As Jan De Nul Group’s Site Manager at Trois-Ponts, Bert Dierick had some freedom to choose the machines deployed on the project. “This is a great job for Jan De Nul, as it is quite specialist and not many other companies can do this type of work within the strict timescale.

“The construction machinery is kept on the fleet indefinitely and some machines have 10-12,000 hours before they are moved on. However, this will depend on several factors, such as their condition, resale value and if they are needed for a specific job. As an example, a 14,000-hour ZX670LCH-3 was recently replaced by the ZX690LCH-7, which we needed with a ripper attachment for this project.

“When my colleagues consider a new machine for purchase, I give them my opinion. The Hitachi excavators are the key to the production on this site and they are working well. They are strong, reliable and the level of availability is very high.”

Kris De Backer, Technical Supervisor at Jan De Nul Group, is the main point of contact for the Belgian Hitachi dealer, Luyckx – a partner he holds in high regard: “The biggest benefit of running a Hitachi fleet is the excellent service provided by our dealer – thanks to Luyckx, we will always buy more Hitachi machines.

“If there’s an issue with any of the large excavators, it costs us money because the dump trucks – and the whole process – will come to a stop. Therefore, reliability is the key. In addition, our operators never complain about the Hitachi machines or request that we should buy any other brands. In fact, they say that Hitachi makes the best large excavator in the market.”

Andy Moreels, a long-standing excavator operator with 23 years’ experience within Jan De Nul Group, has experience of operating all of the Zaxis series machines (from the -1 to -7 range) and his favourite model is the ZX350LC-6 for its “versatility and comfort”.

Of the ZX690LCH-7, Andy says: “Overall, this is an excellent machine. The comfort is much better than previous versions, such as the seat and the way in which it moves as one with the console. I also like the adjustable joysticks, and the monitor and camera have been improved, such as the bird’s-eye view with everything now visible on screen.

“The digging power and strength of the machine are excellent. I can load trucks relatively quickly and the response is good thanks to the hydraulics. It’s also easy to manoeuvre, even with the heavy ripper attachment I’m using now. There is even less noise in the cab, due to the distance from the engine compartment behind me.”

It’s not possible to work on the site from November onwards – as it’s 500m above sea level – and so even though the earthmoving will be complete, the medium excavators will be unable to finish the landscaping work until February 2023. The project is being executed by the civil division of Jan De Nul Group on behalf of ENGIE, the Belgian market leader for electricity, natural gas and energy services.

The upper reservoirs are part of the Hydroelectric Power Station at Coo-Trois-Ponts. Turbines are used to pump water to the upper reservoirs when there is a power surplus. When power demand is high, hydro power from the upper reservoirs is used to power the same turbines. The dykes at the upper reservoirs were raised and widened to increase capacity on the one hand and, by widening, to meet the highest seismic standards on the other.