July 20 · 2005

Using Hydraulic Tools for Underwater Demolition in Downtown Aarhus

In the heart of Denmark’s second-largest city, a contractor faced a unique challenge – revealing the hidden river coursing through the city. The task involved removing submerged foundations, armed with HYCON handheld hydraulic tools and a couple of wet suits.

Aarhus has undergone a significant transformation during the first decade of the millennium, marked by extensive building renovations. Central to this transformation was the decision to unearth the river that had long been hidden under layers of concrete and asphalt. This river, once hidden, was set to become a prominent feature in the new Aarhus city center.

Initial attempts to demolish the foundations using machinery, including an excavator with a bucket and an excavator-mounted hydraulic breaker, were unsuccessful and even risked damaging the excavator's hydraulic system.

The general contractor, Phil & Søn, secured the contract to clean the river and alter its course. During this process, a hurdle emerged – the discovery of underwater foundations supporting a former road crossing the river. These foundations needed to be demolished, which caused a delay in the project and potential fines.

In the nick of time, the only solution was to move forward with handheld tools and wet suits. Identifying the HYCON HH23 hydraulic breaker as suitable for underwater work due to its closed hydraulic system, Phil & Søn found the answer they needed. To execute the task, they enlisted the expertise of demolition specialists, Total Diament, and rented the necessary equipment from HYCON's Danish dealer, Tzacho. Included in the solution was a Honda HPP13 power pack and 30 m (98 ft) of special lightweight hydraulic hose.

The team of wetsuit-wearing workers entered the river and manually demolished the foundation structure. While not the most comfortable working conditions, the job was completed in less than two weeks, averting potential fines, and contributing to the evolving aesthetic of Aarhus city center.