Sheet1Sr. No.Questions AnswersSurveyorFunction1Stroke / Bore RatioEngine power developed =(P*L*A*n*k) of one cy) X no of cylinders. multiply and divide by (2R) where R is the radius of piston = P*(L/2R)*A*n*k*2R = P*(Stroke/Bore)*A*n*2R Hence total power increases as stroke/bore ratio increases. And obviously power reduces when no of cylinders reduces. Also, bearing friction reduces as stroke/bore ratio increases.Trassi4b2Difference bw MECC & AECCTBNTrassi4b3Boiler Cold StartingTrassi4b4Reasons for FWG Vaccum Not coming upTrassi4b5Why air compressor cooler drain open when we stop the compressorIt basically serves the purpose of An Unloader while stopping the compressor to drain any trapped air between the cylinders.It is done so that the trapped compressed air above the piston does not add up to the starting load; the next time the compressor cuts in.6Dischage method of EGE cleaning water?Mixture is collected in soot collecting tank. D tank has heating coils(steam). Once tank full put alkanity control chemical n open steam. Once water evaporates collect d soot. Apart from dat during washing a jute bag is attached to the pipe opening ofsoot through which some amount of soot separation takes place. Apart from all dis v have a connection to bilge tank. But we seldom use it as it creates trouble for ows. Also in case of tank rupturing d content of tank could be transferred to bilge tank.7Why air compressor crank case breath pipe provided and why with flap?if ur piston ring worn out or butt clearance is incresed so at tht time our crankcase is pressurised so we want to avoid tht pressure with the help of breather pipe.. flap is open only when crancase pressure is more thn atmospheric pressure8How to know cyl oil feed is correct?by calculating scoc and comparing it with shop trial reports9VIT & supet VIT difference and how it worksBefore the Super VIT was introduced variable injection timing was obtained by means of a special profile on the fuel pump plunger. Hence there was a fixed relationship between the injection timing and the fuel index. Thus it was not possible to adjustthe fuel index of the individual pumps without also altering the injection timing. For this reason the Super VIT was introduced, where it is possible to adjust the fuel index and the injection timing independently. Both do the same function of maintaining pmax after the break point. Only difference between the two is that VIT has a fixed break point which is usually 85% load and super-VIT had variable break point... Means break point can be changed from 85%............................................................... but why the break point is to be adjusted? Well before that let me explain break point, it is the reduction of vit index at a specified load lets say at 85%mcr after that vit index reduces. As is in fuel rack there is an index on how much fuel is being pumped (you can see that in fuel rack) , just like that; vit index is the adjustment in fuel timing (advancing or retarding). So in VIT this break point is fixed may be at 85%; but in SVIT it can be adjusted these are adjusted electronically; the adjustment of break point depends on scavenge air pressure.Nowadays all man b&w have svit i guess10Dead Man's Alarm11how to remove and check condition of buttom end bearing of A/E without removing cylinder headRemove fuel injecter 1st . . And frm that hold put eye bolt on piston top and connect chain block . . . And nw open crankase door . . Turn the engine to suitable position so that u wil open connecting rod bolt and lower buttom half . . Nw all wt .on chain block . . Guide piston rod and piston and crancase while turning engine so that its top part doesnt damage . . And with flash lgt u can inspect top part . . .612Andvantages of semi balanced rudder ??turning torque is less bcz the force acting on aft part of rudder is counteract by forward part of rudder 2) steering gear can be lighter and smaller13Why flywheel provided in air compressorA flywheel is provided to store rotational inertia and provide mechanical advantage for manual rotation of the assembly. -Providing continuous energy when the energy source is discontinuous. flywheels are used in reciprocating engines and compressors because the energy source, torque from the engine, is intermittent. The amount of energy stored in a flywheel is proportional to the square of its rotational speed14o.w.s probe working?It works on principle of capacitance.... probe interface is filled with dielectric. Dielectric constant of oil and water are different15Diff btw unloader of mac and reefer(draw reefers dia)in case of air compressor Der is a solenoid operatd drain vlv wich vl open d drain durng startng for 2-3 Min der wud b no compression in dat case n al d accumulated water + moisture wud b draind der by preventng d compressor frm heavystartng torque.. In case of refer compressors d purpose of unloader is to unload a particular unit wen d load demand in evaporator room is less..it works on d principle wen say if load demand is less in d refer room der is a pressure sensor wich vl sense d pressure of d room n if pressure is less d pressure sensor vl signal pressure switch to release d oil wich is actn on each individual unit of refer compressor to d crankcase der by unloadn any unit wen d load demand is less in evaporator room.Despande16define scv efficiency. If L is de stroke wat s de formula foer scv efficiency17if V is de total volume L is de stroke give eqn for volumeteic eff of air comp18Why m alkalinity is double dat of p alkalinity.. why it shud nt exceed19why do u need a deaerator.. i said to avoid air lock.. dont u think expn tank can do it.. den wat s de significnce20rudder pressure test21Define critical rpm. Which all machines have dat...does a centri pump posses criti rpm22trammel gauge how is it used..Whr ll u find dat punch mark.. exact location23One gauge glass showing low level and in