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Thialf - Huge Ship / Massive Cranes / Large-scale maintenance!

In September 2013, we received a request from Heerema Marine Contractors to come up with ideas on providing access to a range of work locations during the planned large-scale maintenance on the two cranes on board the SSCV Thialf - The largest crane vessel in the world.


The maintenance work was scheduled for September 2014 and was due to be undertaken in the Caland Canal. In February, however, it emerged that the Thialf would be arriving at the yard earlier than expected, and the work has now been completed in the period May/June 2014.

The Thialf is Heerema’s largest crane vessel, and her figures are indeed impressive:

  • Overall length: 201.6 m

  • Width: 88.4 m

  • Height from ground level to main deck: 49.5 m

  • Draught: between 11.8 m to 31.6 m

  • Lifting height of main crane above main deck: 95 m

  • Lifting capacity in tandem configuration: 14,200 tonnes

The maintenance work on each of the cranes included:

  • Replacing 166 pulleys with diameters ranging from 750 to 1,600 mm. The largest pulleys weigh a massive 800 kg each.

  • To be able to replace the pulleys, all of the cables had to be unreeved.

  • A total of 8 crane cables run over the pulleys. To be able to raise the boom, 2 cables are used, each with a diameter of 60 mm and a length of 3.6 km.

  • The main hoist uses 4 crane cables to achieve a total lifting capacity of 7,100 tonnes.

  • These lifting cables are each reeved through the pulley blocks 10 times, to provide the pulley effect of the main hoist.

Deployment of construction hoists from Alimak Hek;  1 x Alimak Scando 450 14/32 Twin / 4 x Alimak Scando 450 14/32 Single car

Alimak Scando 450 -14/32 Twin 

A construction hoist with dual cars mounted on a special frame suspended from a column. Access to the 1st deck via two openings in the wall. In front of these openings, a special auxiliary platform on which entrance/exit doors are fitted. This hoist was used to transport all personnel from the barges to the 1st deck level at a height of approx. 24 metres.               

Alimak Scando 450 – 14/32 Single

On both cranes, a hoist from the main deck up to the underside of the crane boom, with 1 stopping point fitted with doors. Height approx. 20 metres.

Alimak Scando 450 – 14/32 Single

On both cranes a single hoist mounted on a special frame suspended from the A-frame of the main hoist. On top of the A-frame, an entrance/exit platform fitted with doors. Height approx. 45 metres.

The work was carried out in a fully continuous process, and the Thialf has once again set sail to carry out a range of operations in some corner of the globe.

Source: Alimak Group Sweden AB