Afobaka Dam – 1980s Bulkhead
Suriname Aluminum Company Floating Bulkhead, Suriname, South America
Steel-Fab, a bulkhead fabricator from Fitchburg, Massachusetts, contracted with Suriname Aluminum Company, a subsidiary of Alcoa, to fabricate and deliver a floating bulkhead to the Afobaka Dam in the Republic of Suriname in South America. Steel-Fab partnered with Ayres Associates to design the bulkhead.
The Afobaka Dam was completed in 1964 as part of the Brokopondo Hydroelectric plant. The Brokopondo plant generates 180 megawatts, providing power to about 70 % of the small country of Suriname. Afobaka Dam creates an
Afobaka Dam – Upstream Pier Noses approximately 602-square-mile( 1,559.2-squarekilometer) reservoir that stores water during the rainy season and releases it throughout the year for power production. Since the dam was commissioned, the structure’ s 35-foot-wide-by-45-foot-tall( 10.7-meter-wide-by-13.7-meter-tall) tainter gates have never been opened more than 6 inches.
In the early 1980s Suriname Aluminum Company had a four-section, non-floating bulkhead system fabricated. The four units weighed between 40,000 pounds( 18,143.7 kilograms) to 71,000 pounds( 32,205.1 kilograms). The completed assembly rests on concrete seats at the bottom of the spillway. After the bulkheads were purchased, Suriname Aluminum Company replaced the gantry crane with a crane with a maximum capacity of 48,000 pounds( 21,772.4 kilograms).
The new floating bulkhead system( currently under design) will consist of 11 caissons, each weighing about 27,000 pounds( 12,247 kilograms). The gantry crane will only need to lift one bulkhead at a time and place it on the reservoir for divers to pin together. The lower caissons will be flooded, at which time the bulkhead will rotate vertically and can be positioned upstream of each gate for a full gate testing. Because of the buoyancy of the bulkhead, the load on each concrete seat will be a fraction of the load of the original bulkhead.
6 | THE FLOATING BULKHEAD