the other the level is fluctuating.Action to be taken?u have to consider the reading which is lowest and stop the boiler if no corrective action take then lead to rupture of boiler tube24what is differential pressure in ac comp? Why no diff pres in mac ?In mac air is sucked frm outside nd in case of air refrigeration refrigerant is sucked frm closed line itself n refrigerant acts on d lubricant.....so to get d exact lube oil pressure diffrential gauge is usedDespande25why injection pressure high in diesel engines whereas boiler using same fuel but less injection pressure ?diesel engines are CI engines high pressure n temmperature are required for selg ignition and fuel valves have to overcome this pressure wheras no such pressure in boiler .Despande26reefer compressor suction pressure is constant and rooms maintained at different temperature how ??Despande27Why refergeration compressors are single stage compressors?Becz critical pressure is low fr refrigerant28fuel valve leaking , pax will increase or decrease ?FO v/v leaking leads to after burning resulting in reduction of Pmax n increase in high temperature.... Also black smoke from funnel29Significance of having thrust block inside the engine & as well as remaining outside?30How to adjust tappet clearance if no marks on flywheel or camshaft and push rods are tightOpen the crankcase door and check for the fuel cam to be on rise and the remaining two cams of push rods on base circleTrassi31Why ph of feed water in hot well less than in boilerBoiler water is more alkaline than feed water because chemical added is carried back by steam in reduced concentration.32What type of motor is there in windlass or winchesIn electro hydraulic system winch/windlass motor is hydraulic and pressure generation pump has induction motor.Variable delivery pump .......Also external gear ;vane; axial piston motor is also used..Trassi33how wil u know micrometer is giving exact readings?micrometer is provided with a reference piece that is of standard dimension..50mm i guess..calibrate the micrometer accordingly.Sharma34Crankcase relief door setting.Crankcase Relief Door Setting : Generally done by shore party with Spring Balance Method. P = F/A. Force is found out by a sensitive spring balance and area of the relief door is given in the manual. Hence, pressure can be set.Trassi35Bumping clearance, how it inc or dec, how to check.Air Compressor Bumping Clearance : Increases if the crankpin bearings are worn out and decreases if cylinder head is over tightened over the gasket. Clearance can be measured with the help of a lead wire ball.Trassi36AUTOMATIC COMBUSTION SYSTEM IN BOILER DIAG AND WORKING37Can Governor be manually disengaged38why slipping clutch is provided in windlass..?Windlass is supposed to slip incase of excessive force. Otherwise rope will break and can cause accidents39How do you start a compressor manually?40What is priming in fuel pumps?Removal of air after replacing a fuel pump on the engine. We use the same line that circulates low pressure fuel thru the injector when engine is not running.41Your sea water line flange leking ur hief engineer tols u to cut gasket for that how u will cut.U have to measure outer dia of flange pcd n bolt dia n outer dia of pipe.Shirish42Your hydrophouk pump was licking because there was no gland on pump how will you select gland for punp.U have to measure shaft dia, see the size of gland casing, while assembling gland should put one by one n shouldn't have any twist, cut of glands shouldn't in same line.Shirish43Ur aft bilge well not taking suction possible reasonsFilter may be chocked,gasket licking,other two valve no holding, level of bilge is low, hole in bilge line,suction mouth chovked by clothes.Mishra44How will u rectify that crank shaft deflectionIf deflections are out of range..take main bearing clearance of all units...if mb clearances are not as required..then need to change bearing..if mb clearances are all ok and deflection is out of range...that's a clear indication of distorted bedplate..then.u can check for loose tie rod and foundation bolt..if that is ok..u cannot do anything..take shore help.45Why diffuser if volute casing is there ??Diffuser is more effective than volute casing ..it is used where high pressure is required Its nulify radial thrust too46Why does the hydraulically operated exhaust valve of the main engine not fall in the cylinder if air spring pressure is removed ?Valve will not fall into the combustion space as the spindle is located onto the air piston with the aid of a split cotter which prevents the spindle from falling down even if the spring air is vented completely47Why v r not blowing down boiler to bilgewater flashes off to steam excess possibility of burns damage to equipment... 2. boiler water has chemical which will later effect OWS operations... 3. May result in local heating and thermal stresses and later cracks in the tank top..48Why distribution hole is not provided in clarifier plates?U don't require interface to occur within the disc stack diameter, clarifier is separating out solid within liquid phase. Not required. Hence plugged49Bnkr line pr testing?Procedure...choose any one same bk tk for suction and filling..keeping the valve open which isolates all the bunker tanks from the bunker manifold..make sure bunker manifold valve is also closed.. start fuel oil transfer pump...now slowly slowly start closing the bunker tk filling valve..this will increase the pressure in the bk line Bcz as u have closed the valves for filling bk tk... one has to stay near the p/p breaker with a radio set..the pressure is raised till about 4 bar. ..n remaining 0.7 bar (4.7 bar) with a hydraulic hand pump..time limit I don't remember...I think it was 1 min50how to cut off fuel from sprcific unit ? in manuevring if needed how to do it ?in Man B& W: lift the roller up using chain; in Sulzer RTA: Turn the knob below