Ship’s Dimension and Forms PDF

SHIP’S DIMENSION AND FORMS 2/M FRANK ADRIAN C LAVEGA  PRINCIPAL DIMENSION Principal Dimension- The shapes shown in a lines plan delineate what is called the molded form of the vessel. The principal dimensions of a ship are the following: After Perpendicular...

SHIP’S DIMENSION AND FORMS 2/M FRANK ADRIAN C LAVEGA  PRINCIPAL DIMENSION Principal Dimension- The shapes shown in a lines plan delineate what is called the molded form of the vessel. The principal dimensions of a ship are the following: After Perpendicular Forward Perpendicular Length Between Perpendiculars (LBP or L) Beam (B) Draft (T) AFTER PERPENDICULAR ( A.P.) – A PERPENDICULAR DRAWN TO THE WATERLINE AT THE POINT WHERE THE AFT SIDE OF THE RUDDER POST MEETS THE SUMMER LOADLINE. WHERE NO RUDDERPOST IS FITTED IT IS TAKEN AS THE CENTERLINE OF THE RUDDERSTOCK. AFTER PERPENDICULARS FORWARD PERPENDICULAR (F.P.) – A PERPENDICULAR DRAWN TO THE WATERLINE AT THE POINT WHERE THE FORE SIDE OF THE STEM MEETS THE SUMMER LOAD LINE. FORWARD PERPENDICULARS LENGTH BETWEEN PERPENDICULARS-THE HORIZONTAL DISTANCE BETWEEN THE FORWARD AND AFT PERPENDICULARS IS CALLED THE LENGTH BETWEEN PERPENDICULARS. IT IS CONSTANT FOR A GIVEN SHIP AND DOES NOT DEPEND ON THE LOADING CONDITION OF THE SHIP. LENGHT BETWEEN PERPENDICULARS BEAM- THE BREADTH OF THE SHIP AT THE BROADEST POINT BEAM DRAFT-THE VERTICAL DISTANCE BETWEEN THE WATERLINE AND THE DEEPEST PART OF THE SHIP AT ANY POINT ALONG THE LENGTH IS THE DRAFT. DRAFTS ARE USUALLY MEASURED AT THE FORWARD, TF, AND THE AFT, TA, PERPENDICULARS ALTHOUGH THEY CAN ALSO BE DEFINED AT THE FORE AND AFT DRAFT MARKS WHICH MAY NOT COINCIDE WITH THE PERPENDICULARS. THE MEAN DRAFT, TM, IS THE AVERAGE OF THE FORWARD AND AFT DRAFTS. DRAFT  OTHER MEASUREMENTS In addition to the principal dimensions, the following are also used in describing ships: Length Overall (LOA) Length on Waterline (LWL) Freeboard (F) Depth Base Line Moulded Beam Moulded Draft Moulded Depth LENGTH OVERALL- THE EXTREME LENGTH OF THE SHIP ALONG THE CENTERLINE IS CALLED THE LENGTH OVERALL. LENGHT OVERALL LENGTH ON WATERLINE- THIS IS THE LENGTH ALONG THE CENTERLINE AT THE WATERLINE IN THE SHIP'S DESIGN LOADED CONDITION. LENGTH ON THE WATERLINE FREEBOARD-THIS IS THE DISTANCE BETWEEN THE WATERLINE AND THE UPPERMOST WATERTIGHT DECK AT ANY LOCATION ALONG THE SHIP. FREEBOARD BASE LINE – A HORIZONTAL LINE DRAWN AT THE TOP OF THE KEEL PLACE. ALL VERTICAL MOULDED DIMENSIONS ARE MEASURED RELATIVE TO THIS LINE. BASE LINE MOULDED BEAM – MEASURED AT THE MIDSHIP SECTION IS THE MAXIMUM BREADTH OF THE SHIP. MOULDED BEAM MOULDED DRAFT – MEASURED FROM THE BASE LINE TO THE SUMMER LOAD LINE AT THE MIDSHIP SECTION. MOULDED DRAFT MOULDED DEPTH – MEASURED FROM THE BASE LINE TO THE HEEL OF THE UPPER DECK BEAM OF THE SHIP’S SIDE AMIDSHIPS. MOULDED DEPT  SHIP’S FORMS Sheer Keel rake Camber Tween deck height Rise of floor Parallel middle body Half siding of keel Entrance Tumblehome Run Flare Stem rake SHEER- CURVATURE OF DECKS IN THE LONGITUDINAL DIRECTION. MEASURED AS THE HEIGHT OF DECK AT SIDE AT ANY POINT ABOVE THE HEIGHT OF DECK AT SIDE AMIDSHIPS. CAMBER (OR ROUND OF BEAM) – CURVATURE OF DECKS IN THE TRANSVERSE DIRECTION. MEASURED AS THE HEIGHT OF DECK AT CENTER ABOVE THE HEIGHT OF DECK AT SIDE. RISE OF FLOOR (OR DEAD RISE) – THE RISE OF THE BOTTOM SHELL PLATING LINE ABOVE THE BASE LINE. THIS RISE IS MEASURED AT THE LINE OF MOULDED BEAM. HALF SIDING OF KEEL – THE HORIZONTAL FLAT PORTION OF THE BOTTOM SHELL MEASURED TO PORT OR STARBOARD OF SHIP’S CENTERLINE. THIS IS A USEFUL DIMENSION TO KNOW WHEN DRY DOCKING. TUMBLEHOME – THE INWARD CURVATURE OF THE SIDE SHELL ABOVE THE SUMMER LOAD LINE. FLARE – THE OUTWARD CURVATURE OF THE SIDE SHELL ABOVE THE WATERLINE. IT PROMOTES DRYNESS AND IS THERE OF RE ASSOCIATED WITH THE FORE END OF THE SHIP. STEM RAKE – INCLINATION OF THE STERN LINE FROM THE VERTICAL. KEEL RAKE – INCLINATION OF THE KEEL LINE FROM THE HORIZONTAL. TRAWLERS AND TUGS OFTEN HAVE KEELS RAKE AFT TO GIVE GREATER DEPTH AFT WHERE THE PROPELLER DIAMETER IS PROPORTIONATELY HAVE FORWARD RAKE OF KEEL TO BRING PROPELLERS ABOVE THE LINE OF KEEL. TWEEN DECK HEIGHT – VERTICAL DISTANCE BETWEEN ADJACENT DECKS MEASURED FROM THE TOPS OF DECK BEAMS OF SHIPSIDE. PARALLEL MIDDLE BODY – THE OVER WHICH THE MIDSHIP SECTION REMAINS CONSTANT IN AREA AND SHAPE. ENTRANCE – THE IMMERSE BODY OF THE VESSEL FORWARD OF THE PARALLEL MIDDLE BODY. RUN – THE IMMERSE BODY OF THE VESSEL AFT OF THE PARALLEL MIDDLE BODY. THANK YOU!!!!