A Demag AC 220-5 all-terrain crane lifts a generator on hospital grounds in Birmingham
This job had its challenges. On behalf of UK Generator Manufacturer, crane services provider, McGovern Crane Hire from Derbyshire in central England were required to lift a 21-tonne generator on the grounds of the Birmingham Children’s Hospital. Usually 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 to make use of a Demag AC 220-5 all-terrain crane that was compact enough to fit in the driveway, yet with the innovative IC-1 Plus control system, it offered sufficient lifting power with asymmetrically configured outriggers.
“We knew that this lifting operation would be very tricky. Therefore, we were on site several times in advance to measure the road and driveway spaces. In addition, we carried out extensive lifting simulations with CAD-based computer programs and also made a 3D model of the environment to see whether we could slew the crane’s superstructure completely despite the dense building development,” says Project Manager Kieran McGovern. “Also the “Terex Lift Plan” planning tool was helpful for this preparation.”
Preferred: the “small” solution
Two ways of lifting were considered. The team could have used a large crane with a minimum lifting capacity of 350 to 500 tonnes. However, it would not have been able to fit in the narrow driveway because of its dimensions, 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 50 metres. “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 hospitals 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,” explains Kieran McGovern. However, this only worked because this crane features the IC-1 Plus control system, a feature which is designed for just such applications.
This system makes it possible to take advantage of the maximum available lifting capacity for each slewing position in any crane configuration. This advantage is particularly useful when working with reduced outrigger settings and reduced counterweight. This allows the crane to perform tasks that would normally require a larger crane, such as in Birmingham. Kieran McGovern: “With the available space, we were only able to extend the outriggers to about three quarters. Without the IC-1 Plus we would not have been able to carry out this lifting operation. Thanks to the IC-1 Plus, however, we were able to configure the crane to carry out the lift utilising only 84 per cent of the rated lifting capacity while using reduced counterweight.”
In order to be able to lift the load with its gross weight of 22 tonnes, including hook block and lifting tackle, the AC 220-5 was equipped with a counterweight of 51 tonnes. 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 33.3 meters and a radius of 15.0 meters off the lowbed trailer in the driveway to a height of 10.0 meters. 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 19.7 metres.
Excellent cost-effectiveness with IC-1 Plus
The conclusion of Kieran McGovern is correspondingly positive. “We know that we can perform very complex tasks safely and economically with the AC 220-5 equipped with the IC-1 Plus. Thanks to the IC-1 Plus control system, we can use a smaller crane that is more cost-effective for our customers in many jobs, and we also need less counterweight for the crane.” Of course this also translates into lower costs.