In 1993, the French department of public works staged an open competition to build a high bypass bridge between plateaus at the top of the gorge, based on an initial concept by its engineer, Michel Virlogeux, who proposed a multispan, cable-stayed bridge with a phalanx of seven masts supporting cable fans.
Mr Cable acknowledged the seven companies - which mainly operate in the mining and extractive sectors - faced "unique challenges" in attracting more women since their line of work often involved regular travel and projects in "remote areas of the world".