武汉理工大学：《船舶辅机》课程教学资源（PPT课件，英文版）1.8 Bilge and ballast

1.8 Bilge and ballast A fire and bilge pump has suctions from sea, bilge main and engine room bilge, with discharges to fire main, oily water separator and overboard. a ballast pump has suctions from sea, ballast main, engine room bilge direct and bilge main with discharges to overboard, the ballast main the oily water separator and possibly, the main salt water circulating system

1.8 Bilge and ballast • A fire and bilge pump has suctions from sea, bilge main and engine room bilge, with discharges to fire main, oily water separator and overboard. A ballast pump has suctions from sea, ballast main, engine room , bilge direct and bilge main with discharges to overboard, the ballast main, the oily water separator and possibly, the main salt water circulating system

1.8 Bilge and ballast a general service pump has suctions from sea ballast main, bilge main and engine room bilge with discharges to the fire main, the ballast main the oily water separator and overboard. In this way, three pumps provide effective alternatives for all essential services in the event of breakdown of one or even two. Many ships will have more generous provision and all passenger ships will have a submersible fire and bilge pump, supplied with power from an emergency dynamo

1.8 Bilge and ballast • A general service pump has suctions from sea, ballast main, bilge main and engine room bilge with discharges to the fire main, the ballast main, the oily water separator and overboard. In this way, three pumps provide effective alternatives for all essential services in the event of breakdown of one or even two. Many ships will have more generous provision and all passenger ships will have a submersible fire and bilge pump, supplied with power from an emergency dynamo

1.8 Bilge and ballast There are many differences in arrangement; some ships will be fitted for oil or ballast in all double bottom tanks(except one or two, port and starboard for fresh water)some in only two or three Other vessels will have one(or more) lower holds fitted as deep tanks and most will have peak ballast tanks forward and aft. Some ships will have a tunnel from the engine room to No. 1 hold aft bulkhead for bilge, ballast and oil pipes and fittings and others will have a duct keel to carry the pipes forward

1.8 Bilge and ballast • There are many differences in arrangement; some ships will be fitted for oil or ballast in all double bottom tanks (except one or two, port and starboard for fresh water) some in only two or three. Other vessels will have one (or more) lower holds fitted as deep tanks and most will have peak ballast tanks forward and aft. Some ships will have a tunnel from the engine room to No.1 hold aft bulkhead, for bilge, ballast and oil pipes and fittings and others will have a duct keel to carry the pipes forward

1.8 Bilge and ballast In most other ships the bilge suction pipes will pass through the wings of the holds and the ballast pipes e through the double bottom In the two latter cases the valve chests will be on the engine room(or boiler room) forward bulkhead or in a forward cofferdam. In all cases a the bilge suction valves will be screw-down, non-return, the oil and ballast valves, screw-lift. Ring and blank flanges will be fitted in deep tank suctions, so that ballast e cannot be discharged inadvertently by a bilge pump not the hold be flooded when used for cargo. If liquid cargoes are carried both will be blanked. note that double bottom tanks should never be pumped up

1.8 Bilge and ballast • In most other ships the bilge suction pipes will pass through the wings of the holds and the ballast pipes through the double bottom. In the two latter cases, the valve chests will be on the engine room (or boiler room) forward bulkhead or in a forward cofferdam. In all cases, the bilge suction valves will be screw-down, non-return, the oil and ballast valves, screw-lift. Ring and blank flanges will be fitted in deep tank suctions, so that ballast cannot be discharged inadvertently by a bilge pump not the hold be flooded when used for cargo. If liquid cargoes are carried, both will be blanked. Note that double bottom tanks should never be pumped up

