Ronan Point
Encyclopedia
Ronan Point was a 22-story tower block
in Newham
, east London, which suffered a partial collapse when a gas explosion demolished a load-bearing wall, causing the collapse of one entire corner of the building. Four people were killed in the incident, and seventeen were injured.
Ronan Point, named after Harry Louis Ronan (a former Chairman of the Housing Committee of the London Borough of Newham), was part of the wave of tower blocks built in the 1960s as cheap, affordable prefabricated housing for inhabitants of the West Ham
region of London. The tower was built by Taylor Woodrow Anglian
, using a technique known as Large Panel System building
or LPS. This involved casting large concrete prefabricated sections off-site, then bolting them together to construct the building.
Building started in 1966, and construction was completed on 11 March 1968.
Steel: Here a set of steel members are fixed together to make the frame of the building. The Empire State Building
and other New York skyscrapers are examples of this type of building.
In situ concrete: Here a mould or formwork is made using wood or another similar material. Steel reinforcement is placed in the formwork, then concrete is poured into the mould and allowed to set. The mould is removed, and may be reused to make identical castings in other areas of the building. The resulting building is a solid block of concrete made from multiple castings poured on top of one another.
The use of prefabricated concrete members - large panel systems: 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. It is thought that a failure to join the panels correctly contributed to the Ronan Point collapse. The structure of Ronan Point and other LPS buildings of the time relied on gravity holding everything together.
for her early morning cup of tea. This sparked a gas explosion
, which blew out the load-bearing flank walls, removing the structural supports to the four flats above. It is believed that the weakness was in the joints connecting the vertical walls to the floor slabs. The flank walls fell away, leaving the floors above unsupported. This caused the progressive collapse
of the whole south-east corner of the building.
Because the building had just opened, three of the four flats immediately above Miss Hodge's were unoccupied. Out of the 260 residents of the building, four people were immediately killed in the collapse, and seventeen were injured, including a young mother who was stranded on a narrow ledge when the rest of her living room disappeared. Miss Hodge survived, despite being blown across the room by the explosion — as did her gas stove, which she took to her new address after the explosion.
Despite the extent of the damage, Ronan Point was partly rebuilt after the explosion, using strengthened joints. Nonetheless, public confidence in the safety of residential tower blocks had been irreparably shaken. Within a couple of decades, this lack of confidence, plus the mounting social problems
manifesting themselves within such developments, led to many tower blocks being demolished. Ronan Point was demolished in 1986 to make way for a new development of low-rise housing.
Immediately after the publication of the report the Government brought out interim measures to ensure the safety and integrity of buildings in the event of an explosion. All new buildings constructed after November 1968 and over were required to be able to resist an explosive force of (5psi). Existing buildings were allowed to resist an explosive force of (2.5psi), provided that the gas supply was removed and flats were refitted for electric cooking and heating. The gas supply was removed from Ronan Point and the other eight blocks on the estate.
The Building Research Establishment
published a series of reports in the 1980s to advise Councils and building owners on what they should do to check the structural stability of their LPS blocks. The contents of two of the reports relied on local authorities sending returns in to the Ministry of Housing
over the years 1968–69. This was not exhaustive, with many authorities failing to do so and thus not having their blocks assessed after the issue of interim structural methods by the Ministry 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 5 psi 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
— which has a piped gas supply, and it has been queried whether the existing structure is strong enough to resist a 5 psi explosion.
Tower block
A tower block, high-rise, apartment tower, office tower, apartment block, or block of flats, is a tall building or structure used as a residential and/or office building...
in Newham
London Borough of Newham
The London Borough of Newham is a London borough formed from the towns of West Ham and East Ham, within East London.It is situated east of the City of London, and is north of the River Thames. According to 2006 estimates, Newham has one of the highest ethnic minority populations of all the...
, east London, which suffered a partial collapse when a gas explosion demolished a load-bearing wall, causing the collapse of one entire corner of the building. Four people were killed in the incident, and seventeen were injured.
Ronan Point, named after Harry Louis Ronan (a former Chairman of the Housing Committee of the London Borough of Newham), was part of the wave of tower blocks built in the 1960s as cheap, affordable prefabricated housing for inhabitants of the West Ham
West Ham
West Ham is in the London Borough of Newham in London, England. In the west it is a post-industrial neighbourhood abutting the site of the London Olympic Park and in the east it is mostly residential, consisting of Victorian terraced housing interspersed with higher density post-War social housing...
region of London. The tower was built by Taylor Woodrow Anglian
Taylor Woodrow
Taylor Woodrow was one of the largest British housebuilding and general construction companies. It was listed on the London Stock Exchange and was once a constituent of the FTSE 100 Index but merged with rival George Wimpey to create Taylor Wimpey on 3 July 2007.-Early years:Frank Taylor was...
, using a technique known as Large Panel System building
Plattenbau
Plattenbau is the German word for a building whose structure is constructed of large, prefabricated concrete slabs. The word is a compound of Platte and Bau...
or LPS. This involved casting large concrete prefabricated sections off-site, then bolting them together to construct the building.
Building started in 1966, and construction was completed on 11 March 1968.
Construction
There are three main methods of constructing tall buildings:Steel: Here a set of steel members are fixed together to make the frame of the building. The Empire State Building
Empire State Building
The Empire State Building is a 102-story landmark skyscraper and American cultural icon in New York City at the intersection of Fifth Avenue and West 34th Street. It has a roof height of 1,250 feet , and with its antenna spire included, it stands a total of 1,454 ft high. Its name is derived...
and other New York skyscrapers are examples of this type of building.
