Konecranes Marketing Manager for Port Cranes , Svend Videbaek, says the company has always believed that the heart of the container crane – comprising the motor, gearboxes, inverter drives and associated software – is of such importance that its design and manufacture must be kept in-house. The interaction of the motor, gearboxes and inverter drives represents the heart of lifting: here the crane’s performance, eco-efficiency and total lifetime value are defined to a great extent. “Driven by the customer’s container lifting needs, our R&D personnel are always working to improve the interaction of these core components. One of their main goals is to ensure that the energy requirements of our container cranes are in true balance with the work they do in container yards. This is the bottom line of the performance/eco-efficiency relationship in container cranes. It is of course an ever-moving target that Konecranes is always anticipating,” explains Videbaek. “This is not to say that the “body parts” of a container crane – the bogies, gantries, trolley, lifting mechanisms and so on – are less important than the heart of the crane. On the contrary, they are just as important and a great opportunity to maximise the performance provided by the heart of the crane. Konecranes has introduced many innovations to container crane “body parts” that are highly appreciated by our container terminal customers. A prime example is our patented Active Load Control technology on our STSs, RTGs, RMGs and ASCs which prevents container sway and provides handling precision that was previously unknown,” Videbaek added.
Dampers versus chairs
One of the solutions that have recently entered the market was that of a crane damper design, jointly developed by Siemens and Kocks Kranes (see December 2010 issue) – Kocks developed and designed the damper and Siemens put the ‘brains’ behind the whole design. One of the major benefits is that it counter responds to any movement of the crane – albeit in a certain direction. “We believe the new crane damper design is a significant improvement in order to reduce the vibrations of the crane boom,” said Siro Brieda, Managing Director at Brieda Cabins, Italy. “If we consider that the new crane booms cover 23/24 rows and the trolley’s speed of the new cranes is 240m/m you can easily understand that this situation can produce a lot of vibrations and oscillations, of course this environment produces negative effects to the crane operators.”
Since 2008, Brieda Cabins, as a specialised crane cabin and control station manufacturer, developed a new control station – the Dynamic Control Station. This product is designed to reduce the overall stress, the vibrations and the back pain problems of the crane operators. “The base of our control station has a special shock absorber that reduces every vibration,” said Brieda. “With the dynamic control station we have improved the general ergonomics of the work posture and the health of operators.” Ergonomics, posture and health of the crane operators are also key-words in the answer from Merford Cabins based in the Netherlands.
“The efficiency of a crane depends on different aspects like performance and liability of the crane itself, the controllability of the crane and related processes around the crane,” said Marco Ottevanger, Sales Manager. “However, as long as cranes are man-operated, the efficiency of the crane depends highly on the performance of the crane operator.” The performance of the crane operator depends on various ergonomic factors. “The first factor cognitive ergonomics has to do with mental processes, perception, memory, reasoning, motor response etc. These cognitive ergonomics are influenced by the mental workload, decision making, skilled performance, human-computer interaction, human reliability, work stress and training,” Ottevanger explains.
“Together with organisational ergonomics (like socio technical systems, organisational structures, policies, processes etc) these aspects are more or less internal aspects at the ports. Involving the crane operator in the design and implementation of his working environment will result in higher commitment and performance of the crane operator. Eventually a better working environment will reduce complaints, fatigue and the rate of absenteeism.” In consultation with numerous crane operators, port’s technical staff, port management, drive supplier and crane manufacturers, Merford has come up with specialised crane cabins providing a safe, healthy and efficient working environment. Special attention is paid to mental stress, vibration control, visibility, air and temperature control, physical ergonomics and the man-machine interface. It also looked at the physical loads on the operator, especially in STS cranes. Poor visibility may be the cause of bad posture resulting in physical load of the operator or poor visibility may result in inefficient or dangerous operation. As a result Merford designed the roof suspended Ergoseat, useful for 95% of men and women worldwide providing upper body support to improve posture and unload the lower back when looking downward. It also designed a new generation control station – BalanSeat. The BalanSeat is designed for operators looking downward with specific requirements to a wider vision (for example with RTG and RMG). The seat is provided with an adjustable chest support (to unload the lower back, according to ISO 1122
6). The BalanSeat is provided with a high-tech mechanical suspension/balancing system to make the operators body weightless. Other products from Merford to make life more comfortable while being suspended above a ships hold is a cabin that creates an overpressure. By doing this gases from outside (like exhaust fumes from ships funnels) can’t enter the cabin. This new Merford Filter Unit is both a filter and overpressure unit. It can also install a new HVAC system, the Merford Climate Unit. HVAC Stands for Heating, Ventilation, and Air-Conditioning—three closely related fundamental functions which are essential in creating the perfect working conditions.
Cables
Despite the fact that since January 2009, the price of copper has almost doubled and is perhaps the second most important economic indicator of hard commodities – behind crude oil, cable manufacturers continue to come up with innovative products. We have seen the elimination of the festoon systems on container cranes and looked at the electrification systems of Conductix-Wampfler, although this application was more for RTGs.
According to Thomas Kittel , Product Manager Crane Cables at Prysmian, Germany, the need to turn power feeding cables from passive components into components with active features will become an important issue. Future cranes (no matter the type) will become more automated says Kittel. “As a result these machines will become more intelligent,” he states. The importance of sensing capability for cables will grow to secure reliability and functionality of the equipment. Back in September 2009 Prysmian launched an ‘intelligent’ cable system and the response from the industry was most encouraging. By using ‘traffic light’ symbols the system provides immediate feedback about the condition and remaining life-time of the main power supply cable thus preventing any breakdown. “This is a challenging project but we move ahead and this is unique concept in the crane market so far,” he concluded.