November 21 - Sterett Crane & Rigging has completed the lid removal and replacement of eight anaerobic digester tanks at two wastewater treatment plants in Evansville, Indiana using a 400-tonne capacity Terex CC 2400-1 lattice boom crawler crane.

"Having sufficient space alone to bring in and assemble the crane was challenging enough," said Sterett's crawler crane fleet manager Matt Crisp.

"In order to remove the massive tank lids that weighed in excess of 250,000 lb (113.4 tonnes) each, we needed to mobilise a crane that was small enough to fit into and manoeuvre in the tight area, while at the same time offer the capacity to lift the heavy lids."

The Terex crawler was equipped with its Superlift configuration in order to lift and lower the lids at the sites

"The lids alone were 75 ft (22.9 m) in diameter, and we had to rig to them at 16 points," explained Crisp. "The plan was to pick the lid at a 91 ft (27.7 m) radius, boom up, move the crane a short distance and then swing the ring into position for lowering it onto the cribbing. However, often a tank obstructed the path of the tray as we swung the load, and, at times, we had to be aware of the crane's ground contact pressure."

The Terex CC 2400-1 crane was transported on 25 trucks to the Evansville site. On arrival, the crane was configured with 137 ft (42 m) of main boom and 264,500 lb (120 tonnes) of counterweight. The machine was also equipped with the full 98.4 ft (30 m) of Superlift mast and the Superlift tray was loaded with 352,700 lb (160 tonnes) of counterweight.