Rack and pinion drives for movable glass façades

A group of 1,320 new rack and pinion drives from Framo Morat are providing a movable glass façade

The façade louvers on the architectural prize-winning “Kraanspoor” building in Amsterdam are able to move once again thanks to new, corrosion-resistant rack and pinion drives from Framo Morat.

The 270-meter-long “Kraanspoor” office building was constructed in 2008 on a site previously belonging to a ship crane. The building has a double-layer glass façade, whose outer hull consists of electrically adjustable glass louvers with a silk-screened coating. With the help of rack and pinion drives, these louvers can be opened between 0 and 90° to limit direct sunlight and glare effects from the water’s surface.

At least, that is how the architects imagined it – in practice, it became apparent after just one year that the rack and pinion drives that had been installed were not coping well with the rough sea climate. Many of them were so heavily corroded after just one year that the glass louvers could no longer move.

In order to prevent corrosion problems in the future, the new drive has been manufactured from high-quality, corrosion-resistant materials. The casing consists of a salt water-resistant cast aluminum alloy and is further protected by a double-layered light-gray coat of paint. The worm shaft and rack are made from hardened stainless steel. The gearbox itself is double-sealed; in addition, the pressure inside each drive has been equalized. “We’re happy that all of the louvers are movable again and will be for a long time to come thanks to the high-quality components,” says the project developer responsible at Framo Morat.