Unlike our own vibratory hammers, the Tünkers piling rig is not equipped with integrated elastomers. For this reason, they developed a series of rubber crane shock absorbers for their own vibratory equipment. Combining these with Dieseko Group’s advanced vibration technology results in a highly effective damping mechanism.

This combined damping system proves particularly beneficial when starting and stopping a normal-frequency vibratory hammer, as well as during the extraction of profiles. The latter applies to both normal-frequency vibratory hammers and variable moment models. This product is a valuable addition to the Dieseko Group portfolio, as it aligns seamlessly with one of the core pillars of our corporate philosophy: Limited Vibrations.

As the pulling force increases, the angles $\alpha$ decrease. This causes the compressive stress on the hollow rubber spring to diminish in proportion to the applied pulling force. In practice, this means that high pulling forces (high pretension for heavy-duty extraction) can be applied to the piling and vibratory equipment without overloading the rubber spring.

Simultaneously with the stretching and compression of the hollow rubber spring, the geometric positioning of the cables induces a pivoting movement of the lateral pressure plates around the top flexible joints. Even under maximum tensile load, the machine’s vertical vibrations are absorbed, preventing them from being transmitted to the base machine’s hoist cable.

Shock absorbers available now in our rental fleet:

• Tünkers SD 70 shock absorber

• Tünkers SD 130 shock absorber

• Tünkers SD 185 shock absorber

The shock absorbers were extensively tested at the site of Pilequip, our Australian subsidiary, using a 75-ton crawler crane. To ensure an accurate evaluation, VMS Australia – a specialist in vibration measurement – was engaged to record the vibration levels. VMS installed four measuring points on the crane: above the hook, at the boom tip, halfway up the boom, and in the operator’s cab.

Tests were conducted using two types of vibratory hammers: the ICE 32NF (normal-frequency) and the PVE 28VM (variable moment). Unlike normal-frequency vibratory hammers, variable moment units do not cause shock when starting and stopping, as the vibrations only begin once higher frequencies are reached. However, once the vibratory hammer is subjected to pulling force, the peak frequencies are transmitted through the crane, regardless of whether a variable moment or a normal-frequency vibratory hammer is used.

The results demonstrated that the Tünkers rubber shock absorbers effectively reduced vibrations by up to 93%. This significant reduction not only limits vibration transmission but also helps protect the crane against wear and tear. This extends the operational lifespan and lowers maintenance costs.