One of the great engineering wonders of the world - the Detroit-Windsor Tunnel - was renovated for the first time in 1993 after 63 years of round-the-clock operation. The tunnel operator, Detroit & Canada Tunnel Corp., with consultant M.M. Dillon Ltd., Windsor, embarked on the ambitious restoration project to completely modernize the steel and reinforced-concrete structure and improve travel efficiency. But due to the high volume of traffic that uses the tunnel daily, general contractor Kenaidan Contracting Ltd., Mississauga, Ontario, had to perform all restoration work during a five-hour shutdown period each night. Furthermore, the project had to be completed in six months (from May 1993 to November 1993), giving Kenaidan only 700 hours of total work time. With this tight time schedule, fast-track reconstruction was a must.