Six Potain tower cranes have built two 280 m tall bridge pylons high in the clouds above the mountains of southern China. The cranes spent two-and-a-half years building the pylons at the Chishi Grand Bridge, which will span 1,470 m and carry its road deck 180 m above the ground. The bridge will open at the end of this year.
The China Railway Major Bridge Engineering Group (CRMBEC) is the main contractor on the project which, at 70 m wide, will be one of the widest cable-stayed bridges in the world. CRMBEC owns and operates the Potain tower cranes used on the project and the company has enjoyed a long and successful relationship with Manitowoc, as Jiang Xiong, CRMBEC project manager, explains.
“We have worked with Potain since 2002 and have an excellent relationship with them – we appreciate both their high quality products and their attentive service,” he says. “The advanced technology, excellent efficiency and reliable operation of Potain cranes give us the peace of mind that you need on this type of large-scale project. We cannot have delays as it would have a major impact on the rest of the project. We spent considerable time analyzing the correct crane choice for this project before selecting Potain, and once again they have proven to be the best choice.”
Standing up to 310 m tall, the six Potain tower cranes endured the full force of Hunan’s subtropical climate during their 30-month posting at the Chishi Grand Bridge. Monsoon rain and extreme humidity were among the challenges at the job site. Communication between ground crews and operators was also key as the cranes were often hidden in the clouds, with no view of the ground below.
The Potain cranes built two of the bridge’s four pylons, each of which has 24 exterior sides and 36 interior sides, forming a unique S-shape structure. This technical arrangement made construction all the more complicated.
To ensure the cranes operated at maximum efficiency for the long hours required at the project, Manitowoc Crane Care worked closely with the site. At one stage, the customer support division even needed to deliver some components and parts to the job site by helicopter, to ensure the project stayed on schedule.
The cranes lifted a wide variety of construction materials, including formwork and steel structures, in loads that tested their maximum capacities, which ranged up to 16 t. Work began on the Chishi Grand Bridge in March 2010. The Potain tower cranes were erected at the job site in March 2011 and have recently finished work. The cranes on site included two MC 200s and two cranes that mix the mast of an MC 480 with the jib of an MC 320 K16. All of the cranes were built Potain’s factory in Zhangjiagang, China.
CRMBEC is a wholly-owned subsidiary of China Railway Group Ltd and specializes in bridge construction, completing some of the largest in the world to date. The company has more than 16,000 employees.
The Chishi Grand Bridge forms part of the Xiarong Expressway, which connects Rucheng to Chenzhou in the southeast of Hunan province.