On the Dnieper River in Ukraine, the group visited the Kiev hydropower project, where a 950-ft-long spillway dam and powerhouse combined structure was being built, along with a shiplock and pumped-storage complex. A notable feature was the project’s use of precast concrete units for 70% of the reinforced concrete placed above the foundations, many as large as 20 or 30 tons. The Soviets “adopted precasting because of a shortage of field construction workers, and on the theory that the necessary labor could be trained more easily,” Bowman wrote.

Of numerous dams on the Volga River, a highlight was the 2,543-MW Volgograd power station, the largest capacity hydroelectric facility in the world, completed the prior year. Its water impounding structures consisted of two miles of hydraulic fill embankment and a mile of concrete structures—a 2,100-ft-long powerhouse, 2,400-ft-long spillway dam and two lines of double chamber locks to lift boats 85 ft. To protect against scour and internal erosion of sand below the foundation slab, steel sheetpile cutoffs were installed along both upstream and downstream edges of the foundation mat.

Half of the dam’s power output supplied industrial plants and shipyards, with much of the rest sent 550 miles to Moscow over 500-kv alternating current transmission lines, notably higher than the 345-kv U.S. maximum at that time.

Competence

Bowman noted Soviet abilities on the numerous dams completed, under way or planned. He stated, “It is easy to acknowledge the competence of Soviet engineers in the field of low-head, big river dams and hydro plants; also to understand the confidence they have in their abilities since it stems from two decades of experience on this kind of work.”

But he was puzzled by their similar confidence in high concrete or rockfill dams, despite having almost no experience with them. His group visited a canyon on the Inguri River in Georgia, where officials planned to build the world’s tallest dam, a 990-ft-tall concrete arch structure. At the time, only a short test tunnel had been excavated to examine the character of the foundation rock, a limestone. In addition, Soviet officials talked about the Nurek Dam in the Tadzhik Soviet Socialist Republic, a proposed 980-ft-tall earth and rockfill dam, whose site was not on the tour. Inguri Dam was constructed episodically, and completed in 1979 at a lower height of 891 ft. Deficiencies in the construction process caused ongoing maintenance issues. The Nurek Dam, also built haltingly and completed in 1980, has deficiencies in terms of seismic stability.

Visitors Impressed

The group flew 3,000 miles to visit the Bratsk hydro project in Siberia, set to become the world’s largest capacity hydro power station when finished in 1967, at 4,500 MW. A double-deck steel construction trestle running the length of the 4,650-ft dam crest carried a roadway and rail line and was topped with six 22-ton capacity traveling hammerhead cranes with 360-ft-long trolley hook arms. Project labor force peaked at 14,000, aided by 6,000 workers employed in factories that furnished supplies for the dam. The visitors were impressed with “techniques, materials, workmanship and equipment as good as could be found anywhere.”

Bowman’s overview found the most distinctive characteristic of Soviet construction practice was extensive use of precast concrete. “Precasting is credited with making possible the fast pace of the Soviet housing program, which reached 2.2 million non-farm units in 1960, about twice the U.S. total,” he wrote, while pointing out important constraints.

Another big difference was that women made up about one-third of the U.S.S.R. construction labor force, a huge contrast to the U.S., where in 1960 only 0.5% of construction craft workers were women. Soviet officials explained that not enough men were available, as half its labor force still worked on farms, compared with only 10% in the U.S. at that time.