Spierings increases output with welding automation

Spierings offers the largest mobile tower crane in the market which can be assembled and operated by one person. Due to the strong recovery of the construction sector and expansion of market outside of the Netherlands, the demand for these tower cranes has risen rapidly in recent years. In addition, the introduction of the first hybrid tower crane is being planned, with which the manufacturer has the ambition to grow further into a global brand. As much as possible, all components, including the chassis, masts and booms, are manufactured in-house. The assembly and welding of the masts and booms takes up most space and increasing the throughput had to be achieved within the same space.

Accelerating knowledge acquisition regarding welding automation

Gijs Delissen: “Together with Valk Welding, we looked at the welding process where we could reduce handling and welding time. For the mast production line, a concept was developed consisting of a linear system for automation of the welding of the longitudinal seams, and a welding robot installation for the welding of the sub, end and head parts. Both complex installations had a delivery time of one year. We used that time to familiarize ourselves thoroughly with welding robotization. To this end, we purchased a welding robot for less complex parts. Consequently, we were able to take early measures in the upstream process to control the tolerances to align with the requirements of robot welding.”

Booms, next step

Together with Valk Welding and Spierings engineers, Delissen is now researching how the welding process of the booms can be automated as well. Gijs Delissen: “We may also have to look at how we can take into account handling of individual parts. An exciting process!"

Crane construction is at the forefront of high-strength steel applications

The use of high-strength steels plays an important role in achieving a weight advantage in crane construction. Spierings has been using high-strength steel since 1998 for the load bearing parts, mast, boom and tension rods. “When designing construction cranes, our goal is to be able to lift loads as high as possible within the permissible weight on the pavement of 12 metric tons per axle. Accordingly, in our designs the focus is always on where materials and weight can be reduced. Our model 1265, developed in 2003, is still very popular and is the largest mobile tower crane in the market. This tower crane has a reach of 60 m, a maximum lifting capacity of 10,000 kg and a maximum capacity at the tip of 1,700 kg. Without the use of high-strength steel, we would not have been able to build a tower crane with such capacity. Valk Welding is also our partner for the supply of welding wire for this high strength steel application, another benefit from Valk Welding as supplier. They can advice us not only for the complex robot welding system, but for the total application, including the welding process.” concludes Gijs Delissen.
www.spieringscranes.com