MHC GAINS RECOGNITION IN BULK SECTOR

01 Jun 2004
Liebherrs TCCs in Vietnam: significantly lower operating and maintenance costs Liebherrs LHM400G in Korea where operating rates are twice global average

Liebherrs TCCs in Vietnam: significantly lower operating and maintenance costs Liebherrs LHM400G in Korea where operating rates are twice global average

MHC sales for bulk handling are on the increase and the deck crane has evolved into a land creature. Nick Elliott talks to Liebherr and Gottwald.

The Mobile Harbour Crane (MHC) is increasingly being used for bulk handling work as illustrated by the major manufacturers' sales figures. Totally, Liebherr sold 48 MHC units last year and already have 25 to be delivered in the first four months of the current year. "This is significant proof that the set target of 50 plus cranes within 2004 could even be topped, " says Liebherr's Thomas Bachmann.

But significantly, 14 of the 25 have been ordered in four-rope configuration. "The current tendency for bulk handling is even more obvious when knowing that of these 25 machines on order almost 70% (17 cranes) are at least partly or exclusively used for bulk handling, " says Bachmann. Another 8 cranes are dedicated container, general cargo and/or scrap handling machines.

As a consequence of this trend, Liebherr has during recent months been working on a technical solution for the adjustment of its patented Cycoptronic (cycle optimising electronic) crane control system for 4-rope configuration. "In the beginning this highly effective tool for crane operators has been developed for container handling whereby several gyroscopes could be mounted to the existing rotator and measure the rope angle velocity in the three angle directions, " says Bachmann.

However, in 4-rope operation with a mechanical grab there was no such rotator available which means that the technical department had to think over alternative ways and means to attach the relevant sensors to the crane in order to provide the Litronic crane control system with the essential information on the crane's behaviour. In the meantime this hurdle has been overcome and Cycoptronic is optionally available - and has already been sold to several customers having purchased 4-rope machines."

Liebherr has also developed a semi-automatic function of Cycoptronic: the so-called teach-in function. The feature enables the crane driver to comfortably approach two self-defined end points (teach-in points) by moving the joystick into the direction of the desired end point. "Consequently the crane will remain exactly at the defined position almost without any sway or swing of the load (despite the still activated joystick), " explains Bachmann. "Such teach-in points can at any time easily be set to new endpoints at the push of a button on the joystick.

Meanwhile after several years during which the Korean market seemed to be lost to the competition, Liebherr managed to secure an order for its LHM 400G - characterised by a lifting capacity of 104 tons and an outreach of 48 metres - to Youngjin Enterprise. Youngjin, located in Inchon, is one of the largest stevedoring companies in Korea. Liebherr says there were two reasons why Youngjin changed their purchasing policy and decided in favour of the Liebherr concept: "First the Korean market is a very demanding one for MHCs: 4,500 operation hours/year per crane - almost twice as high as global average rates, so the issue of the crane's (residual) lifetime always is a crucial one in each and every negotiation, " says Bachmann.

Secondly Liebherr proved the benefit of its special winch configuration for grab operations - a 2x70 ton winch arrangement which increases the standard lifting capacity in four-rope operation from 34,7 up to 52 tons.

Links to related companies and recent articles ...

Liebherr Container Cranes

view more