Pre-fabrication

In excess of 50,000 different parts are processed in Pre-fabrication each year, amounting to a use of around 400 tons of steel per week. To assure the reliable Wirtgen quality, the percentage of in-house manufactured production parts amounts to over 50%.

• Flame-cutting machines
  The powerful cutting plants are computer-controlled and easily cut through material of up to 150 mm in thickness.
  
  

• Laser-cutting machines
  Materials of up to 20 mm in thickness are processed by means of a laser beam. Maximum precision is ensured as the laser cuts to an accuracy of 0.1 mm.
  
  
• Bending centre
  The 3D press brakes are the highlights of the bending centre, forming around 30% of the more than 50,000 different parts.
  
  
• Sawing centre
  Powerful trio: a fully automated circular saw, a band saw and a mitre saw cut pipes, sections and solid material to the specified length.
  
  
• Sheet metal working
  Out of the total number of 14,000 different subassemblies, around 7,500 are tacked and welded in this division.
  
  
• Floor-type horizontal boring mill
  Wireless control allows the commands for processing workpieces of up to 25 tons to be transmitted from a central programming station to the boring mill.
  
  
• Flexible manufacturing system
  Workpieces are machined automatically and efficiently in this plant by means of two machining centres with 320 tool storage spaces each.
  
  
• Steel construction
  Steel construction experts at work: large, heavy-duty components – such as machine frames weighing up to 40 tons – are assembled in this division.
  
  
• Continuous blasting plant
  In this plant, turbines working at a blasting speed of 300 km/h clean the edges resulting from flame-cutting from scale or impurities.
  
  
• Powder coating plant
  The plant has a capacity of 50 m² per hour, painting 38,000 different parts – in special customer livery, if desired. Once painted, they are conveyed to the series assembly plant automatically via the Power & Free tunnel.
  
  
• Power & Free tunnel
  The Power & Free tunnel connects Pre-fabrication and Series assembly, covering a distance of 300 m – sufficient cooling time for the freshly painted steel components.
  
  
• Conveyor fabrication
  A field of core expertise: around 20 different conveyor types are manufactured by the Wirtgen experts as complex truss structures for cold milling machines, cold recyclers and surface miners.

Milling drum fabrication

Wirtgen GmbH manufactures in excess of 330 different milling drum types. With milling widths ranging from 14 cm to 4.40 m, Wirtgen offers an unmatched range of solutions in the field of cutting technology.

• Turning shop
  The largest turning lathe in the factory permits accurate processing of milling drum bodies weighing up to 10 tons.
  
  
• Robot line
  State-of-the-art technology enables faster processing: the five welding robots impress with a capacity of between 8 and 10 kg of welding wire per hour.
  
  
• Toolholders
  Maximum precision is applied also to arranging the toolholders on the milling drum. The toolholders are welded to their exactly defined positions at an accuracy of 0.5 mm either manually or by means of a robot.
  
  
• Fine milling drums
  Fine milling drums have a tool spacing of less than 8 mm. Tacking is followed by an optical measurement of the toolholder positions.
  
  
• Milling drum quality
  High demands are placed on cutting technology: all milling drums need to pass numerous tests in terms of quality and accuracy. This is effected by means of detailed verification records.
  
  
• Pre-assembly of milling drum assemblies
  The core component of each cold milling machine is manufactured in the final assembly plant of the series machines: drum, gearbox, bearing and housing are assembled, comprising the milling drum assembly.
  
  
• Special milling drum assemblies
  The cutting drum housing and 4.20 m wide cutting drum of the largest Wirtgen machine – the 4200 SM surface miner – weigh around 30 tons.

Final assembly plant of series machines

Wirtgen GmbH owns the largest final assembly plant worldwide that is specialized on the production of cold milling machines. Covering a floor space of 22,000 m², the plant offers ample room for all assembly steps in its 7 modular bays.

• Goods receiving
  Approximately 1,000 items from selected suppliers, weighing around 160 tons altogether, are processed in this division each day.
  
