This ominous-looking machine partially immersed in the Missouri River was the world’s largest suction dredge when it was introduced. The 10,950-hp, diesel-electric machine’s hull measured 170 ft long, 46 ft wide and 11 ft tall.

It was designed by the Erickson Engineering Co. and furnished to Western Contracting Corp., the excavation and embankment contractor for the Fort Randall Dam, a two-mile-long earthen structure in South Dakota.

Nicknamed the “Western Chief,” the 1,500-ton dredge was made up of 20 hull sections, allowing for disassembly and transport to future jobs.

Internal watertight bulkheads divided the hull into 30 compartments, rendering it virtually unsinkable. Plans and specs for 31 of its components were issued to 24 different manufacturers.

In 1951 alone, the Western Chief dredged 2,350,000 cu yd of overburden, sand and chalk from the dam’s approach and outlet channels, stockpiling much of it for future use in the embankment.