With the use of high technology, shipbuilding in Germany is fit for the future. This is exemplified by Meyer Werft GmbH in Papenburg. Consistent high-volume production in steel structural work with defined planning and production processes, as well as the use of the latest lasers and automation technologies, make the shipyard a model company. Modern plastic energy supply systems from igus GmbH, Cologne, are used for the supply of energy and media to a gigantic crane system with a total of 8 crane bridges. They provide the necessary flexibility and freedom of movement when manufacturing high-precision steel components.
"We process up to 70,000 tons of sheet metal per year. The individual sheet thicknesses are between 4 and 30 mm. In order to remain competitive in the future, our management has decided to invest now in an expansion of the laser centre," says welding engineer Dipl.-Ing. Dirk Wobken. Among other things, he is responsible for steel prefabrication at Meyer Werft Laserzentrum GmbH in Papenburg. The team developed the new system in just under two years. It was inaugurated in early autumn 2009. The shipyard, which is family-owned, invested around 80 million euros in the new production area.
The work is carried out mainly in three shifts, six days a week in the new Hall 10, which is 361 m long, 45 m wide and 20 m high. Mainly lid panels are produced here. These are sheet panels with the dimensions 25 m wide and 30 m long. They are assembled from several different batches of sheets into one large one and automatically provided with stiffening profiles. This is followed by the manual welding on walls and other components. These are then the so-called hotel sections, which are assembled in block construction to form the actual hull. "Of course, we have to manufacture very precisely," says Dirk Wobken. "Our area is therefore also popularly called 'precision engineering'. " One section weighs between 80 and 130 t, depending on the complexity of the later equipment.
The actual construction of the ship begins with the steel construction. "We are currently working on several cruise ships simultaneously," reports Dirk Wobken. Between 200 and 300 employees are employed full time on site in the hall.
At the compact shipyard in Papenburg, about 48 nautical miles from the North Sea, luxury liners, upscale cruise ships and Disney cruise liners are built, as well as ferries, gas tankers and animal transporters. However, the focus is on the construction of sophisticated cruise ships. The 'Made in Germany' quality seal is very much in demand in shipbuilding, says Wobken. For this reason, established national and international shipping companies have commissioned new ocean liners, including the German shipping company Aida Cruises. The latest flagship, the "AIDAblu", the seventh ship in the world famous "Kussmund" fleet, was handed over to them at the beginning of 2010.
The data of the "AIDAblu" are impressive: a total of about 8,000 people were involved in the completion of the 252 m long and 32.2 m wide ship. 20,100 tons of steel were processed, 1,700 km of cable laid, 200 tons of paint applied and 27,500 m2 of carpet laid in all public areas. In total, the cruise ship offers over 1,087 cabins, 728 of which are outside cabins with window or balcony. On her maiden voyage in February 2010 she sailed to the coastal cities of Western Europe. "It is always a spectacle when a large cruise ship is shunted through the small river Ems," describes Dirk Wobken.
Embedded in the new Hall 10 of the Meyer shipyard, a gigantic crane system is used in the prefabrication of the hotel sections over a length of almost 200 m. This system consists of eight individual cranes connected in series, each of which can travel a section of the longitudinal travel of approx. 75 m. The travels overlap here, so that depending on the order, several cranes are available in a certain section.
In principle, the eight individual cranes are customised single girder bridge cranes that are positioned at right angles to the hall. Each crane bridge is equipped with six pivoting arms over a span of around 40 metres. "With these pivoting arms, we make welding technology available at the manual workstations," says Dirk Wobken. Designed and built by Siempelkamp Krantechnik GmbH, these so-called work gantries ensure the high flexibility and availability required by the shipyard.
At each of the welding workstations, welding units specially tailored to the requirements on site are available, which are equipped with welding wire feed, media supply with the respective welding gases as well as compressed air and exhaust. The pivoting arms can be individually adjusted, so that the carrier is available to
the employee at his workstation at the desired height with the required medium. Travel and set-up times are minimised, and necessary parameter settings can be made quickly.
