Port operators, freight forwarders and terminals worldwide are in search of special mobile harbour cranes ranging between the big rail mounted cranes and gantries and the very large mobile harbor cranes with up to 8 to 10 axles.
Germany's Sennebogen has two mobile port cranes - 6120 and 6180 HMC - in its range of high capacity lifting equipment for ports.
Both machines are based on a 4-axle mobile undercarriage with integrated 4-point outriggers (supporting base: 9.5 x 9.5 m). All axles are steerable, both inner axles are drive axles.
All machines are mainly used for general cargo handling. Therefore, two hydraulic winches in the upper structure are being switched together for rapid load handling. The special crane winches feature 200 kN single line pull at the 6180 and 160 kN at the smaller 6120. These cranes are equipped with lattice booms ranging between 37 and 48 m length, says Andreas Ernst of Sennebogen.
The big 6180 has been used at the Danish port of Vejle and is equipped with a 33-m-lattice boom. It is able to lift up to 50 tonnes at a radius of 14 m. The 6180 is powered by a water-cooled Deutz-Engine with 330 kW. An additional 15-kVA-diesel generator supplies electricity for 12 floodlights mounted on the upper structure for work at night or at bad weather. The crane does nearly all the loading work at this port. Every year the crane lifts about 1 million tonnes - mainly iron bars, metal pipes and steel coils, says Ernst.
The harbour cranes are equipped with a telescopic lifting device being mounted on the left side of the upper structure. This boom raises the panoramic cab up to 10 m - so the crane operator very easily looks down into the hatches of the ships. The cabin is quite different to the ones being used for the Sennebogen construction cranes. It is extremely spacey and features all-round windows of tinted safety glass, large skylight, clear instrument panel and adjustable cab heater. Special windows at the bottom ease view down into the ships. These new harbour-cabs feature enough space for additional control monitors (view back camera).
"When it comes to the question 'how to put up a mobile harbour crane's drive train', port technicians are divided between the diesel-electric and the diesel-hydraulic fraction," continues Ernst.
"The Sennebogen engineering department is very confident with an all hydraulic system because it is very powerful, easy to operate and maintain and it features only proven components. All hydraulic pumps are variable displacement piston pumps with individual regulation for each pump.
"The pumps are equipped with an energy-saving flow-on-demand control system and pressure cut-off for high efficiency and reduced loss of energy. The pumps are driving two crane winches which can be operated independently. Both of the large cranes can be equipped with a third crane winch with a line pull of 75 kN," according to Ernst.
Like all Sennebogen machines the mobile harbour cranes can be individualised with a large variety of special attachments. For example, an electro-magnet for scrap-handling can be combined with the lifting equipment. The cranes are also able to handle containers with telescoping spreaders. And the two independently operating winches are necessary for bulk goods handling with grabs. Major changes at the undercarriage can also be made. Under certain circumstances it may be useful to substitute the mobile undercarriage with a crawler undercarriage. In this particular case the machines are named 6120 R/6180 R. The smaller 100-tonne lattice boom crane 6100 R has been sold to several harbours throughout Europe, says Ernst.
