Products and solutions, 2007-03-05, 10:04 AM
Modularity for singularity
High-grade scaffold structures – for maintenance docks or radar towers – are an everyday sight in the aviation sector. These are always tailor-made structures precisely adapted to the specific task in hand. The design, production and assembly of such singular structures have been one of the specialties of RöRo Shoring Systems for decades. The experts from Special Structures and Airport Technology have developed special modular systems facilitating the swift realization of one-off scaffolds.
New radar tower for the “Tiger”
For example, on behalf of EADS Deutschland GmbH (European Aeronautic Defence and Space Company), they developed and constructed a new, 27 meter tall radar tower this year for the German armed forces base in Celle. The new radar became necessary because part of the training on the new “Tiger” combat helicopter is taking place in Celle. Only two months after contract award, the scaffold tower was completed – even though an entirely new substructure had to be designed and built. By contrast with the standard version, the bottom twelve meters of tower splay outward. This yields a broader base for the hot-dip galvanized steel tower and gets it ready for a new generation of significantly larger radar antennas.
Previously, a 6 meter tall, a roughly 1.5 metric ton radar antenna and its entire wiring were installed on the tower. Future systems, on the other hand, will be joined by a so-called IFF (Identification, Friend or Foe) antenna and a container-like shelter accommodating the electronics. Inclusive of lightning conductor, head structure and shelter, the future antenna will be about 11 meters tall and weigh 10 tonness. And even then, the tower has to be strong enough to minimize the swaying induced by the wind and by the motion of the revolving radar antenna so as not to affect the radar image.
Variety of applications
For such extreme loads, the system used for the radar tower is particularly suitable, since it comes originally from the heavy-duty stationary shoring sector. The base structure is a standardized, four-column tower frame with a footprint of 3 by 3 meters. The height of the vertical divisions is either two or three meters. The tower is fully equipped with stairs and intermediate platforms and is suitable for a variety of applications, ranging from radar towers to fire-fighting and observation towers. The uniform dimensions and consistent grid system of the individual components permit subsequent extension and re-equipping without reinforcement or modification of the system as a whole.
From passenger plane to cargo carrier
For the design and construction of various maintenance and conversion docks for EFW (Elbe Flugzeugwerke) in Dresden, the Airport Technology department of RöRo Shoring Systems made use of the successful modular principle. Resorting to the internally developed Rüstfix SR75 aluminum scaffold system, a total of 33 platforms of different sizes were built within the space of eight weeks. With their help, airplanes of the Airbus A300 and A310 models are being converted from passenger planes into cargo carriers in a purpose-built hangar at Dresden Airport.
For this job, the real challenge was the incredibly tight schedule. Rainer Amler, in charge of Airport Technology: “Four weeks after receiving the order, the already tight deadlines were brought forward yet again. This really put the pressure not only on ourselves, but also on our materials suppliers.” For example, the high-grade ribbed aluminum planks (continuously cast sections) were produced concurrently in shifts in Switzerland and Germany. For dock assembly, they also pulled out all the stops in order to keep to the extremely tight deadlines. Engineer Amler recalls: “To save assembly time on site, we fully assembled some of the platforms in our store and transported them to Dresden as exceptional loads.”
The special scaffolds have been in operation since mid-August 2006. For all the required conversion work on the Airbus planes, they afford comfortable and, above all, safe access to the wings, engines and undercarriages. This also applies to the plane’s “on-jack” state, when the entire airplane is raised on hydraulic jacks so that the complete undercarriage hangs in the air with extended suspension. The docks also have to accomplish the change in height of about a meter required for this, i.e. they are all height-adjustable. They also have to be lightweight, safe and extremely strong – after all, they will be in operation for many years to come. To satisfy these requirements, the basic structure developed by RöRo can exploit all its advantages. It has its origin in mobile shoring engineering and has all the required credentials. Thanks to its modular design, the various platform designs can be adapted perfectly to the task in question. The range of special scaffolds extends from a small, mobile individual dock, which is used outside on the runway to check a single maintenance item through to an all-round combination dock which is compatible with several types and sizes of airplane and with whose help a complete airplane can be dismantled down to the outer shell.