International classification society Bureau Veritas will class three Ultra-Large Container Ships (ULCSs) to be built for China State Shipbuilding Corporation (CSSC) and chartered to French operator CMA CGM. The ships are due for delivery in 2015.
The 16,000 teu vessels will be the largest container ships built in China to date. One will be built at the Shanghai Waigaoqiao Shipbuilding (SWS) yard, and the other two at Shanghai Jiangnan Changxing Heavy Industry, part of which came under the management of SWS this year.
In recent years, Chinese shipyards have secured orders for increasingly large box ships, and the three new 16,000 teu ships are only a fraction smaller than the largest container vessels being built today in Korea. The design was developed by the Marine Design and Research Institute of China (MARIC) in co-operation with BV, which performed the drawing approval and conducted a thorough structural examination.
The vessels will have an overall length of 399 m, a beam of 54 m, and a draft of 16 m. Special consideration has been given to hydroelastic design (whipping and springing) issues, which are so important for this size of ship. A hydroelastic examination was performed using BV’s HOMER software in order to take into account extreme whipping loads due to slamming and additional fatigue damage due to springing, factoring in the elastic structural response of the ship. This review provides a higher level of safety compared to the rigid approach traditionally adopted to such issues, and is mandatory under BV Rules for ULCSs of 300 m and above. On the strength of this examination, BV’s WhiSp2 notation has been assigned to the ships.
The vessels will be also granted BV’s VeriSTAR HULL DFL 25-year notation, which certifies various structural details, including hatch corners and coamings, for 25 years of fatigue life, following a spectral fatigue analysis with a 3D finite element analysis model. The importance of fatigue for large container ships, which generally lack torsional rigidity and become more elastic with size, has been confirmed by real measurements on board ULCSs classed by BV.
The 16,000 teu ships will be able to operate at a maximum speed of over 23 knots with a single-screw propeller directly coupled to a 69 Megawatt, 2-stroke electronic engine. The vessels’ environmentally friendly profile is attested to by BV’s class notations CLEANSHIP and FORS. The latter incorporates special arrangements to ensure that the ship’s fuel oil tanks are safely emptied in case of emergency, minimizing the risk of pollution. This is an important safety aspect considering the size of the fuel oil tanks of ULCSs.
Steel cutting for the new vessels is due to begin next year and the ships are expected to be delivered in 2015.