1. Group 1 Michael Day Jean Giblin Chris Maguire James Wilkinson
Ronan Point Collapse
Group 1
Michael Day
Jean Giblin
Chris Maguire
James Wilkinson

2. Ronan Point
22 storey apartment block built in 1960s to provide cheap housing in London.
Larsen-Neilson method of construction.

3. The Problems
A recent change in national policy that “allowed the density of occupancy to double”.
Unskilled construction workers.
Larson-Neilson method:
“…composed of factory-built, precast concrete components designed to minimize on-site construction work.  Walls, floors and stairways are all precast.  All units, installed one-story high, are load bearing”
Relies on skilled and precise construction.
Every wall is load bearing.

4. Flaws in Larson-Neilson Method
Only designed for buildings up to 6 stories.
All units load bearing.
No secondary load path.
Poor construction methods.

5. The Collapse
Gas explosion sparked by a match lit in the South-East corner of the 18th floor.
Load supporting walls were blown out, causing the four floors above to collapse onto the floors below, which in turn gave way under the additional load resulting in a progressive failure.

6. The Explosion
A faulty connection allowed gas to leak slowly into the apartment.
Explosion was so small that the woman that lit the match didn’t damage her hearing.
Car Tyre
20psi
Bicycle Tyre
100psi
Air in lungs
1.5psi
Gas explosion in Ronan Point
<10psi

7. Conclusions
Government investigation concluded “a gas explosion had triggered the collapse of a building that was structurally unsound”.
The report also found that the building was highly susceptible to fire loading.

9. Positives Only four fatalities.
Encouraged massive development in building regulation codes.
Highlighted the importance of on site monitoring of workmanship.