旅客船运行时波浪形态的试验研究英文文献和中文翻译(6)
No shift or additional frequencies were observed. Due to the drift motions of the ship a wake can appear on the windward side. This was shown to not influence the wave amplitudes or wave smoothness. The situation when an evacuating equipment needs to be used is complex and consists of many processes. From the perspective of the wave climate the wave situation is similar on the windward side and leeward side for long incident waves. However, for shorter waves the situa-tion is significantly more favourable on the leeward side. For shorter waves it can also be concluded that the situation is more favourable fore and aft on the wind-ward side compared to amidships. Further, three evacuation systems behaviour was ex-perimentally investigated when the ship was free to drift transversally. A number of parameters and wave condi-tions and their effects on the systems behaviour have been studied. The risk of evacuation by the lifeboat and the chute systems is low in small waves. However the risk increases with an increase of the wave height. The results of the lifeboat and the “fall” system tests have been compared with the previous results (Tsychkova and Rutgersson, 2001a and 2001c). Test results of the lifeboat launching in the longer waves correlate good with previous tests (Tsychkova and Rutgersson, 2001a). The drift speed of the mother ship in these waves is very small therefore the influence of drift on the test results is negligible. In the shorter waves the drift motion of the mother ship influence the risk through collisions between the ship and the lifeboat after the lifeboat enters the water. According to the wave measurements the wave climate on the leeward side of the drifting ship model is the same as for the ship model without drift which indicate that the collisions depend on the drift motion of the mother ship.
The results of the “fall” systems investigation are in good correlation with previous testing of this system (Tsychkova and Rutgersson, 2001c). Increase of the launching speed compared to the conventional system decrease the risk for impacts against the ship side. How-ever when the launching acceleration was higher than 0.5g the risk for impacts or water entry with a heeling angle increased. The chute system is exposed to the waves and the “mother” ship motions during a fairly long time when passengers embark the system. Due to large relative motions between waves and the mother ship and a close position of the chute system to the ship side the platform and the life rafts can be caught on a fender or other constructions on the ship side. Arrangements for stretching the chute and prevention of deformation of the chute form should be used to avoid situations when the chute can be jammed between the ship side and the platform. The total weight of passengers influences only slightly the risk of evacuation. However in the present study the chute system was tested with a maximal num-ber of occupants of 100, but possibly the risk can be influenced by a higher number of passengers.
Acknowledgements The authors are thankful to the Laboratory of Ship Dy-namics of El Pardo Model Basin, Spain and the EU-program "Training and Mobility of Researchers - Access to Large Scale Facilities". References Ekman, P (2003). “Numerical Calculations of the Wave Climate Close to a Ship in Beam Seas at Fn=0”, ISOPE Conference, Honolulu, USA, May 2003. Ekman, P (2004). “Experimental Study of the Wave Climate Close to a Ship in Beam Seas at Fn=0”, ISOPE Conference, Toulon, France, May 2004. Hogben N., Dacunha N.M.C. and Olliver G.F. (1986). “Global Wave Statistics”, British Maritime Tech-nology Limited, Feltham, United Kingdom. Marón A., Tsychkova E., Ekman P., Prieto M.E., Gutiérrez C. and Taboada M. (2003). “Seakeeping Basin Tests for Survivability and Evacuation of Ships”, Proceedings of STAB 03, Madrid, Spain. Simões Ré, A and Veitch, B (2000). “Lifeboat Evacua-tion Performance in a Range of Enviromental Condi-tions”, Marine Hazard Offshore, London, 27-28 No-vember 2000, Section 4 Research and technology development, Paper 5, pp 4.5.1-4.5.10. Simões Ré, A, Veitch, B and Pelley, D (2002). “Evacua-tion by TEMPSC”, Intl. Conf. On Offshore Emer-gencies – Preventing and surviving Offshore emer-gencies in the Oil & Gas Industries, 26-27 June 2002, Aberdeen, UK, Ppr. 4 (15 p). Tsychkova, E and Rutgersson, O (2001a). "Experimen-tal Investigation of Evacuation Systems on Passen-ger Ships. - Part I. Lifeboat/Davit System", TIEMS Conference, Oslo, Norway, June 2001. Tsychkova E, and Rutgersson, O (2001b). "Experimen-tal Investigation of Evacuation Systems on Passen-ger Ships. - Part II. Slide/Liferaft System", TIEMS Conference, Oslo, Norway, June 2001. Tsychkova E, and Rutgersson, O (2001c). " Study of “Fall” System for Safe Evacuation of Passenger Ships in Rough Weather", TIEMS Conference, Oslo, Norway, June 2001. Werenskiold, P and Scarpa, G (2003). “Passenger Ships: Design for ever Safer escape and Evacuation”, FAST 2003, Ischia (Italia), Oktober 2003.