Wind gust and other factors caused Grayston bridge collapse - witness tells department inquiry
Wind gust together with other weaknesses in structure were responsible for the collapse of the temporary structures during construction work in the M1/Grayston Drive Pedestrian and cyclist structural bridge that led to the deaths of two people and injury to 19 others.
Construction firm, Murray & Roberts expert witness, Ric Snowden told the M1/Grayston Drive Pedestrian and cyclist structural bridge collapse inquiry that: “it is common cause that wind was a trigger of the collapse of the temporary structure”.
Snowden further said that the collapse to the Western direction was difficult to explain. He said the occurrence has become a subject of discussion among experts. Snowden said: “there were other factors on the day responsible for the collapse to the Western side”.
He said measurements on the day showed that six minutes before the collapse there was a high wind speed of 10.1 metres per second. The collapse happened at 15h25. Snowden, however, described wind speed on the day of the fateful day as normal. On the day, he said there was wind coming from north easterly direction.
Snowden cautioned the inquiry that when temporary structure were erected not everything would be perfect.
The Department of Labour set-up the Section 32 Inquiry to unearth the causes for the collapse of scaffolding work into the Grayston Drive Pedestrian and cyclist structural bridge collapse. The investigation is being held in terms of the Occupational Health and Safety (OHS) Act.
The inquiry is been presided by Lennie Samuel, assisted by Lesibe Raphela.
Parties involved in the 14 October 2015 incident include the City of Johannesburg and the Johannesburg Development Agency who were clients that appointed Royal HaskoningDHV as an agent. Murray & Roberts is the principal contractor and the supplier of material involved is Formscaff.
Snowden dismissed media reports made after the accident that the missing bolts contributed to the collapse of the structure. "We have investigated that aspect and found it to be untrue," he said.
Snowden took swipe at social media reports that the concrete truck found on the scene of the accident was responsible for the collapse. He said the concrete structure on the western works had not moved for a considerable amount of time before the collapse. He said: “evidence from photos discount that notion as red herring. It is quite clear that scaffolding fell on top of the truck, rather than truck hitting scaffolding”.
The inquiry continues tomorrow (14 July 2016) with another expert witness from Murray & Roberts.
Enquiries:
Mokgadi Pela
Cell: 082 808 2168
