ON 9 AUGUST 2017, the country woke up to the news of a collapsed bridge over the N3, on the section of road between the Van Buuren and the M2 Geldenhuys interchanges.
The bridge was constructed in 1978 to provide pedestrian access between the mining operations on the Germiston side to the east and the Geldenhuys Railway Station to the west. The mining operation ceased some years ago and the bridge had been closed to pedestrian traffic since.
Three people were seriously injured in the collapse – one was airlifted to hospital and two were transported by ambulance. Fortunately, there were no fatalities.
Emergency services arrived at the scene with SANRAL engineers to ascertain the cause of the collapse and facilitate the clean-up of the road. A decision was taken to demolish and dismantle completely the remainder of the bridge. Experts thought this would take two days to complete and the road was closed to motorists for the rest of the day.
An investigation later revealed that the collapse had been caused by an impact force on the central pillar (or “pier”). All evidence suggested that the impact was caused by an 18.1-ton coil of steel, which was found lying 100m north of the collapsed bridge. Marks on the road led directly from the point of impact to the position where the steel coil came to rest.
The weight of the coil, moving at speed, could create an impact force far greater than the pier’s capacity. Debris was scattered radially away from the pier to a distance exceeding 40m, which confirms that the external impact force was massive.
The bridge had last undergone an inspection in July 2016 and there were no concerns about the main structural elements.
The road was reopened to motorists the very next day, on 10 August. SANRAL and the local authorities garnered praise on how they handled the collapse and made sure that motorists were not inconvenienced.
In a letter to SANRAL, Fransesca Pyatt from Edenvale wrote: “I was astounded at the swift and excellent response to clear everything for Thursday morning – they did such a great job you wouldn’t have even known a bridge had collapsed. I travel daily to work and back from Edenvale to Park Central, Selby, and that really would have been a crazy amount of traffic to divert. Well done and thank you for the swift response.”
IT’S easy not to think about all the lights on the inner-
Gauteng freeways when you’re driving along them.
But without these lights, road users would be less
safe. There are about 16 000 of them and SANRAL
manages to keep 90% burning continuously.
Maintaining this target not only contributes to
the safety of motorists, it is a cost-effective way
to reduce the number of vehicle crashes on our
highways at night. Good lighting has implications
for maintenance and repair costs and emergency
services.
“A fundamental aspect of ensuring the safety of all
road users is visibility – ensuring road users can see
the entire road surface clearly and can also be seen
by other road users at any time of day,” explains
Hardy Johnson, who heads up SANRAL’s Electrical
Maintenance in the Northern Region (Gauteng,
Mpumalanga, Limpopo and North West).
“By having well-lit freeways, people who work later
shifts can drive home late at night without finding it
too stressful – and they feel safer driving at night.”
Considering there are 4.2 million registered
vehicles in Gauteng and 1.49 million recorded trips
on the e-toll road network daily, lighting is very
important.
“Besides ensuring improved visibility, highway
lighting also improves accessibility – the ease with
which road users can travel between destinations.
It also enhances mobility – ie the ability to reach a
destination with a minimum of delay,” says Johnson.
“Maintaining the lights on our freeways is not
without its challenges. The lights are subjected to
damage from vehicle crashes, theft, weather and
power outages. But at SANRAL we manage to keep
our burn rate above 90%, for the benefit of all who
use our roads.”