200 000 bus and coach seats made yearly at the Neu-Ulm production facilities
Over 120 employees work in the cutting, sewing, upholstery and assembly sectors
Six basic seat variants and over 600 kinds of fabric and covers in programme
With a total of 450,000 seats made every year, Daimler Buses is Europe’s biggest manufacturer of bus and coach seats. Together with the production facilities in Mannheim and Turkey, the Neu-Ulm-based seat production is a supporting pillar of this order-based in-house production with which the company underscores the high standards it maintains in respect of comfort and safety, as well as emphasising the broad range of individual seating designs it offers. It also supplies other European locations, e.g. France and Portugal.
Work preparation and logistics teams control process down to the finest detail
Year after year, almost 200,000 seats for rural buses and touring coaches for the Setra and Mercedes-Benz bus and coach brands are made on the second floor of the Neu-Ulm assembly plant and thus in immediate proximity of the bus and coach assembly itself, to be delivered directly to the production line “just in sequence”.
Here it is essential that the finished seats reach the vehicles according to a precisely defined schedule. But not only that: since hardly any two bus or coach seating designs are alike because the manufacturing of the seats is based exclusively on each individual order according to customer wishes, there is no such thing as an “off the peg” seat, explains Andreas Niesl, who has been at the head of this 5000 square-metre “factory within the factory” for the past two years.
The strong backbone of the 124-strong seat production team is made up by the employees in the work preparation, production control and logistics sectors. Seat manufacturing itself is divided into three sectors: cutting, sewing and special seats, as well as upholstery line and final assembly. Maximum daily production is around 1500 units, with a model mix that ranges from diverse basic seat models, from the simple “Transit” inter-urban bus seat, to the luxurious “Ambassador” maximum comfort seat with leg rest for touring coaches. These 1500 units correspond to the quantity necessary to equip a total of 30 vehicles.
500,000 square metres of fabric cut every year
At the nearby Setra customer centre, customers can choose from a palette of up to 300 different types of fabric to freely compose their customised seat design. But individual coach and bus operators’ requirements and wishes can also be implemented and processed in Neu-Ulm, so that at the moment around 600 different fabric numbers are active and can be called up. The 200,000 seats made every year require close on 500,000 square metres of fabric, leather and leatherette – enough to cover 70 football pitches.
After their delivery by the suppliers, the raw materials are stored in the fabric warehouse, from where they are called up as required by the current orders. Cutting the layers for the individual seats from the fabric proceeds CNC-controlled by means of a cutter with an oscillating blade moving at a speed of 50 centimetres per second. In cutting seat covers for special customer requirements the team led by Andreas Niesl demonstrates the highest degree of versatility.
Industrial sewing machines sew at a rate of 3000 stitches per minute
A total of 16 employees work in the sewing workshop. Working at ergonomically-designed, fluidly height-adjustable workplaces, each one of them carries out the entire work process of sewing the complete seat cover. The compressed-air-powered industrial sewing machines used work at a rate of 3000 stitches per minute. Driver and tour guide seats are upholstered and mounted in a special sector. Andreas Niesl: “We upholster the driver seats ourselves, as many customers want them to have the same fabric as the rest of the seats. Apart from comfort functions such as seat heating, components of the safety system are also integrated in the driver’s seat. For example the vibration motor for the Lane Keeping Assist system (SPA) is installed here. Lane Keeping Assist warns the driver in the event of inadvertently crossing a lane marking.
A high degree of process reliability through laser-supported seat backrest assembly
In the third sector of the coach and bus seat assembly is the upholstery line, where the backs of the coach and bus seat backrests are assembled. Here, at six workstations, the seat covers are upholstered onto the foam seat backrests. Precise laser-supported positioning makes the job easier for the worker and increases process reliability. After this the seat backrests are fitted with different other parts such as handles, table or luggage nets, at 16 further workstations.
For this stage of the work, the workers can rapidly and flexibly adjust all necessary tools and equipment to the different seat and equipment variants. Specially-developed templates show the desired assembly positions for the components according to customer requirements. The components needed for this have been previously commissioned in a precisely defined sequence and taken to the corresponding assembly station in a load carrier.
After two “quality gates” the seats are available for installation in the vehicle
In the first Quality Gate all the seat backrests are examined for defects, and any faults can be re-worked by the same assembling worker. In the subsequent final assembly the seat backrests, seat cushions and seat frame with its respective mechanism, placed on a slowly rotating roundabout, are assembled together to form the final unit. This “carousel” is designed in such a manner that the worker with the workpiece he/she is working on, goes past the material and tools. Depending on the kind of seat, each revolution results in ten touring coach seats or 20 double seats for the inter-urban buses being finished.
After this assembly process, employees of a second Quality Gate control the quality and completeness of the finished seats, before these – via an electronically-controlled rail system – are “wafted down” into the production hall below. There the seats are incorporated into the assembly line and introduced into the bus or coach through the front of the vehicle by means of an inclined supply unit before the windscreen is put in its place.