.

The environment agency are very unhappy that the acceptable level for commercial buildings above sea level wasn’t raised like the residential level to reflect global warming.

To further complicate matters the environment agency current predicted 1 in 200 year level for Ramsgate is 4.93m ODN. I have warned them that this appears wrong as I believe the pavilion which is about 6 ODN has flooded on numerous occasions.

Chart datum/ordnance datum (Newlyn) for tide levels differential at Ramsgate is 2.58m i.e. chart datum is 2.58 meters below ordnance datum (Newlyn) or ODN.

I asked the environment agency about 2 months ago to check that the ODN levels on the site survey were accurate they haven’t come back to me on it so I don’t know if they have done it

HISTORICAL BACKGROUND

What has changed most significantly since 1953 is the amount of beach, then the whole area in front of the pavilion and where the proposed new building goes had an extensive beach above the high tide mark that had built up on the barbed wire war defences, just below the level of the promenade, this was unfortunately removed for the infill used to build Port Ramsgate.

The best I can work out from studying pictures about 100 yards above 5 ODN between the pavilion and the sea in 1953.

Most of the people I have consulted concur that it was this that stopped the pavilion from being demolished in 1953.

The sand wasn’t there in 1897 so all the buildings where the pavilion now stands were demolished, it wasn’t there in the 1978 storm fortunately this wasn’t combined with a tidal surge so only the harbour wall was demolished.

The existing buildings under the arches below the east cliff are all protected by sandbags during the winter and the people inside would be able to shelter upstairs in their arch in the event of storm and surge.

The rest of the low buildings along the seafront are protected by the harbour.

Thanet Advertiser and Echo 3rd Feb 1953

Hundreds of tons of sand, flints and chalk boulders were washed up on to the Colonnade and the Royal Victoria Pavilion looked as if it was actually on the beach.

Further along the Marina, public seats were smashed and summer kiosks damaged. A twelve-ton crane which was being used for the removal of flints was carried along the promenade and swung into the roadway by the force of the seas.

At the eastern end of the seafront, a door was torn off the public toilet accommodation and a large stone slab lifted.

Ramsgate's Marina Bathing and Boating Pools were filled brimful and dressing accommodation and storerooms completely flooded. Examination of the fabric of the pool's walls showed, however, that there had been no structural damage and their opening for the 1953 season will not be retarded in any way.

This account of the great storm of 1897 from Keble's Margate and Ramsgate Gazette says.

At Ramsgate the gale was not felt with such force as at Margate and other places along the coast, and the tempest lasted, in its worst form, an hour and a half or two hours at the most; or, rather, the bulk of the damage done was confined to that period. The East Pier, which had stood the stress of many winters, was on this occasion considerably damaged. About a quarter to three, when mountainous waves had broken against it for some time, a serious breach was made-about 100ft. in length of the stonework being washed out of position. Huge blocks of granite, weighing several tons, were hurled with extraordinary violence into the harbour; others fell into the water and buried themselves in the sands. The extreme force of the waves can be easily imagined when it is stated that three courses of stonework, the parapet, the base stone, and the half-round moulding succumbed almost simultaneously to the fury of the gale. Several of the large stones forming the paving of the pier were wrenched out of place. Between the inner and outer walls, the material not having the solidity of the remaining portions, as each successive wave swiftly and noisily broke over it, tons of stone and other material were hurled to and fro. But the greatest attention was directed to the colonnade, over which enormous waves broke with tremendous force, reducing almost the entire structure to the ground level. The colonnade was erected some twenty-four years ago. The small shops at each end were totally destroyed, and a great proportion of the wooden material was forced through the rear of the colonnade into the stoneyard. Of the colonnade, all that remained was a few posts and some portions of the iron roofing.

The Esplanade practically escaped scot free, but about 70ft. or 80ft. of the red brick wall at the east end, belonging to the L.C. & D. Railway Co., was demolished together with a portion of the wood fencing separating the railway sidling from the Marina-road. Great falls or the cliff took place between Ramsgate and Dumpton Gap and beneath East Cliff Lodge heavy landslips occurred.

WORST CASE SCENARIO

A tidal surge occurs at night time, unpredicted as was the hurricane, the wave action causes the cars to be washed about in the car park under the building damaging the supporting pillars so the building starts to collapse.

One would expect there to be about 1500 people asleep in the building, with the cliff behind them preventing escape and no escapes onto the cliff top they would not be able to get out.

The emergency services would all be busy on the North Kent coast where the greatest loss of life occurred in the 1953 storm.

There is also the danger that one of the several thousand ton coasters which when unladen only draw about a meter could be swept into the building, this could be seen as a good case for an adequate concrete sea defence wall in front of the building.

I will publish this and any responses at http://www.michaelsbookshop.com/tdc/ as per usual.

Its also published as a comment on Cllr. Dr. Simon Moores blog at http://birchington.blogspot.com/2007/09/bonkers-builders.html#comments should you wish to comment anonymously instead.

Kind regards to you all and my thanks those of you who have taken the trouble to come into the shop and discuss this matter with me. Michael

Eastcliff Richard click here to go there has put a piece about the development on his blog and several people have left comments that may interest you.