Superior lifts

The project involved the replacement and removal of multiple 308t (680,000lb) vessels.

This was the first project Superior Cranes’s crew would complete with the new CC 6800-1 crawler crane.

Demag engineers assisted the company to devise a lift plan for a site with limited access and crane mobility after the load was lifted.

The Demag CC 6800-1 crawler had to be positioned far away from the 6.1m (20ft) diameter, 12.2m tall vessels.

Superior Cranes’ crew used a 300USt (275t) crawler assist crane to build-out the CC 6800-1.

“It took ten days to set up and six days to disassemble the (CC 6800-1) crane, which is excellent given the space we had to work with and it being our first time.

The process will get faster, especially on wide open job sites,” said Joe Everett, president of Superior Cranes.

Crew members installed 79m of main boom and 41m of Superlift boom. To aid in construction safety, the CC 6800-1 is equipped with the Demag Fall Protection system.

“This system stops a fall prior to the worker reaching the ground, reducing the possibility of injury,” said Hans Hofer, service engineer for Demag. It is installed from ground level and includes a vest harness equipped with a shock absorber.

The lifts required 780t of counterweight: 250t superstructure, 80t central ballast, and 450t on the Superlift tray. The lifts were made at 38.1 and 41.5m radii due to site access limitations.

A total of 12 picks were made in the month Superior Cranes was on site. The operator carefully kept the boom within lifting radius with the variable Superlift counterweight tray connected to the carbody. After the vessel was secured, the crane boomed up and positioned the load close to the carbody.

Crews then disconnected the Superlift tray to rotate the vessel and reposition it to its staging area.

“The tray had to be removed to allow the crane’s counterweight to clear the building,” explained Hofer.

“The crane’s Quadro-Drive on-demand system improves versatility on jobs like these by allowing the base to move and spin under load.”

Superior Cranes’s months of meticulous planning paid off. The difficult lifts were safely made in less time than planned.