Page 114: of Offshore Engineer Magazine (May/Jun 2013)

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Vessels

The modern liftboat could be a jackup

Liftboats started as a concept in for Building and Classing Liftboats The newly designed SUDA 450-L3T

South Louisiana with the frst-known came out in the 1990s, and the most liftboat has 450-ft legs.

L liftboats conceived in Braithwaite. recent update was published in

The technology was developed March 2013. designer A.K. Suda, Inc.’s model locally and has continued to im- Until recently, there has not been 320-L3 liftboat has 1.5-in. maximum prove. A liftboat a high-degree of global leg-wall thickness and has a higher is a self-elevating, recognition for liftboats. VDL and environmental criteria than self-propelled ves- Whatever recognition there the 2.5-in. leg-wall vessels.

sel equipped with has been outside the US VDL means Variable Dead Load. at least one crane for liftboats has been as It is the sum of weights of liquids and with open deck small jackups. In Europe (consumables, not ballast) and deck space that can be and Southeast Asia, where cargo. Environmental criteria consist used for multiple these vessels have found of Wind, Wave Height and Period, purposes. a home, the designs are and Current. All these produce a

That there is only infuenced by jackups. load on the structure. A higher Envi- a local understand- Larger liftboats may look ronmental Criteria set is a combina- ing of these vessels like jackups, but they are tion of these items that produces a cannot be more not jackups and the design higher load on the structure. evident than by the philosophy should refect There is also the problem of the fact that only one that. A jackup-infuenced jacking system. A liftboat requires,

The SUDA 320-L3 liftboat major class society, liftboat design leads to in some ways, a more complex and

American Bureau ineffciencies. For example, robust jacking system. Suda found of Shipping, has rules specifcally some 320ft leg liftboats have leg that it is no more expensive than one written for liftboats. The ABS Guide walls up to 2.5-in. thick. Liftboat used in the traditional jackups.

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