Lexington, KY  Kinnick Stadium at the University of Iowa, built in 1929, is undergoing an $89.9 million renovation to its north endzone with 124,000 sq. ft. of new space on three levels. Portzen Construction of Dubuque, IA was awarded sub-contract to place and pour 6,000 cu. yd. of concrete for foundation, lower floor stadium risers, concrete building decks and sidewalks.

Portzen purchased a 75-ton (70-mt) Link-Belt 75RT rough terrain crane for its crab steer ability and V-CALC system utilized throughout the job in the tight jobsite.

“Using V-CALC (Variable-Confined Area Lifting Capacities) on the 75RT changes throughout the day for me,” said operator Duane Hermsen.


The lone access road in and out of the north endzone construction must remain open at all times. Often the 75RT is situated narrowly close on either side of the access road but is able to maneuver large rebar cages and stadium forms with the use of V-CALC.

“When I go out in the morning, I’ll have outriggers on the right side half extended and the left side will be fully extended. When I move across the road, I will switch to opposite that. It changes day to day. There is no problem switching it around, either, wherever I have the room, basically, is how I decide the configuration,” said Hermsen.

Heavy lifting for the 75RT includes lifting forms for retaining walls as much as 20 ft. (6.09 m) tall, and rebar cages up to 60 ft. (18.2 m) long for forming grade beams. Large forms are also placed on compacted recycled concrete material to form stadium steps, which butt up against the in-ground concrete foundation walls. 75RT’s reach of 142 ft. (43.2 m) enables operator Hermsen to lift and place stout #9 rebar making up cages being handled by the crane and weighing up to 8,000 lbs. (3 628 kg).

“In the span of three hours, it’s not unusual to move this crane three or four times. We travel from one end of the jobsite to the other, and crab steer is especially helpful. As far as tear down - to move across the site – and set back up, it takes about half an hour. This is a smart machine. It’s dummy proof, and the computer is a big help with the load weights and charts that I use, especially when using V-CALC,” Hermsen said.