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Polish firm selects another Doosan loader

Doosan DL420-7 wheel loader

Doosan wheel loader chosen again after 18,000h of untroubled service for the Wroński Group

THE Wroński Group, a family-run quarrying and construction company based in northern Poland, have purchased a latest-generation Doosan DL420-7 wheel loader – a decision strongly influenced by the performance of the company’s existing Doosan DL420-5 wheel loader, which has completed more than 18,000 hours of trouble-free service and is still going strong.

‘We know the Doosan brand very well. The first machines in our fleet were two DL400s, which to this day are still used for smaller jobs,’ said managing director, Mateusz Wroński.


The company has always been focused on developing the business with regular investments in new equipment, and in 2015 the Wroński Group management began discussions with Grausch and Grausch Maszyny Budowlane, the authorized Doosan dealers for Poland.

‘At that time, they offered us a new-generation DL420-5 machine to test out. We were amazed by its speed and efficiency. The reduction in fuel consumption was so big compared with our old machine, that the money we saved allowed us to pay the leasing instalment, Mr Wroński explained.

After the successful test, the machine never left Węsiory Quarry, where it continues to work without any problems to this day, and has so far achieved 18,000h of trouble-free work. ‘So, in 2020, when we wanted to buy a new wheel loader, we immediately knew it would be a Doosan,’ added Mr Wroński.

The need to purchase a new machine coincided with the introduction of the new-generation of Doosan DL-7 wheel loaders. The existing products have been completely redesigned, and once again the number of standard functions on the machines is said to exceed those on competing models. The company chose a new DL420-7 loader, which, with an operating weight of 23.4 tonnes, is one of the larger models in the new Doosan DL-7 range.

The DL420-7 is powered by a Scania DC13 6-cylinder engine that produces 257kW of engine output at 1,800 rev/min. The new engine meets Stage V emission regulations without the need for exhaust gas recirculation (EGR), through the use of selective catalyst reduction, diesel oxidation catalyst, and diesel particulate filter (DPF) after-treatment technologies.

The soot cleaning cycle on the DPF has been improved to more than 6,000 h and the operator is fully informed about the status of the DPF via a soot level indicator on the new touchscreen display in the cab. Moreover, with no EGR valve and a choice of three power modes (SAT2, Standard, or Power), fuel consumption is reduced by 5%.

According to Doosan, the machine performs very well in difficult terrain, thanks to another standard feature, the hydraulic differential lock (HDL), which is activated automatically at full torque without any additional action from the operator.

The five-speed PowerShift transmission gives the driver the option of three modes: manual, automatic, or semi-automatic. A torque converter lock is also standard equipment, which significantly reduces fuel consumption during passes. The lift arm with Z-kinematics is said to provide impressive breakout power and lifting capacity, whilst the large drop angle allows for efficient unloading.

The LIS (Load Isolation System) provides a smoother ride and higher comfort for the operator, as well as higher productivity due to improved stability when the wheel loader is moving. Following the supplier’s recommendation, the bucket capacity has been increased from 4.3 to 4.5 cubic metres and the blade has been fitted with rounded edges and a higher spill guard. This makes loading even more efficient and has a direct impact on reducing cycle times and increasing productivity.

‘Our wheel loaders are mainly used to pick up material from the quarry face and to load trucks,’ said loader operator Rafal Pawlowski. ‘I can safely say that with the DL420-7, the work has become much faster, and the machine never lacks power. The loader is very stable, and the hydraulics are smooth, which provides dynamic movements.’

He continued: ‘The ability to control the direction of travel with the joystick is especially praiseworthy, particularly when the work requires repetitious manoeuvres; for me, this hits the bull’s eye for loader operation. Operator comfort has certainly increased, the protection against shocks is clearly noticeable, especially when you are working a 10h day. Another important improvement for me is the easy access to filters and components, which means that daily maintenance requires a minimum of effort.’

The operator’s cab is spacious, and the steering is electrically controlled. All settings and information can be accessed via an intuitive 8in touchscreen, which is easy to read in all conditions. Safety was one of the most important aspects when designing the DL-7 loaders. The operator’s field of vision is increased by enlarged windows, whilst LED work lights in a four-front, four-rear configuration provide excellent illumination, especially in the winter months.

‘We work with relatively light material, such as sand, gravel, and stone, but the quarry is quite steep and the terrain is bumpy, which means the machine is heavily laden during loading. With this workload, the average fuel consumption of 13 litres/h is a very good result,’ said Mateusz Wroński.

‘Since delivery of the machine, we have used it for more than 2,500h without a hitch, so I consider this to be an extremely successful investment. I’m glad that I was the first in Poland to have the opportunity to test the capabilities of this excellent machine. When I choose Doosan, I get quality at a reasonable price, without compromises.’

Like all Doosan DL-7 wheel loaders, another advantage offered by the DL420-7 is the factory-installed DoosanCONNECT TMS 2.0 wireless fleet-management system, which provides extensive information about operating parameters, including work efficiency, via satellite and mobile networks. Also, the standard warranty on all Doosan DL-7 loaders is 36 months or 5,000h, whichever comes first.


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