CITIC Pacific

Laser-proven accuracy: First underwater installation of Beluga successfully finished

MV “Beluga Shanghai” transports project cargo from China to Australia

MV “Beluga Shanghai” discharges huge stop dolphins directly onto the sea bed of a future port // Full service solution delivered

“Pin point accuracy with a pin of 700 tons”, outlines Tambek Jakson, Cargo Superintendent of Beluga, the challenge of handling two 22 meters high stop dolphins with a diameter of 16 meters. “For the discharge we had to place the two items directly into the turbid water of a semi-constructed port basin. The conditions on site allowed only a tolerable error range of five centimeters which was measured via laser from ashore. We had only a single shot to get it right as we were not supposed to lift the cargo again in case we missed.”

As MV “Beluga Shanghai” was freely floating and only fastened by a tug boat and several – due to the high tidal movements with four meter tidal range – loose 100 meter lines, the whole scenery gave an offshore impression. Thus, the brand new multipurpose heavy lift carrier of the Beluga P2-series had to keep stable only by its powerful anti-heeling and ballast water system even when the cargo was dipping into the water. “The fenders attached to one side of the dolphins acted like corks and generated uplift at one side. That made the exact placement extremely difficult”, explains Jakson after the discharge of the two giants at Cape Preston, Australia, between the October 21 and 24, 2010.

Both of the dolphins look like huge cylinders made of steel but they differ quite a lot concerning their internal structure. Their characteristics challenged the Beluga team already during the loading from October 7 to 10, 2010 in Penglai, China. The heavier one weighed 645 tons but together with the rigging it reached almost 700 tons. “We had to mount the rigging in a height of 17 meters above ground operating there – amongst others – with 400-ton shackles. Just a pin of them weighs 90 kilograms”, describes Beluga Transport Engineer Loren Eckardt some of the issues that had to be sorted out on site.
The lighter dolphin weighed “only” 545 tons but featured a highly offset center of gravity. During the loading in Penglai using one of the two 700-ton cranes of the vessel, the given data proved to be not absolutely accurate as the cargo tilted about half a meter on the hook. “We used the gained data to calculate the center of gravity ourselves and designed a new rigging for the discharge. For the underwater installation no tilt was accepted”, says Eckardt. “Due to the offset center of gravity the rigging looks quite unorthodox but proved to be effective as the cargo took up absolutely straight.”

The size of the cargo blocked not only the deck space and the view from the vessel’s bridge but also the resting position of the two portside cranes. Thus the Beluga team took advantage of an option by the manufacturer to stow the jibs in an upright position during the sea passage. Infrared cameras, an additional radar device and more crew members for lookout compensated the restrained visibility while sailing.

At Cape Preston, located in the remote Pilbara region of Western Australia one of the largest magnetite mines in the world is being developed. At the moment, most of the necessary infrastructure simply does not exist and even the port jetties themselves are still under construction. This environment presented an excellent opportunity for the world market leader in the heavy lift and project market to prove its ability to perform almost anywhere. “This was our first underwater installation but surely not the last one. As a full service provider we delivered an efficient solution from the preplanning of the project in close cooperation with the customer up to filling up the dolphins with concrete ballast on site in Cape Preston”, resumes Jakson.

Or, as the client side puts it: “We have been very impressed with the professionalism of Beluga who overcame certain difficulties with site conditions, it all went nice and smoothly. I definitely use their capabilities in future projects”, states Nathan Fuller, Senior Project Engineer of CITIC Pacific Mining.

See more about the MV “Beluga Shanghai” and the P2-Series

 

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