Liebherr says the the new crane, with a load moment of 78,000tm, will be one of one of the biggest offshore slewing cranes worldwide. Four units of the new heavy-lift crane have already been ordered to date, and should be delivered by the end of the year.
The MTC 78000 achieves a maximum lifting capacity of 1,600t at up to 35m radius while still being able to slew over 360°. At a maximum radius of 74m for the main hoist, the crane achieves a lifting capacity of almost 530t. The boom length of the cranes currently ordered is 87m. In addition to the main hoist, the MTC 78000 offers two auxiliary hoists with lifting capacities of up to 500 t and 50 t respectively. The dead weight of the new crane is 1,420t, plus up to 300t for the base column.
The crane is powered by an electrohydraulic drive manufactured by ABB, with 8x500kW (or 4 MW) power. The two main winches offer a line pull of 500 kN (50t) with a rope diameter of 48mm. As the crane is mainly intended for application on mobile installations, reducing its dead weight was one of the main design requirements. To achieve this, the supporting steel structure is made exclusively of high-strength fine grained steel with a yield strength of 690 N/mm².
The standard equipment of the MTC 78000 features the proven Litronic control system with integrated display of load and radius as well as automatic load moment limitation. This is completed by special overload protections which are either activated electronically (AOPS “automatic overload protection system”) or manually (MOPS “manual overload protection system”). The crane’s auxiliary hoist is fitted with a constant tension system exerting a tensile force on the hoist rope in case of significant wave height, thus ensuring that the hook follows the moving load.
Two of the ordered MTC 78000 units will be used as heavy-lift cranes for the overhaul and/or renewal of existing offshore platforms. Their main field of application is the assembly and disassembly of main components such as drilling derrick, accommodation module or various production modules. The cranes are also used for converting platforms from oil to gas production or vice versa and are mounted on a crane ship specially designed for these jobs. Approximately 300 of these ships specially designed for crane applications are in operation throughout the world.
Liebherr will deliver the remaining two MTC 78000 units currently on order for applications on jack-up barges for assembly of wind power stations of the 5MW class. The heavy-lift applications include the installation of tripod foundations weighing up to 1,400t as well as the assembly of single components with a dead weight of up to 500t up to a height of 120m above sea level or 106 m above deck.
