OCEN 402HW # 5
Title
Stability Report
Description
Determine the hydrostatic properties of the given hull, the cross curves and the righting arm (GZ) curves. Thereby compile a stability report. Use the stability package StabCad available in CE 220.
Determine if the IMO (International Maritime Organization) stability criteria, enclosed in appendix are satisfied for the given loading conditions.
Loading condition
Group / 1&12 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11Cb / 0.6 / 0.6 / 0.65 / 0.65 / 0.7 / 0.7 / 0.75 / 0.75 / 0.8 / 0.8 / 0.8
∇, Tons / 7807 / 7807 / 9051 / 9051 / 10456 / 10456 / 12048 / 12048 / 13859 / 13859 / 13859
VCG, ft from keel / 14.93 / 15.13 / 15.46 / 16.46 / 16.13 / 17.13 / 16.59 / 17.59 / 17.21 / 18.21 / 18.21
LCG, % from midship / 1.6 A / 1.5 A / 0.0A / 0.5 F / 0.5 F / 0.0 A / 1.5 F / 1.0 F / 2.5 F / 2.0 F / 0.0 A
Detailed outline
Prepare a stability report , the report should be sent in both as a pdf file and as a hardcopy
The report should contain
●Objective and introduction
●Main Particulars of the ship
●A perspective of the ship model from StabCad
●Hydrostatics Tables
●Hydrostatics as a plot
●Displacement
●LCB
●VCB
●MCT
●TPC
●LCF
●BML
●BMT
●Cross curves of stability in tabular form
●Cross curves of stability as a plot
●A loading condition summary which summarizes the following
●Displacement (Volume and Mass)
●LCG
●VCG
●TCG
●LCB
●VCB
●TCB
●Mean Draft
●Trim
●Heel
●BM
●GM
●A righting arm (GZ) curve plot
●A conclusion commenting on the compliance / noncompliance of the ship with the IMO stability criteria.
Your report should have a table similar to the one shown,
Compliance with the IMO intact Stability Criteria
Criteria / Minimum recommended / Attained / OK/NOT OK1 / The initial metacenter , corrected for free surface at 0o heel, shall not be less that 0.15 m / 0.15 m
2 / The area under the GZ curve from 0o to 30o should nor be less that 0.055 m-rad. / 0.055 m-rad
3 / The area under the GZ curve from 0o to 40o or the angle of downflooding, whichever is lesser should nor be less that 0.09 m-rad. / 0.09 m-rad
4 / Tha area under the GZ curve between 30o to 40o or the angle of downflooding, whichever is lesser should not be less than 0.03 m-rad. / 0.03 m-rad
5 / The righting lever GZ shall be ateast 0.20 m at an angle of heel equal to or greater than 30o. / 0.20 m
6 / The maximum righting arm shall occur at an angle of heel preferably exceeding
30o but not less than 25o. / 25o
●An appendix should be enclosed which contains a print out of the input file from stabcad (Beta file)
The report should have a table of contents list of figures and should be properly titled and sections numbered.
Appendix
Glossary
LCGLongitudinal center of gravity
VCGVertical center of gravity
TCGTransverse center of gravity
LCBLongitudinal center of buoyancy
VCBVertical center of gravity
TCBTransverse center of gravity
Mean DraftMean of the draft between perpendiculars.
(Ta+Tf)/2
where Ta=Draft Aft, Tf=Draft Fwd.
Trim(Ta-Tf)
Heeldegree inclination from upright, port heel being taken as positive.
BMHeight from center of buoyancy to metacenter
GMoHeight from center of gravity to Metacenter
IMO intact Stability criteria
- The initial metacenter , corrected for free surface at 0o heel, shall not be less that 0.15 m
- The area under the GZ curve from 0o to 30o should not be less that 0.055 m-rad.
- The area under the GZ curve from 0o to 40o or the angle of downflooding, whichever is lesser should nor be less that 0.09 m-rad.
- The area under the GZ curve between 30o to 40o or the angle of downflooding, whichever is lesser should not be less than 0.03 m-rad.
- The righting arm GZ shall be at least 0.20 m at an angle of heel equal to or greater than 30o.
- The maximum righting arm shall occur at an angle of heel preferably exceeding 30o but not less than 25o.