Framing Systems Double Bottom Construction Stem & Stern Construction Ship Construction Framing Systems Double Bottom Construction Stem & Stern Construction

Transverse Framing: Many, closely-spaced Frames Deck Beams tie upper ends of frames Fewer, deeper & more widely spaced Longitudinals … Support Inner Bottom & give longitudinal strength Longitudinals supporting Decks are called (Deck) Girders Additional Decks (supported by Beams & Girders) increase Transverse & Longitudinal strength Transverse Bulkheads provide watertight boundaries, contribute significantly to transverse strength, and provide vertical support for Decks

Transverse Framing: Many, closely-spaced Frames Advantages Open, nearly rectangular interior space Ideal for stowing large, irregular, break-bulk items, or Vehicles (Ro-Ro’s) Disadvantages Vertical support for decks requires more closely spaced transverse bulkheads (hence smaller compartments) or Pillars (stanchions) or Longitudinal bulkheads

Longitudinal Framing: Deep (Web) Transverse Frames Few & widely spaced Smaller, closely-spaced Longitud-nals support shell plating Side shell longitudinals call stringers Inner Bottom gives additional longitudinal & transverse strength Girders in high-stress areas: Double bottom spaces and … Under main deck

Longitudinal Framing: Deep (Web) Transverse Frames Advantages Widely spaced transverse bulkheads allow for large (i.e., long) continuous cargo spaces (“tanks”) Ideal for stowing liquids (reduced free surface effects) Disadvantages No large, open interior spaces Difficult to load or unload break-bulk items Difficult to stow large, irregular shaped items

Framing Systems: Typically, most ships have some combination of transverse & longitudinal framing L L L L L L L L L L T T T T T T T T T T T T T T T T T Bulkhead STIFFENERS UPPER TWEEN DECK LOWER TWEEN DECK Stringer (LOWER) HOLD Web Frame Typical Transverse Frames SECTION VIEW FLOOR C L PLAN VIEW C L

Double Bottom details: Rider Plate Inner Bottom (Tank Top) Air- hole Margin Plate Frame Bilge Bilge well Center Vertical Keel Limber hole Longitudinal “SOLID” FLOOR Keel Plate Outer Bottom Lightening hole Reverse Frame “OPEN” FLOOR Frame Longitudinal Strut

Shell Plating details: (Longitudinal) Rows of plating are called “strakes” The Keel Plates form the “Keel strake” The strakes outboard (P&S) of the Keel are the “A” Strakes or “Garboard Strakes” Strakes are consecutively lettered moving outboard and up the side shell “G” Strake “F” Strake (Bilge Strake) “B” Strake “C” Strake “D” Strake “E” Strake Keel Strake Garboard Strake (“A” strake)

Shell Plating details: (Longitudinal) Rows of plating are called “strakes” Welded horizontal joints between strakes are called seams Welded vertical joints between plates in a given strake are called butts Strakes that do not run the entire ship length (as the hull surface area decreases at the ends) are drop strakes “K” Strake Sheer Strake “J” Strake Through  “H” Strake drop  “G” Strake Bilge (“F”) Strake Strakes running stem to stern are called through strakes An oversized plate merging a drop & through strake is a stealer plate The strake at the deck edge is the sheer strake and is heavier than typical side shell plating

Openings in shell plating must:. have rounded corners Openings in shell plating must: *have rounded corners *be reinforced to make up for missing material … and on weather deck -- COAMINGS portholes Hatch openings below decks Watertight doors

Stem Construction Decks Forward Wrapper Collision Plate Stem Bulkhead Stringers Vertical Stem Post Rider Plate Breast Hooks Deep Floors C.V. Keel Keel Plate

Stern Construction UNBALANCED RUDDER SEMI-BALANCED RUDDER Stern Frame After Collision Bulkhead Stern Frame Steering Gear Room Deck Mach’y Rm Cant Frames Rope Locker Lug Rudder Stock After Peak Tank Stern Tube Pintle Gudgeon Rudder Post UNBALANCED RUDDER Propeller Post SEMI-BALANCED RUDDER