Durban - An essential part of Sanral’s N2 Wild Coast Toll Road project is the construction of two record-breaking mega-bridges over local rivers. One will become the highest bridge in the southern hemisphere, and the other possibly the longest cable-stayed suspension bridge in Africa.
Two spectacular mega-bridges are about to be added to South Africa’s growing national road network. These are part of the South African National Roads Agency SOC Limited’s (Sanral) N2 Wild Coast Toll Road (N2WCTR) project. They will offer visual and engineering delights to citizens and tourists alike. The first mega-bridge will cross the Mtentu River just outside of Xolobeni. The second will cross the Msikaba River near Lusikisiki.
The Mtentu Bridge will be one of the longest main-span balanced cantilever bridges in the world, and the first of its size in South Africa.
Reaching heights of around 220 metres, it will become the highest bridge in Africa and the whole of the southern hemisphere. The current highest is the Bloukrans Bridge, which has a 217-metre deck height.
The construction of the 1.1-kilometre-long bridge in a remote location is a major undertaking requiring specialised engineering skills and building techniques, according to Edwin Kruger, Sanral’s Bridge Network Manager.
“No South African firm has ever done a balanced cantilever bridge of this magnitude before. As such, South African tenderers have joint ventured with international firms to bring skills and expertise into the bridge’s construction," Kruger said.
The second mega-bridge, the Msikaba Bridge, will be 580 metres long.
“This bridge will cross the spectacular and pristine Msikaba river gorge and will be the longest span cable-stayed suspension bridge in South Africa – and possibly Africa. Cable-stayed bridges are distinct in their use of towers and cables to support the bridge deck. This single span bridge will be anchored back into rock on either side of the gorge," he said.
One of the environmental requirements was that Sanral does not touch the unspoiled Msikaba gorge at all. The cable-stayed design will ensure that the construction of the bridge will have no direct impact on the environment in the gorge, almost 200 metres below.
Environmental lobby groups have expressed concern related to the N2WCTR’s impact on the Pondoland Biome. But Sanral has used specialist studies conducted during the environmental impact assessment to ensure that the route avoids the most sensitive areas of the Pondoland.
More than this, rehabilitation measures include a search and rescue programme for threatened or protected flora species. A biodiversity offset agreement has also been established with the Eastern Cape Parks and Tourism Board. This will ensure that the Pondoland Biome is preserved for generations to come through the declaration, rehabilitation and ongoing protection of some 15 000 hectares of new conservation areas.
Conservation measures are put in place before any work begins on the highway, according to Craig McLachlan, Sanral Southern Region’s Project Manager.
Before we start any construction we will send a specialised team into the area to retrieve bulbs, succulents, and other plants that can be relocated,"Kruger said.