fuel pump. it can be done while engine is running Fuel cut off lever...turned to 180 degree by hand..so roller lift up frm the fuel cam.. .take air hose..and connect it to puncture valve..u can cutoff when running also..51relief valve n Safety valve differences atleast 51.SV: Fully opern at set pr. RV:Start open at set pressure.Fully open at15-20%above the set pressure 2.SV: Close at set pressure. RV: Set at pr. Lower than the set pr. 3:SV: Relieve excess mass RV: REleive excess pr. 4:SV: Can open manually RV: Can't open manually 5:Set to open 3% above the working pr RV: Set to open at 10% above the working pr52how we can order a pipePrepare the data for what u have to order. Like for pipe - its nominal dia, shedule, material, legnth, pressure, etc. whatever is known. Send these data to company through the software service provided onboard for ordering, with CEO and captain approval. Other method is to find respective code for what u have to indent in IMPA or ISSA manual, and forward a spare request to captain through ceo.53Exhaust gas boiler n Eg economiser ....Differencesexhaust gas boiler is an integrated system having its own water and steam drum. Economiser is a separate heat exchanging system getting water from and putting steam into aux boiler water and steam drum54Wt is the function of mixing collum in f.o system...??Mainly :1) Gradual change over of fuel from Heavy oil to diesel oil and vice versa, As name said it allows mixing of two grades of fuels 2) Any vapour or air lock in sys is vented through top of column chamber 3) It prevents return of fuel oil which isalready at injection temp to again mix with comp low temp fuel in sevice tk...thereby saving thermal efficiency of fuel ciculating sys. 4) An already counted fuel through flowmeter is required to preserved from return line by bringing to mixing column back rather than serive tk. 5) Maintains postive press at fuel circulating sys55in cascade tank oil is found and was is ur immediate action ???(boiler is firing now)..If u see oil in cascade tank...stop main engine, change generator to diesel oil, then stop boiler, change over all d heaters to stby heater. N then check one by one which heater is leaking n rectify.Shirish56wat r the safeties in steering gear and its location..???3 level switches are present in system, relief valve, manual bypass valve, low pressure valve, electrcial stopper, manual stopper, motor overload alarm. level switch 1 will give an alarm in case of loss of oil due to bursting of pipe, level switch 2 will activate in further loss and resulting in activation of solenoid valves which will operate both bypass valve and isolating valve simultaneously as a result splitting of system such dat each power system will operate 2 rams only, further loss of oil will results in activation of 3rd level switch in such situation faulty system willb isolated and one system will operate 2 rams as emergency steering gear...RELIEF VALve IS PRESENT in system to release over pressure in case of rudder shocks during rough weather location unknown. MANUAL bypass valve is provided incase of isolating one sysetem and rudder to turn mechanically. low pressure valve is NRV which opens for oil filling from header tank57why the high pressure line(eg.steering gear system) has square type flanges and not round type?becz in high pressure lines v cANT put gaskets so proper sealings and o rings v use sqaure flanges58from telescopic pipe , how does lo goes to xhead bearing , any othr conection is thr after telescopic pipe??telescopic pipe is arrangement has one inner pipe one outer & stuffing box at d lower end of fixed outer pipe having floating bush. outer pipe is joined to the main oil supply & inner one to the guide shoe for Mc c. floating bush is not packed at bothsurfaces. man b&w crosshead journal has a central axial bore which has connecting bores to upper shell. lower bore has a transeverse slit at d surface which is aligned with the large bore of the shell. large bore is longitudinally connected with other grooves. design has certain features such that bigger journal dia ,minimum play bw d surfaces, channeling through grooves. so very largeload bearing area and better distribution of oil therefore pressure required at the bearing surface during load also does not exceed 3 bar59during manuevring, how to know if starting air valve is leaking ?Thermal Patch, Relief v/v lifting, Paints peeling off, Smoke from starting air manifold drain60fitted bolts?? can anybody explain??They have interference fit... U hav to tap litl while fitting.... Used to join two stuffing box half...61what u have done onbrd to control nox??how u know that nox are in limit??Maintained the nox technical file.. The spares used were according to it..62How to order nut n bolt?63Why settling tank temp is not maintain above 60 degree celcius.convectional currents sets in due to which its not settling anymore64Why we blow through engine in ahead direction normaly?Generally cams at the time of testing after the previous finsih with engine are in forward direction , so first its forward is tested to avoid excess air use and then , astern aftr abt 15 mins once air resv tanks are back 2 capacity .. If distributor cams are ahead after FWE than blow through will be ahead and vice versa65How to check the trueness of omd alarm??Check O setting= flushing omd with O2 frm O2 cylinder in omd itself......check for Span setting which sends gas....don't rembr name....havng highest LEL.....if alarm comes omd is properly working.....corrections r welcum66How ll u remove broken tie rod?1.pass a braided wire down the bottom half and pull it out 2. if the break s midway then go for this method... pull the top part out using chain block... for the remaining piece.... clamp it at the bottom exposed side... use pull blocks and hold thetie rod pice with clamp... now remove the bottom nut....and use a hyd jack below the