Woltman THW 7528-D
Van 't Hek
This attractive Woltman THW 7528-D of Van 't Hek from Z.O. Beemster (NL) was deployed near Muiden (NL) to drive foundation piles for a new bridge for cyclists and pedestrians. This was the first piling rig of this type in the large and diverse fleet of Van 't Hek.
The undercarriage of the rig is 6.56 metres long and 4.8 metres wide. For road transport the width can be reduced to 3.5 metres by means of a hydraulic system. The rig is powered by a Caterpillar C-18, an 18.1-litre 6-cylinder diesel engine with an output of 562 kW (765 hp).
A total of 10 tonnes of ballast is mounted on the upper structure, which has a turning radius of 4.69 metres.
As standard, the THW 7528-D is equipped with three winches: a main winch with a line pull of 10 tonnes, a pull-down winch with a line pull of 10 tonnes and a service winch with a line pull of 6 tonnes. Optionally, a 5-tonne auxiliary winch and a 0.6-tonne lifting winch could be selected.
Although the THW 7528-D was primarily developed as a drilling rig, it can also be deployed for piling work with hammers, as was the case here. The leader is assembled here in the shortest possible configuration of 19 metres. The maximum length is 33 metres. In the shown configuration, the piling rig weighs approximately 105 tonnes.
A Delmag D55 diesel hammer operates in the leader. The hammer has a total weight of approximately 12 tonnes and a ram weight of 5.4 tonnes. The length of the hammer is 5.4 metres.
The rig was working under overhead power lines, which is why the leader had to be assembled as short as possible. The piles consisted of two sections that were lifted under the Woltman and connected using a small crawler crane. A very beautiful deployment by Van 't Hek!