EMSA
Study on Damage Stability of RO-PAX Vessels
- supported by
EMSA
- Partners
HSVA, FSG, TUHH-M6
- Duration
01.01.2009 - 01.08.2009
Two new RoPax ships were designed to meet the requirements of the new probabilistic SOLAS 2009 damage stability standard. The safety levels attained by the different ship damage stability rules to these two ships were determined with Monte Carlo simulations. For both ship designs the safety level presented by the SOLAS 2009 Reg. B-1 rules clearly drops down to a significantly lower level than that presented by SOLAS 90 Reg. II-1/8 standard together with the Stockholm Agreement. The hydrostatic calculations show that the smaller ship suffers from a general lack of stability, but the designed subdivision is reasonable. The larger ship has a sufficient level of stability, but the ship would capsize or also in calm water, if the lower hold got damaged. In general the numerical simulations give a good picture of the ship heeling and vehicle deck flooding process, but they predict a somewhat too survivability for these two vessels. Typical damage cases were chosen for the tests, which the following results: The smaller ship capsized already at significant wave height H s 3.0 m. In some other damage cases ship is expected to capsize in much lower waves, also when there is no water on the vehicle deck. Excluding the lower hold damage the larger ship would probably survive some likely damage cases in a sea state of Hs 4.0 m. Altogether the present investigation of the two RoPax vessels shows that in the framework of the new probabilistic damage stability rules (SOLAS 2009) for passenger ships built from January 1, 2009, it is possible to create ship designs with significant deficits with regard to safety. In view of this it is difficult to come into any other conclusion that the ship stability required by the SOLAS 2009 rules is not likely to be sufficient in all cases. Corrective action should be taken to amend the SOLAS 2009 rules. A suggestion for the direction of future is given.
For more detailed information please get in touch with one of the contact persons: Stefan Krüger, Hendrik Dankowski
| [57654] |
| Title: On the safety level of the SOLAS 2009 damage stability rules for RoPax vessels. |
| Written by: Hendrik Dankowski, Stefan Krüger |
| in: <em>PRADS, Rio de Janeiro</em>. (2010). |
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Note: EMSA
Abstract: The new probabilistic damage stability rules in SOLAS 2009 and their impact on the safety of the ship subdivision design have been widely discussed. Especially the safety level of RoPax designs are considered for further investigations. This paper describes a methodology to compare the safety provided by different damage stability regulations for a certain ship design. The determination of the damage cases probabilities are based on a Monte Carlo simulation for the damage distributions. The damage cube itself is modeled by distribution functions retrieved from statistics based on the HARDER project. This gives a very elegant, fast and direct approach of damage calculations. Together with the calculation of the survivability of all damage cases, this allows to identify and compare the safety level indices of different damage stability standards. The method has been used in the “EMSA Study on Damage Stability of ROPAX vessels”. The theory of the simulation methodology and some extracts of the results of the EMSA study will be presented in the following. It has been shown in the study that for the investigated RoPax designs the new SOLAS 2009 rules are less stringent than the old, deterministic rules according to the Stockholm agreement. This means that especially the old water-on-deck requirement results in more severe designs and that the required index of the new damage rules is too low for the investigated RoPax vessel designs.