In some seaborne supply chains the rapid rise in export possibilities has not been matched by an equally fast expansion in port infrastructure. Today, much emphasis is laid on reliable offshore floating terminals, transshippers or geared tonnage. These are the ideal solution when port infrastructure does not allow for the direct loading of large vessels. This may be due to limitations in the port itself or draught restrictions in access waters or even impositions of local authorities.
 
To this end, Liebherr has further developed its range of special four-rope grab cranes which display their true ability in continuous operation, not only on land but also in open seas. The range includes slewing CBG type cranes as well as double girder MPG cranes. Both are specially designed for heavy duty continuous operation and provide excellent turnover rates. Two major transshipping projects involving Liebherr’s heavy duty marine cranes have recently been realized.
One of the world’s leading logistic companies, Coeclerici, has selected ten units of Liebherr heavy duty four-rope grab cranes type CBG 350 for installation on its two new tailor-made Supramax offshore transshipping units. These vessels will operate off the shores of Mozambique on behalf of the South American mining giant Vale and the handling of over 11 million tonnes of coal per year is anticipated. The first vessel has been put into operation and the second, just delivered, will be operating within the first half of 2012. Depending on tidal depths the average load for the transshipping will be 44,000 tonnes of coal, which will then be transshipped to open waters, where it will be transferred to ocean-going vessels of up to 180,000dwt using the five Liebherr four-rope grab cranes (one for each hold). The transshipper will be loaded using onshore conveyer belts. During this time the Liebherr cranes are parked towards the aft of the vessel. A specially developed interlock device is installed in the slewing column of each crane and the jib is rested on a console positioned to the side of the pedestal of the next crane.
This locking system allows for the jib to be parked (or locked) without having to dismount the four-rope grab and so saves valuable time when putting the cranes into operation and/or when storing the cranes for the short journey between port and ocean going vessel and return.
The Liebherr CBG 350 is a dedicated heavy duty high- performance four-rope grab crane. Designed for high speed continuous operation, these CBG cranes incorporate specific features for heavy duty conditions and operation in open water, including compact slewing column design, specially designed heavy duty hoisting winches, heel trim alarm systems and emergency operation functions. Additionally, an extended cabin ensures optimum visibility of the hold for the operator leading to safer and more efficient operation. Safe and precise crane operation is
further supported with Liebherr’s own Litronic® crane control and management system. Litronic® facilitates smooth and high speed operation as well as preventative maintenance. Amongst other information, the load indication and limitation as well as the load recordings are displayed. The machine data is recorded, including alarms and failures, and service and inspection intervals can be determined. Optionally, modem access is available for remote fault-finding through skilled Liebherr engineers. The software is available in several languages.
The latest major transshipping project for Liebherr involves the largest transshipping facility to date which has just been delivered by a Chinese shipyard, also for the South American mining company Vale. This facility is handling iron ore from Valemax vessels in Subic Bay in the Philippines. Design and advisory services were provided by Logmarin Advisors of Genoa, Italy, and the 285,000 tonnes buffer storage floating terminal — the only one of its kind — is equipped with five Liebherr MPG cranes and a sophisticated conveyor belt/loading system designed and built by Bedeschi.
The cargo handling facility is certified by RINA. The five Liebherr MPG 40 tonnes high-speed,
heavy duty, double girder jib cranes are side- mounted on the Vale vessel and have an outreach of no less than 42 metres. Safety, performance and low maintenance requirements are of utmost importance and the design of the MPG cranes considers all of these points:
  • reduced crane height leading to low centre of gravity;
  • no luffing ropes/mechanism meaning less maintenance and better stability of the crane in offshore operations;
  • driver’s cabin is positioned on the underside of the grab rotating arms allowing unrestricted views of the hold on both vessels;
  • significant reduction in grab swing during slewing;faster crane cycle thanks to double geared configuration and faster hoisting/lowering speeds;
  • independent drive systems ensuring continuous operation with full load, should a single drive fail operation can continue at reduced speed and so reduce downtime;
  • less wear and therefore longer lifetime of ropes due to special positioning of the hoisting winch; and
  • Liebherr’s own Litronic Robot Control (LRC) and Dynamic Anti-Collision System (DACS®).
 
LRC and DACS® have been developed in- house by Liebherr in order to increase safety and enhance performance. The robot control eases operation between two pre-defined fixed points. DACS® prevents collision between the cranes and/or fixed obstacles as each crane knows and compares its position with the other crane or any defined obstacle. This allows operation of two cranes on the same hold or close to any obstacle and therefore offers highest flexibility and safety. Dynamic anti- collision does not mean only sector limitation, but dynamic position monitoring of the cranes.
Therefore no limitations in the crane working area. With the design focus on maximum safety and operating
capacities as well as minimum maintenance and life-cycle costs the Liebherr cranes are ideally suited to round-the-clock working cycles.