Video – Waiting for the drop…

Drop-hammer destroys bridge in Finland.

As anyone that has ever been near or by a Rammer breaker in full flow, those Finns know a thing or two about hammers. So we were intrigued to learn that a bridge deck in Finland was being demolished using a drop-hammer.

Built in 1977, the bridge is 170 metres in length and 12 metres wide and is being demolished by contractor Huhtakallio. After removal of surface, the bridge deck was fractured with an MEP Breaker drop-hammer fitted to a 45 tonne class excavator.

Weighing nine tonnes and featuring a four tonne “bullet”, the drop hammer delivers an impact force of 200 kJ. This massive impact loosens the rebar from concrete, weakening it and making it easier to process further with a traditional hydraulic hammer and a crusher installed on smaller excavator.

Petri Kiiskinen, sales manager of MEP Steel says the contractor Huhtakallio has demolished dozens of bridges using the same method. It has used drop hammers for 20 years, and have influenced the development of the MEP breaker. The result is a simple, reliable and powerful machine. Most important of all, the operating cost is kept low, without compromising the productivity.

According to the company, a typical 500 m3 bridge is often demolished with two heavy hydraulic hammers and a pulverizer. “When one of the hammers is replaced with an MEP breaker, the productivity easily doubles, even triples,” Kiiskinen says.