U.S.S. MASSACHUSETTS – BRIEF DESCRIPTION – ENGINEERING DEPARTMENT
|Folks,U.S.S. MASSACHUSETTS – BRIEF DESCRIPTION – ENGINEERING DEPARTMENT, is a training manual created aboard the ship to introduce new men to the ships engineering systems.In this online version of the manual we have attempted to keep the flavor of the original layout while taking advantage of the Web’s universal accessibility. Different browsers and fonts will cause the text to move, but the text will remain roughly where it is in the original manual. In addition to errors we have attempted to preserve from the original, this text was captured by a combination of optical character recognition and human typist. Each method creates errors that are compounded while encoding for the Web. Please report any typos, or particularly annoying layout issues to the Mail Feedback Form for correction.|
A BRIEF DESCRIPTION OF THE ENGINEERING DEPARTMENT
PURPOSE. This brief is prepared with a view to enlightening those men, who join the ship without having much previous experience in engineering matters, on the scope of activities of the Engineer Department. It is hoped that by reading this paper carefully, much of the mystery regarding the raze of machinery and piping will vanish, and the new man will be able to proceed systematically to educate himself in his job below decks. By following the various steam, water, oil, electrical, and air cycles from start to finish, the novice can, step by step, trace the path of each and learn the purpose and method of operation of every unit along the path. To further aid self instruction, here are available the following means:
No man should hesitate to ask the Log Room Yeoman for any of the above instructive matter. There are of course limited numbers of publications available, so you nay have to wait your turn for a book.
Also, do not hesitate to ask officers or petty officers to explain things you don’t understand.
It will be noted that numerous items throughout this paper are capitalized. This is done to emphasize an important unit or system which should be investigated separately in complete detail. When studying a unit, you should satisfy yourself on the following:
LOCATION OF MACHINERY SPACES
The principle units of the Engineering Department are installed in four large machinery spaces located below the second deck, extending from frame 73 to frame 113. Other units outside these spaces are located as follows: On the first platform deck, on the starboard side between frames 65 and 73 is found the Interior Communication room, while far aft on the same deck, between frames 136 and 142 ½ is located the Refrigerating Machinery. Still further aft, on the same level, between frames 142 ½ and 155 are the two separate Steering Engine roams. On the deck below, known as the second platform, between frames 65 and 68 is the Forward Electrical Distribution room, in which is #1 Distribution Board. Just aft, between frames 68 and 73 is the evaporator room, where most of the fresh water used on board is made. Between frames 113 and 117 ½ is the After Electrical Distribution room, in which is located #4 Distribution Board. Directly under the After Distribution Room is located the after Emergency Diesel-Generator Room, in which, besides the generator, are diesel oil pumps and medium pressure air compressors. On the port side of the second deck, about amidships may be found the Engineer Office, the Machine Shop, Metalsmith Shop and the Fuel Oil Test Shop.
For watertight integrity reasons, the ship is so built that passage between spaces below the second deck is very difficult. In order to assist the newcomer aboard ship in finding his way to the many different engineering compartments mentioned above, a mimeographed diagram has been prepared which shows the hatches and routes to follow from the second dock to the different spaces. A copy of this diagram is attached.
|Each man should take this guide and visit each room, going over the various possible routes many times, until he knows exactly how to get about the ship below decks. One must realize that many of the hatches shown will be closed during wartime cruising, therefore alternate routes must be known.|
DESCRIPTION MAIN PROPULSION INSTALLATION
The main power plant of the ship consists of four separate engine units, each developing 32,500 horsepower and each connected to its own propeller shaft. There are therefore four propellers. The propeller shafts are numbered from starboard to port, numbers one, two, three, and four respectively. Number one engine unit in #1 machinery space drives number one shaft. But in #2 machinery space, number four engine unit drives number four shaft. Likewise, in #3 machinery space, number two engine unit drives number two shaft, and in #3 machinery space, number three engine unit drives number three shaft, This may be confusing at first, but remember that the first two machinery units drive the outboard shafts, while the after machinery units drive the inboard shafts.
As each of the four engine units are similar, only one need be described. If you understand the plant in one machinery space, you’ll be familiar with the other three as all four are identical.
First we’ll start with the BOILERS. There are two in each machinery space. Each one can change 16,500 gallons of water an hour into steam at 600 lbs. per sq. in. pressure and 850 degrees F. Temperature. In order to do this it burns about 1400 gallons of fuel oil per hour.
Hundreds of thousands of gallons of fuel oil are carried in tanks spread the length of the ship along the sides and in the bottom. Those adjacent to the machinery spaces on the side of the ship are called service tanks; the others are called storage tanks. Oil is pumped aboard ship through deck fittings and is distributed to all or any desired tanks through transfer piping by use of TRANSFER and BOOSTER PUMPS. One of these latter pumps is located in each machinery space, and one is in a pump room located in the HOLD between frames 46 ½ and 55. Important fuel oil manifolds are in the forward pump room between frames 28 & 31, in the C&R pump room between francs 46 ½ & 54, in the evaporator room, in each machinery space, and in the outer shaft alleys. The OIL KING is a petty officer who insures that the fuel oil is distributed properly and is available for the boilers.
For use in the boilers, fuel oil is drawn from one of the nearby SERVICE tanks by a FUEL OIL SERVICE PUMP. This pump discharges through STRAINERS, FUEL OIL HEATERS, OIL LETERS, and ATOMIZERS into the furnaces. In order to burn properly, the oil must be at the right PRESSURE and TEMPTERATURE. It must also have the right amount of AIR. Turbine-driven BLOWERS are therefore provided which force air into the furnaces under great pressure. The blowers are so regulated that just the right amount of air is sent into the furnace to burn completely all the oil sprayed by the atomizers. Water, which the boiler turns into steam, comes from the MAIN FEED . PUMP, through the ECONOMIZER located in the boiler uptake and then discharges through CHECK VALVES to the steam drum. Once inside the steam drum, the water flows down tubes in the “saturated” side of the boiler where it is changed into steam.
