New Doosan Wheeled Excavator Outstanding in Forestry Work 

Kunz & Co. GmbH from Todtnau in the Black Forest region of Germany has purchased a new Doosan DX190W-5 wheeled excavator, specially modified for forestry work. Already in its first few weeks, the Doosan excavator has impressed in the timber harvesting, logging and excavation work carried out by Kunz & Co.

Uli Thoma, Managing Director of Kunz & Co., purchased the new excavator from the Doosan dealer, Ummenhofer Baumaschinen GmbH, based in Pfullendorf/Schönau. The conversion for use in forestry work was carried out by Ummenhofer working with Wirkstoff Technik, an engineering consultant for construction and forestry machines, based in Constance. 

Performance and Stability Count

The use of powerful excavators in forestry operations has increased significantly in recent years. This is because when they are appropriately equipped, they can be used not only in timber harvesting and processing, but also in road construction. These excavators can be used for a wide range of applications, thus ensuring high utilisation of the machines. 

In this environment, the external conditions place high demands on the machines. So the correct selection of the carrier machine, which is to be adapted to meet the individual customer’s needs through appropriate conversion measures, is of great importance. To find the right machine for himself, Uli Thoma turned to the Doosan dealer, Ummenhofer, and the specialists at Wirkstoff Technik. 

Requirements Fulfilled

Uli Thoma had high requirements when selecting the carrier. It had to be powerful and have a high hydraulic output. From his point of view, there were many factors in favour of a Doosan machine: “We had had good experience with a Doosan excavator we owned, so when Ummenhofer became active as the Doosan dealer in our vicinity, it was a foregone conclusion for us to return to the Doosan brand. We also found that our good experience is mirrored by more and more forestry companies relying on Doosan machines as their forestry excavators.” 

A tracked excavator was out of the question for Uli Thoma, as the excavator had to be transported using the company’s existing three-axle low-loader. In addition, there were factors such as the engine, hydraulic power, the price and the dealer. The excavator also had to be particularly stable and manoeuvrable in the demanding conditions in forests. As a result, the Doosan DX190W-5 wheeled excavator was chosen. 

Strong Performance

The Doosan DX190W-5 wheeled excavator has a powerful and reliable Doosan DL06P six-cylinder engine with an output of 129 kW. This is complemented by a high hydraulic output of 2 x 200 l/min as standard, which can be combined via pump summation. This means that an attachment with a high flow requirement can also be operated. This hydraulic output also meets the high performance requirements of processor-aggregate operations. The dozer blade and claw attachments also increase the stability. 

Extensive Conversion

Forestry excavators work in a wide variety of areas at Kunz & Co. GmbH. One of the main tasks is as process excavators. Here, logs are measured, delimbed and cut to length in one step and thus prepared for further use. In addition, the machines are used for forest road construction.

A number of conversion measures were necessary for this. In addition to the safety modifications required for a forestry excavator, such as the forestry protection shoring, a frame-mounted protective roof and the chain-shot-proof windscreen, a number of additional works were carried out in order to adapt the excavator individually to its future uses. These included an Oil-Quick quick coupler to change the various attachments needed, a conversion to bio-oil and 700 mm wide tyres. The core of the conversion was the P60 processor unit including Koller Forsttechnik controls. This weighs 1.6 tonne and delivers its optimum performance at a hydraulic output of 280-300 l/min. After the conversion, the excavator had a total weight of 24 tonne and can thus be transported on the low-loader.

Worthwhile Investment

After just a few weeks in operation, Uli Thoma is very pleased with the DX190W-5: “The forestry excavator has proven itself in a wide variety of application scenarios and has proved to be extremely reliable. The comfort in the driver’s cab and the sensitive controls are like nothing I‘ve experienced before.”

Founded in 1980, Kunz & Co. GmbH is primarily active in the areas of logging, timber harvesting, excavator work and snow removal. The company employs a total of 12 people and has an extensive fleet of machinery ranging from special forestry tractors to excavators, self-propelled snow blowers and trucks.

Wirkstoff Technik

Wirkstoff Technik from Constance was founded in 2015. Wirkstoff Technik provides designs and developments for large OEMs, but also builds individual machines for end customers. The direct connection to the user is reflected in the designs. For this purpose, engineers, fitters, technical draughtsmen and service fitters work hand in hand. 

The high level of expertise in the areas of design, steel construction and welding technology designs make it possible to develop add-ons, attachments and complete solutions that optimise existing systems and machines.


Ummenhofer Baumaschinen GmbH, founded in 2006 and headquartered in Pfullendorf, currently employs 25 people, four of whom work in sales and 14 in service. In 2019, Ummenhofer opened a new branch in Schönau. In addition to the sale, rental and service of construction machinery, Ummenhofer also offers its customers a wide range of workshop services for the repair, maintenance and care of commercial vehicles and construction machinery. In order to offer the high-performance service on-site at the customer’s premises, the company maintains eight fully equipped service vehicles.

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