As project director on London’s $1.2-billion Silvertown highway tunnel, Juan Angel Martinez Diaz successfully adopted hovercraft-like skates to rotate the job’s 39-ft-dia tunneling shield to drive both bores of the 0.9-mile crossing, saving critical time on the project’s tight schedule.

Cross passages between both bores of London's 0.7-mile Silvertown tunnel are nearing completion, marking the end of excavations on the River Thames crossing.