GHS Port Reference Center
Information for maritime designers, engineers and builders
Maintained by Creative Systems, Inc., Creators of GHS
Click here for information about GHS and other fine marine software.
Go to Main page

Example run file for IMO High Speed Craft Annex 7
    project HSCIMO
    
    enter pm
    units mt
    title block catamaran
    create cathull\stbd.s
     class hull
     ends 15f, 15a
     top 4
     bot 0
     out 1.5
     vector 0, 5, 0
    comp prow.s
     top 4
     bot 3 @ 18f, 0 @ 15f
     out 1.5 @ 15f, 0.1 @ 18f
     vector 0, 5, 0
     join stbd.s
    comp port.p
     shape cathull\stbd.s
     vector 0, -5, 0
    comp deck
     ends -14, 15
     top 8
     bot 4
     out 6.5
    /
    create sail
     class sail
     top 30 @ -8, 10 @ 10
     bot 10
     out 0.01
    /
    create cmpt1
     ends -5, 5
     fit stbd
    /
    
    write
    quit pm
    
    report /box:bw
    
    `di print /nooff
    \\\\\\\\\\\\\Stability Report\
    \\After IMO HSC code\
    
    `Light ship & loads:
    vcg 6
    draft 2
    solve weight, lcg
    
    `Set these constants as appropriate:
    VARIABLE NPASS = 30 `Number of crowding passengers
    VARIABLE WPASS = 0.8 `MT/passenger?
    VARIABLE DCROWD =  5.0 `Distance off CL of crowd center
    VARIABLE WINDMPS = 30 `Wind speed in meters/sec
    VARIABLE TURNRAD = 50 `Turn radius in meters
    VARIABLE TURNSPEED = 20 `Knots
    VARIABLE MAXDEQ = 15 `Max damage equilibrium 15 for passenger, 20 for cargo craft
    
    MACRO WINDHM `%1 - I for intact or D for damaged
     VARIABLE P
     SET P = {WINDMPS} DIV 26
     SET P = {P} TIMES {P}
     IF "%1"="I" THEN SET P = {P} TIMES 500 ELSE SET P = {P} TIMES 120
     \\Wind pressure = {P} N/sqm\
     SET P = {P} DIV 9800
     WIND (PRESS) {P}
     TRIM = 0
     HMMT WIND /CONST
     HMMT REPORT
     HMMT = {HMMT}
    /
    MACRO CROWD
     VARIABLE %1
     SET %1 = {NPASS} TIMES {WPASS} TIMES {DCROWD}
     \\Passenger crowding heeling moment: {%1:2}\
     \
    /
    MACRO TURN
     HMMT TURN {TURNRAD}, {TURNSPEED}
     HEEL = 0
     SOLVE TRIM
     VARIABLE %1 = {HMMT}
     HMMT REPORT
     HMMT OFF
    /
    MACRO FINDFLD
     HEEL = 0
     RA 0, 5 ... 40 /STOP:FLD /HOLD /NOPRINT
     VARIABLE FLDANG = {HEEL}
     HEEL = 0
    /
    MACRO FINDMAX
     HEEL = 0
     RA 0, 5 ... 60 /STOP:MAX /HOLD /NOPRINT
     VARIABLE MAXANG = {HEEL}
     HEEL = 0
    /
    MACRO LIM1
     HMMT OFF
     .FINDFLD
     .FINDMAX
     VARIABLE A = {FLDANG}
     IF {A} > {MAXANG} THEN SET A = {MAXANG}
     IF {A} > 30 THEN SET A = 30
     UNITS MT
     VARIABLE T
     SET T = 1.65 DIV {A}
     LIMIT AREA FROM 0 TO {A} > {T}
    /
    MACRO ROLLRA
     LIMITS OFF
     LIMIT AREA FROM EQU TO 15 OR FLD > 0.028
     SOLVE
     VARIABLE A
     SET A = ABS {HEEL}
     MACRO SAY
      \\Capsized to an angle of {HEEL:0} degrees with this heeling moment.\
      \
     //
     IF {A} > 20 THEN .SAY ELSE RA 0, 2 /LIM:ATT
     HEEL = 0
    /
    
    `Area to limiting angle without considering heeling moment:
    SUBTITLE
     \Intact Stability\
     \Absolute area\
    PAGE
    LIMITS OFF
    .LIM1
    LIMIT ANGLE AT MAX > 10
    LIMIT REPORT
    MACRO SAY
     \Downflooding angle%1\
    /
    IF {FLDANG} > 30 THEN .SAY " is greater than 30 degrees." ELSE .SAY ": {FLDANG:1}"
    \Angle of maximum righting arm: {MAXANG:1}\
    \
    HEEL = 0
    RA 0, 2 /LIM:ATT
    
    `Equilibrium angle with gust:
    SUBTITLE
     \Intact Stability\
     \Equilibrium angle with wind gust\
    PAGE
    TRIM = 0
    .WINDHM I
    VARIABLE GHM
    SET GHM = {HMMT} TIMES 1.5
    \Gust Heeling moment is 1.5 x {HMMT:2} = {GHM:2}\
    \
    HMMT = {GHM}
    LIMITS OFF
    LIMIT ANGLE AT EQU < 10
    RA 0, 5 /LIM:ATT /GRAPH:NONE
    
    `Residual area in roll with wind plus crowding or turning:
    SUBTITLE
     \Intact Stability\
     \Residual Area with wind plus crowding or turning\
    PAGE
    .CROWD PHM
    .TURN THM
    VARIABLE HM = {PHM}
    IF {HM} < {THM} THEN SET HM = {THM}
    SET HM = {HM} PLUS {GHM}
    HMMT = {HM}
    MACRO SAY
    \Total heeling moment: %1 plus wind gust {GHM:2} = {HM:2}\
    \
    /
    IF {PHM} > {THM} THEN .SAY "passenger {PHM:2}" ELSE .SAY "turning {THM:2}"
    .ROLLRA
    
    `Damage:
    SUBTITLE
     \Damage Stability\
    PAGE
    .WINDHM D
    VARIABLE HM3 = {HMMT}
    VARIABLE HM4
    SET HM4 = {HM3} PLUS {PHM}
    \Heeling moment with wind {HM3:2} plus crowding {PHM:2} = {HM4:2}\
    \
    MACRO FLDCASE
     TYPE (%1) FLOOD
     HMMT = {HM3}
     SOLVE
     STATUS
     PAGE
     LIMITS OFF
     LIMIT ANGLE AT EQU < {MAXDEQ}
     HEEL = 0
     RA 0, 5 /LIM:ATT /GRAPH:NONE
     HMMT = {HM4}
     .ROLLRA
     TYPE (%1) INTACT
    /
    .FLDCASE CMPT1
    
    print preview
    report off
    end
    
    
    
Add a free link to your site
Copyright © , Creative Systems, Inc.
Privacy policy