Shipbuilding at Meyer Shipyard is generally a continuous flow process. "The work gantries are made available depending on the workload and size of the section," explains Dirk Wobken. One cycle lasts eight to ten hours. A block with many hotel rooms is often more complex than, for example, the pool or theatre area. "In the latter case, one work gantry is sufficient, while for other sections, up to three work gantries are in use simultaneously. “
Robust energy supply systems of the E4/4 system are used on the longitudinal and transverse axes of the 'Megacrane' to supply media to the flame-cutting and welding systems. These were delivered with easy-to-assemble aluminium troughs for safe guidance of the energy chains on long travels.
On longitudinal travel, the cables and hoses laid in the energy supply system serve purely for media supply. "Here the requirement was that the various hoses should be given a certain amount of freedom of movement. Because they are subject to pressure and can change. They become shorter or stretch out," explains Dirk Wobken. "Nevertheless, they must be positioned as accurately as possible and may only be bent or rolled within certain bend radii defined by the energy chain. " Thanks to the special interior separation elements of the "E4/4" chains, the hoses are also laid cleanly. They can move freely at any time in the longitudinal direction and do not exert any pulling force on the energy chain system in the radius.
The travels of the longitudinal axis are 75 m. In order to implement an arrangement of the work gantries on eight overlapping travels, the energy chains run partly in parallel, partly in opposite directions on two adjacent tracks in aluminium guide troughs. Heinrich Kampen, CEO of Siempelkamp Krantechnik GmbH: "An extremely compact arrangement of the eight energy supply systems was important here in order to ensure that all eight welding gantries were supplied with power. " The special challenge during the installation was the order of the gantries. They must be able to travel in their respective areas without the moving ends getting in each other's way.
Virtually half of the two parallel guide troughs disappear into the double-T girder of the crane track. "The entire energy chain system has a very compact design, nothing is hanging in the field of view or vision," explains Carsten Jeschke, technical sales consultant at igus. "Added to this is very high stability and quiet operation. “
On the transverse axis, the energy chain systems are also equipped with highly flexurally resistant "chainflex" special cables from igus, which serve to transmit power and control signals. In detail, these are special control and motor cables for energy chains, which achieve a long service life in dynamic continuous operation. Because in steel construction things are particularly rough. Both the plastic energy chains and the cables are exposed to demanding external conditions: Welding and grinding, the energy supply systems are exposed to dust and dirt, and often flying sparks.
In addition to the harsh ambient conditions and the possibility of integrating the system into the crane structure in a very space-saving way, there was another reason to rely on an energy chain solution early on: the radius limitation of the hoses with their sensitive media defined by the chain. In addition, this system has already proven itself for many years in similarly demanding applications at Meyer Shipyard. "This is an ideal solution for the high demands prevailing here," confirms Heinrich Kampen of Siempelkamp Krantechnik.
"In the past, the welding machines were located in the peripheral areas and had to be transported up to 40 m to the respective location by the employee with a hose package and media," says Dirk Wobken. There was a very high risk that welding machine components would break during the relatively complicated process. Sharp corners and edges, falling components as well as the ubiquitous industrial vehicles could damage cables and cause downtimes. "In addition there were the travel times," recalls Dirk Wobken. "Today, however, the availability is right. The work gantry moves to the place where it is needed. It can be welded at eight different points simultaneously. “
Energy chain expert igus has already provided intensive consultation in advance at the Meyer shipyard and also at Siempelkamp Krantechnik. The energy chains with the "chainflex" special cables and the aluminium guide troughs were exactly matched to the requirements on site. The subsequent installation of the energy chain system at a fixed price was an additional service provided by igus. "We had a very tight time window for the installation," reports Dirk Wobken.
"Since we work with flammable gases, the work gantries had to be approved for gas, so that only two weeks were available for the installation of the energy chain systems on the eight gantries. But everything went smoothly. “