Section 107: Ship's Service/Emergency Diesel Engine Fundamentals
107.1 State the type and application of diesel engines. ALCO 251C 16V 2800 Horse Power
107.2 State the location of each diesel engine. LOCATION’S: FWD Diesel (4-41-2-E) AFT Diesel (3-114-2-E)
107.3 State the function of the following systems: a. Jacket Water - Provides cooling for lube oil and the engine block.
b. Lube Oil (L/O) - Reduces friction, cools and cleans internal parts.
c. Fuel Oil (F/O) - Supplies clean JP-5 fuel to diesel by using 16 fuel injection pumps under pressure.
d. Air Start/Assist - 3,000 psi air reduced to 300 psi for turbo jet assist and 150 psi for starting the engine. Onboard USS Boxer you have 10 starts with a full flask of HP Air.
e. Saltwater - Open system supplied by remote booster pump, which cools the jacket water cooler, Lube oil cooler, and generator air box cooler. Augmented by firemain reducer in an emergency.
108.1 State the type of distilling plants used onboard and their maximum daily distilling capacity.
BOXER is equipped with (2) two low pressure, 6 stage, flash type distilling plant (evaporators). They are capable of distilling 100,000 gpd (gallons per day) each of fresh (potable) or feed (boiler) water.
108.2 State the difference between potable, boiler/feedwater and demineralized water. Ř Potable Water - Water used for galley services, drinking water, head and shower services, hospital services, fire fighting (for electronic components) and laundry.
Ř Boiler/Feedwater - Water used in boiler to generate steam. Reserve feed water to make up for water and steam leaks in basic steam cycle.
Ř Demineralized water - Untreated water for various electronic cooling water systems and flight deck aircraft washdown.
108.3 State the location of the following potable water components: a. Potable water pumps - Used to transfer potable water from potable water tanks to potable water system throughout ship. - #1 & 2 Potable Water Pumps are located on the lower level of the Forward Main Machinery Room (6-65-0-E). - #3 & 4 Potable Water Pumps are located on the lower level of the Aft Main Machinery Room (6-81-0-E).
b. Potable Water Risers - All risers will receive and transfer potable water. - Port riser is located at RAS #2 (upper vehicle storage, port side OOD station). - Starboard risers are located at RAS station #5 (hanger deck level trash storage) and RAS #1 (flight deck starboard).
c. Distilling Plants - #1 Evaporator located on the upper level of the Fwd Main Machinery Room (6-65-0-E). - #2 Evaporator located on the upper level of the Aft Main Machinery Room (6-81-0-E).
108.4 State the basic operation of the ships distilling plants. A flash type evaporator boils water into a vapor under a vacuum at a lower temperature (170° F vice 212° F at atmospheric pressure). By “cooling” this vapor and collecting it, we have distilled water. The flash type evaporator is made up of five separate circuits as follows:
1) Salt water - Salt water is pumped from the ocean by a feed water pump. This pump discharges saltwater through the condensers of all 6 evaporator stages, where the salt water is pre-heated. It then enters the air ejector condenser where it is also preheated. It next enters the feed water heater where the most pre heating takes place. After it leaves the feed water heater it enters the flash chamber of the 1st of six different evaporator stages and some water is flashed into vapor. The remaining water passes through the 2nd then 3rd stage and so on until the remaining water leaves the 6th stage as brine. In each stage some of the water flashes into vapor. Vapor rises around the outside of the condenser tubes in each of the six stages and is condensed as it is cooled. This water now known as distillate.
2) Distillate - Distillate is collected in a distillate trough in all six stages and pumped with the distillate pump to either a potable water tank or feed water tank. Distillate purity is monitored at each stage and the final output should be less than .065 ppm (parts per million) (what?).
3) Brine - Saltwater that did not flash into vapor after the 6th stage is known as brine and is pumped overboard by the brine pump.
4) Air Ejector - The air ejectors are used to draw a vacuum on the entire evaporator. This is accomplished by removing all air and non-condensable gases from the evaporator. The air ejector is a jet-type pump that uses 150 psi auxiliary steam as a motive force (similar to the way an eductor uses firemain). The steam, air and non-condensable gases are discharged into the air ejector condenser. The air and gases are vented to the atmosphere and the steam is condensed into water and discharged to the fresh water drain collecting tank.
5) Auxiliary Exhaust - Used to heat the feed water. 5 psi auxiliary exhaust steam is admitted into the feed water heater at the top of the heat exchanger. The saltwater flowing through the tubes is heated as the auxiliary exhaust steam flows across the outside of tubes. Heat transfer condenses the auxiliary exhaust into condensate and raises the temperature of the saltwater in the tubes. The salt water feed condensate pump discharges this condensate to the main condensate system.
108.5 State the location and maximum storage capacity for potable water tanks. BOXER has a total of six potable water storage tanks with a combined capacity of 184,250 gals.
