Northwest was offered the opportunity to team with Maxon Industries in 2012 on the project known affectionately as the “Big Straw” in Las Vegas. This was an extremely logistically challenging and complex placement.
A raw water intake structure, basically a concrete-and-steel funnel 100 feet (30.5m) tall and weighing 1,200 tons (1,088 metric tons), was floated almost three miles (5km) from shore and methodically sunk to the bottom of the lake, making its home in a huge 60-foot (18m) deep pit that was previously blasted with explosives. A single continuous 12,000 cubic yard (9,175m³) concrete pour was needed to fill in the hole and keep the structure in place.
Putzmeister concrete placing system supplied by Northwest consisted of two placing booms, two large trailer pumps Putzmeister 14000, and Putzmeister 1409, and tower. Maxon provided conveyors that transferred the concrete to a Maxcrete remix surge hopper. The 10-cubic yard (7.65m³) Maxcrete provided surge capacity during the transition.
The multifaceted concrete placing process started on shore with an on-site batch plant set up to continuously supply a specially-designed concrete mix. Ready mix trucks, each loaded with 10 cubic yards (7.65m³) of concrete drove onto a transport barge, eight at a time, to be ferried across the water with their drums turning. Their destination—an equipment barge about three miles (5km) from shore. To maintain a non-stop flow for more than 250 hours, three transport barges kept 32 ready mix trucks cycled between the shore and barge.
The project was a huge success finishing 72 hours ahead of projections and setting a world record for pumping 12,000 cubic yards of concrete 400 feet under the surface. Las Vegas will now have water until the lake runs dry!