The hidden treasure of Calanca Valley

Alfredo Polti SA is typical of the family businesses working in the natural stone industry in the south of Switzerland – and the secret of its success is a strong foundation. For more than 100 years it has been following the tradition of craftsmanship in the Calanca Valley, yet its way of working and philosophy are anything but outdated, including its choice of quarrying machinery.

After owning some used 20- and 30-tonne Hitachi machines in the early Nineties, the Arvigo-based gneiss quarry has been home to: two ZX500LCHs, purchased in 2003; two ZX520LCR-3s delivered in 2010; and the latest acquisition of a new ZX530LCH-7 in 2022. The three generations of Zaxis large excavators were all purchased from the Swiss Hitachi Construction Machinery (Europe) NV (HCME) dealer, Probst Maveg.

Powerful and reliable

“For the heavy work in the quarry, we have used Hitachi machines for excavating, preparing the benches and digging loose materials for many years,” says Giovanni Polti, the Managing Director. He has been working with Alfredo Polti since 1990 and became an equal partner in the business with his sister in 2000. Giovanni’s grandfather started the quarry in 1920 before Alfredo Polti SA was established in 1950 by Giovanni’s father, Alfredo. The company currently employs 40 staff across the offices, production facility and quarrying site.

The latest ZX530LCH-7 has accumulated 870 working hours and was supplied with a five-year, 5,000-hour full-service contract by Probst Maveg. “It’s a very strong and powerful machine, but yet we also benefit from low fuel consumption,” adds Giovanni. “In our opinion, it’s very reliable for the tough jobs and working conditions in the quarry.

“We are also able to analyse the performance of the machine from the monthly ConSite reports that we receive from Hitachi. This not only helps in our analysis of the fuel efficiency, but also on the travel and idle times – as well as making decisions on how to achieve the best use of the machine.”

Best technical support

Alfredo Polti has enjoyed a 30-year working relationship with Probst Maveg and Giovanni confirms that they are satisfied with the service provided: “One of the most important factors in our loyalty to Hitachi is what we consider to be the best technical support available in the region from Probst Maveg. The closest branch is nearby in Ticino, and the engineer can be with us within 30 minutes if there’s any issues with the machine.

“Overall, we have much more than just a business relationship with Probst Maveg. They are open, honest and fair – and this is more important than saving some money elsewhere. We are very happy, and because of this we would not consider buying another brand of excavator.”

Strong and precise

Lorenzo Savoia has 13 years’ experience as an operator and has worked exclusively with the ZX530LCH-7 since it was delivered 12 months previously: “I have found the Hitachi to be very fast, even though it is a massive machine. So, this makes it quite easy to operate.

“It has so much strength, and yet it's very precise in moving and handling the blocks – so much so that we don’t damage them. The comfortable cab is very spacious. The seat is also of the highest quality, the controls are all within easy reach and you can easily see the new colour monitor.”

After removing the top layers of materials, Alfredo Polti blasts the rock on the next level and it falls down on to the quarry floor. The ZX530LCH-7 then removes the loose rock and loads it on to an articulated dump truck, as well as preparing the ground before the next blast, and other excavation and grading work. In addition, the large Zaxis excavator lifts the 700-1,500m³ gneiss blocks that have been extracted from the face of the quarry on to a wheel loader for transporting to the storage area before production.

A metamorphic stone

Calanca gneiss is one of the oldest rock formations on the planet. The natural grey stone was formed over 300 million years ago and surfaced with the Alps 65 million years ago. The entire production of around 18,000m³ of gneiss per year was moved to the current location of Arvigo in 1960 in order to further process the raw material in a modern workshop. Between 6 and 10% is exported, mainly to the neighbouring Germany, Italy and Austria, but pieces from the Calanca Valley have also been delivered to Japan and the USA.

“Gneiss is a metamorphic stone and is as hard as granite, however it can be easily split and we extract up to 140 tonnes per day,” explains Giovanni. “We need all of the materials from the quarry for different applications, and not just the best quality stone. Our main business is in the landscaping sector, but we also supply our customers with products for cladding buildings, tiles and kitchen worktops.

“We are committed to an environmentally conscious approach and an appreciation of the nature around us. To reduce the impact to a minimum, we optimise our work processes, for example by using diamond wire, blasting and drilling techniques for stone extraction. We also reprocess the geological and technical waste into gravel, which is reused both in road construction and for our quarry needs.”