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| Popularity of Potain topless cranes continues to grow  Potain's topless cranes are gaining popularity and appearing on more construction sites worldwide. Even with the economic downturn, there is pressure to finish jobs on or ahead of schedule. Potain topless cranes can work together in closer proximity when overswinging each other allowing more cranes on site. One of the latest companies to turn to Potain topless cranes is Germa building a multi-use block in Hamburg's HafenCity harbor n construction company Höhns-Bau GmbH & Co. KG., which is area. The development is one of the largest European urban makeovers of the 21st century, and it's no surprise Potain cranes were the company's first choice. Two cranes, an MDT 218 and an MDT 268, arrived on site in July 2009, and are expected to work together on the project until April 2010.Jens Höhns, managing partner and engineer at Höhns-Bau, said using topless 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." Potain topless cranes do not have a cathead above the jib and can be can be operated in closer proximity to other cranes on site. This design makes them especially well-suited to the Hamburg site. Once it was decided to use two topless cranes on the Hamburg project, transportation was easy. Höhns-Bau opted for the Potain MDT 268 for the optimum combination of lift strength and ease of erection. The heaviest elements for the mobile crane erecting the MDT 268 were the 8.7 t counterjib and the 8 t revolving platform. Jens Höhns said he was impressed with getting both cranes in the air on the project. "Both cranes were extremely quick, easy and safe to assemble," he said. "The MDT 268, including the base, 95 t central ballast, 25 m jib, 13.8 t counterweight and over 50 m of mast, was easy to transport on eight articulated trucks. The crane can be moved economically with a light assembly load that gives a real advantage when calculating the costs of construction. We also like the counterjib on the crane, which can fold for transport." The first Potain crane on site, the 8 t capacity MDT 218 A J8, was erected with a 40 m jib giving it a jib end lift capacity of 4.6 t. The crane was mounted on a 4.5 m x 4.5 m base with 1.6 m 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 on the job 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 t maximum capacity, and at its jib end can still lift 9.4 t. Jens Höhns said the two cranes worked perfectly together. "The components we're lifting weigh up to 9 t, so with the combined lift ability of 20 t, there is plenty of flexibility," he said. "They work really efficiently together even though they are operating in a tight space." write your comments about the article :: © 2010 Construction News :: home page |