While building a new sludge drying installation in Alkmaar, Visser & Smit ran into a height challenge. Boels stepped in with BIM (Building Information Modeling) to find the right aerial work platform. The result: less time, lower costs and no unnecessary complications. “We quickly gained a clear insight into the possibilities within the limited available space. With this approach, we saved time and money compared to more costly alternatives, such as dismantling the aerial work platform after the work was completed.”
Over the past year, Visser & Smit has been working hard on a new installation at the edge of Alkmaar. A complex project that suited their expertise. “The complexity of this project mainly lay in the limited access with level differences, the restricted space inside the structure and the required reach of the aerial work platform,” says site manager Alfred Van Luenen.
The company essentially built a concrete bunker with compartments. Concrete was poured layer by layer using slipform construction. Work at height was required to install the steel roof structure, so they turned to Boels’ aerial work platform specialists.
No standard requests
“The client’s request was clear: an aerial work platform with a working height of 26 metres, a reach of over 18 metres, sufficient load capacity and the right articulation height. Because the work took place in a (partially) enclosed space, it also needed to be electric. A fairly standard request – except for the challenging location and access.”
“The work area was located 3.5 metres below ground level. Initially, the client considered filling the pit with sand so the aerial work platform could be driven inside. This would require more than 1,000 cubic metres of sand – a complex and costly logistical operation involving over 100 truckloads for filling and removal,” explains Boels technical specialist Job Spiekermann.
Digital advice
Richard Le Blanc, manager at Boels, adds:
“After visiting the project, I immediately suggested working with BIM. Based on this, a 40-metre hybrid spider lift proved to be the best option. The BIM model showed exactly whether the machine would fit inside, whether there was enough space to operate, how far it could reach, which areas were accessible and – most importantly – whether we could get it back out again.”
A tense moment
A truck-mounted crane lifted the aerial work platform through an opening into the bunker. Despite the calculations, it was still a tense operation, says Alfred.
“We had to lift the platform over the crane itself. Given the reach, depth and weight, it was quite nerve-racking. We didn’t even have 10 centimetres to spare – it just fit. It was my first time working this way. At first, I had doubts: nice system, but does it really work? At some point, you have to trust BIM. Now I’m convinced – and even positively surprised by how well it works in practice. I’ve worked in construction for almost 30 years. I’m used to combining digital designs with paper drawings, but I’m fully aware that digital systems like BIM are the future. In the end, they simply make the job easier.”
