Spierings SK488-AT7

The Spierings SK488-AT7 was developed as a heavy mobile tower crane for projects requiring higher load moments and long reach while remaining compliant with road transport regulations. Built by Spierings, the SK488-AT7 uses a distinctive transport concept in which the crane superstructure is mounted on a four-axle carrier, supplemented by a detachable three-axle rear dolly. This configuration distributes the transport weight across seven axles, allowing the crane to travel on public roads within axle load limits while maintaining a relatively compact main carrier.

In working position, the rear dolly is removed, and the crane operates as a four-axle mobile tower crane. This keeps the on-site footprint manageable while still providing the stability and performance expected from a larger class machine. The detachable axle system is a key reason the crane may visually appear to be a four-axle unit despite its AT7 designation.

The SK488-AT7 is equipped with a lattice jib offering a long working radius, typically up to around 60 metres depending on configuration. In horizontal trolley jib mode, the crane delivers solid capacities at maximum radius, while at shorter radii it is capable of lifting heavy loads suitable for concrete elements, large formwork assemblies, and structural components. By raising the jib to steep angles, the crane achieves significant hook heights, making it suitable for multi-storey residential, commercial, and industrial construction.

As with all Spierings mobile tower cranes, erection is fully automatic and can be carried out by a single operator at the push of a button. The erection sequence follows a controlled and compact assembly curve, allowing the crane to be set up in restricted spaces without extensive auxiliary equipment. Once erected, the crane can remain standing between work phases without dismantling, improving efficiency on longer projects.

All crane working motions—including hoisting, slewing, trolley travel, and erection—are electrically driven. Power is supplied either by an onboard diesel generator or via an external electrical connection, enabling quiet, low-emission operation when site power is available. The electric drive system provides smooth, stepless control and precise load handling comparable to that of a conventional top-slewing tower crane.

The crane is supported on a four-point hydraulic outrigger system with automatic leveling and electronic inclination monitoring. Multiple outrigger base widths allow the crane to adapt to varying site conditions. Thanks to its balanced design and favorable center of gravity, limited repositioning on site while erected is possible in accordance with manufacturer guidelines.

Overall, the Spierings SK488-AT7 stands out as a technically robust mobile tower crane that combines high lifting performance with a clever transport solution. The combination of a four-axle carrier and detachable three-axle dolly allows it to achieve heavy-class capability while remaining road-legal and flexible, making it particularly well suited for large urban and infrastructure projects.