This steam is known as “saturated” steam because its temperature at 600 lbs. pressure is about 489 degrees temperature. If, at that pressure, it became cooler, it would begin to turn to water. This saturated steam is collected by a pipe in the top of the steam drum and sent through tubes in the “superheated” side of the boiler. Here the steam is heated to 850 ° and is now called superheated steam, because, at this pressure of 600 lbs, it has to cool to 489 degrees before it begins to change to water. In other words, it is “superheated” far above the saturation point or the temperature at which it begins to condense. The reason why steam is heated to that temperature is that a great amount of energy is added to it which is used to drive the engines; it would be heated to higher temperatures if the metal of the pipes could stand up, but, at present, the steel will soften and “creep”.
At high power, over ninety per cent of the steam made in the boiler goes out as superheated steam to drive the main engines and the electric generators. It leaves through STOP VALVES and enters the MAIN STEAM PIPE. The remaining ten per cent or loss of the steam made leaves the boiler as saturated steam through STOP VALVES and enters the AUXILLIARY STEAM LINE.
In each machinery space, some distance away from the boiler stop valve, there is a connection to the 600 lb. auxiliary steam line to a REDUCIG VALVE. This valve reduces the pressure from 600 lbs. to 150 lbs. and connects with a steam line known as the 150 lb. STEAM LINE. There are, then, three high pressure steam lines: the MAIN STEAM LINE, the AUXILLIARY STEAM LINE, and the 150 lb. STEAM LINE.
The main steam line goes directly to the MAIN TURBINES, passing through the THROTTLE TRIP VALVE, the STEAM STRAINER, to the TURBINE CONTROL THROTTLES. Ahead of the throttle trip valve is a connection for superheated steam to the MAIN GENERATORS.
The MAIN TURBINES are the main engines of the ship. By opening the-ahead or astern throttles, the ship is made to go ahead or astern. When a throttle valve is opened, steam is admitted to nozzles through which the steam blows at high velocity and strikes blades attached to wheels on the rotor. This action causes the rotor to turn. In the HIGH PRESSURE TURBINE, there are twelve sets of fixed nozzles blowing steam against twelve rotating wheels attached to the rotating shaft. These combinations of nozzles and wheels are known as stages. At high power, when steam leaves the last stage of the high pressure turbine, it has about 60 lbs. pressure remaining. This can still be used to drive the ship; so is piped over to the LOW PRESSURE TURBINE where it again expands through nozzles against blades on the rotor as in the high pressure turbine. When it leaves the last wheel of the low pressure turbine, the steam has about 1 lb. absolute pressure or about 14 lbs. less pressure then the air about us. It has also cooled by expansion to about 100 degrees F. temperature, and it is because of this low pressure and temperature that it is of no further use to us for producing power. In the low pressure turbine casing is installed the ASTERN TURBINE consisting of one pressure stage at each end of the low pressure rotor so arranged that steam will strike the blades and turn the rotor in the reverse direction.
But in order that the turbine can function at all, there are several features about its construction which must be understood. Each man must therefore investigate these features which follow, thoroughly, The turbines are supported by BEARINGS in which the shafts or journals as they are called rotate at high speed. Hence lubricating oil must be supplied under pressure to these bearings to keep then cool. Also the rotors must not move fore or aft so that the moving wheels hit the nozzles. TURBINE THRUST BEARIGS are provided for this purpose. In order to know whether the BEARINGS or THRUSTS are wearing, MICROMETER GAGES are installed. As steam under high pressure is in one end of the turbine while at the other end it may be less than that of the outside air, it is necessary to have some way of providing steam from escaping along the shaft where, it comes through the casing, or of preventing the air from getting into the turbine. This is done by means of GLANDS which are sealed by the GLAND SEALING SYSTEM. This system operates automatically but its workings should be understood by engineers. The ahead throttle reach rod connects to a number of valves on the top of the high pressure turbine casing. Those valves control a number of nozzles. By opening them in turn more steam is gradually cut into the engine with the result that the speed of the ship increases. It will also be noted that there are valves installed at, various stages known as EXTRACTION VALVES. These exist for the purpose of taking steam out of the turbine to boost the pressure in the EXHAUST STEAM line which will be discussed later. There are other connections installed for DRAINAGE purposes.
Turbines must operate at very high speeds to work efficiently while propellers must turn relatively slowly. The rotors of the high pressure and low pressure turbines therefore are connected to the pinions (high speed gears) of the DOUBLE REDUCTION GEARS, where the high speeds of the turbine rotors are reduced so that the propeller turns at efficient speed. The reduction gears at full power reduce the speeds of the turbines from 6000 rpm. for the high pressure rotor and 4000 rpm. for the low pressure rotor to 185 rpm. for the propeller shaft. There are also a large number of bearings in the reduction gear which require lubrication while the gears themselves need plenty of oil. It is therefore of great importance that plenty of cool, clean oil be delivered to the gears, and that the thermometers on the bearings be watched carefully for a rise in temperature which indicates trouble.
On the reduction gears is a JACKING GEAR for turning the turbines and gears without the use of steam.
When the propeller turns over, the shaft moves forward, pushing the ship. This thrust is absorbed by the THRUST BEARINGS located forward of the gears, and it is here that the ship is actually pushed through the water. Many thousands of pounds of pressure as applied to this thrust at high speeds; so how it is withstood by this device should be studied.
The SHAFTS extend from the bull gear flange to the propellers in sections known as line shafting, stern tube shafting, and propeller shafting. SPRING BEARINGS support the weight of the shaft and require good lubrication.
Where the stern tube goes through the side of the ship is a STERN TUBE bearing. Water is prevented from entering the ship by a STERN TUBE GLAND. How to keep these spring and stern tube bearings cool should be investigated.
The THROTTLEMAN by means of his GAGE BOARD controls the operation of his engine and the speed of the propeller. On the gage board are instruments giving him all the information he needs for operating according to the wishes of the officer-of-the-deck on the bridge. Each man should study these instruments and satisfy himself that he knows the purpose of each.
It was mentioned before that when the steam leaves the last stage of the low pressure turbine, its pressure and temperature have decreased to the extent that the steam can not longer be of use to develop power. It must nevertheless be recovered for use again in the boilers, where it will be heated and will then repeat its cycle through the engines. The unit where this steam is recovered is called the CONDENSER, located directly beneath the low pressure turbine. Here steam from ½ lb. to 1 ½ lbs. per. sq. in. absolute pressure exhausts from the low pressure ahead turbine, or, when going astern, from the astern turbine. But before it can be pumped back to the boilers, it must be turned to water. Therefore, thousands of tubes through which sea water circulates are placed in the condenser, and the steam in striking these tubes, cools, and condenses to water. This “condensate” water is fresh, very pure, and is called FEED WATER.
it is treated with BOILER COMPOUND to give it the right chemical characteristics for use in the boiler, otherwise the boiler would quickly become inoperative. Salt water leaking from the condenser tubes soon ruins the feed, and must be detected as soon as the leak occurs.
