Spierings SK488-AT4

The Spierings SK488-AT4 occupies an important position in the Spierings lineup, sitting between the compact AT3 class and the heavier AT6 and AT7 machines. Developed by Spierings, the SK488-AT4 was intended for contractors who require higher load moments and longer reach than the smaller models can provide, while still keeping axle count, transport complexity, and on-site footprint under control. Unlike the AT7 variant, the AT4 version is a true four-axle crane without a detachable rear dolly, making it simpler to transport and quicker to deploy on sites with limited space.

Mounted on a four-axle all-terrain carrier, the SK488-AT4 offers good road mobility with a maximum travel speed of around 80 km/h. Multiple steerable axles provide excellent maneuverability, allowing the crane to access tight city streets and confined construction sites. The four-axle configuration keeps overall transport length and axle loads within practical limits for many regions, reducing the need for additional trailers or special permits compared with larger axle configurations.

The crane superstructure features a lattice jib designed for trolley operation, typically offering a maximum working radius in the range of approximately 45 to 50 metres, depending on configuration. Within this working envelope, the SK488-AT4 delivers a maximum lifting capacity of around 8 tonnes at short radii, with practical capacities at maximum outreach suitable for handling formwork, reinforcement, prefabricated concrete elements, and general construction materials. By raising the jib to steep angles, the crane achieves increased hook heights, making it effective for multi-storey residential and commercial buildings where vertical reach is as important as horizontal coverage.

As with all Spierings mobile tower cranes, the SK488-AT4 is designed around a fully automatic, one-man erection concept. The crane can be set up at the push of a button, following a controlled and compact assembly curve that requires minimal space around the machine. This allows erection close to existing structures and in narrow working areas where conventional tower crane assembly would be impractical. Once erected, the crane can remain standing between work phases without dismantling, which is a major advantage on projects with intermittent lifting requirements.

All crane working motions on the SK488-AT4 are electrically driven, including hoisting, slewing, trolley travel, and erection. Electrical power is supplied either by an onboard diesel generator or via an external site power connection. When connected to external power, the crane operates with very low noise and zero local emissions, making it well suited for urban environments with strict environmental and noise regulations. The electric drive system provides smooth, stepless control, allowing precise load placement comparable to that of a conventional 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 varying site constraints, balancing available space with required lifting capacity. The stable four-axle carrier and well-balanced superstructure provide predictable handling and good stability 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 long shifts. Integrated monitoring and safety systems provide continuous feedback on crane configuration, load status, and wind conditions, contributing to safe and efficient operation.

Overall, the Spierings SK488-AT4 can be described as a versatile and well-balanced mobile tower crane that delivers solid lifting performance without the transport complexity of larger axle configurations. Its combination of four-axle mobility, fast self-erection, electrically driven crane motions, and tower-crane-like precision makes it a strong choice for urban construction projects where flexibility, speed, and efficient use of space are key considerations.