Tower cranes in Shenzhen

Chinese engineering and construction services provider China Construction Seventh Engineering Division, a subsidiary of the government-owned China State Construction Engineering Corporation, is using two Manitowoc Potain MCH 175 hydraulic luffing jib tower cranes (badged as the MCH 170 in China) on different projects in the city of Shenzhen, southeastern China.

One is working on a fire station project on Jingtian Road and the other on a housing project on Panlong Road. The projects are part of the Chinese government’s effort to transform Shenzhen into a global business centre by 2025.

Both MCH 175 towers are new additions for China Construction Seventh Engineering Division. On the fire station project, the first MCH 175 was operating around 12 hours per day lifting construction materials. Configured with a 35 metre jib length and at an 80 metre working height, the MCH 175 was expected to remain on site until early 2021.

On the housing project, the second MCH 175 works around 16 hours per day lifting construction materials, including rebar. Configured with a 35 metre jib and at a 130 mertre working height, this MCH 175 is also expected to remain on site until early 2021.

The MCH 175 lifts 10 tonnes, offers a maximum radius of 55 metres, and a tip capacity of 1.5 tonnes. “We selected Potain cranes because… we are fans of the MCH 175’s VVH hydraulic luffing system,” said Ma Guihong, chief engineer, China Construction Seventh Engineering Division. The MCH 175 hydraulic luffing technology moves the jib from horizontal to 87 degrees in less than two minutes, for faster work on site. The design also eliminates the need for luffing ropes, which saves on assembly time, said manufacturer Manitowoc. “The crane has a short out-of-service radius which makes it easy to work in tight spaces, such as downtown construction sites,” Guihong added.

To further reduce on-site assembly time, the crane’s hydraulics are pre-connected at the factory, while the hydraulic cylinder that powers the luffing motion offers lower energy consumption than conventional luffing jib cranes, Manitowoc said. This means it requires a smaller generator, lowering costs for owners.