tie rod piece.. now use a spacer to push the piece up... repeat procedure and use more spacers till broken piece emerges out from top.. use e/r crane to lift it up by clamping top portion and using a welded bead to prevent slippage67One generatar not taking more than 50kw, why? any onespeed droop settings need to be altered. as the load increases, the rpm tends to decrease before stabilizing itself again. that means your generator speed is falling below a certain rpm when load is increased more than 50kW. So what should be done is, run the generator at no load and check its RPM. make sure that it is within the limits prescribed in the manual. If not, adjust it accordingly. Problem should be solved. Agar gen is not taking load, check the governor setting, possible it's load setting has been set at a lower level, then check droop, if these are correct, check power management system.... Bcoz if problem is with t/c dat can be seen by many other ways, t/c will start making abnormal noice , also if aur faulty gen will not come on load.... Paralleling wud fail.68STP blower fails? What will do?service air connection provided with pressure reducing valve...69one of the plate heat exchanger is ruptured what will u do? nyone pleaseRemove 2 consecutive plates if new plate are nt available. and tighten wth the same amount corrsponding to the thickness of the 2 plates removed.70I.g oxygen high level..ReasonsCooling air given to uptake valve leaking , blower seal leaking , air damper opened more71How to test the relief valve of air compressor????????Remove relief valve from compressor n fix it to hydraulic pump with a flange ..use water for testing ..now raise pressure ..n keep checking pressure at which it lifts72In fuel oil service system for main engine. ..why the heater is placed after the circulating pump why not before the pump?fuel is a mixture of lot of products with different boiling point hence if heater is placed before circulating pump then it can lead to gasification ...so if it is after circulating pump then due to increase in pressure boiling point of products of fuel also changes hence prevents gasification73why cant we turn generator in reverse directionthe lube oil pump won't run in the other direction hence the engine will seize74surveyor on board show him HP relief valve is working .Close the discharge... Run the compressor in manual... If it lifts at correct pressure it's working fine if doesn't lift stop the compressor immediatelyTrassi75Scavenge space inspectionwhat you will check before cleaning and after cleaning and before entery what precaution you will take..Shirish76How u will calculate compression ratio..Shirish77You have to make a pipe..how you will make..78Gear pump, how does it generate pressure, cross questioning; How is the discharge pressure of the gear pump regulated?79On the fuel pump side, a pipe coming out of the fuel pump with spring, I said SHOCK ABSORBER; Which is the point at which shock absorption is needed?80Function and need of lamellas? (cross questions)81Fuel pump overhaul of A/E? what is the most important aspect while boxing back the fuel pump which can go wrongshims and marking on the fuel rack and plunger to be matched82Diff. B/w ref. Comp. Mech seal and pump mechanical seal?83if water is mixed with lb oil viscosity will incr or decr.??Decrease84what action after an a/e is tripped on low lub oil pr?Keep the pre-lub pump running; Keep turning the engine using turning bar...followed by Crankcase inspection after 45 minutes; Simultaneously try to find the reason for trip.; But practically we check the LO filter first85Omd alarm sounds Ur actionrun from engine room as per man b&wTrassi86Why pressure test is carried by water not by air/gas?If the system bursts under the pressure Test the air or gas will expand, accelerating the broken pieces of metal outwards.So, Pressure tests are always carried out Hydraulically, this usually means water, because that is cheap, safe and readily available87what is the cause of ext gases is coming out from all cylinder head of aux engine?nozzle ring of turbochargerTrassi88what will happen to the main bearing of aux engine if lub oil pr is just near to the lub oil trip pr?Exactly....there will not be a major problem as long as the engine is operating at low loads....at high loads, the load on the bearings will be higher which will require a higher lub oil pressure at the bearings for the hydrodynamic lubrication to take place.Trassi89Crankcase relief v/v lifting presure1.05 absolute90what r the advantaged of long stroke engine?1. Slow speed 2. Low grade fuel can burn completely 3. Moment of inertia is less and hence flywheel of less weight can be used91during lub oil water testing if i add reagent quantity half or 50%, what reading will show by gauge??Trassi92What are diferrent euipment use in vapour compression and vapour absorption cyclekamath93Measurement of impeller of centrifugal pump94Where mouth seal is fixed95if distance (clearance) between wear ring and casing ring is increased, motor ampere increased or decreased.96Boiler water test, full?97Difference betn boiler water and jacket water?For jcw i said we usually dose Nitrate to stop corrsion, n in boiler water we do phosphate test , pH for protecting the boiler tube for scale formation.98What is diff betn cetan and octane number?99T-Alkalinity test?Take sample from P-alkalinity test, titrate it with N/50 sulphuric acid n add methayle orange( M- alkalinity), the colour of solution should become colourless from pink. It measures the whole carbonate concentration and hydroxile ion...100What is performance curve?Orion101How will U calculate power of main engine except power card method?for calculation of power other than PLAN formula is, calculate the torque from torsion metre and multiplied it by 2pieN/60. ie. P=2pieNT/60.Orion102hw fuel pump is connected with governerOrion103air compressor valves