Potains dual working in Hamburg

German construction company Höhns-Bau GmbH & Co. KG. took delivery of two Potain flat top tower cranes to be used in the development of Hamburg's HafenCity harbor area.

It is one of the largest European urban makeovers of the 21st century, says Potain parent company Manitowoc. An MDT 218 and MDT 268 arrived on site in July 2009, and will work on the project until April 2010.

Jens Höhns, managing partner and engineer at Höhns-Bau, said using flat top cranes gave more flexibility on the project. "We started with an MDT 218 on this project, but as the schedule accelerated, it was clear we would need to erect another crane," he said.

"There were two options available to us. Either we could erect a larger crane, farther away from the project that could swing over the construction. Or we could erect a topless crane with a shorter jib that would swing underneath the crane that was already erected. We chose the second option."

The MDT 268 is particular;y economical to transport, says the manufacturer. Including the base, 95 tonne central ballast, 25 m jib, 13.8 tonne counterweight and over 50 m of mast, it can be transported on eight articulated trucks. The counterjib on the crane also folds for transportation.

The MDT 218 A J8, was erected with a 40 m jib giving it a jib end lift capacity of 4.6 tonnes. The crane was mounted on a 4.5 x 4.5 m base with 1.6 x 1.6 m mast sections. Height under hook for the crane is 55.7 m.

The second crane, the MDT 268 J12, was assembled farther away and above base level. The MDT 268 is able to rotate under the MDT 218 as it is installed with a 52.4 m height under hook, and its base is 2.5 m lower than the MDT 218. As the distance between the mast of the two cranes is just 30 m, the MDT 268 is working with a 25 m jib. It has a 12 tonne maximum capacity and at its jib end can lift 9.4 tonnes.