Komatsu PC700 with special boom conversion for raw gravel extraction

The German construction company Kann GmbH Baustoffwerke required a customized hydraulic excavator to extract gravel from deep underwater deposits.

The German construction company Kann GmbH Baustoffwerke required a customized hydraulic excavator to extract gravel from deep underwater deposits. Komatsu's PC700LC-11E0, equipped with a long boom and 3D Machine Guidance was the ideal solution. The excavator has significantly increased productivity and safety at the Kann site, surpassing its target production of 1,000 tonnes of gravel per shift.

The production of concrete products is the core business of Kann GmbH Baustoffwerke, a family business founded in 1927 with 18 locations throughout Germany. The company obtains some of the raw materials it processes itself, while 50 per cent of the raw materials obtained are sold externally. Around 500,000 tonnes of raw gravel are extracted annually at its site in Mülheim-Kärlich. The most recent challenge at this site was the replacement of the over 40-year-old scraper bucket.

The special nature of the excavation area, with gravel deposits up to 12 metres below the water surface, places high demands on the successor machine, which is to handle both the excavation and loading of the raw gravel. In the end, Komatsu sales partner BRR Baumaschinen Rhein-Ruhr was able to offer a customised PC700LC-11E0 hydraulic excavator that was ideally suited to the application. The basic machine, including the lifting cylinders from the Komatsu factory in England, provides the necessary stability and lifting power. The steel construction of the boom and arm was customised by a thirdparty supplier so that the required length can be achieved when digging to reach the deep gravel below the waterline. The excavator also has a hydraulic ditching bucket and is equipped with GPS and Smart Construction 3D Machine Guidance. Due to the underwater use, BRR's subsidiary AP Deutschland installed a special solution to protect the sensors and connections.

"The bucket's movement options save us a lot of time, as we don't have to constantly move the excavator and it can work from the same spot. This is currently only necessary about once per shift," says Technical Manager Frank Hergenroether. "Another advantage of the excavator is that it is still very mobile despite its size. This is not only a relevant aspect in this gravel pit, but also for the future, when the machine changes the extraction area, as the areas are becoming ever smaller and more urbanised," Hergenroether continues.

Increasing urbanisation is both a trend and a challenge that runs through the entire construction industry. However, examples like this show that it is possible to grow and find future-orientated solutions. The Komatsu PC700LC-11E0, which has been in operation at Kann since April 2024, is expected to produce 250,000 tonnes per year.

"The decisive factor in our decision to purchase the Komatsu hydraulic excavator was that, despite its length, the boom does not rest on the chassis to achieve the required depth, does not dig up the ground itself and can also maintain a safe distance from the bank. In addition, BRR was a competent partner right from the start, understanding and realising our requirements," explains Frank Hergenroether.

Machine operator René Münch sees further advantages: "The lifting power speaks for itself. In addition, the comfort during operation is impressive thanks to the superior cab suspension and low noise level. Overall, the machine is very clear, tidy and intuitive to operate. Within a very short time, all machine operators were trained to work safely on the excavator and were ready for action," summarises Münch. "The length of the arm and how quickly we were able to achieve the required performance was surprising. The target of being able to extract at least 1,000 tonnes of gravel per shift has already been exceeded," says the machine operator. "This is also thanks to the detailed on-site instruction and training provided by BRR and Komatsu on delivery," adds plant manager Andreas Müller, "The increasing performance curve of the employees with the new PC700LC-11E0 is clearly visible."

To summarise, a unique special construction project was implemented in partnership. The result is a machine that offers increased safety during operation thanks to its ability to keep its distance from the bank, while still being extremely efficient by reaching the required depth.