The Shanghai Waigaogiao Shipbuilding Company (SWS) is situated at the southern harbor of the Pudong district in Shanghai, just opposite the Changxingdao port district at the mouth of the Yangtze River. The company has three shipyard cranes equal in size to 30-story high-rise buildings. Each one uses energy chain cable carriers from igus® to guide and protect the machine’s moving cables. The energy chains - which carry loads of 66 pounds over distances of 590 feet - are impervious to the harsh winds, lashing rain, and saltwater prevalent at the mouth of the Yangtze. The annual, two-month monsoon season leaves components at risk for corrosion, but due to their high-performance polymer construction, the Energy Chain Cable Carrier Systems® operate problem-free. Even a typhoon two years ago did not shut down operations.
igus® is responsible for the assembly and inspection of the energy chain cable carrier systems and checks them regularly. The two shipyard cranes - with lifting capacities of 600 to 800 tons - and the 32-ton material crane are supplied with energy and data via low-friction roller energy chains, which run inside igus® guide troughs made from steel. These cable carriers are designed for high loads and long travels at high speeds. In ship-to-shore applications, travels up to 1,640 ft and speeds topping 19.7 ft/s have been achieved. When compared to a gliding energy chain, the reduction of thrust force is nearly 75%.
SWS also uses chainflex® continuous-flex cables, which are designed for constant flexing and have a highly wear-resistant, TPE outer jacket. They are resistant to UV radiation, corrosion caused by coolants, lubricants and bio-oil and also withstand temperatures from -31°F to +212°F.
In 2006, one of the shipyard cranes was equipped with an energy chain, chainflex® cables and an additional system component: a 'Push-Pull Force Detection' (PPDS) system from igus®. 'PPDS' monitors the sliding forces of the energy chains online in order to avoid system damage and failures through preventive maintenance or remote intervention. The system operates twenty-four hours a day and compares the data of the functioning chain system with the permissible values four times a second. Detected malfunctions can be automatically transmitted via SMS or e-mail to a pre-programmed computer to ensure an immediate response. For accident analyses, the data in the system memory can be traced back three months. Instead, SWS saves on storage by not keeping any spare igus parts on-site. These parts can all be found in the 32,292 square feet igus® warehouse in the free trade zone of Waigaoqiao, just 12 miles from the cranes’ location.