A pound of steam at 1 lb. absolute pressure occupies over 300 cu. ft. When this pound of steam condenses to water, the water formed is just one pint, which occupies very little space. This tremendous contraction of the steam on condensing leaves a lot of space containing nothing except a little air and water vapor and is the chief reason why the pressure in the condenser is so much lower than that of the outside air. If the steam space in the condenser where, completely devoid of any steam, air, or vapor, there would be no pressure at all inside the shell and the absolute pressure would be zero, or we would have what is called a complete VACUUM. If the top of a tube one square inch in diameter filled with mercury were connected to the condenser at this time, and the other end were open to the air, the mercury would rise in the tube the number of inches equal to the reading of the barometer, which measures the outside air pressure at that moment. But if there is in the condenser some steam vapor, air, or other gas, there will be some pressure exerted by these gases which would press down on the top of the mercury in the tube and the mercury column would not be as high as that in the barometer. The difference in the height of the columns will then be a measure of the pressure in the condenser or the degree of vacuum in the condenser.
It is desired that as high a vacuum as possible be maintained in the condenser so that the steam expands as much as possible, otherwise a “back pressure” against the last stages of the turbines will be created which will reduce the power of the engines. Check up on the means of measuring vacuum provided on this ship.
The sea water flows through the condenser tubes is scooped in when the ship is moving through the water. When the Ship is stopped or backing, a MAIN CIRCULATING PUMP is used.
The condensed steam, now feed water, must continuously be removed from the condenser, This is accomplished by the CONDENSATE PUMP which draws the water from a well in the bottom of the condenser and discharges it, through the AIR EJECTOR CONDENSERS, the VENT CONDENSER on the DEARATING TANK, into the DEAERATERING TANK. A by-pass on the line from the condensate pump permits some condensate water to pass through the GLAND LEAK-OFF CONDENSER and then on to the DEAERATING TANK. Study the different thermo-control valves and by-passes on this section of condensate piping.
It was aforementioned that air in the condenser reduces the vacuum. Hence, as it is impossible to make an engine plant completely proof against leakage of air into the units under less than atmosphere pressure, some means must be provided to remove air which leaks into the system. The AIR EJECTOR performs this duty. Steam, expanding through nozzles, sucks air from the main condenser into the EJECTOR. Here it builds up in pressure until it is above the pressure of the outside air and it then discharges into engine room.
The steam from the nozzles condenses in EJECTOR condensers and the resulting feed water is returned to the system. Check carefully how this water returns, especially that from the first stage condenser.
The DEAERATING FEED TANK acts as a device for removing air from the feed water. If any air is contained in the feed, it carries oxygen to the boilers, where, under the influence of the high temperatures, this oxygen reacts with the steel of the drums and causes heavy pitting. Air is removed by causing the incoming feed water to mix with steam from the AUXILIARY EXHAUST STEAM LINE. Both water and steam are sprayed through nozzles with the result that the steam heats the water to the boiling point and all air is boiled out of it. The vapor formed by the boiling feed rises with the released air and the original steam from the exhaust line until they reach the vent condenser and pass between tubes containing relatively cool condensate water. The water vapor and steam then condense and drip to the bottom of the tank, while the air passes out to the atmosphere in the engine room.
Another function of the deaerating feud tank is to act as a reservoir of feed water. If too much water enters the tank, an overflow valve operates to discharge the excess water to a FEED BOTTOM as the boiler water tanks are known, if the water level gets too low, water can be sucked into the main condenser from a feed bottom. Find this connection and see how it is done. Also learn where the feed bottoms are.
It is necessary that some mechanism control the amount of steam that goes into the deaerating tank otherwise the pressure inside the tanks would vary as the amount of condensate water delivered to the tank varies and the deaerating process would not function. To insure a constant pressure, counterbalancing weights and linkages actuated by springs operate to control the opening of the exhaust steam valves inside the tank so that if the pressure decreases in the tank the valve is opened; if it goes too high, the valve is closed. It is possible to set the desired tank pressure by setting the spring pressure on the controls outside the tank.
From the deaerating feed tank, the feed water is drawn by the FEED BOOSTER PUMP which discharges it to the MAIN FEED PUMP. The main feed pump increases the pressure of the feed water to about 750 lbs. per sq. in. so that it can be sent into the boiler steam drum against the pressure of the boiler steam. The water has now returned to the boiler to be again made into high pressure, high temperature steam and the main cycle begins again.
MAIN GENERATOR (STEAM END)
We said in the, beginning that some of the superheated steam goes into the MAIN GENERATORS. In following this steam from the boilers along its cycle through the generator turbines and back to the boilers, we find that the generator plants are miniature main plants. The principle difference being that the generator turbines have electric generators connected to their shafts instead of propellers.
However, after the feed leaves the DYNAMO CONDENSATE PUMP it goes Into the main deaerating feed tank instead of a separate deaerating tank, for use in port, when the main feed pumps are not in use, in AUXILIARY FEED BOOSTER PUMP is provided which discharges to an EMERGENCY and PORT USE FEED PUMP.
MAIN LUBE OIL SYSTEM
The LUBRICATING OIL SYSTEM for the main machinery is very important, Whenever any piece of machinery operates, the proper type of lube oil is required, and great care must be used to insure that plenty of oil, clean, free from dirt, water, hard particles, and acid is supplied otherwise the unit served will soon be ruined, but the greatest of care must be used in maintaining the oil for the main turbines, gear, and thrusts. This latter OIL known as symbol ?190T is stored in the system in the sumps under the reduction gears. From here it is drawn through STRAINERS by the LUBRICATING OIL PUMPS and discharged through LUBE OIL COOLERS to the various bearings, and thrusts. The pressure at each bearing is regulated by NEEDLE VALVES. Thermometers at each bearing give an early indication that the bearing is becoming hot. Some of the oil goes to small pumps in the main turbine GOVERNORS which operate the steam trip valve should the turbine overspeed. The oil, after passing through the bearings and thrusts etc., drains back to the pumps. Should it be necessary to purify the oil, it can be pumped to SETTLING TANYB and heated. Heating causes water in the oil to separate. Also, PURIFIERS are installed which act to separate the oil and water mechanically.
