Ronan Point was a 22-storey tower block in Newham, East London, which partly collapsed on 16 May 1968 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 17 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 (LPS), which involves casting large concrete prefabricated sections off-site and bolting them together to construct the building.
Construction started in 1966 and was completed on 11 March 1968.
There are three main methods of constructing tall buildings:
- Steel building. Here a set of steel members are fixed together to make the frame of the building. Skyscrapers in New York City like the Empire State Building 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 Bank of America Tower in New York is an example of this.
- Large panel systems (LPS). Here a set of prefabricated concrete parts are transported to the site, where they are lifted into place with a crane and joined together. This is the type of structure that Ronan Point used. 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.
At approximately 5:45 am on 16 May 1968, resident 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 stove for her early morning cup of tea. The match sparked a gas explosion that 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 and causing the progressive collapse of the south-east corner of the building.
The building had just opened, and three of the four flats immediately above Hodge's were unoccupied. Four of the 260 residents were killed immediately and seventeen were injured, including a young mother who was stranded on a narrow ledge when the rest of her living room disappeared. Hodge survived, despite being blown across the room by the explosion – as did her gas stove, which she took to her new address.
Ronan Point was partly rebuilt after the explosion using strengthened joints, but public confidence in the safety of residential tower blocks was irreparably shaken.
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 5 storeys were required to be able to resist an explosive force of 3.4×104 Pa (34 kilopascals) which is equivalent to 5psi. Existing buildings were allowed to resist an explosive force of 1.7×104 Pa (17 kilopascals) which is equivalent to 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
In 1984 Newham Council voted to demolish Ronan Point. All nine blocks on the estate, comprising 990 flats, were demolished in 1986 and the area was redeveloped with 20 two-storey houses with gardens. Many other similar LPS buildings have since been demolished.
The Building Research Establishment published a series of reports in the 1980s to advise local councils and building owners on checking 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 Lambeth and Southwark in London and Birmingham. 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 those 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; it has been questioned whether the structure is strong enough to resist a 5 psi explosion.
Within a couple of decades of the collapse of Ronan Point the public's lack of confidence in the LPS construction technique, together with the social problems within such developments, led to the demolition of many tower blocks.
A number of books have covered the collapse of Ronan Point, including 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.
Building Research Establishment reports:
- The Structure of Ronan Point and other Taylor Woodrow-Anglian Buildings 1985 ISBN 0-85125-342-3
- Large panel system dwellings: preliminary information on ownership and condition 1986 ISBN 0-85125-186-2
- The structural adequacy and durability of large panel system dwellings 1987 ISBN 0-85125-250-8