Locations and Capacities: Forward Main Machinery Room (5-65-0-E) has (3) three tanks:
Tank Number Capacity Fwd 7-67-2-W 33,221 gal Fwd 7-69-2-W 35,335 gal Fwd 7-71-4-W 32,302 gal
Aft Main Machinery Room (5-81-0-E) has (3) three tanks:
Tank Number Capacity Aft 7-84-1-W 21,803 gal Aft 7-85-3-W 31,552 gal Aft 7-87-3-W 30,035 gal
109.18 State the function of the following major components
a. Ship’s Service Turbine Generators (SSTG) - Converts steam energy into electrical energy. - Ship service power is provided by five steam-driven turbine generator sets. - Parameters: - 2,500 kW; - 4,000 amp; - 450V; - 3 phase; - 60-Hz - Designed to operate on main steam supplied from the ships propulsion system. - #1 & #2 SSTGs and associated switchboards are located in Machinery Room No. 1 (6-65-0-E); - #4 & #5 SSTG and their associated switchboards are located in Machinery Room No. 2 (6-81-0-E); - #3 SSTG and its associated switchboard is located in the Auxiliary Machinery Room.
b. Electrical Plant Control Panel (EPCP) - There are (2) two EPCP's. - The forward EPCP is located within the enclosed operating station (EOS) in the forward main machinery room. - The aft EPCP is located within the EOS in the aft main machinery room. - The EPCP’s provide: 1. Monitoring of turbine alarms. 2. Control and operation of the local ship service generators, SS/EDG, and shore power. 3. Control and indication for paralleling the SSTGs, SS/EDG, and shore power. 4. Paralleling of two or more generators by a manual permissive mode using synchronizing monitor interlock or by the manual mode using direct control. 5. Paralleling any SSTG set with shore power for uninterrupted load transfer. 6. Monitoring of generator performance parameters and generator status 7. Monitoring of 60 HZ distribution system performance parameters and distribution system status.
c. Switchboard - Distributes power from the generators to the load centers. - Locations: - 1S and 2S are located in the Forward MMR; - 3S is located in the Auxilary Machinery Room; - 4S and 5S are located in the Aft MMR.
Bus Ties - High current circuit breakers located in the switchboards that are used to connect switchboards to other switchboards.
Disconnect Links - Used to isolate a damaged generator, switchboard section or bus tie from undamaged switchboard sections.
d. Shore Power Connections - Shore power entry into the 60 Hz power distribution system is though the 3S-2SA bus tie forward and the 2E-5SA bus tie aft. - Thirty (30) receptacles deliver shore power through thirty individual breakers, twenty from the forward shore power (10 port and 10 starboard) and ten for the aft shore power. - Control and monitoring may be accomplished at the shore power switchboard and the EPCP. - Normally 10 cables are connected forward and 10 cables are connected aft.
e. 400 Hz Solid State Frequency Converter - The 400 Hz power system provides precision regulated 450V, 3-phase, 400 Hz power to meet the sensitive operational voltage requirements of navigation, fire control, communication, aircraft servicing and high speed assault systems. - The system converts 450V, 3-phase, 60 Hz power to 450 V, 3-phase, 400 Hz power and provides power distribution to the user equipment. - Two frequency changers, SSFC No. 1 and SSFC No. 2, are located in the 400 Hz Power Conversion Room No. 1 (2-49-4-Q). - SSFC No.3 and SSFC No. 4 are located in 400 Hz Power Conversion Room No. 2 (2-84-2-Q). - The landing craft air cushion (LCAC) service 400 Hz power is provided by one solid state frequency changer which is identical to the other four. SSFC No. 5 is located in the LCAC 400 Hz Conversion Room (3-98-3-Q).
f. Load/Control Centers - Load center switchboards receive power from ship service and/or emergency switchboards and supply power throughout the ship. - Some load center switchboards, receiving power from two supply sources, have a manual bus transfer (MBT). - Sixteen load center switchboards are located in various part of the ship. - Group control center switchboards receive power from ship service & emergency switchboards and supply power to select 450-volt, 3-phase motors and other electrical auxiliaries. - Group control center switchboards contain: - motor controllers, - circuit breakers, - fuses, - bus bars, and - terminal boards.
109.2. State the difference between Automatic Bus Transfer (ABT) and Manual Bus Transfer (MBT).
Ř Automatic Bus Transfer (ABT) switches are used to transfer loads from one power source (normal) to another (alternate) automatically when voltage drops on the primary source below a preset value and beyond a preset time delay. Transfer can be accomplished manually (testing/planned losses) and/or automatically (casualty).
Ř Manual Bus Transfer (MBT) switches provide manual switching between normal and alternate power sources by means of mechanically interlocked circuit breakers. They are interlocked to prevent simultaneous application of normal and alternate power to loads. Upon loss of normal power, the MBT switch must be manually transferred to the alternate power source
109.3 State the maximum electrical capacity of the following:
a. Ship’s Service Turbine Generator (SSTG)
- 450 V, - 3 Phase, - 60 Hz, - 2,500 kW, - 4,000 amps
b. Shore Power Connections
- 450 V, - 3 Phase, - 60 Hz, - 2,500 kW, - 4,000 amps (forward and aft).
AZC(AW/NAC) Kimberly King
FC2(SW) Daniel A. Girimonte