Information AboutRonan Point |
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The partial collapse of Ronan Point led to major changes in the building regulations. The first of these came with the 5th Ammendment to the Building Regulations in 1970. These are now embodied in Part A of the Building Regulations and cover Dispropotionate Collapse. Immediately after the publication of the report the Government brought out interim measures. All new buildings constructed after November 1968 and over 5 storeys had to resist an explosive force of 5lbs per square inch (psi). Existing buildings were allowed to resist an explosive force of 2.5psi. This was provided that the gas supply was removed and flats became all electric. This did not always happen. The gas was removed from Ronan Point and the other eight blocks on the estate. A gas explosion of the force recorded in Ronan Point of 3-12psi was not extreme. Other forms of explosion could have caused a similar removal of the loadbearing panels including an electrical explosion. It was found, though never revealed in the Public Inquiry that most of the electiric underfloor heating panels mats in the floor panels of the 18th floor were incorrectly wired up. An inspection was carried out by a firm of electrical engineers for the Inquiry of all the elctric meters in the entire block which had only been occuoied about 3 weeks. While they all recorded the amounts of power used in the oredrs of tens of units the meter in Miss Hodge's flat where the explosion occured registered thousands of units of electricity. No satifactory explanation was ever given for this discrepancy and nothing appears either in the transcripts of the inquiry or in the Inquiry Report. What was mentioned, albeit briefly, was the danger of possible collapse from high winds and a domestic fire. Ronan Point was not unique. Many other buildings of that time were found to fall well below safe limits with regard to windloading. All wind loadings were subsequently raised and new codes introduced. While a high wind would not blow over a building like Ronan Point, a peak gust of 105mph could have removed non loadbearing face panels - these are the ones at right angles to the loadbearing panels which they join at the corners - at the upper corners of Ronan Point in certain conditions. This could have resulted in a peeling off of part of the facade which could have led to progressive collapse. The engineer who sat on the Tribunal of the Public Inquiry, Sir Alfred Pugsley, was very concerned about this aspect of Ronan Point's structure. In his draft chapter written prior to publication he said: " However in popular terms to make walls strong enough to resist 60 pounds per square foot is only to make them about as strong as the glass in a good window." This passage by one of the most eminent engineers in the UK was struck out. Pugsley then wrote in the margin the following note: "However it would seem to us very unfortunate if in a wind liable to break many glass windows (those at Ronan Point have been found by test to break at 16 pounds per square foot) the inhabitants at Ronan Point should also have to worry about its structural stability." This passage was also struck out. Non of this concern appears in the Public Inquiry Report. The much more common danger of possible structural failure from a domestic fire was ignored. Each flat in a multi storey building, however constructed, must contain a fier for a specified period laid down in the Building Regulations. Thereis nothing to stop the fire venting out of windows but what it must not do is pass through the structure into another flat or escape corridors. So all elements, floors, walls, ducts, and certain doors have to resist the action of fire for a specified period. This is laid down in the Building Regulations. At the time Ronan Point was built each flat had to resist the action of fire on the structure for a minimum of one hour. This meant that not only should each structural element - particularly the floor/ceiling panel not fail - but that the junctions between the edge of the floor and walls also resist the action and passge of fire for one hour. On 23rd October 1983 Community Links organised the "First National Tower Blocks Conference" held at the Labour Party Rooms in Plashet Grove East Ham. It was attended by over 150 people from all over the UK. They included councillors, engineers, architects, housing officials and MPs. After the conference some tenants from Ronan Point and other blocks on the estate including Sue MacDowall and Lil Hopes- they had formed the Newham Tower Blocks Tenants Campaign (NTTBC) - asked one of the speakers Sam Webb RIBA to carry out a survey of Ronan Point to assess its structural stability. Cllr Fred Jones, the Chairman of the Housing Committee, Cllr Jean Reeves his Deputy were keen for this to happen as was the local MP Nigel Spearing. With the aid of the tenants, Fred Jones, Jean Reeves, Frances Clark of Community Links and students from the School of Architecture in Canterbury College of Art, Sam Webb carried out a series of surveys of the whole estate. The defects found in Ronan Point were so serious that it was demolished together with the other 8 similar blocks. During surveys it was found that a critical joint between the external non-loadbearing window wall (face panel) - would allow smoke and fumes to pass through the gap between them. This was demostrated on ITV news by dropping a coin down the slot into the flat below. Noise would travel up this gap so that it was possible to hear conversations of people two or three floors above or below. A form of fireproof skirting was developed by the engineers working on the block and tested by BRE/FRS at the Fire Research Station at Warrington. Although this passed the test under clinical laboratory conditions the real situation where it would be installed on site could have led to problems. The NTTBC asked for a full scale fie test to be held in one of the flats. This was held on the 18th July 1984 under the control of the BRE?FRS and Newham's own engineers, with the West Ham Fire Brigade in attendance. Flat 26 on the thrid floor was prepared. The living room and the flat above was fireproof to one hour standard with the new fire proof skirting. Engineers from the FRS/BRE occupied the flat above with monitoring equipment which measured temperature and the movement of structural elements. The floor of the flat above which formed the ceiling of flat 26 was supported by a steel structure. The living room of flat 26 was furnished with second hand furniture - a sofa, easy chairs, a table, carpet, curtains etc and a Britsih Standard Fire Crib which was palced on the sofa and ignited. The temperatures reached in the fire exceeded 1000C with two minutes. The effect of the expansion of the ceiling caused the concrete ceiling/floor panel to fracture allowing flamesand