Ship Design & Engineering

References Required: Intro to Naval Engineering Optional: Ch 20 Optional: Principles of Naval Engineering Ch 2

Introduction Principles of ship design Basic ship structure, including forces Ship structural elements Compartment Numbering Submarine Design Piping Systems & Coloring

Basic Design Considerations Operation Employment Mission: task or job ship is designed to perform Armament: measure of offensive & defensive power of ship Protection: features designed to thwart or minimize destructiveness of enemy attack Maneuverability: rapid course/speed changes Cruising range: distance a ship can travel at cruising speed without refuel/reprovision

Basic Design Considerations Seaworthiness: the ship’s ability to operate in all types of weather and sea states Factors affecting seaworthiness Stability: ability of ship to return to an upright position when heeled over Displacement: weight of the water replaced by the ship Freeboard: vertical distance between ships deck and the waterline Hull shape Beam: ship’s width at the widest point

Basic Forces Acting on Ships Stress Load per unit area (psi) Tension, compression, shear, torsion Strain Deformation per unit length Longitudinal Bending Sagging Hogging

Stress Def’n: load a member is carrying per unit area (psi) Types: Tension: axial stress exerted by pulling Compression: axial stress exerted by pressure on ends Shear: equal but opposite forces at right angle Torsion: stress caused by twisting motion

Strain Def’n: the distortion/deformation per unit length as a result of stress Measured in inches per inch (in/in)

Sagging Condition where ship is supported more at its ends Compression of main deck Tension of the bottom/keel

Hogging Condition where ship is supported more in its middle Tension of main deck Compression of bottom/keel

Ship Structural Elements

Ship Structural Elements Keel Centerline backbone of ship Runs the length of the ship Framing Ribs of ship, provide structural strength -> define form of ship Types: Transverse (extend outward from keel) Longitudinal (parallel to keel, run length of ship)

Ship Structural Elements Bottom Cellular region comprised of keel & framing Plating Skin over framework -> rectangular steel plates welded together

Ship Structural Elements Decks “Floors” of a ship (sometimes called “levels”) Horizontal partitions that form tiers Main deck is uppermost complete deck Bulkhead “Walls” of a ship Horizontal partitions that form compartments Can either be structural or non-structural (joiner)

Ship Structural Elements Doors Passage between spaces on SAME level Can be Water-Tight (sealed with “dogs”) Individually acting v. Quick-acting Hatches Passage between spaces on DIFFERENT levels Most are water-tight boundaries

Compartment Numbering System used for ships built after 1949 4 main parts Deck Frame Compartment Use ex: 5 – 32 – 0 – E Deck Frame Compartment Use

Compartment Numbering Deck: Meaning: “Space is located on this deck” Upper levels are 01,02… successively from main Main deck is 1 Lower decks are 2,3,4… successively from main

Compartment Numbering Frame: Meaning: “Forward boundary of compartment is on or immediately aft of this frame number” Sequential number given to transverse frames fore to aft

Compartment Numbering Indicates position of compartment relative to centerline Centerline compartments are “0” Numbers follow in succession from centerline outboard Even numbers for Port side (2,4,6, …) Odd numbers for Starboard side (1,3,5, …) … 6 4 2 0 1 3 5 … Port Centerline Starboard

Compartment Numbering Use: Letter that designates primary use of the space Examples “A”: Supply & Storage “C”: Control (ship control or fire control) “E”: Engineering “F”: Fuel tank “L”: Living “M”: Ammunition “T”: Trunk “V”: Void “W”: Water tank

Submarine Design Hull (made of high strength steel) Watertight envelope designed to resist submergence pressure at CRUSH DEPTH Inner hull (pressure hull) Outer hull (non-pressure hull)

Submarine Design Structural Members Similar to surface ship but rounded for submarine hull shape and THICKER All levels have expansion joints (varying submergence pressures)

Piping & Valve Numbering Systems White Yellow Purple Dark Gray Light Gray/Tan Blue Light Blue Orange Steam Oil JP-5 HP Air LP Air Chillwater Feedwater Hydraulics Numbering system for valves similar to that for compartments (ie: MS-1, MS-2, etc.)

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