Spierings SK597-AT4

The Spierings SK597-AT4 was developed as a higher-capacity alternative to the smaller AT3 class, aimed at contractors who require increased load moment and working radius without moving into heavier multi-axle transport solutions. Built by Spierings, the SK597-AT4 follows the core Spierings concept of combining tower crane precision with road-going mobility, making it particularly well suited for urban construction and projects with frequent relocations.

Mounted on a four-axle carrier, the SK597-AT4 offers a practical balance between transport efficiency and operational performance. The four-axle layout keeps overall length and axle loads within manageable limits, allowing easier road travel compared to larger AT5 or AT6 machines. Multiple steerable axles provide good maneuverability, enabling the crane to access narrow streets, inner-city sites, and confined industrial areas. Road travel speeds are typically up to around 80 km/h, supporting efficient movement between job sites.

The crane superstructure features a lattice jib designed for trolley operation, providing a working radius generally in the range of approximately 45 to 50 metres, depending on configuration. At short radii, the SK597-AT4 delivers a maximum lifting capacity of around 8 tonnes, making it suitable for handling heavy formwork panels, concrete elements, reinforcement cages, and structural components. At larger radii, the crane maintains practical capacities for everyday material handling tasks. By setting the jib at steeper angles, the crane achieves increased hook heights, allowing efficient work on multi-storey residential and commercial buildings.

A key strength of the SK597-AT4 is its fully automatic, one-man erection system. Erection is carried out at the push of a button, following a controlled and compact assembly curve that requires minimal space around the crane. This allows setup close to existing buildings or within tight site boundaries where conventional tower crane erection would be difficult. Once erected, the crane can remain standing between work phases without dismantling, improving productivity on projects with intermittent lifting requirements.

All crane working motions—including hoisting, slewing, trolley travel, and erection—are electrically driven. Electrical power is supplied either by an onboard diesel generator or via an external site power connection. When external power is used, the SK597-AT4 operates with low noise and zero local emissions, an important advantage for city-center projects and noise-sensitive environments. The electric drive system provides smooth, stepless control, enabling precise load placement comparable to that of a traditional top-slewing tower crane.

The crane is supported by a four-point hydraulic outrigger system with automatic leveling and electronic inclination monitoring. Different outrigger base widths can be selected to adapt to site constraints, balancing available space with required lifting performance. The stable four-axle carrier and well-balanced superstructure contribute to predictable handling and consistent performance throughout the working range.

The operator’s cab is designed to tower crane standards, offering good all-round visibility, ergonomic controls, and a comfortable working environment for extended shifts. Integrated monitoring and safety systems provide continuous feedback on crane configuration, load status, and wind conditions, supporting safe and efficient operation.

Overall, the Spierings SK597-AT4 can be described as a versatile and well-balanced mobile tower crane that delivers strong lifting capability without the transport complexity of larger axle configurations. Its combination of four-axle mobility, fast self-erection, electrically driven crane functions, and tower-crane-like precision makes it a strong choice for urban and regional construction projects where flexibility, reach, and efficient deployment are key requirements.