This cover photo from 1967 shows the construction of the Nagarjunasagar Dam in India. The three-mile-long gravity dam, with a central masonry section nearly a mile long, flanked by embankments and embankments, was built almost entirely by hand.
Tower cranes were used, but workers carried baskets of mortar up ramps supported by bamboo scaffolding and spread them 2 inches. layers
Other workers then placed 2.5-cubic-foot blocks of stone into the fresh mortar and vibrated them by hand to achieve a firm fit. The mortar was surki, a powdered burnt clay mixed with sand, which was cheap and readily available, while cement was scarce and expensive in India.
The workforce in 1967 was 50,000, both men and women. Two associated aqueducts that channeled water from the reservoir created by the dam to irrigate large tracts of farmland had a separate workforce of 80,000 people.
The construction lasted between 1955-69. At 411 feet tall, it was the tallest masonry dam in the world when completed.
