It was used to excavate 10,000m³ of earth from 11 metres below ground in preparation for an extension to a children’s hospital in Sweden’s second city.
The Drottning Silvias Barnsjukhus (Queen Silvia’s Children’s Hospital) is being enlarged and its new facilities are due to be completed in 2021. The work carried out by the Hitachi excavator, owned by Kolvikens Gräv AB, will make way for tunnels that will link the existing and new hospital buildings, and pipe systems for sewage, water supply and rainwater.
The soft but heavy clay in this area usually makes deep excavation difficult but the Hitachi ZX350LC-6 CTA seems well up to the job.
Owner Kenneth Kolviken says: “Previously, we would use long-reach excavators for deep shaft excavation. However, the CTA excavator has a longer reach (25 metres compared to 12 or 13 metres) and twice the bucket capacity (1.3m³) of a long-reach excavator, which makes it more efficient. It loads between 25 and 30 trucks a day on average, with 11 to 13 passes per truck.”
A further advantage of the ZX350LC-6 CTA is that it requires less swing space than a long-reach excavator, making it more suitable for compact locations. And it does not require the construction of ramps into the shafts for trucks to drive down.
“In soft clay, that could be a problem,” he says. “This machine makes it much safer, as no roads are required.”
The enhanced visibility offered by the ZX350LC-6 CTA is also appreciated by the operator, Patrik Backström, who says: “Thanks to the sliding cab and the floor window, you can see right over the edge of the shaft – it’s perfect.”
The cab is positioned 96cm further forward than on a standard ZX350-6 excavator and can also slide a further 130cm, giving a clearer view of the ground below.
“Over the years, I’ve noticed small and subtle improvements to the design of Hitachi excavators, but the quality has always remained high,” Kenneth Kolviken says. “The hydraulics make it easier to do a good job, and I’ve never had any breakdown issues or unscheduled stops, so they are extremely reliable. And the service from [official Hitachi dealer] Delvator in Gothenburg is also very good.”