Established in 1878, Doll Fahrzeugbau GmbH, based in Oppenau, is managed as a family-owned business in the fourth generation. It is the largest manufacturer of timber transport vehicles worldwide, says Demag. It adds: “The company also manufactures special transport vehicles and mobile systems. The latter include catering vehicles for airports, a market segment in which Doll, together with a partner in Thailand, is the world leader.” In Oppenau, the company manufactures complete vehicles, but also kits for final assembly by partner companies in Asia and Africa.

When Doll reached its capacity limits, the company had to extend its production area. The construction of the final assembly shop marks the completion of the first milestone to transform the premises. The new building will not only help to secure the jobs of the current 300 employees, but it will also create new jobs in the foreseeable future.

Planning

Demag was involved in the planning and architecture process of the 4,500 square metre workshop. Four double-girder overhead travelling cranes operate in each of the four workshop bays. Together with indexed staging areas, they form the basis for the continuous production line. The 6-11m long vehicles are each cycled through the final assembly line by two cranes. Since four cranes are operated in each bay, two vehicles can be moved along each line at the same time. The capacity of the workshop is sufficient to complete the assembly of approximately 1,000 towed vehicles – such as semi-trailers and trailers, as well as truck bodies, for catering vehicles, for example – every year.

Doll’s primary requirement of the double-girder overhead travelling cranes is to provide sufficient load capacity. The cranes have to be able to lift and turn the 20-25t vehicles safely. For this reason, each crane is fitted with two DR rope hoists, which each have a load capacity of 6.3t. The DR rope hoists have reserve lifting capacities that enable the load capacities to be increased to 8 or 10t. Doll will need the reserves if large and heavy export vehicles for oilfield exploration are added to the range.

To enable the DR rope hoists to lift the vehicles on the level, they are controlled in parallel by means of an integrated Canbus. Also connected to the bus are the load display and strain gauge carrier link, which offers the possibility of electronic load limitation and also overload protection.

In addition to the high load capacity, Doll requires permanent availability to ensure that the Demag cranes operate throughout three-shift operation from Sunday evening to midday on Saturday. In addition, the cranes have to be simple to operate.

Work on the new building started in April 2006. To reduce installation time, Demag lowered the cranes through the roof while it was still open.


Demag was involved in the planning and architecture process of the 4,500 square metre workshop demag 1 The cranes lift and transport vehicles weighing up to 25t demag 3 Each crane is fitted with two DR rope hoists, which each have a load capacity of 6.3t demag 2