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Demonstrates a method to find the Maximum Steady Heel Angle to Prevent Downflooding in Gusts.
    proj sailship
    
    `Demonstrates a method to find the
    ` "Maximum Steady Heel Angle to Prevent Downflooding in Gusts"
    
    MACRO MaxHeel
     VARIABLE T,TF0,TFL,TF,TMX,TSS,TSA
     VARIABLE GZF
     VARIABLE HA1,HA2
     `Find downflooding angle:
     SET TFL=60.0
     SET TMX=27.0
     RA 0 10 ... 90 /STOP:FLD /HOLD /NOTAB
     SET TF0 = {HEEL}
     SET TF = {TF0}
     IF {TF} > {TFL} THEN SET TF = {TFL}
     `Find RA at max allowed DF angle:
     HEEL = {TF}
     SOLVE TRIM
     SET GZF = {RAH}
     `Calculate HA1, zero degree heeling arm to produce this heel:
     SET T = COS {TF}
     SET T = {T} POWER 1.3
     SET HA1 = {GZF} DIV {T}
     `Calculate HA2, half of HA1:
     SET HA2 = {HA1} TIMES 0.5
     `Set up heeling moment function using HA2:
     SET T = {HA2} TIMES {WEIGHT}
     HMMT = {T} /C:1.3
     `Find heel under this HMMT:
     SOLVE
     SET TSS={HEEL}
     `Check whether exceeds allowed limit:
     SET TSA={TSS}
     IF {TSS}>{TMX} THEN SET TSA={TMX}
     HEEL 0
     `Report:
     \
     \Sailing Ship Maximum Allowed Steady Heel\
     \
     \Actual downdlooding angle:  { TF0:2}\
     \Maximum DF angle:           { TFL:2}\
     \Angle used for HA1:         {  TF:2}\
     \GZ at this angle:           { GZF:2}\
     \              HA1:          { HA1:2}\
     \           HA2(0):          { HA2:2}\
     \Steady heel:                { TSS:2}\
     \Maximum steady heel:        { TMX:2}\
     \Allowed steady heel:        { TSA:2}\
     \\
    /
    
    `Testing ...
    
    `Read a GF:
    read fv.gf
    
    `Define downflooding point:
    crtpt "Flood point" 0 10 13
    
    `Set weight & CG:
    depth 5
    vcg 5
    solve weight lcg
    
    `Start report file:
    report
    
    `Execute the macro:
    .MaxHeel
    
    `Support with a righting arm curve:
    RA
    
    `View the result:
    report /preview
    report off
    

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