A Hangar on Wheels

The past few weeks have been very exciting in Hamburg. One of the most discussed topics associated with the prestigious future project of European aircraft manufacturing, the Super Airbus A380, had been the necessary partial filling of the Mühlenberger Loch (‘Mühlenberger Hole’). Apart from that extension of surface area, some changes to existing factory buildings had been required in order to make room for new final assembly facilities.

One of the project’s requirements was to cause as little impact as possible on the ongoing production. A trans-shipment hall which was important for the ongoing production processes had to be relocated. To accomplish such a task, some extraordinary methods were needed. And time, of course, was a critical and very limited factor. The construction of a completely new hall would have required a down time of at least eight months. Furthermore, the construction works for the new assembly facilities were supposed to begin as soon as possible. Dismantling the old trans-shipment hall was not an option because that would have delayed the commencement of the constructions works for the new final assembly facility considerably.

The question now was: what to do? The idea to relocate the entire hall in one piece seemed most promising. But how could such a task be accomplished? The date of relocation was fixed for the first weekend in March. The spectacular relocation was made possible thanks to the cooperation of several companies that specialize in the application of sophisticated technology. As a first step, the empty hall was equipped with a ‘scaffold’ that was made of a special steel structure. The hall’s supporting pillars were then firmly connected to that ‘scaffold’. The large gates, the crane, lamps and other parts of the hall were kept in place and fixed to avoid any uncontrolled movements. The task of the steel structure was to act as the hall’s base plate during the relocation process. Four multi-axis hydraulic vehicles were positioned under the steel structure which was in contact with the vehicles at eight support positions. Each individual vehicle axis could be lifted and lowered by remote control.

After the hall pillars had been separated from the old base plate the hydraulic vehicles lifted the entire hall and the relocation process covering a distance of 800 meters to the new location was ready to begin. The lifting, the horizontal movement and the lowering of the hall had to be done simultaneously. In the process it was crucial that the hall did not deviate more than ± 5 cm from its original horizontal plane at each of the eight support positions. FPM Holding GmbH and their team were responsible for monitoring and detecting any changes in height during the relocation process. To that end a horizontal plane made of laser beams was created approx. 1 meter above the steel structure.

The laser beam was emitted by an automatic laser line level FG-L3 manufactured by FPM. Laser receivers were positioned at each of the eight support positions of the steel structure. In order to monitor any movements those receivers continuously transmitted the measured values to a display panel. That display was positioned very close to the control panel for the hydraulic vehicles. Once the value of one of the eight measuring positions exceeded the limit for the permitted height difference the hydraulic mechanism was set in motion to correct the error. After a short initial testing phase the team was able to optimize the procedure of detecting a vertical displacement and correcting it, so that the hall could be moved forward almost at a record pace. That way it was possible to perform much better than anticipated, because the hall arrived at its new location on Saturday afternoon already and not on Sunday noon as initially scheduled. There are two different methods available for the data transmission of the height monitoring system. The data can be transmitted from the measuring point to the control panel either with a normal cable connection or wireless over distances up to 200 meters.

The accomplishment of this extraordinary relocation of an entire hall was only made possible thanks to the enormous efforts and an exemplary team spirit of all people involved. Despite the fact that the method of relocation was very unusual, it was also cheaper than all other alternatives. Time was the most important factor of success. The relocation resulted in a downtime of only 14 days, so that normal production operations could be resumed right on Monday the next week.