The Msikaba River Bridge will cross a deep, forested gorge with high sandstone cliffs flanking its sides. It will be 580m of single-span cable-stayed bridge. And because the national roads agency takes care to protect the environment wherever it builds, no work will be done in the gorge itself. Construction will start off from the two sides of the gorge and the bridge will be joined in the middle – nearly 200m above the river. Now that’s going to be a sight to behold!

Just to the north is the Msikaba River, where the other of the two planned bridges will sit more than 200m above the river and the structure will be 1 132m long. It’s going to be one of a very few large concrete balanced cantilever bridges with spans of more than 260m in the world. These bridges will join a long and distinguished line of world-class engineering structures throughout history. Most of the work in ancient and medieval times was carried out by artisans such as stonemasons and carpenters, who could rise to the role of Master Builders. The knowledge was retained in guilds and there were seldom advances in these fields. Structures and infrastructure tended to be built repetitively and scale was increased incrementally.

But there are early examples of a scientific approach to physical and mathematical problems in the field of civil engineering. These include the work of Archimedes in 3BC. He created what is known as the Archimedes Screw, which rotates to deliver water from a lower level to a higher one. And in 7AD, an Indian mathematician named Brahmagupta used arithmetic for excavation calculations.

However, Prof Felix Okonta, who heads up Civil Engineering at the University of Johannesburg, points out that while these early engineering projects were certainly novel, they were not very cost-effective and “much more than disproportionate energy and an enormous amount of human and other resources were expended to achieve the result”. But there was a massive leap forward in the application of civil engineering principles in the 1700s, he says.

“Early efforts toward a cost-effective application of resources – today called civil engineering design – could be traced to UK-born John Smeaton and his colleagues, including the Scottish architect and stonemason Thomas

Telford, a little more than 200 years ago.” In 1818, the Institution of Civil Engineers was founded in London and in 1820, Telford became its first president. The institution received a Royal Charter in 1828, formally recognising civil engineering as a profession. The charter defined civil engineering thus:

“The art of directing the great sources of power in nature for the use and convenience of man, as the means of production and of traffic in states, both for external and internal trade; as applied in the construction of roads, bridges, aqueducts, canals, river navigation and docks for internal intercourse and exchange and in the construction of ports, harbours, moles, breakwaters and lighthouses and in the art of navigation by artificial power for the purposes of commerce, and in the construction and application of machinery, and in the drainage of cities and towns.”

So basically, everything we consider necessary for modern life.

Roman roads were a marvel of ancient engineering and spanned more than 400 000km through the Roman Empire. They were mainly constructed using layers of crushed stone, mortar, sand and paver stones. The paver stones were laid at a certain angle in order to drain off water, so that the roads wouldn’t be damaged by floods and other environmental hazards. Many Roman roads and routes have survived to the present day.

The influence of commerce on engineering decisions still holds today. It’s one of the most important aspects of planning a new SANRAL interchange, bridge or road, or indeed the upgrading of any of these. One example is the massive Mount Edgecombe Interchange on the N2. Because of the expansion of the nearby uMhlanga and La Lucia Ridge areas, the existing interchange had been operating at full capacity, which caused huge traffic delays, disrupting business and private lives. Who wants to sit in choking traffic every day?

The upgraded interchange will be both visually impressive and relieve congestion. It is a four-level interchange with two lanes on each of the major movements. It includes directional ramps that will negate the need for controlled signals, while ensuring the free flow of traffic in all directions. And a new pedestrian bridge over the N2 will connect to the new footways, enhancing pedestrian safety as well.

Not all roads have consistent traffic

flows throughout the year and, beyond economic concerns, have to be upgraded to ensure the safety and comfort of motorists. This was the driving force behind the (now completed) upgrade of the interchange near the Zion Christian Church in Moria, Limpopo. Easter pilgrimages to Moria are going to be so much easier. Not just for the hundreds of thousands of congregants who flock there every year, but also regular road users who can now avoid the traffic build-up and partial blockages on the R71 caused by the annual pilgrimage.

The new interchange has solved this periodic problem, just as good civil engineering has improved the lives of humans throughout history.