July 13 - Liebherr has delivered its first type MTC 78000 heavy lift offshore crane.
Constructed in the company's Rostock manufacturing facility, the MTC 78000 is one of the biggest offshore slewing cranes worldwide. With a maximum dynamic torque of 78,000 tonnes, the MTC 78000 is the most powerful machine within the extensive range of cranes and material handling machines offered by the Liebherr group of companies. Four units of the new heavy-lift crane have already been ordered to date.
Despite its size, the MTC 78000 has been designed as a slewing crane and is supported by traditional large diameter anti-friction bearings. With a weight of 70 tons, the swing ring has a diameter of approximately nine metres.
Some special challenges were involved in the onsite erection and assembly of the huge crane onto the heavy lift vessel OSA Goliath; planning the individual hoists so that the maximum permitted ground pressure of the pier was not exceeded, for example.
Two Liebherr LHM 600 mobile harbour cranes were used in tandem operation for the heavy duty lifts. Both cranes with their maximum load capacity of 208 tons each enabled parts weighing up to 400 tons to be mounted in tandem operation. The machines were equipped with the recently patented Liebherr "sycratronic" control system. This Dynamic Anti Collision System controls the simultaneous operation of the mobile harbour cranes, so ensuring best possible performance and protection for the cranes.
The assembly of the MTC 78000 required several spectacular heavy duty lifts. First, the slewing platform was mounted - at 370 tonnes, the heaviest of the components. Then, the machinery compartment with the drive components (approximately 240 tonnes), the mast lower section (about 250 tonnes) and the mast upper section (around 160 tonnes) of which the lowest point needed to be hoisted up to over 43 metres above the pier level.
The last step in the assembly process involved putting the boom in place. In a tandem hoist operation, the 87 metre-long boom was positioned with minute precision at the respective connection points enabling the boom to be pinned to the slewing platform on both sides. The sheer size of the pins required a specially developed hydraulic pinning machine.
The heavy lifting test of the large crane was carried out in the open sea with a 1,760 tonnes test weight - corresponding to 1100f the nominal load capacity. The test loads consisted of two water filled pontoons which were lifted out of the water and turned around.
After the successful test, the client, Handel Maritime S.A. could deliver the heavy load vessel OSA Goliath to its purchaser, the Mexican company Oceanografia. The OSA Goliath is one of the largest heavy load vessels worldwide and is being used for platform reconditioning, pipe laying and to set up offshore wind power plants.
Equipped with its new MTC 78000 heavy lift offshore crane, the OSA Goliath is scheduled to work in the Gulf of Mexico on behalf of the Mexican oil company Pemex over the next few years.
The MTC 78000 achieves a maximum lifting capacity of 1,600 tonnes at up to 35 metre radius. This corresponds to a maximum dynamic moment of 78,000 tonnes, the crane still being able to slew over 360°. At a maximum radius of 74 metres for the main hoist the crane achieves a lifting capacity of almost 530 tonnes. In addition to the main hoist, the MTC 78000 offers two auxiliary hoists with lifting capacities of up to 500 tonnes and 50 tonnes respectively.
The size of the MTC 78000, which is in response to customer requirements, represents a new dimension in product development for Liebherr.