Group 1
Michael Day
Jean Giblin
Chris Maguire
James Wilkinson

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



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.

 Only designed for buildings up to 6 stories.
 All units load bearing.
 No secondary load path.
 Poor construction methods.

 Gas explosion sparked by a match lit in the South-East corner of the 18 th 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.

 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
Bicycle Tyre
Air in lungs
20psi
100psi
1.5psi
Gas explosion in Ronan
Point <10psi

 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.

 http://www.youtube.com/watch?v=J96
Fzk1OdBQ

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