Moscow's new landmark

The 432 m Federatsiya office tower is part of the new Moskva City development in Moscow. Built on a 223,048 m² footprint, Moskva City is being billed as “a mini-city within a city” and will be completed in 2010.

The Federatsiya (Federation) tower will consist of two skyscrapers, 354 and 242 m high, and a 432 m spire between the two that will house stairs and elevators. An elevator with a 360 degree panoramic view of Moscow will take visitors up through a 20 m high aquarium to a viewing platform at the top of the spire.

The US$500 million Federation tower will house restaurants, a luxury hotel, apartments and offices. Construction of the complex is due to be completed in 2007.

Mirax City, the Russian contractor building the skyscraper, is aiming to complete construction of the triangular, sail-shaped buildings in record time and is allowing a building of time of two to three days per storey. To help achieve this, five Liebherr 160 HC-L top slewing luffing jib tower cranes are being used on the site. Three luffing jib units were used in the first phases of construction, the lowest of which had an under the hook height of 79 m. This crane was anchored to the building while two others, with under hook heights of 295 and 288 m, were erected inside the building's footprint. When construction of the second tower begins, Mirax will add the last two Liebherrs to the site. At the time of writing in late March, foundation work on the second tower had just started with the first concrete pours taking place.

All cranes on the site have frequency regulated 65 kW hoists, which, Liebherr claims, provide a higher output and allow the operator to move loads precisely and without jerks in any speed range. Another feature of the cranes on the Moskva City site is the level luffing technology, which operates the hoist gear during jib movement to ensure that the hook travels horizontally. The system also allows overlapping both of the jib and hoist gear.

One of the potential problems encountered when erecting the tower cranes was the narrowness of the building's lift shafts, which have a cross- section of 2.6 m. This was solved, however, by the crane's internal climbing tower system, which was specially designed for use in such confined spaces. Its exterior measurements are 1.9 m x 1.9 m, which makes it suitable for use in such a restricted area. •