CHAPTER 3 SHIP COMPARTMENTATION AND …

1 CHAPTER 3 ship COMPARTMENTATION AND WATERTIGHTINTEGRITYL earning Objectives:Recall the definitions of termsused to define the structure of the hull of a ship and thenumbering systems used for compartment numberdesignations. Identify the different types of watertightclosures and recall the inspection procedures for theclosures. Recall the requirements for the three materialconditions of readiness, the purpose and use of theCompartment Checkoff List (CCOL) and damagecontrol closure log, and the procedures for checkingwatertight ship s ability to resist sinking after sustainingdamage depends largely on the ship scompartmentation and watertight integrity. Whenthese features are maintained properly, fires andflooding can be isolated within a limited area. Withoutcompartmentation or watertight integrity, a ship facesalmost certain doom if it is severely damaged and theemergency damage control (DC) teams are notproperly trained or this CHAPTER , you will be introduced tocompartmentation, material conditions of readiness,watertight integrity, and how they relate to each will also learn about compartment checkoff lists,the DC closure log, the proper care of access closuresand fittings, compartment inspections, the ship s draft,and the sounding and security patrol watch.

2 Theinformation in this CHAPTER will assist you incompleting your personnel qualification standards(PQS) for basic damage Objective:Recall the definitions of termsused to define the structure of the hull of a ship and thenumbering systems used to identify the differentcompartments of a COMPARTMENTATION of a ship is a major featureof its watertight integrity. COMPARTMENTATION dividesthe interior area of a ship s hull into smaller spaces bythe use of structural to figure 3-1 while reviewing the informationon structural 3-1. Illustrative hull keel is the backbone of the ship . The keel doesnot extend below the ship s bottom. Its usual shape isthat of an I-beam. All other members used inconstructing the hull are attached, either directly orindirectly, to the athwartship structure consists of transverseframes and floors. The floors run outboard from thekeel to the turn of the bilge (where the bottom turnsupward). This is where they are attached to thetransverse frames that extend upward to the main , running parallel with the keel, are knownas longitudinal frames.

3 From the turn of the bilge upthe sides, they are called stringers. The network offloors and longitudinal members resembles ahoneycomb and is known as cellular construction,which greatly strengthens the bottom. When platingcovers the honeycomb structure, double bottoms areformed. The space between the inner and outerbottoms (known as tanks) is used for liquid forward end of the keel is extended upward in thestem. The after end has a similar extension, called thesternpost. The part of the stem above water is the prow;the forward edge of the stem is the interior of a ship is divided into compartmentsby vertical walls, called bulkheads, which run bothtransversely and longitudinally. Most bulkheads aremerely partitions, but transverse watertight bulkheadsare spaced at appropriate intervals. These structuralbulkheads extend from the keel to the main deck andfrom side to side. They provide extra transversestiffening and partition the hull into independentwatertight sections.

4 Large ships have a series oflongitudinal side bulkheads and tanks that provideprotection against torpedoes. The outer tanks usuallyare filled with oil or water. The inner tanks, which arecalled voids, are empty. The innermost bulkhead iscalled a holding bulkhead. When a torpedo hits, theouter tanks, although ruptured, absorb enough energyfrom the explosion that the holding bulkhead willremain intact. This helps to prevent flooding of thevital hull plating is fastened to the framework inlongitudinal rows, called strakes. The keel forms thecenter strake. The strakes are lettered, beginning withthe A-strake on either side of the keel and extending upto the main deck. Some of the strakes also have A-strake is called the garboard strake; the strakealong the turn of the bilge is the bilge strake; theuppermost strake is the sheer stated, the projecting keel, running along thebottom near the turn of the bilge, is called the bilgekeel.

5 The purpose of the bilge keel is to reduce rollingof the shiprollsfrom side to side. A shippitcheswhen it goes up and down fore and shipyawswhen the bow swings to port andstarboard because of wave upper edges of the sides where the sheerstrakes join the main deck are called the gunwales(rhymes with funnels). The foremost part of the ship ,where the gunwales join the stem, is known as the eyesof the ship (fig. 3-2). Where the gunwales curve inwardto the sternpost are the port and starboard water level along the hull of a ship afloat is thewaterline. The vertical distance from the keel to thewaterline is the ship s draft. Freeboard is the distancefrom the waterline to the main floors of a ship are called decks (fig. 3-3).Decks divide the ship into layers and provideadditional hull strength and protection for internalspaces. The lower surface of each deck forms theoverhead (never the ceiling) of the compartmentbelow.

