The dam, 450 miles south of Cairo, was the center of one Cold War's skirmish. In 1956, the U.S. and Great Britain offered loans, but withdrew the offer when Egyptian President Gamal Abdel Nasser became too friendly with the Soviet bloc. Nasser then seized the Suez Canal to use its income to finance the dam. This led to the fruitless British-French-Israeli invasion of Egypt, which made it impossible for the West to intervene in the Hungarian revolution against the Soviets later in the year. In 1958, the Soviet Union agreed to finance the dam, but only if Soviet equipment and engineering were used. Construction began in 1960.

The dam was built in the reservoir of the original Aswan Dam, a 144-ft-high embankment built in 1902 by the British. The contractor, Arab Contractors Ltd., Cairo, diverted the Nile through six 49-ft-dia, 1,000-ft-long tunnels, but it was not economically feasible to lower it to its natural river level. As a result, nearly one-quarter of the new dam was placed in water more than 100 ft deep (ENR 12/9/65 p. 48).

Upstream and downstream cofferdams, which eventually became the heel and toe, were installed by dumping rock muck from barges. Next, screened rock and sand was discharged into each 13-ft layer to fill the voids. Dune sand, much of it transported by slurry pipelines, accounts for 20% of the dam's volume. For the central base course, pipelines deposited dune sand in 49-ft layers. Vibrators reduced them to 41 ft. Once the sand layers had been built up to the water surface, work in the dry began. Clay from a nearby deposit formed the core; its base is extended upstream to form an internal blanket to protect against seepage.

Aswan Dam was built on a sieve. Beneath the quarter-mile stretch that crosses the Nile is a permeable layer of sand and gravel twice as deep as the dam is high. The Nile's V-shaped granite gorge, 1,640 ft wide at the river bottom and 720 ft deep, is sealed off by a grout curtain 765 ft deep, 130 ft thick at the top, tapering to 16 ft at bottom. Completed in 1970, Aswan controls flood waters, maximizes irrigation and produces 2,100 Mw of power. On the other hand, productivity of riverside lands is down. Rich silt that once fertilized them during annual floods is now building up behind the dam.

Preparing for 'The Beast'
An airport construction boom occurred in the advent of the new Boeing 747. Called "The Beast" by aviation officials, the jet could easily peel chunks of asphaltic concrete from runways with its 178,000 lb of thrust, and its engines beneath its wingspan of 196 ft overhung the pavement of the 75-ft-wide taxiway. Air traffic growth was another problem faced by planners who weren't sure how to prepare properly (ENR 2/19/70, p. 42). British Overseas Airways Corp. claimed its terminal, a reinforced concrete inverted pyramid, was the first designed specifically for the jumbo jet (ENR 3/26/70 p. 24). A 23-in. thick bituminous overlay was applied at Dallas' Love Field, and an overlay of continuously reinforced concrete increased the gross weight capacity of an old runway at Palmdale, Calif., eightfold (ENR 3/12/70 p. 28).

Vietnamization of Construction
Roadbuilding was a principal strategy of the Vietnam war. The Lines of Communications (LOC) program, a 2,700-mile, three-level network of roads, originally scheduled to complete in 1974 was moved up to 1971. This hurry-up completion was vital to safe military traffic flow. According to a general of the 18th Engineer Brigade, every man lost, killed in action or wounded on a road completed late would be due to loss in time completing it. It was a vicious circle in that roads couldn't be built until areas were relatively secure, and roads couldn't be secured until they were fully built. Roads were also built, said the Navy's I Corps Seabee commander, so the people could "act like they're a nation" (ENR 1/15/70).

Building Bans Around
"Pollution people" cracked down on new construction, placing bans until treatment plants or sewers were built or upgraded to handle the increased load. Reactions ran from anger to outrage among the builders associations who felt the country needed more housing and penalties should not be placed on them until it was proven that domestic waste was a major pollution factor. Construction in Cleveland was down, with only about 3,000 building permits issued in the first quarter of 1970, compared to 4,000 permits for the same period the prior year. In San Francisco, during a temporary lifting of the State Water Quality Board's ban, which caught the state's legal expert out of town, building permits went like hot cakes. But most state agencies held out until the desired measures were taken (ENR 4/30/70, p. 9).