Tank Refurbishment8/5/2004 1

The gas tank operated by the city utilities in Ludwigsburg is currently being refurbished, and corrosion prevention experts have to treat the entire surface of the tank. Safe access to all parts of the gas tank is assured with the use of a modular scaffolding system. By using Layher's superior Allround equipment, the company Feig Gerüstbau GmbH from Seewald, secured the contract.

The advantage lies in the speed with which not only the right angle can be automatically obtained with the system, but also variable angles can be achieved if required. This is done by fitting the ledgers in rosettes each with four holes at right angles, with four further larger holes (usually used for diagonal braces) being used to facilitate variable angles. This means that the erectors can also make connections at any angle as dictated by the conditions on site. The scaffolders can easily, thanks to the eight possible connections in every connector, make adaptions quickly and optimally for almost any application.

These advantages ensure the optimum conditions for effectively enclosing the round tank with scaffolding. Allround was easily adapted to follow the contour shape of the sphere without difficulty. The erectors didn't need to create complex tube structures, saw off tubes all the time, repeat measuring of connections or constantly align the upright elements. The wedge head provides an all in one simple yet stable connection, coupled with a logical assembly sequence and integral safety. Hot-dip galvanisation and certified quality assure Layher's top-quality products are extremely long-lived.

Several work levels were required plus a lift going up 16 meters were required to be integrated into the scaffolding. The challenge set by this particular job was to follow as precisely as possible the double-curved surface of the tank. This was possible due to the extensive catalogue of parts Layher are able to offer.

Conventional anchoring to the tank was not possible. The scaffold erectors were only able to make connections to the all-round steel profile – the runner rail for the inspection ladders – at the tank's "equator" using scaffold couplers. Above and below this anchoring level, the scaffolding was secured by all-round steel cables. A Layher landing-type stairway tower allowed convenient access to the scaffold at various levels.

The top lift of the scaffold at the top of the tank called for Layher’s expertise. Following the increasingly tapered scaffolding radius above the equator, Layher’s Technical Bureau designed a series of connected lattice girders to the topmost Allround standards which made them converge in tension-resistant form. The scaffolders then placed the structure on the highest point of the gas tank using four Allround standards.

This method has already proven its worth in time saving alone. Eight scaffold erectors of Feig GmbH were able to assemble 250 tons of material up to a height of more than 30 meters within 3 weeks.