fumes to go through into the flat above. One of the tenants from the NTTBC picked up the length of concrete which had fallen and took it away with her to use, she said, "As a doorstop." Newham Council voted to demolish Ronan Point in the Autumn of 1984. Eventually the Minister of Housing agreed. Work on systematic demolition started in July 1986. every single joint in the building was recorded. As the first panels were removed it was quickly discovered that the loadbearing joints far from being full of concrete were in fact full of rubbish - cement bags, newspapers, cigarette ends, bottle tops and floor sweepings. This extended throughout the building and it was possible to date when the joint had been made from the date on the newspapers. After the partial collapse of the SE corner Ronan Point was reuilt and reoccupied in 1971. What gave a great deal of cause for concern in 1986 was that the joints on the rebuilt corner also had joints stuffed with newspapers. The whole nine blocks on the estate containing 990 flats were demolished and the area rebuilt with two storey houses with gardens. Many other large panel system buildings like Ronan Point have been demolished. The Building Research Station published a series of reports in the 1980s to aid Councils and building owners on what they should do to check the structural stability of their LPS blocks. 1. The Structure of Ronan Point and other Taylor Woodrow-Anglian Buildings 1985 ISBN 0 85125 342 3 2. Large panel system dwellings: preliminary information on ownership and condition 1986 ISBN 0 85125 186 2 3. The structural adequacy and durability of large panel system dwellings 1987 ISBN 0 85125 250 8 The contents of 2 relied on local authorities sending returns in the Ministry of Housing in 1968/69. This was not exhaustive and many authorities failed to do this and their blocks were not assessed after the issue of interim structural methods by the MOHLG in 1968/69. Among these authorities were Birmingham, Lambeth and Southwark in London. Birmingham owned over 300 LPS blocks and when these were assessed in 1998 it was found that a number which did not meet 5psi still had a piped gas supply. A number of these blocks were demolished. The London Borough of Southwark owns the largest LPS estate in the UK - the Aylesbury Estate - this has a piped gas supply and it has been queried whether the existing structure is strong enough to resist a 5psi explosion. At the time of writing the council are still discussing with the government what to do about the estate with the likelihood that it will be demolished and rebuilt. The NTTBC was formed following the tragic death of a young woman who jumped from the window of an upper floor of a block of flats overlooking Stratford Station in Newham. She had asked to be moved. From her window she could see the platform on the station where her mother had jumped in front of a train. Suicides such as hers - jumping from buildings - were fairly frequent in Newham as were accidental deaths from falling out of windows or balconies. The First National Tower Blocks Conference was held to as a result of the death of a young boy who fell from a balcony of Abraham's Point in August 1983. Abraham's Point was the first of the LPS blocks built using the TWA system. Ronan Point was the second. There was considerable coverage of the systematic demolition of Ronan Point both in the national and technical press. Best national coverage is in The Times written by Charles Knevitt from 1984 onwards. This can be found in the Times Index for 1984 onwards. The best technical coverage is in Building Design (BD) by Alan Thompson and Paul Finch. Other technicla journals to cover the story include New Civil Engineer, Building, RIBA Journal etc. A number of TV programmes were made including the tenants' own story in "The Blockbusters" 1984 shown on BBC1. The demolition was widely covered on ITV and BBC News. Newsnight on BBC2 covered the fire test in early August 1984. A number of books have covered the collapse of Ronan Point most notably: "Collapse: Why buildings fall down" by Phil Wearne ISBN 0 7522 1817 4. This was written to accompany the TV series of the same name shown on Channel 4 in early 2000. The implications of the original collapse in 1984 were covered in Footnotes in Private Eye, written by Paul Foot from September 1984 onwards. Covereage in technical journals was sparse. This si surprising given the huge implications that the partial collapse of Ronan Point had on public perceptions of postwar highrise housing and the techniocal implications. One of the best accounts in a technical journal is to be found in the Journal of the Institution of Structural Engineers July 1969. This is an account of a meeting held in the City University London in february 1969 when interested parties were invited to put their views. It was chaired by Sir Alfred Pugsley. Updated May 2 2006 A total of three main methods of building tall buildings exist. These are:
Here a set of steel members are fixed together to make the frame of the building. The World Trade Center and the Empire State Building are examples of this type of building. In such a structure care must be taken to provide thermal insulation around the load bearing steel members to prevent a rapid collapse in case of a fire. This is because as the steel is heated up it becomes softer and weaker, and it was the heat of fire which caused the World Trade Centre towers to fall down.
Here a mould of formwork is made using wood or other similar material, steel reinforcement is placed in the formwork, concrete is poured into the mould and then allowed to set. Then the mould is removed and used again to make another part of the building. The resulting building is a block of concrete.
Here a set of concrete parts are made at a factory and are transported to the site, where they are lifted into place with a crane and then joined together. This joining process takes great skill, and it is thought that a failure to join the panels correctly lead to the Ronan point collapse. The structure of Ronan Point and other LPS buildings of the time relied on gravity holding everything together. A Public Inquiry into the Ronan point collapse found that the gas explosion had triggered the (corner) collapse of a building that was structurally unsound. It had been "system-built" using Prefabricated Concrete panels bolted together. It was found that the joints between the panels were not correctly made. {Link without Title} {Link without Title} As a result new British Standard Structural Design Codes were introduced with regards to Robustness of concrete design to prevent such a disaster happening again. The block was repaired but its collapse was a significant event in dissuading local authorities from building such blocks. Ronan Point was Demolished in 1986 . EXTERNAL LINKS |
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