  
• Central warehouse
  Some 17,000 items altogether are stored in three warehouse zones for provision to Final assembly and for supplying customers with spare parts.
  
  
• Shipping
  Quantity and quality extend to Shipping as well: on average, 2,700 different items are moved here each day, packed and labelled with information in the customer’s national language.
  
  
• Electrical workshop
  Pre-assembly of the power unit is carried out in the Final assembly division, constituting some 25% of the entire assembly effort. A 910 HP engine, for example, provides the largest cold milling machine from Wirtgen, the W 2200, with all the power it needs.
  
  
• Assembly stations
  The intelligent manufacturing concept makes the assembly plant of the series machines a “plant of short distances”: All materials are stored in line with the different assembly stations.
  
  
• Small milling machines
  Small milling machines are manufactured on cyclic assembly lines but each machine is built to customer specifications nonetheless: some 35 equipment options can be combined, for instance, in the small milling machine model W 100 F.
  
  
• Large milling machines
  Cold milling machines having milling widths of 2 m or more are also assembled in series production. A single large milling machine has as many as 2,000 bolted connections.
  
  
• Series recyclers on wheels
  The wheeled recyclers from the cold recycler product division, such as the WR 2000, are also manufactured on cyclic assembly lines.
  
  
• Finishing
  This is where the machines are given their finishing touches: they are cleaned once again, washed and provided with general labels as well as hazard and safety symbols.

Final assembly plant for special machinery

In the final assembly plant for special machinery, which covers a floor space of around 11,000 m², all assembly stations in the plant’s bays can be flexibly adapted to suit the machine model in question. Cold recyclers, hot recyclers, slipform pavers and surface miners are produced in this division.

• Separate warehouse for special machinery
  The great flexibility at the assembly stations places high demands on logistics: that is why the special machinery division has a separate warehouse with a commissioning system that ensures timely provision of the required materials at the assembly station in question.
  
  
• Electrical workshop for special machinery
  The workshop’s proximity to the place of assembly of the special machines permits the electrical installation to be carried out quickly and efficiently. Some 5,000 electrical items are provided in this division.
  
  
• Painting facility for large components
  A separate powder coating facility, which complies with the most recent Environmental Directives stipulated by the EC, is capable of accommodating large components of up to 12 m in length, 3 m in height and 3 m in width. The plant has a total capacity of 225,000 m² per year.
  
  
• Pre-assembly of power station
  The 4200 SM surface miner is the undisputed leader in terms of power: the 200-ton mining expert is driven by a power station comprising a 1601 HP engine.
  
  
• Special-purpose recyclers
  The track-mounted WR 4200 and 2200 CR cold recyclers, as well as the hot recyclers, are built in the final assembly plant for special machinery.
  
  
• Slipform pavers
  The spacious assembly stations in the special machinery plant enable even large machines, such as the SP 1600 slipform paver with a paving width of up to 16 m, to be assembled without difficulty.
  
  
• Surface miners
  The machines in the surface miner product division are produced to customer specification. Space conditions and crane lifting capacities in the special machinery plant have been specially geared to the 4200 SM, the biggest and heaviest machine.
  
  
• Finishing
  This is where the machines are given their finishing touches: they are cleaned once again, washed and provided with general labels as well as hazard and safety symbols.

In-house quality assurance

The machines need to pass an initial extensive quality assurance procedure even during final assembly, being checked by means of numerous verification records. Information desks additionally provide all relevant machine parameters to the fitters.

• State-of-the-art measuring technology
  Once a machine has left the final assembly plant, it is checked yet again by a special quality assurance division: each machine must pass a stringent quality check that is carried out using state-of-the-art measuring technology.
  
  
• Test runs on a special testing ground
  Quality assurance also includes a separate testing ground where, in a final step, the machines are subjected to numerous safety checks and test runs yet again to ensure that only top-quality products will leave the Wirtgen factory gates.
  
  
• Transport safety
  Experienced Wirtgen employees load the machines with great care for their long journey to customers in all parts of the world. A 2500 SM surface miner, for instance, is dismantled into several separate modules for transport by truck, ship or aircraft.