Higher, faster, further – advanced brake technology in the port sector follows the global productivity developments of the international maritime trade in the last decades. With the main objective of an even faster and more profitable stock turnover, the container vessels are getting bigger and bigger and the ship to shore cranes higher and higher consistently. Ever heavier loads will be lifted and current twin lift spreaders come with 80 tonnes SWL and 105 tonnes lifting capacity. Boom hoists, main hoists and gantry travel drives must be able to deal with such loads, and advanced brake technology must keep pace and has to safeguard the crane operations permanently and in case of emergency. But service, emergency or storm brakes cannot be getting bigger and bigger as well to meet these increasing demands. The ‘Post-Post-Panamax-Brake’ could not be a sufficient solution -quite the contrary. Space is in short supply in machine houses. Give us more braking torque, said the crane manufacturers to the brake people, but keep it small. And while you're at it, please include low maintenance and high lifespan. This is another important point. With higher lifespan the extent of follow-up costs are more relevant for the buying decision of a crane manufacturer or port operator than the initial costs. Brake manufacturers can react to these demands with several options. The main strategy of the manufacturers was to change the design of the brakes. Intelligent brake design results in higher braking forces, smaller envelope sizes and weight reduction at the same time. An intelligent design also helps in achieving wear reduction and guarantees the shortest possible maintenance operation. A better material quality enables longer service intervals.
Facing the demands with intelligent brake design
Here is a brief overview of some selected successful solutions SIBRE Siegerland Bremsen has developed to meet these demands. Static storm brakes are a good example in answer to the demand for weight reduction, because the designers can take advantage of the crane weight as a selfenergising device for generating the braking force. In this case, storm brakes RTCB go without springs as generators of the braking force. Non-existing parts do not need to be changed and weigh nothing. The brake is easy to install because it needs no hydraulic power unit, no hydraulic field piping and no springs and comes with field replaceable brake shoes for simple maintenance (see Figure 1). Another example of intelligent brake design is hydraulically operated calliper disc brakes SHI, which decouple the hydraulic piston from the immediate load transmission. This eliminates tangential forces onto pistons and seals, which in turn virtually prevents from the risk of leakage. In addition, it is useful to mechanically optimise the load transmission onto the brake shoes and to equally distribute the clamping forces onto the entire surface of the brake linings to gain maximum braking torque. The unique design of these brakes provides small envelope sizes and an obvious weight reduction with remarkable higher braking torques at the same time. This advantage comes along with a low spare parts and maintenance requirement (due to only one dynamic seal