Water, especially salt water, has a very damaging effect on steel and must be kept out of all lubricating oil. The main units are usually well cared for, but many of the lesser units are sometimes neglected in this respect which results in their failure. Take care of auxiliary machinery oil. Spare oil is stored in STORAGE TANKS in the engine room. In order to determine what oils should be used in the different machinery units, reference should be made to the chapter on lubrication in the MEI (Manual of Engineering Instructions) and the manufacturers instruction book.
During the discussion of the main propulsion steam cycle, many machinery units were mentioned such as blowers, fuel oil pumps, feed pumps, air ejectors, etc. Those units themselves all require some power in order to operate. Most of them are driven by small turbines which do not exhaust to condensers as in the case of the big main drive and generator turbines because of weight and space limitations; hence it is impossible to expand the steam in them as much as it is in the big engines. Therefore, superheated steam is not used in the auxiliaries nor is the steam expanded to a vacuum. Instead 600 lb. saturated steam, exhausting to the AUXLIARY EXHAUST LINE at about 15 lbs. pressure, is used to run the auxiliary turbines and the RECIPROCATING PUMPS (the EMERGENCY FEED and the BILGE PUMPS). This 600 lb. steam is used also to heat the fuel oil in the heaters, whence it drains as water through the HIGH PRESSURE DRAIN LINES. Make a list of all the connections to the auxiliary steam line.
Steam in the 150 lb. AXILIARY STEAM LINE is used chiefly for heating purpose and for operating the WHISTLES and SIREN. There are connections to this system for ship heating, galley use, obtaining shore steam, smothering fires in the bilges, steaming out tanks, heating fuel oil tank heating coils and raising the pressure of the AUXILIARY EXJAUST LINE to 15 lbs. if an insufficient amount of exhaust steam is obtained from auxiliary machinery or extraction from the main turbines or generator turbines. Make a list of all connections you can find on the 150 lb. line.
MAIN AUXLIARY PLANTS
So far in this paper, attention has been focused in the main on the machinery which drives the ship through the water, with some brief mention of the electric generating units. Yet in addition to the main engine plants there are needed in the ship several minor machinery plants to support the operation of the main units, and also to make it possible for two thousand men to live aboard for weeks away from shore.
The most important of these minor plants is the ELECTRICAL GENRATOR INSTALLATION, which consists of seven 1000 Kilowatt GENERTORS. Two main generators are located in each of the machinery spaces with the exception that in number four machinery space, there is one. An emergency diesel-generator is located in the port side of the main evaporator room forward and another is located in the after diesel generator room under the after distribution room.
The generators produce alternating voltage of 450 volts in three phases at 60 cycles, by the action of a rotating direct current field excited by a small D.C. generator attached to the rotating shaft whose flux cuts the windings of the stationary armature. The generator turbine rotates the shaft on which the main generator field and the exciter armature are attached. This turbine steam cycle has already been discussed. For the operation of electrical machinery it is essential the voltage and the frequency be constant regardless of the load upon the machine. On these machines, the voltage is maintained at constant value by a voltage regulator which controls the amount of current flowing through the generator field, while the frequency is maintained by keeping the speed of the turbine constant. This speed control is accomplished by an oil operated governor on the turbine throttle. When a motor is started somewhere on the ship, amperes flow through its armature in order to cause the motor to do work. These amperes flow back through the main generator armature and add to the other amperes already flowing, increasing the “load”. The effect of these additional amperes is to cause the main generator rotor to slow down, which acts to decrease the voltage produced and lower the frequency. However, when the voltage goes down, the voltage regulator increases the strength of the generator field until the voltage is normal again, while at the same time, the oil operated turbine governor opens the turbine throttle so that more steam is admitted and the turbine speeds up. This procedure will continue until the wires of the generator armature are carrying all the amperes they can without burning up.
If, for some reason, the generator loses the load and the governor fails to shut off the steam, an emergency trip is provided to cut the steam supply before the turbine flies apart from overspeeding. as the load increases, the current lags the voltage more and more so that less of the current is in phase with the voltage. As only current in phase with the voltage produces power, the kilowatts produced will not equal the product of the volts times amperes, but just a percentage, known as the “power factor”. These machines operate at 80% power factor at full load.
NOTE:- If the reader has not had any previous knowledge of electricity he should study the meaning of the terms “VOLT”, “AMPERE”, “KILOWATT”, “PHASE”, “CYCLE”, “FREQUENCY”, “FLAG”, “LEAD”, “POWER FACTOR”, “RESISTANCE;”, “IMPEDANCE”, “REACTANCE”, “INDUCTANCE”, “CAPACITY”, “SYNCHRONIZE”, “FIELD”, and “LINES OF FORCE”.
The power produced by the main generators is lead to distribution boards. There are four of these main boards, one in the forward distribution room, one in number two machinery space, one in number three machinery space, and one in the after distribution room. The switchboard for controlling the generators are also attached to these distribution boards. Each man, especially those desiring to become electricians, should study these boards and learn the purpose of every device on then. Each one has an important function. The power delivered to the distribution boards is sent to all parts of the ship through feeders to LOAD CENTERS by closing the proper switch on the board.
Also the boards may be interconnected so that number one generator can supply power to number four board etc. From, the load centers, power can be further distributed through mains and sub-mains. If the units supplied do not operate on 440 volts, transformers are used if AC voltage is required; or motor-generator sets if DC voltage is needed. Big MOTOR GENERATOR sets are installed to provide direct current for searchlights, degaussing, and battery charging. The emergency diesel powered generators supply voltage for a few vital circuits in the event that the main voltage fails. Should the main voltage drop to 350 volts, the diesels will start automatically by air pressure and supply the vital circuits. When the main voltage rises to 405, the emergency voltage is disconnected and the diesels must be stopped manually. These sets have their own distribution boards, which can be energized from the main boards; however, the main boards cannot be energized by the diesel generators. Learn what circuits are connected to the various boards, low the boards are connected to each other, and how the generators can be cut in on the line or taken off.