and how u will find out which side will be facing the piston ? draw the diagram104why there is negative cam for air distributor & positive cam for fuel cam?Negative cam ensures positive closing of starting air vlv through air distributor...in negative cam the cam remains mostly on base circle and only portion of cam at rise which prevents cam from wear down...fuel cam is always in operation when engine is running.105wat is meant by Boiler safety valve floating?Floating of a safety valve means setting the safety valve pressure.106Fuel pump and exhaust valve actuating sys in camless engine107Was ur boiler medium or low press boiler108Capacity control in ac.Diagram of unloader in capacity control109Air comp not starting on Auto & ManualLO Pressure trip; overload relay active110Purpose of turning gear1. Turning gear is a starting interlock in an engine. Connecting the turning gear to the flywheel, operates a switch, thereby starting becomes impossible. 2. To check the free rotation of the engine's parts, running gear, chain drives, shaft, propeller.111Method of cutting fuel pp of a unit in main engine112How you will keep crosshead bearing ready for survey including method of bearing removal?113Method of removing main bearing of main engine.114Wht all checks you will do in gearcase of fuel oil separator?115How you will come to knw purifier bowl has attained required speed?116If a stud is broken evenly with head surface..how you will you remove it ?117Draw scrubber tower and explain till IG reaches cargo tanks118What all possible reasons 4 incresed lub oil consumption after 1000 hrs of decarb of generatorIf your piston ring damaged then they can cause large consumption of oil. If o ring in your lo pipe line of turbochager then oil will escape through that but no ex high temp will be noted119hot & cold corrosion120draw stuffing box and xplain121Air compress H.P side ka pressure 25bar hai to suction side pressure kitna ho ga exactly?5 barTrassi122what is the purpose of Mast riser, PV breaker and individual PV valves which are located on each cargo tank???pv breaker is located in the line and pv v/v is on the tank ... purpose is to prevent from overpressure or vaccum Pv breaker is located in a line its work for a line safety at a time of putting of ig for tank collapsing its 200 mm of wter gauge and for vaccum its -700 mm ag of vaccumand pv valve its indivisual tank safety .. Pv vv setting is 1400 & -350 mmwg for individual tk, to compensate expn n contraction of cargo during sailing.Pv breaker 1800 & -700 mmwg is a common sec safety fr full ig line/ cargo tanks in case any pvv doesn't operate Mast riser (manual operation) to allow gases to escape n thus prevent overpressurisation of tanks while loading...when pvv cant cope up123how to know injetion point of fuel pump124How to take butt clearance of piston ring?? ...procedure and instrument used??For new ring it is taken by placing it on the least weared area of liner and for old ring it is taken on the most weared area of the liner.. At that area for used rings there is more chance of blowpast because of lack of sealing125why pulse type turbo charging system is used in aux engineBecause of load variation126why centrifugal pump not used for hfo ...while it is used for loThe pr reqd is imp..For hfo we need pr. .For l o the quantity of l o is imp127all things do you check during axhaust valve overhaul ??128what all checks you do just before mounting exhaust valve back ???checks v r doing after overhauling are leak test for air and drop down test of the spindle.. in drop down test test v ll supply air to the non return valve in exhaust valve assembly then v ll remove the air connectn.. if valve fall down with in 1 hr then it indicate leakages with in the sytem.....for leakge test v ll supply air to the non return valve.. if air comes through a bore below the oil drain pipe then it means ur stem seal is leaking..then remove the oil drain pipe and check.. if air comes through oil drain hole then it means either ur air piston is leaking or ur relief valve is leaking..129which 1 is better mechanical seal or gland packing ?? y ??130how can v control cavitation ??v can control cavitation by controling the temp of the fluid and also controling the suctn pressure.. suctn pressure should not reach high vacuum.. this can b controled by proper maintenance of sutn filter131why 4s stroke governor faster than 2sAs d speed of governor increases its sensitivity increase...it can detect small speed variations due to change in load.As we know dat 4_t auxiliary engines r used as prime mover for driving alternators...& load changes r frequent due to starting & stopping of electrical equipments132Jacket water line of genTrassi133How to show surveyor testing of bilge injection valve?take a gunny bag...Fill with water...And put it near d suction valave of the pump...And start the pumpTrassi134Fwg if 100% vaccum?If vacuum is 100% boiling rate of water vl increase n salinity increases..+ scalling in evaporater increases...Rapid boiling,carryover of salt,adjust vacuume adjusting valve.. Shell temp lowTrassi135aft bilge well not taking sucnleak in the lineTrassi136you are about to do decab of one unit in main engine ,, so what parameters you gonna record before doing that ??? and the precautions??check peak and compression pressure, exhaust temp, jcw in and out temp, l.o pressure main engine, piston cooling oil pressure and temp, scavenge air pressure and temperature, check the stuffing box l.o tank level, make sure u have a safety meeting, immobilization certificate, propeller clearance and work permit before hand137m/e , a/e eng lubricationOrion138how you know AE piston is in tdc ?flywheel marking,fuel pump marking...... by checking the freeness of push rod and rocker arm.... by checking the position of cam shaft... extreme case by putting head inside crankcase and looking inside liner ....remove fuel