World’s largest drydock site of fast-tracked marine engineering feat

Rotterdam job a huge stretch

ROZENBURG, the Netherlands – The Keppel-Verolme Shipyard with the speedy completion of a major alteration and ship-stretching contract, has significantly enhanced the reputation of the Dutch as high-tech specialty rebuilders. In record-time, the shipyard cut the 1997-built cruiseship ‘Enchantment of the Seas’ in half, inserted a Finland pre-fabricated addition and then welded the three part together. Instead of spending a billion dollars on a larger ‘floating village’, the ship’s owners opted for a major rebuild.

The $60 million stretch of the Royal Caribbean International (RCI) cruiseship added 22 metres (73 feet) to its length, 151 cabins, and a range of other facilities. The 7-deck ship is now 301 metres long. While the ship sections were in the drydock, numerous facilities were refurbished as well.

Stretching the ship presented a series of challenges. The shipyard worked six days around the clock with 16-men crews on eight hours shifts to split the ship, cutting through nearly 2,000 linear feet of steel with gas/oxygen torches and circular saws. They also severed 1,100 cables, 120 pipes and 60 air ducts. They then moved the foreship section to insert the new midship piece.

Once cut in two, the ship’s bow and aft sections were positioned with skids and hydraulic jacks and the new midship section – weighing nearly 3,000 tons – was guided into place by a laser-aligned system. After the positioning was done, the workers rewelded the ship together, rejoining all the individual cables, pipes and ducts. The entire process of stretching took only 31 days.

Third job perfected

The ‘Enchantment of the Seas’-job is not the first stretch rebuilt. In fact, RCI pioneered the ”stretch” in 1978 when it took the concept, previously used on cars, buses, and planes, and applied it to the ‘Song of Norway.’ Two years later, the ‘Nordic Prince’ got a similar refit. Those jobs were partially done in the water, were more complicated and took three months to finish.

RCI first approached the Enchantment’s original builder in Finland for the overall responsibility of the job. Aker which built the midship section, then hired Keppel Verolme to install it in its huge drydock, the largest in the world. Aker’s midship section took seven months to build and was barged over a 2,300 kilometres distance to Rotterdam. The tugboat Varius complete the job with the Smitbarge I in tow, on which the midship had been welded to ensure smooth sailing from Finland. RCI also has two new cruiseships on order. The latest ship to get launched from the Turki shipyard is the Freedom of the Seas, the largest cruiseship in the world.

Keppel Verolme’s challenges to complete the job on time were not all technical in nature. Diminishing their importance, a job supervisor stated that the shipyard at times was more concerned with the logistical challenge of getting its workers on time to its jobsite through Rotterdam’s congested roads.