Throughout the ship are innumerable electrical devices, motors, lights, heaters, etc. They are fed however by two principle circuits, POWER or LIGHTING. The leads have special markings on them telling what kind they are, and the degree of their importance. Learn these markings.
Electric power, as aforementioned, is directed to electrically operated devices by cables.
Between the distribution boards and the LOAD CENTERS the cables are known as FEEDERS; from the load centers to the distribution PANELS they are also called feeders; but from the panels to JUNCTION BOXES they are called MAINS and SUBMAINS. They then separate into BRANCHES and SUBBRANCHES to the lights or units served. Every unit or light is operated from a switch or control box. As stated previously, some power units operate on less then 440 volts, so the voltage is reduced by transformers to the proper voltage. Three phase power, however, is employed nevertheless. On the LIGHTING CIRCUITS, the voltage is first reduced to 115 volts and single phase power is distributed to the various circuits by using just one of the three phases on a circuit. Study the connections to a lighting transformer and see the phase connections. Also get a piece of cable and note how three phase power is carried in this cable by the three wires inside the insulation.
For purposes of communicating throughout the ship, four systems are provided. One is the SHIP’S SERVICE TELEPHONE system, a miniature shore telephone installation. Dial telephones are located in the principle parts of the ship, and are connected through an AUTOMATIC SWITCHBOARD in the telephone exchange an the port side of the first platform deck just forward of frame 73. The next general communication means is the GENERAL ANNOUNCING SYSTEM, by which, through loud speakers, information may be passed over the entire ship to specially selected stations. Then, in addition, stations which must be in communication with each other during special periods are connected by means of SOUND-POWERED telephones.
Call bells are provided for this system so that other stations may be contacted. Some of the sound powered systems are paralled by AUXILIARY SOUND POWERED systems. The sound powered circuits are given numbers and letters to distinguish them such as 1JV or 2JY. Each system connects a special group of stations, although it is possible to connect two or more systems by “Cross-jacking”. Auxiliary systems are lettered the same as the main systems, but are preceded by an X, as X1JV.
The INTERIOR COMMUNICATION room on the starboard side of the ship from the telephone exchange contains the switchboards and motor generator sets for controlling all the interior communication systems, which include besides the sound powered telephones, all the interior alarm circuits, signaling circuits, steering circuits, etc.
Some STORAGE BATTERIES are provided for use on the automatic switchboard, motor boat starting, and a few other uses. These batteries require continuous care. Visit the battery charging station and familiarize yourself with what is done there. The ship is provided with four 36-inch gunnery SEARCHLIGHTS, four 24-inch signal SEARCHLIGHTS, and four 12-inch signal SEARCHLIGHTS. The two larger type burn carbons fed by a special mechanism whose workings must be thoroughly understood in order that the lamps are burned. These big lights use D.C. current furnished from motor-generator sets.
Another very important auxiliary installation is the EVAPORATING PLANT. The main units of this plant are located in the space on the second platform deck forward, between frames 67 and 73. Over eighty thousand gallons of distilled water can be made every day by these sets. Another smaller set, capable of waking twelve thousand gallons a day will be located in #4 machinery space, so that, should the big sets be damaged, the ship could still make some boiler water and be able to steam.
Sea water, as every one knows, contains a considerable amount of salt and other solid matter which render it unfit for either drinking purposes or for boiler feed water. The EVAPORATORS remove those salts and solids from sea water for use on the ship. Fresh drinking water need by distilled only to a purity which permits several grains of salt per gallon, but boiler water for use in modern high pressure boilers must be water of exceptional purity – less than 0.1 grains of salt per gallon for, as thousands of gallons of water are boiled per hour under great pressure, the tubes in the boiler would soon be coated with heavy scale from deposits of salt while dangerous chlorine acids would at the same time be formed which eat away the steel. Hence, the principle purpose of the evaporators is to prepare pure boiler water which is called BOILER FEED WATER.
In the forward evaporator room are two identical sets of forty thousand gallons daily capacity each.
As these two sets are the same, the operation of only one will be described.
Sea water is pumped by the DISTILLER CIRCULATING PUMP through the cooling tubes of the CONDENSATE (newly made fresh water) COOLER, then through the DISTILLING CONDENSER and overboard. This sea water has picked up some heat in going through these units so about one tenth is drawn from the overboard pipe by an EVAPORATOR FEED PUMP and discharged to the FIRST EFFECT SHELL, first passing successively through the INNER HEATER, the COIL DRAIN HEATER, the DISTILLER AIR EJECTOR CONDENSER, the second effect and the first effect VAPOR HEATERS, and a FEED REGULATOR. In passing through these various heat exchangers, the evaporator feed water becomes progressively hotter. When it enters the first effect shell it is quite warm but not yet hot enough to boil. To accomplish boiling the evaporator feed and so causing the formation of pure fresh water vapor, steam from the auxiliary exhaust line is passed through coils in the shell where it condenses to water, drains through a DRAIN REGULATOR and is pumped by a TUBE NEST DRAIN PUMP to a feed bottom or deaerating feed tank as this drain water is condensed boiler steam, already treated with boiler compound. The exhaust steam, by condensing in the first effect coils, gives up its heat to the salt water in the shell and causes part of it to boil. The salt, however, remains in the remaining water making it saltier. The first effect vapor leaves the shell, passes through the first effect vapor heater where it heats the incoming evaporator feed and goes into the SECOND EFFECT coils, where it boils some of the saltwater in that shell.
