Ronan Point Collapse
Group 1:John Mulhaire
David Hatch
Rob Patterson
Robert Morgan
Background
Housing sector decimated by World War 2
Solution: the construction of many
high rise pre-cast buildings.
Reasons: Saved land
Large numbers of people
Constructed quickly
Cheap
Perhaps too Cheap!!!
The Building
110 apartments
22 storeys high
Construction began on July 25th & took
only 2 years.
Cost:£500,000
The method
Larsen-Nielsen
Developed in Denmark 1948
Walls, floors and stairways were all pre-cast
Each floor was load bearing AND supported the
floor above……
Collapse
The southeast corner of the Ronan Point Tower
collapsed on May 16, 1968 at approximately
5:45 a.m
Collapse was initiated by a gas-stove leak on the
eighteenth floor in apartment ninety
Explosion knocked out the opposite corner walls
of the apartment
Walls were the sole support for the walls directly
above, created a chain reaction
Floors fell onto level eighteen, which initiated a
second phase of progressive collapse.
Domino Effect
Domino Effect
Collapse (cont’d)
4 people died and 17 were injured
The lack of fatalities were due to the fact
that below floor 18 only the kitchens were
destroyed
Layout
Technical aspects
Public pressure led to an government inquiry
Revealed that strong winds and/or the effects of
a fire could also have caused a progressive
collapse
The building was designed to withstand wind
velocities of up to 63mph
However a wind of 105mph could be expected
at 200 feet above the ground every 60years,
within the life expectancy of the building
Technical aspects (cont’d)
Building code used for the design of the building
were published in 1952 however they weren’t
kept up to date
In 1963 a new study showed higher than stated
winds were likely
Fire also would have had a similar effect on
Ronan Point
It was estimated that fire could so expand and
‘arch’ the floor slab and bend the wall panel
16 years after the collapse architect Sam Webb
conducted a fire test which proved this theory
Professional aspects
Findings of poor workmanship led to the
demolition of the remaining Larsen – Nielson
system built towers.
The collapse initiated changes to the regulation
codes
Building codes now take in account for the
possibility of progressive collapse and of forces
from an internal explosion
Also require minimum amounts of ductility and
redundancy.
Educational aspects
An example of what can happen when an
alternative load path is not provided
The importance of building codes
the importance of monitoring construction
quality