Flexifloats support dredge & dive operation on John Martin Reservoir
Hasty, CO
John Martin Dam was completed in 1948 on the Arkansas River to create John Martin Reservoir. The reservoir was named after the U. S. Representative who advocated for the project through the 1930s. Also known as the The Sapphire on the Plains, the reservoir was originally built for flood control, but is now a popular recreational destination along with being used for irrigation.
After 75 years, a large amount sediment had accreted on the upstream side of the dam. A joint venture between Ahtna and J. F. Brennan was contracted by the U. S. Army Corps of Engineers Albuquerque District to hydraulically dredge the accumulated sediment. In addition, Ahtna-Brennan JV also performed dive operations to remove and replace existing bulkhead seals on the dam.
Dredging in up to 50 ft. of water, Ahtna-Brennan JV supported a Hitachi ZX470LC-6 long reach excavator with a hydraulic cutterhead attachment on an 40 ft. x 80 ft. S-50 Flexifloat assembly. The Flexifloat platform was held in position with a pair of 60 ft. spuds along with J. F. Brennan’s custom “kicker” spud on the stern. The S-50 Flexifloat assembly was also used to support the dive operation working on the bulkhead seals. In addition, a 22.5 ft. x 30 ft. H-50 Flexifloat assembly was used as a fuel and support barge.