injecrtor and fix a gaugethere ...when piston is coming to tdc it will rotate in one direction at one point it will stop and rotating in opposite coz it started moving to bdc..by this way also u can find139Decompression lever of a diesel generator operates(opens) which valve. exhaust or suction??exhaust140Why do we use storm valve in sewage system instead of non return valve?what is the advantage of using storm valve?If we use non return valve what will happen?And also for the fact that normally these valves remain in close condition only open due to the weight of discharge so unlike a regular say globe NRV need not be always kept in an open position141if u see the sewage system there is on u bend in the discharge line...can u tel me why it's is there? Wat is the reasonSiphoning effect by bend.Ya if der s no height of liquid coloumn on discharge side there s a chance of air lock or vaccum lock in d inpeller of the centrifugal discharge pp ...due to which pp ll loose suction142compressor liner lubricationCompressor liner lubrication is done by injecting drops of oil through the inlet valve along with the air143stuffing box n clearances144why we caliberate cyl liner he wanted to listen very specific answer145lantern ring position and function in cen p/p,146reversing of staring air cam147swelling , panting in boilerSwelling : sudden load increase steam pressure goes down ,,water level shows than normal148boliers-mountings, working of dp transmitter, how feed water is controlled to boiler, working of diaphragm control valve, draw the control diagram of boiler feed water controller149generator- now u r gng to lay up generator for 2 months, what all precautions you will do before lay up?, what all checks you will do after 2 months for restartig the generatorlay up means we have to keep generator for 1 or 2 months in idle,,,, first and important thing is condition of space heater,,, it will take care of the insulation of windings,,, he is happy with this answer,,, then we have to tell abt the prime mover side like condition of lube oil, preheater, fuel line checks, any rust or corrosion to the prime mover after lay off etc.150what is the capacity of ur air bottle? Regulations and he asked safety too151what is ums checklist, he told me dat, now u r 4th engr coming to engine room for ums round, tell me procedure one by one.152what is the purpose of puncture valve, how it will activates,..Then he asked,, even in running time of main engine at sea, air is present on top of the puncture valve but why it is not activating???153what is mean by steam hammer?.....what is mean by water hammer?in steam hammering..the steam goes to the cold pipe which is having condensate inside and not been drained..so when it goes in it cools down and form water rapidly which lowers the pressure in at that spot and the condensate which was not drained fullyget sucked on to that place and bang the walls of the pipe..thats steam hammering but water hammering is when a valve(other then steam)is opened and pressure is high like water from a pump and that water hits the bends of the pipe creating noise and damage to the pipe..154why gudgeon pin floating type in engine but not in compressor??In air comp the c'shaft is driving the piston in all strokes,but in case of AE c'shaft is driving the piston in all strokes except power stroke,where the piston now drives the crankshaft.So the sudden change in direction of force can cause an IMPACT LOADING on the pin if it is floating due to clearance in AE piston155What is NDTWhich all NDT can be done onboardnon destructive testskamath156What is initial setting of dial guage what's it's least count what's it's rangekamath157Why would there be rpm fluctuations in case of scavenge fires?In scavenge fire, there will b less air available for scavenging, n thus the Pmax will b less, in short, power will b less so the firing will affect n the crankshaft movement will Fluctuate.. thus rpm will fluctuate in accordance.158Maneouvering diagram bnwOrion159How to select gravity discOrion160U have to weld crack in a plate..what is the surface preparation u will do..Explain dye penetrant testOrion161Safety in gas cuttingOrion162Some Bearing no 6366RS what does it all representOrion163What is batch purification?Normally done if some contamination is found in oil...mostly water..Take entire oil from sump...transfer it to lube oil settling tank...let it settle for at least 24 hours...drain little water from it...start purifier doing suction and filling to lube oil settling tank..do water test in oil...and keep checking water content..164A sea water pipeline on your vessel is corroded and leaking, how will you prepare new pipeline on-boardHe wanted to know about how jig is prepared and flanges are made...For flange you measeure the diameter of the flange,bolts,PCD and the inner diameter of the pipeOrion165Impeller of a centrifugal p/p is stuck in the pump. How will you remove it without any damage.try to heat the impeller and then use bearing puller to remove itOrion166can anyone help me with the back pressure relationship in a purifier...i mean if i increase the back pressure (by closing the valve) or reduce the back pressure (by opening the valve) what will be the effect on the purity of oil?...apart from the E-LINE moving outward and inward respectively.how will back pressure affect the opening and closing of bowl?See if no back pressure oil vl come n go like a pump ..if back pressure is there oil vl stay for a while to overcome that pressure ..so more tym oil stays in purifier so more purification167how to select gland packingBased on fluid, temp mainly, OD,ID168if no viscothrm onboard , how u maintain fo viscosity?We maintain the temp required of fo...as given in bunker analysis169boiler not firing what would be our actions?take to manual operation. Close fuel and atomizing medium (steam). Run purge cycle (if possible). And then start fault finding. First check for alarm on the boiler control panel. Then stop the boiler 1.low water level ( check hotwell water level if water level is ok check running auxilary feed pump nd do purging if neccessary.put water transfer pump in auto) 2.flame failure (take out pilot burner nd adjust the electrodes nd clean the filter inside the burner nd blow with air) 3.flame failure( open main burner door clean the air nozzle thoroughly nd swirl plate) If have flame failure just reset the alarm nd check the pressure of the pilot d.o pump. If no pressure fill up pilot d.o tank nd do pilot d.o pump purging.170Why back pressure valve in refri veg room even though a thermostat is there???1.hold back a high evaporator pressure when an evaporator feeds into a common compressor suction line fed by evaporator working at lower pressures. 