6 Compartments are the spaces within a DECKBULWARKFORECASTLEEYESOVERHANGRUDDERF REEBOARDWATERLINEDRAFTHAWSEPIPESTEMBOWPR OPELLERSTRUTPROPELLERSHAFTDCf0302 Figure 3-2. hull DECKSUPPER DECKFORECASTLE DECKMAIN DECKMAIN DECKPOOP DECKFORWARD WELL DECKAFTER WELL DECKDCf0303 Figure 3-3. Weather steel deck is made of strakes running fore andaft. The outboard strake in the deck plating iscomposed of stringer plates, which are welded orriveted to the side plates and are, therefore, importantstrength members. Decks are supported by transverseframes (deck beams) and by longitudinal (deck)girders. Vertical steel pillars that are called stanchionsprovide other means of deck support. These aremounted one above the other or one above a strengthbulkhead. (The short posts used as lifeline supportsalso are called stanchions.) Decks usually are archedfrom the gunwale to the centerline to provide fordrainage of water and to strengthen the deck or part of a deck exposed to the weather iscalled a weather deck (fig.)

7 3-3). Bulwarks are solidfencing along the gunwale of the main (weather) are fitted with freeing ports (scuppers) toallow the water to run off during heavy deck that extends from side to side and stem tostern is a complete deck. In aircraft carriers theuppermost complete deck is the flight deck, from whichaircraft take off and land. In all ships (except for aircraftcarriers) the uppermost complete deck is the main aircraft carriers the hangar deck is the main deck. Thehangar deck is the deck on which aircraft are stowed andserviced when not on the flight first complete deck below the main deck is thesecond deck (fig. 3-4), the next the third, the next thefourth, and so strength deck is a complete deck (usually themain deck) designed to carry not only deck loads on itbut also the hull stresses. The damage control deck is thelowest deck having access through the main transversebulkheads, from forward to aft. The main repairequipment and the principal facilities for the control offlooding, sprinkling, and pumping under conditions ofdamage are located on the damage control deck.

8 The DCdeck is either the second or third deck on most definition and location of the decks in modernships (figs. 3-3 and 3-4) are as follows:FORECASTLE (pronounced folk sul): Forwardsection of the main deck, generally extending from thestem aft to just abaft the anchor DECK: Any partial deck between : Partial decks below the lowestcomplete deck. They are usually broken to admitmachinery or other spaces and are called platformdecks or just platforms. They are numbered downward,as first platform, second platform, and so : Plating or gratings installed only toprovide working or walking surfaces above : Level is a general term used to designatedeck heights above the main deck. The first level abovethe main deck is the 01 (pronounced oh-one) level, thesecond the 02 level, and so on. Different decks at aparticular level, however, carry different names. Forexample, both a poop deck and a boat deck (usually) areon the 01 DECK: A partial deck extending from sideto side above the main deck amidships.

9 It is part of thesuperstructure, which is the part of a ship s structureabove the main deck, exclusive of masts, yards, stacks,and related parts. The side plating extends upward tothe upper DECK: A partial deckabove the main, upper, or forecastle deck that does notextend to the sides of the ship (if it does, it does nothave the side plating carried up to it.).3-3 Figure 3-4. Deck numbering DECK: A partial deck above the main decklocated all the way WELL DECK: Forward part of themain deck between the upper deck and WELL DECK: Between the upper deckand the poop DECK: First deck or platform belowthe flight : The quarterdeck is not anactual deck, but an area designated by the commandingofficer for the conduct of official functions. It is thestation of the officer of the deck in port and usually ison the main deck at the starboard (ladders) lead from onedeck level to another. They may or may not becovered by number of compartments into which the decksand bulkheads subdivide the ship s interior areadepends upon how many the ship s mission will the compartments are both above and below thewaterline, when the degree of COMPARTMENTATION on aship is increased, the ship s resistance to sinking is serves the following functions: Allows for more effective control of fires andfloods.

10 Strengthens the ship s structure. Helps defend against a chemical, biological, andradiological (CBR) attack. Segregates various ongoing activities. Provides underwater protection by the use oftanks and voids to help control the ship sbuoyancy and large combatant ships have an armor belt toprotect the vital machinery spaces. Armor plating mayreduce the ship s speed or have an adverse effect on theoperation of the ship . Aircraft carriers are a primeexample where excessive armor plating wouldinterfere with the ship s operation by reducing theship s speed. Therefore, armor plating on aircraftcarriers is reduced, while COMPARTMENTATION isincreased to compensate for the reduction of NUMBERINGL earning Objective:Recall compartment numberdesignations for ships built after March on Navy ships are numbered foridentification following a standard system. Eachcompartment has a four-part number separated byhyphens; the four parts indicate the deck upon which the compartmentis of the compartment by position of the compartment relativeto the ship s compartment keel is the backbone of the is the forward edge of the stem called?