Demag AC 220-5 on hospital grounds
17 July 2018 by Sotiris KanarisHaving legs that are different lengths might be a good reason for a visit to hospital; for McGovern Crane Hire, the ability to set up their Demag AC 220-5 on asymmetric outriggers was key to winning a contract to lift a 21t generator in cramped conditions at Birmingham Children’s Hospital.
Terex explained this would normally be a simple task, ‘if not for the extremely tight space conditions that made it impossible to use a sufficiently large and strong crane in the hospital driveway’.
The solution was using a Demag AC 220-5 all-terrain crane that was compact enough to fit in the driveway, yet—with Terex’s IC-1 Plus control system—offered sufficient lifting power with asymmetrically configured outriggers.
The team could have used a large crane with a minimum lifting capacity of 350 to 500t. However, it would not have been able to fit in the narrow driveway, so it would have to be set up on the opposite side of the road. From there the crane would have to lift the generator at a boom radius of about 50m.
“We decided not to use this lifting scenario, as the site had concerns regarding the larger cranes due to ground capacity and having to lift the loads over the hospital’s nitrogen tanks ,so we opted for the second version with a smaller crane and decided to use our new AC 220-5 for this operation,” said project manager Kieran McGovern. This only worked because this crane features the IC-1 Plus control system, which is designed for such applications.
“Thanks to the IC-1 Plus, however, we were able to configure the crane to carry out the lift utilizing only 84% of the rated lifting capacity while using reduced counterweight,” said McGovern.
In order to be able to lift the load with its gross weight of 22t, including hook block and lifting tackle, the AC 220-5 was equipped with counterweight of 51t. The outriggers were set as required to meet the needs of the job site. Thus, it was possible to lift the generator at a boom length of 33.3m and a radius of 15m off the lowbed trailer in the driveway to a height of 10m. It was then lifted over adjacent buildings by slewing the crane directly over the front right rigger which was completley retracted, the crane continued slewing right until over the back right rigger which was extended to three quarters and easily lowered down at the desired location with a final radius of 19.7m.
