SAFETY INSPECTORS investigating the collapse of an aircraft hangar in Australia are focussing on the sequence for placing the roof on the structure.
Safety officials working for Australian Capital Territory Work Cover believe that contractor Spantech was fixing roof decking as the structural frame was being stress erected.
The hangar at Fairbairn Royal Australian Air Force Base in Canberra collapsed on 7 May this year shortly after the superstructure was erected (NCEI last month).
Six workers on the roof narrowly avoided death as the partially complete structure collapsed.
The 14m high, 85m span structure was raised using stressed arch technology patented by Strarch International.
This involves assembling most of the structure on low level falsework before raising it into position using tension cables.
'We understand the project was running behind schedule when the accident occurred, ' said the Work Cover spokeswoman this week.
'But we do not yet know who made the decision to start stressing the arch into position before the roof was complete.
This goes against Strarch's erection method.'
Nobody was available at Strarch or Spantech to comment on the claims.
The site has now been cleared of the wreckage and engineers Connell Mott Macdonald will produce a report in the next few months.