It condenses in the second effect coils, and drains through a DRAIN REGULATOR to the bottom, of the THIRD EFFECT COILS. This condensed vapor is pure fresh water. The salt water in the second and third effect shells is the feed remaining from previous effects, which is pumped from one effect shell to the other by the second and third effect FEED BOOSTER PUMPS. From the third affect shell this feed water, which has now become one half again as salty as it was originally, is pumped overboard by a BRINE PUMP. The vapor from the second effect, as in the case of the vapor from the first effect, passes through a vapor feed heater to the third effect coils where it condenses, draining through a drain regulator, a COIL DRAIN HEATER, a regulator, to a FLASH CHAMBER. The vapor from the third effect flows through an INNER HEATER to the DISTILLING CONDENSER, where it condenses and flows to the FLASH CHAMBER. In this flash chamber, the condensate whose temperature is such that it would “flash” into vapor at the pressure existing in the chamber, does so partially. This flashing of part of the condensate into vapor absorbs heat from the remaining condensate, and thereby cools it. The vapor formed returns to the distilling condenser. The condensate remaining in the chamber, still quite warm, is drawn off by the CONDENSATE PUMP, passed through a CONDENSATE COOLER to a MEASURING TANK, where the quantity made is recorded and tested for purity. It is then pumped by a FRESH WATER PUMP through a meter to a fresh water tank. As water boils at a lower temperature when the pressure on its surface is lower, a partial vacuum is maintained in the shells by a DISTILLER AIR EJECTOR which draws air from the distiller condenser.
This action coupled pith the condensing of the third effect vapor in the distilling condenser creates about 25 inches of vacuum in the distilling condenses with consequent partial vacuum in the succeeding shells, for they are connected by the vapor pipes. As result, it is possible to boil the evaporator feed water with steam whose temperature is much less than 212 degrees Fahrenheit. With regard to evaporator operation, it must be remembered that the incoming exhaust steam temperature must be between 200 and 230 degrees Fahrenheit, and that the pressure of the steam is not the governing factor. Hence steam of zero lbs. gage pressure or even less may be used. Also, it is the condensationof the steam in the coils which causes the feed to boil. Hence, do not permit the coils either to fill with water or permit the exhaust steam or the new vapor to blow clear through them. The feed in the shells must be neither at too high or too low a level, nor should the feed be allowed to become too salty. It is of paramount importance, too, that the fresh water made is of great purity. Learn how it is tested, and also how the flow of steam and feed in the evaps are controlled.
Aft, on the first platform dock, between frames 129 and 142 ½, are located the ship’s refrigerated spaces where fresh meats, eggs, butter, and vegetables are stored. If the spaces are properly cooled, it is possible to carry fresh provisions for several weeks cruising.
The machines which cool these refrigerated rooms belong to the Engineering Department and are located at the after section of the ice box area. Three units are provided, any two of which will maintain the proper temperatures.
The units consist of an electrically driven compressors which compresses a gas known as FREON or F-12. This substance is a gas at room, temperatures, but by compressing it, and then removing the heat caused by it in a cooling unit known as the condenser, it turns to a liquid and will remain as a liquid so long as the pressure is maintained upon it. In the cooling system, however, it is passed though an expansion valve which allows just enough of the liquid Freon to enter the cooling coils as will permit a reduction of the pressure to the point at which Freon will boil. In boiling, heat is absorbed from the surrounding medium-in this case the air about the cooling coils in the ice boxes-and cooling is effected. Thus, liquid Freon enters the cooling coils, boils, absorbing heat, and leaves the coils as a gas on its way back to the compressor again to repeat its cycle. The expansion valves are controlled automatically by thermo valves, but nevertheless a careful check must always be maintained on the temperatures in the boxes or the food will spoil. It is important that the Freon be kept free of water which would freeze in the expansion valves and prevent operation of the system. A drier or dehydrator is installed in the Freon lines to remove any water in the Freon.
Learn the usual box temperatures, Meat Box 15° F., Butter and Eggs 35° F., Fruit 40° F., how to detect Freon leaks, and how to replace Freon which leaks out.
The ship is provided with two rudders, both of which are operated simultaneously by steering controls at the navigating bridge, at the secondary control station, the central station, or by the use of “Trick” wheels in each steering engine room.
At each helm, except in the steering engine rooms, are small SELSYN TRANSMITTER AC MOTORS whose stators, or stationary windings, are energized by 440 single phase voltage. The rotors of these motors are wound for three phase voltage and are connected to the rotors of similar SELSYN RECEIVER rotors in the steering engine room. In both transmitter and receiver rotors a voltage is induced by the alternating stator field, but if both rotors occupy the same relative position to their stators these voltages balance each other and no current would flow in the circuit connecting both rotors. Now when the steersman turns his wheel, he turns a shaft which is connected to the rotor of the motor at his helm and thereby causes the rotor to turn and change its position relative to its stator. By this movement an unbalanced voltage is induced which causes current to flow through the circuit to the rotor at the steering engine room. When this current flows through this latter rotor, it sets up a field which causes that rotor to turn until it occupies the same position relative to its stator as the rotor at the helm does to its stator.
Thus the rotor in the steering gear room follows the one at the helm.
The rotor of the receiver motor in the steering gear room is connected by gears-end shafting; to the PILOT VALVE of a SERVO MECHANISM. Movement of this pilot valve permits oil under pressure from the SERVO PUMP to operate on either side of a piston, depending on which way the rotor moves the valve in response to movement of the helm. Movement of the piston, actuated by the aforementioned oil, moves a TILTING BOX on a WATERBURY SPEED GEAR. This Waterbury Gear is just a large oil pump operated by big 75 HP electric motor. Its operation is briefly as follows: this motor through a reduction gear, turns a shaft on which is a keyed cylinder. This cylinder has in it several little holes, into which project the pistons on the tilting block. These holes always contain oil. Then the tilting box is at right angles to the shaft, the pistons do not move relative to the cylinder and there is no pumping action in the holes. But if the tilting box is rotated so as not to be at right angles with the shaft, the pistons on one side of the box project further into the holes than the pistons on the opposite side as the cylinder rotates, and a pumping action results which puts pressure on the oil in the holes and piping to the rams. By tilting the box one way or the other, the pressure on the oil can be revered in direction.
The rudders are actually moved by CROSSHEAD operated by two oil filled RAMS.
If pressure is put on one ram and reduced simultaneously on the on the other ram, the crosshead will be turned, turning the rudder. This shifting of pressure in the rams is accomplished by the tilting box as described above. On the crosshead gear shafts as a FOLLOW UP MECHANISM to return the tilting box to a vertical position as the rudder turns otherwise the rudder would keep on going to the “hard-over” position every time the tilting box is moved from the vertical.
In each steering engine room are two complete sets of steering motors and oil mechanisms for operating the rams. Shifts from one motors to the other can be quickly made, as can the shift of oil flow from one tilting box to the other. Furthermore, a separate motor is provided so that the rudder can be returned to the mid-ship position in case the main motors fail. Should the SELSYN SYSTEM fail, the “trick” wheel can be used to operate the pilot valve on the SERVO MECHANISM.
