Bring it on down!

In January 2003 Hyundai Heavy Industries erects a 'new' crane at its offshore yard in Ulsan, South Korea. This 1,500t capacity gantry crane in fact has been transported from Sweden where it had previously seen service in the - now closed - Kockums shipyard in Malmö, Sweden.

The crane stood 136m high, spanned 174m and weighed just under 7,900t. Dismantling it and shipping it out was never going to be easy and required three years of planning. Not only did the sheer size of the crane mean that the sail area was going to be a significant factor, but also the exact weights were unknown. On top of this, space was restricted because the site had been partially developed since the closure of the dockyard. A fourth problem was that the crane was constructed largely of thin steel plate which meant many of the lifting points had to be strengthened.

Hyundai Heavy Industries brought in Fagioli PSC as its main contractor to dismantle, load and transport the Malmö crane to its offshore yard in Ulsan, South Korea. Assisting Fagioli PSC were the German mobile crane rental company Brandt, and the Dutch marine lifting specialists Smit and Dockwise.

Kranservice Rheinberg, a subsidiary of Demag Cranes & Components, fabricated all of the temporary steelwork and modified the existing frame so that it could be dismantled.

Before the main structure of the crane could be brought down by Fagioli PSC, mobile cranes had to be put into action. Brandt's 600t capacity Demag TC 2800 lattice boom truck crane lifted up a 50t Demag AC 50 all terrain and a 45t Tadano Faun ATF 45-3 onto the main beam of the gantry crane. Up there, exposed to the elements, these cranes lifted out machinery, stairways, fittings and other parts from within the massive runway structure. According to Brandt, these cranes working at such a height constitutes a world record.

The TC 2800, rigged with 84m of main boom and 78m of luffing jib, then lifted each piece from on top of the beam down to the ground. A Demag TC 1100 truck crane, supplied by Swedish company Ralling, assisted with smaller dismantling, removal and handling tasks. Ralling's local knowledge was also a great help on the project, Brandt says.

Other mobiles cranes supplied by Brandt for the project included a 650t Demag AC 650 telescopic, and AC 160, a 200t Liebherr all terrain, a 160t Liebherr and two 80t Liebherr ATs.

The gantry crane structure itself was lowered to the ground in three sections: the main beam, weighing 4,100t; then the shear leg, which weighed 920t; and finally the 1,480t pier leg.

For the main beam Fagioli PSC designed two ring frames to strengthen the main girder lowering points. Arrangements of four 600t capacity strand jacks were positioned on top of each leg, mounted on Fagioli PSC cantilever beams. These were twinned to combine two lowering points at each end of the girder. From a control room 300m away from the jacks, the lowering was controlled by computer. A complex arrangement of guys was installed to ensure that the legs and the beam all remained stable during lowering. The beam was laid on two temporary supports and two 12m Fagioli PSC towers were constructed in the dry dock. Supported in this way, the beam was cut into two pieces for sea transportation.

For the legs Fagioli PSC designed temporary lifting points which were welded on each leg. A floating sheerleg vessel supplied by Smit Heavy Lift was used to lower the legs to the ground. The legs were first tilted using Fagioli PSC leg guys, then they were lifted clear of the crane and lowered to the ground for preparation for their journey.

Aided by a Fagioli self-propelled modular transporter (SPMT) and Brandt's massive 600t capacity TC 2800 lattice boom truck crane, a total of 11,000t of gantry crane, jib crane and ancillaries were loaded onto the Dockwise vessel Mighty Servant 3 that was docked alongside the yard.

Fagioli PSC's scope of work also included dismantling and transporting two dockside jib cranes and demolishing another. These each weighed 1,500t. Brandt's Demag TC 2800 was again in action for this part of the project.

The project started in April 2002 and the dismantling and shipping was completed last month. Re-erection starts next month with the intention of finishing in March.