Tham khảo tài liệu 'ship stability for masters and mates 5 episode 7', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Calculating the effect of free surface of liquids FSE 199 The following worked example shows the effect of subdivisions in slack tanks in relation to free surface effects FSE Question A ship has a displacement of 3000 tonnes. On the vessel is a rectangular double-bottom tank 15 m long and 8 m wide. This tank is partially filled with ballast water having a density of t m3. If the GMy without free surface effects is m calculate the virtual loss in GMy and the final GMy when the double bottom tank has a no divisional bulkheads fitted b one transverse bulkhead fitted at mid-length c one longitudinal bulkhead fitted on T of the tank d two longitudinal bulkheads fitted giving three equal divisions. Answer h 15m bi 8m Fig. a FSE virtual loss in GMy or rise in G - 1 w 1 X b3 X psw . _ _ . . TT TTf see Fig- a 12 X w v s n . . . 15 X 83 X . . virtual loss in GMy ------------ ------- --------- 3000 X 12 t GMy finally - T . unstable ship 200 Ship Stability for Masters and Mates l2 72 m 2 7Ỉ m 8m BHD Fig. b FSE virtual loss in GMy or rise in G 2 @ l2 X b3 12 X w x Psw see Fig. b . . 2 X X 83 X . . virtual loss -------------------- 12 X 3000 t This is same answer as for part a . Consequently it can be concluded that fitting transverse divisional bulkheads in tanks does not reduce the free surface effects. Ship is still unstable _2 @ lyb - w Psw FSE vertical loss in GMy or rise in G . . virtual loss in GMy 2x 15 X 43 X 12 X 3000 see Fig. c m I . 2 of answer to part a Hence final GMy m m Ship is stable. Calculating the effect of free surface of liquids FSE 201 GMt is now ve but below the minimum GMt of m that is allowable by . regulations. FSE virtual loss in GMt or rise in G 3 @ 11 X . . TX Psw see Fig. d 12 X W . Virtual loss in GMt 3 X 15 X 8 X _ 3 _ 12 X W m . 1 of answer to part a Hence final .