Each man should read the instructions regarding the shifting of controls from the different stations and know how to operate the switches necessary to line up the gear.
COMPRESSED AIR SYSTEMS
Three compressed air systems are provided for the ship, the HIGH PRESSURE, MEDIUM PRESSURE, and LOW PRESSURE. The high pressure system is supplied by tow motor driven H.P. COMPRESSORS, one in the forward emergency diesel generator room and on in the #4 Machinery Space.
These compressors will deliver thirty cubic feet of compressed air per hour at 3000 lbs. per sq. in. pressure, which air is used for charging air storage banks for use by the turret guns and for starting certain diesel engines. The medium pressure system is supplied by four motor-driven M.P. COMPRESSORS, two being located in each emergency generator room. These compressors deliver 250 cubic feet of free air at 200 lbs. per sq. in. per minute used primarily for the rammers of the five-inch guns. The low pressure system is supplied by two rotor driven L.P. COMPRESSORS located one in the forward machinery space (#1) and one in the after machinery space (#4). These compressors deliver 100 cubic feet of free air per minute at 100 lbs. per sq. in. This air is used for miscellaneous ship work as cleaning motors, testing compartments for tightness, operating the forge, operating the pneumatic dispatch system, etc.
When compressing air, the principle features occurring are the high discharge temperatures and the precipitated water. Therefore, means must be provided for cooling the air as its pressure increases and for removing the water which is formed. This water is simply the water vapor which all free air condenses. Therefore, on compressed systems, look for these cooling provisions and the means for the manner in which water is removed.
The air after compression is usually stored in ACCUMULATORS
In addition to the systems already described in brief, there are in the ship a number of installations necessary for its operation, but are of relatively miner engineering importance. They are listed below with a short description, mainly to bring their existence to your attention with a view that you will investigate them carefully and learn of what each system consists and what peculiarities of operation may obtain.
THE HIGH PRESSURE STEAM DRAIN SYSTEM
This system collects the drains from high pressure valves on the main and auxiliary steam lines and a few other H.P. fittings and discharges through impulse traps to the deaerating feed tanks.
The FUEL OIL HEATER and FUEL OIL TANK HEATING COIL drain system collects the drains from these units and discharges them through inspection tanks to the deaerating feed tanks. Water seals are maintained in these tanks by means of needle valves.
THE FRESH WATER DRAIN COLLECTING SYSTEM.
This system collects fresh water which drains from various steam machinery units into open funnels and conducts this water to a DRAIN COLLECTING TANK in the bilges. From the drain collecting tanks, the water is drawn through a vacuum trap into either the dynamo or main condensers.
THE LOW PRESSURE AND WHISTLE AND SIREN DRAINS
The steam heating system drains are collected primarily by this system.
The drains from the whistle and siren connect to this system in the forward machinery space. Because of the extent of heating system drain piping throughout the vessel, the drain collecting tank for this system in the after machinery space (#4) is maintained under 15 inches of vacuum by a two stage AIR EJECTOR in order to maintain the flow. Water collected by this system is pumped to the deaerating feed tanks by an L.P. STEAM DRAIN PUMP.
THE BILGE SUMP TANK DRAINS
This system collects contaminated water, waste oil, etc., from open funnels and discharges it to a BILGE SUMP TANK. From here this waste matter is pumped over the side by a BILGE PUMP.
THE FIRE AND FLUSHING SYSTEM
Five FIRE AND FLUSHING PULPS, four motor drive and one turbine drive, one located in each of the four machinery spaces and one in the forward emergency diesel generator room connect to the FIRE and to the FLUSHING MAIN. These pumps have a capacity of 1200 gallons per minute at 65 lbs. pressure and 750 gallons per minute at 150 lbs. pressure. They also discharge to JET PUMPS which operate at 150 lbs. pressure and increase the drainage capacity to 1200 gallons per minute per pump. Water for the machinery cooling service system can be obtained from this system pump. The FIRE AND pumps take suction only from the sea.
THE BILGE DRAINAGE SYSTEM
Five reciprocating BILGE PUMPS are provided, one in each machinery apace and one in the forward emergency diesel generator room.
These pumps have a capacity of 225 gallons per minute at 50 lbs. pressure. Suction can be taken from a bilge drain tank in the machinery spaces, from a BILGE WELL in the forward emergency diesel generator room, and from contaminated fuel oil tanks. The MAIN CIRCULATING PUMPS can also be used for bilge drainage purposes. Discharge from the bilge pumps can be to the sea, to hose connections, and to contaminated fuel oil tanks.
THE MACHINERY COOLING WATER SERVICE SYSTEM
Six motor-driven AUXILIARY MACHINERY COOLING WATER SERVICE pumps, one in each of the four machinery spaces, and one in each of the emergency diesel generator rooms, connect to a COOLING WATER main which extends through the machinery spaces from the forward emergency generator room to the after emergency generator room. This system provides cooling water for auxiliary units as lube oil coolers, bearings, etc.
FUEL OIL TANK DRAINAGE SYSTEM
Three FUEL OIL TANK DRAIN PULTS of 50 gallons per minute capacity at 50 lbs. pressure are located, one in the pump room at frame 30, one in the C ∧ R pump room at frame 46, and one in the after Emergency diesel generator room, and one connected to a piping system which permits suction from all fuel tanks and discharge to the contaminated oil tanks.
DIESEL OIL TRANSFER AND SERVICE SYSTEM
oil is stored in tanks directly beneath the emergency diesel generators.
In each diesel generator space is a motor driven DIESEL FUEL OIL SERVICE pump of 25 gallons per minute capacity at 50 lbs. pressure, a 150 gallon per hour PURIFIER, a CLEAN OIL SERVICE TANK of 8 hours capacity and a GENERAL SHIPS USE TANK of 600 gallons capacity. The pumps take suction from the storage and service tanks either forward or aft and discharge to the clean oil tanks via purifier, the generator diesels, or to the SHIPS SERVICE line to boat filling connections, forges, etc.
