June 2019

BRAKES, CLUTCHES AND COUPLINGS n 1,800-tonne ships are lifted safely past Chinese dam T he 232.5m-high Goupitan dam, located on theWujiang River in southwest China’s Guizhou province, is one of the world’s tallest. It incorporates one of the most powerful hydroelectric stations ever built, with a generating capacity of 3,000MW. The massive construction, operated by GuizhouWujiang Hydropower Development Company, required a large and efficient lift lock that would allow boats and small ships to move past the dam easily and quickly. The ship lift system, developed by the Changjiang Institute of Survey, is designed to raise vessels weighing up to 1,800 tonnes in three stages, each lifting the vessel through a height of 79m. The decision to split the lift into three stages was made to maximise efficiency, and to handle the river’s busy boat traffic without causing congestion. Three vessels can occupy the lift system at any one time and each stage comprises a gate and separate ship chamber. Each elevator uses two rows of hoist cable drums with gearboxes positioned over either side of the boat-lifting reservoir. This design provides a hoisting speed of around 8 metres per minute, thus raising or lowering a 500-tonne vessel (the typical weight for passenger boats on that stretch of the river) in about 10 minutes per stage. This complex civil engineering project needed durable and reliable brakes to support the ship chamber at any height and to prevent the machinery from being overloaded. The brakes had to meet several challenges. First, they needed to withstand the massive weights that occur when hoisting the ship chambers and the boats on them. In addition, they had to fit into the confined spaces of the lift towers: the components are pedestal- mounted on the hoist drum brake discs of each elevator. The Changjiang Institute of Survey chose Stromag to supply the braking systems for the project. The company had previously been involved in the construction of the world’s second tallest lift lock, the Strépy-Thieu boat lift in Belgium, as well as similar projects across China, including at the Silin, Shatuo and Yantan dams. The brakes chosen for the Goupitan project are robust spring-applied caliper brakes specifically designed for heavy-duty lifting and able to provide dynamic braking forces up to 334kN. The SH32 hydraulic disc brake brakes have a compact design making them suitable for applications with limited space. The brakes are coupled to hydraulic power packs with touchscreen controls, also supplied by Stromag. These allow the braking force to be adjusted easily and applied in a controlled, progressive way. Because of the size of the dam, the vertical locking mechanism needed more than twice as many brakes as other ship lifts that Stromag has worked on in China. To supply the large numbers of brakes and power packs, and to ensure building operations stayed on schedule, engineering teams in China and France worked together to manufacture and perform real-world tests on the brakes in a tight timeframe. This close collaboration allowed the project to be completed in just 12 months. n One of the world’s largest ship lifts, capable of raising ships weighing up to 1,800 tonnes through a height of more than 200m, has been commissioned at a Chinese dam. The braking system for the three-stage lift is critical to ensuring its safe operation. The yellow-coloured hydraulic disc brakes ensure that the massive cable hoists used on the ship-lift system operate safely. DISCOVER HOW REXNORD CENTA CAN SOLVE YOUR TRANSMISSION PROBLEMS AND SAVE YOU MONEY - CALL US TODAY ON: 01274 531 034 OR VISIT: WWW.CENTA-UK.CO.UK/DRIVES T: +44 (0) 1274 531034 E: post@centa-uk.co.uk @CentaUK MISALIGNMENT | VIBRATION | NOISE | MAINTENANCE COSTS