Caption: Canadian National's St. Clair Tunnel at Sarnia was too small to handle higher cars such as Double stacks so the decision was made to bore a new, larger tunnel. A special ceremony was held on Sept 16, 1993 to celebrate the start of the new bore. The old tunnel was built in 1891, 6025 ft long and had a bore diameter 19 ft 10 inches. The new tunnel would be opened in 1994 ,6129 ft long and have a bore diameter of 27 ft 6 inches.

Seen here is "Excalibore", the name of the tunnel boring machine (TBM) made by the Lovat Tunnel Manufacturing Co., ready to start on the new larger tunnel on the Canadian side. In the background, a special CN train of high-clearance cars including double stacks, an autorack and a hi-cube auto parts boxcar, sandwiched by a pair of CN GP40-2W's, sit on the tracks nearby that lead through the old St. Clair tunnel.