4 DC C20 B工Tc& BALLAST SYSTEM 05.03.02 13:27:00 AFT PEAKBw20 翻翻翻翻 WB TK BW34 02,0 363.2M3 298.7 Bw14 BW12 文文e|w| ow Bw ew ew 27262524222 OREPEAK BWc FROM BILGECROSS 0.0 BALLAST/ BAR 0,00M B418 X BW15 XBW13 区B X BWO7 BW05 XBW03 ALL XXX EJEC BWBWBW 4 SB M DRAFT PORT 0.00 M AFT 0.00. M FORE 0 TRIM 0.00 STBD 0.00 M 5T0,00 OCP DISPLAY ALARM/SOUND OFF AL粪R网 TAG DETAILS ECR WATCH GROUP ACKNOWLEDGE

1.8 Bilge and ballast The minimum number and capacity of bilge pumps and fire pumps and their dispersement within the ship is governed b 1 Classification Society Rules a 2 National requirements a 3 The IMCO International Convention for the Safety of Life at Sea, 1974(SOLAS 74)

1.8 Bilge and ballast • The minimum number and capacity of bilge pumps and fire pumps and their dispersement within the ship is governed by:  1 Classification Society Rules  2 National requirements  3 The IMCO International Convention for the Safety of Life at Sea, 1974(SOLAS 74)

1.8 Bilge and ballast The basic philosophy is similar in all three cases but Solas 74 only defines bilge pump capacity for passenger ships and the Convention only applies to vessels trading internationally; more over it excludes cargo ships of less than 500 gross tons. The Classification Societies generally rescribe the bore of the main bilge line and branch bilge lines and relate the bilge pump capacity of each pump to that required to maintain a minimum water speed in the line the fire pump capacity is related to the capacity of the bilge pump thus defined e. g

1.8 Bilge and ballast • The basic philosophy is similar in all three cases but SOLAS 74 only defines bilge pump capacity for passenger ships and the Convention only applies to vessels trading internationally; more￾over it excludes cargo ships of less than 500 gross tons. The Classification Societies generally prescribe the bore of the main bilge line and branch bilge lines and relate the bilge pump capacity of each pump to that required to maintain a minimum water speed in the line; the fire pump capacity is related to the capacity of the bilge pump thus defined e.g

B+D) 1.8 Bilge and ballast Bilge main dia. d1=1.68L(B+D)+25 mm Branch dia. d2=2.16 C(B+D)+25 mm d2 not to be less than 50 mm and need not exceed 100 m d 1 must never be less than d2 where L=length of ship in m B= Breadth of ship In m D= Moulded depth at bulkhead deck in m C-Length of compartment in m

1.8 Bilge and ballast Bilge main dia. d1=1.68 +25 mm Branch dia. d2=2.16 +25 mm d2 not to be less than 50 mm and need not exceed 100 m. d1 must never be less than d2 where L = length of ship in m; B = Breadth of ship in m; D = Moulded depth at bulkhead deck in m; C = Length of compartment in m. L(B + D) L(B + D) C(B + D) C(B + D)

1.8 Bilge and ballast Each pump should have sufficient capacity to give a water speed of 122 m/min through the Rule size mains of this bore. Furthermore each bilge pump should have a capacity of not less than 0.565 d, 2 m3/h 10

1.8 Bilge and ballast • Each pump should have sufficient capacity to give a water speed of 122 m/min through the Rule size mains of this bore. Furthermore each bilge pump should have a capacity of not less than • d1 2 m3/h 3 10 0.565

1.8 Bilge and ballast The fire pumps, excluding any emergency fire pump fitted, must be capable of delivering a total quantity of water at a defined head not less than two-thirds of the total bilge pumping capacity. The defined head ranges from 3.2 bar in the case of passenger ships of 4000 tons gross or more to 2. 4 bar for cargo ships of less than 1000 tons gross

1.8 Bilge and ballast • The fire pumps, excluding any emergency fire pump fitted, must be capable of delivering a total quantity of water at a defined head, not less than two-thirds of the total bilge pumping capacity. The defined head ranges from 3.2 bar in the case of passenger ships of 4000 tons gross or more to 2.4 bar for cargo ships of less than 1000 tons gross