2. controlling evaporating presssure and hence temperature to avoid low temperature which could cause problems ( freezing in water cooler )171whn omd will give alarm? at what percent LEL2.5% for 2 stroke..1.25% for 4 stroke medium speed engine172Engine room crane maintenance?beam defection when hook is at minimum distance . Running test for 30 mins to check temperature Limit switch Break testing and lubrication... Overload testing...........Wire renewal 5 years173How to tighten boiler gauge glass??174How to carry out leak test in shell and tube type H.Efirst open the both end cover of the cooler shell and then fill the shell with water , and finally pressurise shell using compressed air through vent connection & check the both end of shell . if any tube is leaking then water must coming through the tube which is leak..175How do you weld 2 Al plates??Tig welding is used ...tungsten inert gas ...argon is provided with torch which shield the metal from oxidation and arc is struck between tungsten electrode and parent metal176Centrifugal pump air extraction method?Air ejector method; liquid ring priming method;vane pump for priming 3 method is only for priming177Sweating of refer cc ?causes and action?Means liq ref is returning... Slight sweating is ok...excess sweating shows faulty txv bhai hm sure nhi hai....agar wet saturated low temp ref gas c/c me ayega to outside c/c moisture will condense....i.e sweating.....causes faulty tev setting , frosting of evaporator coil & excessive fall in s.w temp where condensor is s.w cooled that will lead to excess subcooling dan expected.....actions throttle d cooling water outlet....so dat ref gas temp increases....defrosting by passing hot ref gas or by external heaters if present Reasn is liq ref cumin bak to cc..means al d ref is nt used in d evaporator.dt may be due to evaporatr fan nt running,incorrect setting of txv,txv malfunction,solenoid vlv malfunction,evaporatr tubes frosted or fouled,crankcase heater nt wrking178Bearings used in purifier?in mitsubishi selfjector purifier....upper bearing is supported by spring.....lower part has 2 bearing....The higher one is roller type....and below that a thrust bearing.....The lower two are immersed in oil in the gear case....The direction of the thrust bearing is important. ....If placed up side down then it will go off in 10 min. thus in the vertical shaft total 3 bearings. Horizontal shaft is supported by two ball bearing or roller bearing at the two ends.Vertical shaft contains three bearings.Two bearings at the extreme ends are roller or ball bearings.The upper bearing containing the shaft is made radially stable by the spring loaded assembly,which is responsible for the vertical inclination of vertical shaft.The next lower bearing is an angular bearing to support the shaft axially and counteract the thrust force.179positive cam and negative cam differences..?when the movement of roller is upwards for actuation, then its positive cam. and when roller moves downwards then its a negative cam. for example fuel cam is positive cam and start air distributor is negative cam.180why a negative cam is used instead of positive camTo positively shut ofc pilot air to starting vv...& also a negative cam wont be in contact of rollers the tym of whole engine operation (when start air is cut off)...thus reducing its wear In negative cam at the working face of cam the follower or valve will act in downward direction as in case of starting air distributer whrere pilot valve actuate in downward direction and it shuts because of spring pressure in case spring fails negative cam will positively shut it. snd in normal operation its no more in contact with valve rod so reduces cam's wear and tear181In what case Local emergency manoeuvring to be carried out..? List all the steps involved in emergency manoeuvring..?Failure of remote ctrl sys, Fail of govr,, Procedure- take control frm bridge to engine room ...put blowers on auto ..turn governor knob to local manuvering ..go to local platform and change selector switch to engine side ..check starting air pressure ..contact bridge with walkie talkie ..accept telegram ... Give air kick after reaching a certain rpm ..increase fuel lever from zero ..n give fuel according to rpm required (Pass d critical rpm or braided zone quickly) 182Is there any tel tale hole provided in plate type heat exchangeryes 183And while opening we tighten the jack fully first and then loosen it a bit ... by how mucch angle do we loosen itapprox quarter turn so dat jack & nut is not jammed....bcoz when hyd press is released d bolt will come to its normal length alongwith d nut....den it wont be possible to open d nut..Coz when u release the hydr pr, the nut will get jammed against jack184What happens to efficiency if u go from cold sea water to hot?185How to detect leaks in plate type heat exchanger?Tell tale hole is provided in gasket..Individually inspect plates one by one in a darkened space with a lamp against the plate and you can spot if any minute holes in the plate. These holes cause internal leakage