Murray & Roberts Construction (MRC) left out significant sections of the temporary structure over the M1 highway it constructed in Sandton in October 2015 – and the parts it did construct showed poor workmanship.
This resulted in a weakened structure that was unable to withstand the wind and collapsed, with 120 tons of steel crashing down onto the afternoon traffic at around 15:25 on October 14.
These are among the findings of an inquiry by the Department of Labour (DoL) into the disaster.
The department would not make the report public, but provided copies to the implicated parties. The report did however become available after the Johannesburg Development Agency (JDA), which appointed MRC to build the pedestrian bridge over the highway, made it available to Rapport newspaper.
WATCH: Semi-retired civil engineer Gregory Harington, who worked for Murray & Roberts at Medupi Power Station before his contract ended, followed the incident attended the DoL hearings from June to August 2016. He explains what went wrong here:
The inquiry contains recommendations to the National Prosecuting Authority to prosecute MRC, the JDA and scaffolding supplier Form-Scaff, as well as Nemai Consulting, a health and safety consultancy appointed by the JDA to ensure health and safety compliance on site.
The listed Murray & Roberts group has since sold MRC, but retains any liability in relation to the event. It said in an announcement to shareholders that it does not agree with some of the department’s findings, but would not comment any further.
The JDA also stated that it does not agree with findings in relation to itself, and is seeking legal advice.
The report shows that in terms of its contract with the JDA, MRC was supposed to appoint an engineer to design the temporary works. It failed to do so, and used Form-Scaff’s general arrangement drawings instead.
These drawings were however only aimed at determining the quantities of elements for Form-Scaff’s costing of the job. They did not contain any calculations with regard to the loads the structure would be able to withstand, and no sequence planning done for the construction was done.
Even so, MRC’s construction deviated significantly from the “design”.
Some of these deviations include:
- Large sections of scaffolding were left out on the eastern and western side, and in the sections that were erected, a large number of vertical diagonal supports were omitted.
- On the median for example, only 12 of 33 vertical diagonals were installed. The whole structure basically rested on this median support.
- The construction of a permanent pylon on the eastern side and a pier on the western side that were incorporated in the Form-Scaff drawings had not yet started.
- During the inquiry it came to light that a total of 96 bolts meant to hold the components together were omitted.
Where the elements were erected, the couplings were not properly tightened, the inquiry found.
The Form-Scaff drawings complied with the design codes and, if fully erected, would have been strong enough to withstand a wind speed of about 38 metres per second (m/s).
Due to the deviations, however, the structure collapsed in a wind with peak gust speeds of 15-24 m/s.
The report also revealed that MRC appointed a candidate engineer with many other responsibilities as site engineer. Oliver Aadnesgaard was supposed to work under supervision of a registered engineer, but did not.
During the hearings Aadnesgaard refused to disclose who made the decision to reopen the road for traffic, for fear of incriminating himself. The report indicates that he might have taken the fateful decision himself, without first inspecting the structure or doing a risk assessment.
Hein Pretorius, MRC’s contracts manager, was not a registered engineer and had no experience of bridge construction, the report found.
Aadnesgaard and Pretorius both had inadequate knowledge of health and safety legislation.
Nemai Consulting’s representative Roxana le Roux noted lapses in health and safety practices on site, but failed to stop construction to ensure compliance, the inquiry found. She was not registered with the professional body for health and safety practitioners.
Attorney Willem le Roux of ENSafrica, who specialises in health and safety matters and represented the JDA, says that although the department stopped short of recommending the prosecution of any individuals, the NPA is not bound by the department’s recommendations and can use its own judgement in the regard.