Ronan Point Collapse
{
Group 1:
Martin Phelan
Michael Grimes
Matthew Arnold
Background
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Large number of tower blocks constructed in London during
the 1960’s.
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High-rise buildings constructed as a quick, cheap and
economical solution to the post-war housing crisis.
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Built by Taylor Woodrow - Major UK housing provider.
Ronan
Point:
PreCollapse
Design
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Larsen-Nielsen system of construction used.
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Precast elements formed off-site, moved into place and
connected using bolts and mortar joints.
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Minimised on-site construction. This was problematic due
to lack of skilled labour at the time.
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Each floor supported by load-bearing walls directly
beneath. In effect the building was held together by
gravity.
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Lack of an overall structural frame. Hence lack of
alternative load paths and limited structural redundancy.
Example of Larsen-Nielsen Construction
Collapse
• 16th May 1968 5.45 am
• Small explosion on 18th floor
• Caused huge structural failure
• Load bearing flank wall blown out
• 4 deaths
• 17 Injuries
Could have been
much more!
“Domino effect”
“flaking like a pack of
playing cards”
“I wouldn’t live there rent
free"
Report

The Report of Inquiry into the Collapse of Flats at
Ronan Point, Canning Town was published in
August 1968.

This report concluded that “a gas explosion
had triggered the collapse of a building that
was structurally unsound.”
The design of the building was flawed.
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The tower consisted of prefabricated panels without a
structural frame.
There was not sufficient redundancy to allow for load
redistribution in the event of a localized collapse.
The design wind pressures did not account for the building’s
height.
The existing building codes were inadequate.
The Larsen-Nielsen system was extended past the point of
safety without testing.
In addition the construction methods were also responsible
for the structural failure, in particular quality control of
workmanship was severely lacking.
New Building Regulations

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The collapse of Ronan Point led to the development of
new regulation codes.
Immediately following the original report the
government agreed to a dual standard for system-built
flats, with all new structures being built to resist internal
explosions of 35 kPa pressure while existing ones had to
be strengthened to resist 17.5 kPa.
They also highlighted the need for ductility and
redundancy in the structural design.
The subsequent inspection and demolition of Ronan
Point, more than 15 years later, highlighted the extent of
the poor workmanship in the building.
It is imperative that quality of workmanship is
monitored onsite to prevent any abnormal structural
loading or safety-issues throughout a building’s designlife.
Questions?