A prestige building is only then properly accepted by the inhabitants of a city, if it has received a nickname. The cheese shop in London did it. However, the sloping south façade has not only given the 225 high building a distinctive nickname, it also made the custom-made construction of a façade access system necessary. The corresponding Drive train technology comes from Nord Drive Systems And provides lift and power for power and safety.
Integral Cradles Ltd specializes in solving architectural challenges in facade access systems. As one of its most recent projects, the British construction company has completed two Building Maintenance Units (BMUs) for an 52 storey and 225 m tall skyscraper in London's financial district. Nicknamed Cheese Grater, the 122 Leadenhall Street building has a 10 ° inclined glass facade. The mission to Integral Cradles was to provide access for all four sides and all areas of the facades.
The tailor-made BMUs are permanently installed on the roof. Each consists of a traveling crane, fastening elements and the suspended scaffolding. The crane boom can be extended to a range of over 20 m. The hoists transport window panes with a total weight of up to 1 t Safety and availability played a key role in the design of the systems. As drives come Helical and Frequency inverters of the "Nordac" PRO series used by Nord Drivesystems.
In demand worldwide serviceIntegral Cradles developed the BMUs for the Leadenhall building together with its Spanish supplier Góndolas in Design, SL (GinD), which provided essential components from its own production or from proven suppliers. GinD is a longtime customer of the drive specialist with headquarters in Bargteheide. The company, headquartered in Madrid, has already equipped numerous BMUs for similarly spectacular construction projects worldwide with North Drives.
Integral Cradles and GinD place the highest emphasis on quality, service and international technical customer service when choosing a supplier. The accompaniment of Nord during the project planning was therefore essential. The engineers of the German drive manufacturer dealt in detail with all critical specifications and designed each drive axle optimally for the application. Local support was provided by the English subsidiary Nord Gear Ltd - one of many in 36 countries worldwide.
Drive functions for lifting technologyEach BMU comprises four frequency converter controlled axles: The crane, which is balanced with a counterweight, can travel on rails over half the roof length and turn around a pivot axis. The crane arm can be extended telescopically and the working scaffolds on the building facade are lowered via a winch. The rocker axis for positioning the crane arm has a hydraulic drive. The application requires a gentle acceleration and deceleration, which is implemented by Nordac PRO frequency inverters.
With the user-friendly software "Nord CON", the frequency inverters can be set up quickly and safely. The list of parameters relevant to the application tasks includes, for example, acceleration and deceleration ramps for smooth starting and stopping, different speeds and braking behavior, and safety functions.
The optional "Parameter box" allows the user to quickly change a few parameters on site and to copy the same parameter sets to several inverters. Precise vector control and high overload capability allow safe operation of the geared motors at high torque requirements. Each Nordac PRO has a comprehensive range of interfaces, including the connection to the customer PLC, which controls the synchronization of all axes. The frequency converters are mounted in a weatherproof control cabinet near the BMU.
All drive components from our own productionThe gearmotors on the BMU axles were also manufactured and assembled by Nord. The motors are energy-efficient IE3 models with rated outputs up to 5,5 kW. For some axles they were equipped with safety brakes, which can be ventilated manually. All motors mounted vertically have a protective cover over the fan cowl to prevent the rain and dirt from penetrating backwards. All motorized axles are equipped with highly efficient bevel gearboxes.
The well-proven block housing, made of a cast-iron block, withstands the heaviest loads without deformation. All bearings and seal seats are integrated into the block housing. There are no weak spots such as joint surfaces or attachments where mechanical wear or oil leakage could occur. The use of larger journal and gear diameter also increases the torque capacity as well as the life and reliability over comparable makes.
Picture above: Above the rooftops of the city, a bevel-helical geared motor from Nord allows the boom of the facade access system to be extended.