RONAN POINT COLLAPSE
GROUP 1
GARETH NOLAN
JAMES O’BRIEN
JENNIE QUIGLEY
LAURA WOODBYRNE
The Ronan Point Disaster, 16th May 1968
In 1961, the first of many tower blocks began to be built to accommodate the needs of
the thousands of local people of West Ham in east London, an area badly mauled by the
Second World War.
Ronan Point was one of a number tower blocks built in the 1960s as cheap, affordable
housing. It was a 23 storey block of flats (apartments) in Clever Road. The construction
cost was approx. £500,000. The tower was built by Taylor Woodrow Anglian, using a
technique known as Large Panel System building.
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
requires precision and skill, and it is thought that a failure to join the panels correctly lead
to the Ronan Point collapse.
The construction of Ronan Point began on the 25th July 1966 and the building was
handed over to Newham Council on the 11th of March 1968.
Materials
The building was constructed mainly from three materials. Steel, in situ concrete and
prefabricated concrete.
The Steel made up the frame of the building. Steel members were jointed together to
make up the frame.
Formwork, supported by steel reinforcement members, set the moulds for the in-situ
concrete pour. Later the formwork could be removed and used somewhere else on the
site. This made the tower a solid block on steel and concrete.
Concrete parts were 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 requires
precision and skill, and it is thought that a failure to join the panels correctly lead to the
Ronan Point collapse.
Collapse
At 5:45am, in flat 90 on the 18th floor, a gas explosion blew out the load-bearing flank
walls of the apartment. Structural supports to the four apartments above were removed.
This caused the progressive collapse of the whole South-East corner of the building.
The explosion was caused by a faulty gas connection to a stove. The building became
occupied just two months before the explosion. This was the main factor in the
relatively low number of deaths and injuries coupled with the fact that three of the four
flats above the explosion were unoccupied. Out of 260 residents, four people were killed
immediately and 17 were injured.
Miss Ivy Hodge, who caused the explosion by lighting the match for the stove, survived,
despite being blown across the room by the explosion.
It is believed that poor jointing between the vertical walls and horizontal floor slabs
allowed the prefabricated load bearing concrete panel to blow out so easily. Removing
the load path for the tower caused it to fall like a house of cards.
Under the action of gravity the flank walls fell away, leaving the floors above
unsupported. This caused the progressive collapse of the whole South-East corner of
the building. [1]
The result of the explosion was much greater than would have been predicted. Damage
to the load paths of the building was not taken into account in the design of such
structures.
Aftermath and effect on legislation
Public inquiry into the collapse in August 1968 concluded that a gas explosion had
triggered the collapse of a building that was structurally unsound. It had been "systembuilt" using prefabricated concrete panels bolted together like a giant meccano set.
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
Ronan Point was repaired with all section joints strengthened and other similar buildings
were also 'strengthened', but by then the public confidence in their safety had largely
disappeared.
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.
Many believe that cost-cutting building methods, bad workmanship and poor inspection
of the section joints during the actual construction left the new blocks unsafe from the
start.
Ronan Point itself was pulled down in 1986, and replaced with two storey housing.
All new buildings constructed after November 1968 and over 5 stories were required to
be able to resist an explosive force of 5 lbs per square inch (psi).
References
1. [WWW document] Ronan Point. From Wikipedia, the free encyclopedia.
Available from http://en.wikipedia.org/wiki/Ronan_point
2. www.lalamy.demon.co.uk/ronanpnt.htm
3. news.bbc.co.uk/onthisday/hi/dates/stories/may/16/newsid_2514000/2514277.stm