In situ concrete: Here a mould or formwork is made using wood or another similar material. Steel reinforcement is placed in the formwork, then concrete is poured into the mould and allowed to set. The mould is removed, and may be reused to make identical castings in other areas of the building. The resulting building is a solid block of concrete made from multiple castings poured on top of one another.
The use of prefabricated concrete members - large panel systems: 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. It is thought that a failure to join the panels correctly contributed to the Ronan Point collapse. The structure of Ronan Point and other LPS buildings of the time relied on gravity holding everything together.
Collapse
At approximately 5:45am on 16 May 1968, 56-year-old cake decorator Ivy Hodge went into her kitchen in flat 90, a corner flat on the 18th floor of the building, and lit a match to light the stoveGas stove
In cooking, a gas stove is a cooker which uses natural gas, propane, butane, liquefied petroleum gas or other flammable gas as a fuel source.-History:...
for her early morning cup of tea. This sparked a gas explosion
Gas explosion
A gas explosion is an explosion resulting from a gas leak in the presence of an ignition source. The principal explosive gases are natural gas, methane, propane and butane, because they are widely used for heating purposes. However, many other gases like hydrogen, are combustible and have caused...
, which blew out the load-bearing flank walls, removing the structural supports to the four flats above. It is believed that the weakness was in the joints connecting the vertical walls to the floor slabs. The flank walls fell away, leaving the floors above unsupported. This caused the progressive collapse
Progressive collapse
A building undergoes progressive collapse when a primary structural element fails, resulting in the failure of adjoining structural elements, which in turn causes further structural failure, similar to a house of cards....
of the whole south-east corner of the building.
Because the building had just opened, three of the four flats immediately above Miss Hodge's were unoccupied. Out of the 260 residents of the building, four people were immediately killed in the collapse, and seventeen were injured, including a young mother who was stranded on a narrow ledge when the rest of her living room disappeared. Miss Hodge survived, despite being blown across the room by the explosion — as did her gas stove, which she took to her new address after the explosion.
Despite the extent of the damage, Ronan Point was partly rebuilt after the explosion, using strengthened joints. Nonetheless, public confidence in the safety of residential tower blocks had been irreparably shaken. Within a couple of decades, this lack of confidence, plus the mounting social problems
Tower block
A tower block, high-rise, apartment tower, office tower, apartment block, or block of flats, is a tall building or structure used as a residential and/or office building...
manifesting themselves within such developments, led to many tower blocks being demolished. Ronan Point was demolished in 1986 to make way for a new development of low-rise housing.
Effect on legislation
The partial collapse of Ronan Point led to major changes in the building regulations. The first of these came with the 5th Amendment to the Building Regulations in 1970. These are now embodied in Part A of the Building Regulations and cover Disproportionate Collapse.Immediately after the publication of the report the Government brought out interim measures to ensure the safety and integrity of buildings in the event of an explosion. All new buildings constructed after November 1968 and over were required to be able to resist an explosive force of (5psi). Existing buildings were allowed to resist an explosive force of (2.5psi), provided that the gas supply was removed and flats were refitted for electric cooking and heating. The gas supply was removed from Ronan Point and the other eight blocks on the estate.
Effect on housing
Newham Council voted to demolish Ronan Point in the autumn of 1984. The whole nine blocks on the estate, containing 990 flats, were demolished and the area rebuilt with twenty two-storey houses with gardens. Many other large panel system buildings like Ronan Point have since been demolished.The Building Research Establishment
Building Research Establishment
The Building Research Establishment is a former UK government establishment that carries out research, consultancy and testing for the construction and built environment sectors in the United Kingdom...
published a series of reports in the 1980s to advise Councils and building owners on what they should do to check the structural stability of their LPS blocks. The contents of two of the reports relied on local authorities sending returns in to the Ministry of Housing
Ministry of Housing and Local Government
The Ministry of Housing and Local Government was a United Kingdom government department formed after the Second World War, covering the areas of housing and local government....
over the years 1968–69. This was not exhaustive, with many authorities failing to do so and thus not having their blocks assessed after the issue of interim structural methods by the Ministry in 1968–69. Among these authorities were Birmingham
Birmingham
Birmingham is a city and metropolitan borough in the West Midlands of England. It is the most populous British city outside the capital London, with a population of 1,036,900 , and lies at the heart of the West Midlands conurbation, the second most populous urban area in the United Kingdom with a...
, Lambeth
Lambeth
Lambeth is a district of south London, England, and part of the London Borough of Lambeth. It is situated southeast of Charing Cross.-Toponymy:...
and Southwark
Southwark
Southwark is a district of south London, England, and the administrative headquarters of the London Borough of Southwark. Situated east of Charing Cross, it forms one of the oldest parts of London and fronts the River Thames to the north...
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 5 psi 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
Aylesbury Estate
The Aylesbury Estate is a large housing estate located in Walworth, South East London.Along with the Ferrier Estate, Aylesbury is considered the most notorious estate in the United Kingdom. It was for this reason that Tony Blair chose to make his first speech as Prime Minister here, in an effort to...
— which has a piped gas supply, and it has been queried whether the existing structure is strong enough to resist a 5 psi explosion.