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Finding the angle theta3, where A2 = A1 as in the RINA Cargo Loss criterion. |

`Finding the angle Theta3, where A2 = A1 as in the RINA Cargo Loss criterion. `In this run file, the TCG of the vessel is set to create conditions during `lifting and after the cargo loss. Since the effect of TCG varies with the `cosine of the heel angle it is equivalent to setting a cosine based heeling `moment. `When using this method, the run file should either set up actual loading `conditions with and without the crane load, or use a heeling moment to represent `the counterballast weights. Keep in mind that the equilibrium angle during `lifting is saved as variable t1 and is necessary to evaluate the criteria. proj theta3 read subdivy crt(1) Vent 25a, 5s, 11 /sym report draft 6 vcg 8 solve weight lcg macro findt3 `finds Theta3, then evaluates RINA Cargo Loss macro t3 `incrementally adjust t3 until t < 0.05 lim title --Find Angle Theta3---------- lim(1) res ratio from abs {t1} to abs {t3} > 1 ra /lim /noprint \limmarg: {limmarg}; t3: {t3}; t: {t} `prints iteration history if {t} < 0.005 then exit if {limmarg}>0 then set t3={t3} minus {t} else set t3={t3} plus {t} set t={t} times 0.5 exit t3 // variable t3=30 `theta3-terminating angle for res ratio limit variable t `amount to increment or decrement t3 set t={t3} div 2 lim off .t3 \\Theta3 is {t3:1} degrees, as demonstrated below.\ \ ra /lim:att /graph:none `/stop:fld if {t3}>30 then set t3=30 | ,, \Theta3 not to be taken greater then 30, therefore Theta3=30\ page lim off limit title RINA Pt E, Ch 19, Sec 2: 2.2.3 lim(1) res ratio from abs {t1} to FLD or RA0 > 1 lim(2) angle from abs {t3} to FLD or RA0 > 20 ra /lim:att /stop:fld / tcg=.5 `Simulate lifting condition - hook load on starboard side solve variable t1={heel} `Equilibrium heel angle during lifting tcg=-1.5 `Simulate dropped load condition - counterballast on port side so `Setting angles direction and sign of starting angle, t1, if RAH to port. `(Righting arm direction is determined by equilibrium angles before and ` after the hook load is dropped. When the righting arm is to port, ABS ` angles are the opposite of the normal sign convention, which is +=STBD. ` Angles * is not sufficient to direct the righting arm direction for all ` combinations of equilibrium with and without lifting.) if {t1}>{heel} then angles 0 -5 ... -30 | set t1=minus {t1},, else angles 0 5 ... 30 .findt3 print preview report off end |

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