logging in or signing up brigid mary brigidm Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 17 Category: Product Traini.. License: All Rights Reserved Like it (0) Dislike it (0) Added: November 03, 2009 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript STABILITY : STABILITY FIRST PRINCIPLES : FIRST PRINCIPLES BUOYANCY CENTRE OF GRAVITY RIGHTING FORCE FACTORS WHICH CAN CAUSE CAPSIZE CBCentre Of Buoyancy : CBCentre Of Buoyancy Force generated by boat displacing water CB is point of concentration of this force Changes with HEEL ANGLE, TRIM and LOADING CB CG Centre of Gravity : CG Centre of Gravity Determined by structure and weight distribution of boat Best when it is low down GZ The Righting Lever : GZ The Righting Lever Force that combination of CG and CB make, to return boat to the upright. CG CB GZ RM Righting Moment : RM Righting Moment Mass (Weight and volume) of boat affects stability When multiplied with GZ it gives RM CB GZ X mass = RM ANGLE of HEEL : ANGLE of HEEL As boat heels more, RM becomes greater RM POINT OF VANISHING STABILITY : POINT OF VANISHING STABILITY RM is ZERO BOAT INVERTS CB RIGHTING MOMENT CURVE(Flat Water) : RIGHTING MOMENT CURVE(Flat Water) DIFFERENT TYPES OF CURVE : DIFFERENT TYPES OF CURVE DESIGN CATEGORIES : DESIGN CATEGORIES CATEGORY TYPE WIND FORCE WAVE HEIGHT A OCEAN >F8 >4M B OFFSHORE F8 4M C INSHORE F6 2M D SHELTERED WATERS F4 0.5M CATEGORIES : CATEGORIES RE-RIGHTING : RE-RIGHTING A = Re-righting factor B If it is large then re-righting is good RE-RIGHTING FACTORS : RE-RIGHTING FACTORS Type A will be harder to re-right than type B A’s re-righting factor is lower than B’s FACTORS THAT CAN CAUSE CAPSIZE : FACTORS THAT CAN CAUSE CAPSIZE SWAMPING OR FLOODING FREE- SURFACE EFFECT LARGE BREAKING WAVES CG MOVED UPWARDS RESONANT ROLLING BROACHING FACTORS WHICH CAN IMPROVE STABILITY (1) : FACTORS WHICH CAN IMPROVE STABILITY (1) INCREASED LENGTH HEAVY DISPLACEMENT FOR SIZE HIGH PROPORTION OF OVERALL WEIGHT AS BALLAST HIGH ANGLE OF VANISHING STABILITY HIGH RE-RIGHTING FACTOR GOOD RM AT 90° OF HEEL MODEST BEAM IN RELATION TO LENGTH FACTORS WHICH CAN IMPROVE STABILITY (2) : FACTORS WHICH CAN IMPROVE STABILITY (2) GOOD BUT NOT EXCESSIVE FREEBOARD MINIMAL TOPSIDE FLARE ABSENCE OF LARGE NEARLY FLAT AREAS OF DECK LARGE ANGLE OF HEEL BEFORE FLOODING CAN OCCUR INCREASED KEEL PROFILE AREA ABSENCE OF BULWARKS IN ROUGH WEATHERDO : IN ROUGH WEATHERDO CLOSE HATCHES, WASH BOARDS ETC. PUMP OUT BILGE REGULARLY WATCH OUT FOR GUSTY CONDITIONS AVOID BEING CAUGHT BEAM ON TO LARGE, BREAKING WAVES BE AWARE OF CATEGORY AND CAPABILITY OF YOUR BOAT IN ROUGH WEATHER DO NOT : IN ROUGH WEATHER DO NOT SAIL IN CONDITIONS THAT ARE OUTSIDE THE CAPABILITY AND CATEGORY FOR WHICH YOUR BOAT WAS DESIGNED DELIBERATELY SAIL THROUGH KNOWN TIDAL RIPS, RACES, OVERFALLS OR WHERE THE BOTTOM SHOALS RAPIDLY You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