THE STEAM HEATING SYSTEM
This system obtains its steam from the 150 lb. steam line in the forward (#1) and after (#4) machinery spaces through reducing valves which lower the pressure from 150 lbs. to 50 lbs. Two lines run from the machinery spaces, the CONSTANT pressure line and the INTERMITTENT steam line, and go practically to every part of the ship. The CONSTANT line supplies the galley, the SHIP SERVICE ACTIVITIES, principally the LAUNDRY, and also other stations where a continual flow of low pressure steam is needed. The drains from this system have been discussed.
AIR CONDITIONING PLANTS
There are thirteen AIR CONDITIONING UNITS scattered about the ship far the purpose of cooling essential battle stations and SICK BAYs. These units operate essentially like the refrigerating units, for cooling the air. The humidity is controlled by removing moisture from the air by means of lime trays, or adding moisture by use of steam.
SHOPS AND STOREROOMS
For upkeep purposes, a MACHINE SHOP, an ELECTRICAL WORKSHOP, a METALSMITH SHOP, and OIL TESTING SHOP, and a BATTERY MAINTENANCE station have been provided. Visit those shops and learn the purpose of all the tools installed. A STOREROOM under the charge of the engineer force is also provided in which are kept tools and material necessary for daily use and minor repair.
ORGANIZATION OF THE ENGINEER DEPARTMENT
The Engineering Department of this ship is organized in three Divisions, the AUXILIARY (A), the PROPULSION (P), and the ELECTRICAL (E). Each Division is in the charge of a DIVISION OFFICER who has to assist him junior division officers and repair officers. The CHIEF ENGINEER is in charge of the Department and has as his assistant the SENIOR ASSISTANT ENGINEER.
The Engineer Office called the LOG ROOM is the headquarters of the Department. This office is in the charge of the LOG ROOM YEOMAN who has a number of assistants.
When you report aboard, and after you have been given a berth and locker, you will be assigned to a division. The division officer will assign you to a station which will be noted on the WATCH, QUARTER, and STATION BILL posted in a conspicuous place. Study his bill carefully and learn your job as required. Ask your division petty officers and your division officers if you are in doubt about anything.
NEVER FAIL TO CONSULT YOUR DIVISION OFFICE;; IF YOU THINK IT NECESSARY, but TRY to help yourself.
In a subject so wide as safety, the listing of every situation that is likely to reproduce an accident is, of course, impossible, but an attempt has been made in the following outline to group the many kinds of accidents that occur aboard ship according to the nature of their causes. This outline can do little more than call the attention of everyone to these causes; it is then up to the individual to be continuously alert to see to it that neither through negligence nor ignorance is he the cause of damage to himself or others, or to material upon which the fighting ability of this vessel depends.
The attention of all hands is called to the following causes of accidents:
(a) Collision. This applies not only to collisions between ships and small boats, but collisions between persons, and persons and parts of the ship’s structure. Watch your step. Constant care is necessary in going up and down hatches to avoid slipping or striking one’s head on sharp projections.
(b) Falling Weights. Don’t leave weights like buckets and tools lying around on overhead beams and elsewhere, where they may fall on persons or fragile material. To remain under suspended weights such as boats being hoisted aboard and materials being handled by booms and cranes is foolhardy and a direct tempting of Fate.
(c) Falls. Falls are a common on source of injury to people aboard ship.
Gear improperly secured or left adrift is a menace; and the next person who cores along trips over it, and receives severe cuts or bruises, or broken bones. Use caution on slippery surfaces, particularly when carrying hot liquids or heavy weights.
(d) High Temperatures. Burns from hot gases and liquids are not only extremely painful but they frequently result in the laying up of a man for weeks. Labor is thereby made unavailable; the ship loses a man’s services, and his shipmates must absorb the extra work load.
(e) High Voltages. Practically all the power and light circuits aboard the MASSACHUSETTS carry high alternating voltage. This voltage is vicious and many serious fatalities have resulted from carelessness in candling it. Should a person inadvertently strike one of the 440 circuits while it is energized, he would in all probability be fatally electrocuted. Men must never go aloft either on the mast or smokepipes without permission, as the high-frequency radio antennae constitute a continual hazard to personnel.
(f) Pressure. The danger of steam pressure is too well known for discussion here. However, water pressure too is dangerous; an unattended hose nozzle with water pressure on it can cause serious damage by swiping either persons or material. High air pressure used in charging gunnery air flasks and diesel starting units is very dangerous, and only experienced personnel will be permitted to operate valves on this system. A loose H.P. air lead is particularly deadly.
(g) Moving Objects. Care must always be exercised around machinery, rotating shafts, propellers etc., so that one’s body is not brought into contact with them. Be careful that your clothes are not caught and serious injury sustained thereby,
(h) Explosives. The care and handling of explosives (both powder and fuel) are exhaustively covered by safety precautions. follow these precautions to the letter. Accidents from this source are almost invariably the result of carelessness.
(i) Inflammables. Wood, paper, or cloth fires are generally the result of a cigarette butt carelessly disposed of. Don’t throw cigarette or cigar butts over the side; they may land in boats along-side. Ash receptacles are provided for smokers; use them. And don’t smoke in bunks.
(j) Weapons. Handling of small arms, in particular the .45 automatic pistol, require eternal vigilance. Accidents resulting from small arms can only be the result of carelessness, because all personnel aboard the MASSACHUSETTS, who will be required to use them, will first be qualified in their use by the Gunnery Officer.
(k) Asphyxiation. Suffocation by gases has been one of the common causes of fatalities in our Navy. Men painting in enclosed compartments like fresh water tanks and cofferdams have been overcome by gases and in many instances killed. No work in such spaces will be undertaken unless under the direct supervision of an officer. Gases released by the use of CO2 fire extinguishers against fire in confined compartments or PYRENE extinguishers or an electric arc are other causes of asphyxiation, and must be always considered when CO2 or PYRENE fire extinguishers are used under these circumstances.
When Foamite is used on an electric arc or cable carrying voltage, there is danger of electrocution.
(l) Drowning. Each year many men are drowned in the Navy. It gales without saying that the best way to avoid drowning is to be a good swimmer. However, many drownings of both swimmers and non-swimmers can be prevented by prompt action on the part of the men on the spot; that is, the throwing of a life ring to the man overboard, by getting a boat out to the drowning man, and then after his rescue the application of resuscitation methods with which all men in the Navy should be acquainted.