Site report: Down on the water

German lifting specialist Thömen chose a 750 tonne capacity barge-mounted Liebherr mobile crane for its project to dismantle the last construction crane on the Philharmonic Hall waterside construction site in Hamburg. Alex Dahm reports.

Construction is approaching completion on the Elbe Philharmonic Hall, a new concert hall in the Port of Hamburg, Germany. Tower cranes have been on site since building work began in 2007. Local crane and heavy haulage contractor Thömen used a 750 tonne capacity Liebherr LTM 1750-9.1 wheeled mobile telescopic hydraulic crane to dismantle the last of the four large top slewing tower cranes that were on site for years.

A challenge with this particular tower crane, erected on the south west façade, was that it had to be dismantled from the river. In 2007 Thömen erected it using a 500 tonne capacity LTM 1500-8.1 mounted on a floating pontoon in the tidal river.

Jörg Marahrens, Thömen project manager, was charged with the job of removal. A larger crane on a fixed jack-up platform was needed because the height of the tower crane, tied in to the building, was around 120 metres. It had been climbed down as far as possible, until the boom could just still be slewed over the edge of the building. In addition, a larger crane could remove several tower sections at a time, speeding up the job.

The 750 tonner on nine axle carrier is Thömen’s most powerful crane. It was erected and prepared for the job at Burchardkai, in the west of the Port of Hamburg, on a jack-up platform 75 m long.

The crane was rigged with 114 tonnes of ballast, 19 m telescopic boom extension and a 66 m luffing jib for the required hook height of 127 m. Space was restricted on the barge by the jack up legs, a crawler crane and other equipment on deck. Erection of the luffing jib was completed with the help of a Liebherr LHM 320 mobile harbour crane on the quay.

Two tugs towed the platform with the crane upstream through the Port of Hamburg, taking an hour to travel around ten kilometres, passing the old Elbe Tunnel, the St Pauli Piers and the dry docks of the extensive Blohm+Voss shipyard.

Immediately in front of the Elbe Philharmonic Hall, the jack-up platform pushed its legs into the river bed to raise the platform to the water level of the high tide. This meant that the crane work could be completed without any hindrance from the tides or the bow waves from passing shipping.

The two crane drivers, Jens Kohlmorgen and Ralf Ramm, had to exercise great caution and work very precisely when dismantling the construction crane, which was just three metres away from the glass façade of the concert hall.

After removing the ballast blocks and the boom, however, the wind speed increased, which meant that the work had to be stopped for several days. Problems with undoing the crane bolts after seven years caused an unforseen delay in the removal of the crane and meant that the initial timeframe with ideal weather conditions, which should normally have sufficed for the work, had to be extended significantly.

Thömen has three Liebherr LTM 1750-9.1 wheeled mobile telescopic cranes, stationed at depots in Leipzig and Potsdam and at the headquarters in Hamburg. “These cranes are mainly used for erecting wind farms,” explains Marc Bernschneider, a member of the external sales team at Thömen. “Our first one went straight from Ehingen to wind power work and was then in use without a break for nine months until its first service. The crane is simply unbeatable for erecting wind turbines.”

This site report was taken from the March 2016 issue of International Cranes and Specialized Transport magazine.