brigid mary brigidm Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 17 Category: Product Traini.. License: All Rights Reserved Like it (0) Dislike it (0) Added: November 03, 2009 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... Premium member Presentation Transcript STABILITY : STABILITY FIRST PRINCIPLES : FIRST PRINCIPLES BUOYANCY CENTRE OF GRAVITY RIGHTING FORCE FACTORS WHICH CAN CAUSE CAPSIZE CBCentre Of Buoyancy : CBCentre Of Buoyancy Force generated by boat displacing water CB is point of concentration of this force Changes with HEEL ANGLE, TRIM and LOADING CB CG Centre of Gravity : CG Centre of Gravity Determined by structure and weight distribution of boat Best when it is low down GZ The Righting Lever : GZ The Righting Lever Force that combination of CG and CB make, to return boat to the upright. CG CB GZ RM Righting Moment : RM Righting Moment Mass (Weight and volume) of boat affects stability When multiplied with GZ it gives RM CB GZ X mass = RM ANGLE of HEEL : ANGLE of HEEL As boat heels more, RM becomes greater RM POINT OF VANISHING STABILITY : POINT OF VANISHING STABILITY RM is ZERO BOAT INVERTS CB RIGHTING MOMENT CURVE(Flat Water) : RIGHTING MOMENT CURVE(Flat Water) DIFFERENT TYPES OF CURVE : DIFFERENT TYPES OF CURVE DESIGN CATEGORIES : DESIGN CATEGORIES CATEGORY TYPE WIND FORCE WAVE HEIGHT A OCEAN >F8 >4M B OFFSHORE F8 4M C INSHORE F6 2M D SHELTERED WATERS F4 0.5M CATEGORIES : CATEGORIES RE-RIGHTING : RE-RIGHTING A = Re-righting factor B If it is large then re-righting is good RE-RIGHTING FACTORS : RE-RIGHTING FACTORS Type A will be harder to re-right than type B A’s re-righting factor is lower than B’s FACTORS THAT CAN CAUSE CAPSIZE : FACTORS THAT CAN CAUSE CAPSIZE SWAMPING OR FLOODING FREE- SURFACE EFFECT LARGE BREAKING WAVES CG MOVED UPWARDS RESONANT ROLLING BROACHING FACTORS WHICH CAN IMPROVE STABILITY (1) : FACTORS WHICH CAN IMPROVE STABILITY (1) INCREASED LENGTH HEAVY DISPLACEMENT FOR SIZE HIGH PROPORTION OF OVERALL WEIGHT AS BALLAST HIGH ANGLE OF VANISHING STABILITY HIGH RE-RIGHTING FACTOR GOOD RM AT 90° OF HEEL MODEST BEAM IN RELATION TO LENGTH FACTORS WHICH CAN IMPROVE STABILITY (2) : FACTORS WHICH CAN IMPROVE STABILITY (2) GOOD BUT NOT EXCESSIVE FREEBOARD MINIMAL TOPSIDE FLARE ABSENCE OF LARGE NEARLY FLAT AREAS OF DECK LARGE ANGLE OF HEEL BEFORE FLOODING CAN OCCUR INCREASED KEEL PROFILE AREA ABSENCE OF BULWARKS IN ROUGH WEATHERDO : IN ROUGH WEATHERDO CLOSE HATCHES, WASH BOARDS ETC. PUMP OUT BILGE REGULARLY WATCH OUT FOR GUSTY CONDITIONS AVOID BEING CAUGHT BEAM ON TO LARGE, BREAKING WAVES BE AWARE OF CATEGORY AND CAPABILITY OF YOUR BOAT IN ROUGH WEATHER DO NOT : IN ROUGH WEATHER DO NOT SAIL IN CONDITIONS THAT ARE OUTSIDE THE CAPABILITY AND CATEGORY FOR WHICH YOUR BOAT WAS DESIGNED DELIBERATELY SAIL THROUGH KNOWN TIDAL RIPS, RACES, OVERFALLS OR WHERE THE BOTTOM SHOALS RAPIDLY