The contractor was Transmanche Link (TML), a consortium of five British and five French contractors. Operations began at seaside shafts, Shakespeare Cliff, near Dover, and Sangatte, southwest of Calais. This meant tunneling not only under the Channel, but to rail terminal sites at Folkestone, 5 miles west, and Coquelles, 2 miles east.

For most of its route under the channel, the three-tunnel project follows an undulating seam of chalk marl, also known as blue chalk, that was expected to be ideal for tunneling. This seam sloped downward near the French coast. The French contractors were obliged to begin their tunneling in fractured chalk filled with water. Because tunneling at the western end was expected to stay within the dry blue chalk, the British force was assigned a longer marine length of tunnel, 13.4 miles.

Despite hundreds of geological samplings over more than a century, the British contractors found themselves in bad, water-laden ground soon after tunneling began. While the French tunnel boring machines (TBM) had been designed to work in watery chalk, the British were not. It took them considerable improvising to get through 2 miles of wet ground before reaching dry chalk. Once the two forces reached dry chalk, boring progressed rapidly. They broke through on Dec. 1, 1990.

Coping with the spoil from the tunnels was a challenge. At the base of the Shakespeare Cliff, the British built a 5,600-ft-long, double sea wall of sheet piles to create an 84-acre spoil lagoon. Conveyors took muck from the British bore to dump into the enclosure, which subsequently became a park. The French pumped their spoil out in a slurry and dumped 4 million cu yd into a nearby valley they had dammed. On each side of the channel were casting yards to produce some 675,000 concrete tunnel liner segments.

The tunnel was formally opened Dec. 10, 1993, and commercial traffic began in 1994

Egypt, U.S.A.
An Egyptian-theme resort was erected on Las Vegas Blvd., kicking off a new trend for attracting adventure seekers. The Luxor Hotel & Casino is a bronze glass-and-concrete pyramid that is 600 ft on each side at the base and 30 stories high. A 1,600-ft-long, 18-in.-deep "River Nile" was planned to run around the 90,000-sq-ft casino. The project's architect said that it started with an adventure concept that was to be in the conventional hotel, but when he realized that casino facades are traditionally elaborate, he said, "why not make the hotel guest rooms the facade." And the design evolved into a pyramid. Crews worked around the clock to build the 2,521-room hotel in 18 months (ENR 8/16/93)

World Trade Center Survives Bomb
A terrorist's bomb ripped through several levels of the substructure of the World Trade Center, killing six and injuring over 1,000 people. But despite "extraordinary damage," the structure was not endangered. The explosion ripped out sections of three structural slabs in the basement levels under the Vista Hotel and tore apart a giant bracing diagonal between the perimeter steel box columns that formed the tower's structural steel tubular framing system. The towers had been deliberately designed with redundancy, far exceeding city building code requirements at the time it was built (ENR 3/8/93 p. 8).

Digging Deeply in Ancient History
Some of the richest ground in the world of antiquities had to be dug up to build the $2.6-billion, 10.9-mile, two-line extension to the Athens metro. Uncovering an ancient city called for expertise that was part archaeological and part engineering. When Bechtel International Inc., San Francisco, started digging tunnels, it put an archeologist-engineer in the driver's seat. The consortium planned to excavate six deep stations using the New Austrian Tunneling Method (NATM) and the rest in cut-and-cover method for shallow stations. Archeological digs slowed the construction start-up schedule by six months. The extension doubled the capacity of the one-line system that was built in the 1860s (ENR 8/23/93).