between the two mediums. if any plate perforation found, plates to be discarded in pairs.............................................................. visual inspection or fluorescent dye penetrate is used to find any defeats. (Dye penetrate is used on one side, followed by ultraviolet rays on the other side)186If while opening a nut with hyd jack it is not opening at specified pressure then wat to doI don't think this may occur..If so increase little by little more pr but not more than 50 to 100 bar187What is fuel pump lead in jerk type fuel pumpThe distance the top of plunger is above the cut off holes when that unit's piston is at tdc. By checking the fuel pump lead markings and the plungers position with respect to the markings, we can determine whether piston is at TDC. This is in addition to to its major reason, which is to check fuel timings with respect to plunger wear. .188How many wear ring and casing ring are present in a centrifugal pump.Till now whichever centrifugal pump i hv overhauled i hv found one wear ring at suction throat to prevent short ckt of suction & discharge side, n two casing rings to prevent erosion of the casing189expansion tank over flowing and bubbles coming out reasons and actions ?1..Jackey water suction pump gland leaking so pump tking suction frm tht place so these air ir coming out frm expansiin tk in bubbles form 2..Crack in liner change the liner 3.inter cooler in Mac leak if bubbles reason is, liner crack,jcw heater leaking,air compressor jacket leaking .......if ex tk overflow,1. jcw heater leaking and steam passing thruoh jacket water side2.luboil cooler leaking and oil going to ex tk,3. ex.tk filled when the engine is stopped r cold,when engine started t water pre heated and will expand ,4.filling valve left open190aft bilge well not taking suction where as forward bilge well is alright are the reasons?strainer of aft bilge well choked....or gasket of strainer broken so sucking air....hole on pipeline...Trassi191Steps for preparing M/E for departure.192how ball Bearing is fitted on shaft?trassi193types of filler gauges There are 6 types of feeler gauge available: 1. Go NoGo feeler gauge 2. Straight leaf feeler gauge 3. Tapered feeler gauge 4. Double ended gauge 5. Offset gauge 6. Feeler strip.194what are the eddy losses in centrifugal pump?pump start with outlet valve close....nw as we knw power is rate of doin wrk...in pump work is to transfer the water..as the outlet valve is close n no water transfer take place, den theoretically no power consume..bt practically as v start the pump vid outlet valve close there is still some power consumption take place, which can b seen as amperage's of motor....dis power consumption is due to circulation of water within casing...due to centrifugal force generated by pump....this is called eddy losses in centrifugal pump...195How air motor lubrication is done?by FRL unit(filter regulator lubricator) on the air line196What is moment compensator?197what is Mark no. In 6s50ME c8.2198what does C in 6s50ME C8.2 stand forRead difference b/w MC & MC-C199Hw to check garter spring properly wrkingDespande200Autoback flush filter workingDespande201Name the deck crane movements n safety of deck crane1. Hoisting: jib moving up with cargo load. 2. Slewing: crane rotating. 3. Luffing: grab moving down to release cargo load.kamath202T/C surging in A/E....what will be ur action?? 1. Check the load. 2. Check the condition of turbocharger filter, if dirty then renew. 3. Ensure no engine room door is left open(to maintain positive pressure.) 4. Ensure the blower is providing enough air and is directed towards the turbocharger. On my ship, the air ducting was divided and one of the branch led to the workshop store, the favourite spot for Gaala makers. Often the oilers use to shut the ventilation at other places to get more hawa in the store. lol..203Why do we need to pump down all the refrigerant before refilling??if we charge the refrigerant by weighing bottle, we know that certain amount has left the bottle. But we are not sure wheather the same amount has reached the system.(maybe leaks in charging connection) Secondly, if we charge the refrigerant by only seeing level in reciever, then we know certain amount has entered the reciever, but we dont know if the same or more amount has left from the bottle(due to leaks in the ref system). Hence we pump down all the refrigerent and note down the initial and final bottle weight. Now, by tallying the rise of level in reciever and ensuring that bottle weight difference is also the same, we know for sure that the right amount has been charged204Purpose of damper plates in compressor valvesThe ppurpose of damper plate is to protect the valve plate from uneven compressive force and hence to prevent undue weardown against valve plate and seat when compressor having variable speed drive,,,,,this plate may not be fitted in case of induction motor drive as a driver of compressor205How to repair damged thread of stud?with a needle file or a die nut...Mainly done using the die which matches the threading already present. Use a metal polish solution along with lube oil on the area and then use the die slowly making sure u don't damage the other threads. Ensure not to apply too much pressure..206Performance of 4s engine and what all parameters taken.Compression pr taken or not, how taken207What is written on taps and dyes, which type of thread?Tap and die have written: A. Thread per inch(pitch) B. Tap material C. Thread form symbols D. Pitch dia. Limit208Difference in gauges of refer gauge and other gauges209Is there any bellow before steam stop valve in boiler ,..???No..but ek demister jaisa hota he.. to stop water particles getting carried out...trassi210pressure relief valve on discharge side of air compr opens what will be the reason211how to do interpolation of sounding while taking bunker values given212in bdn ul get density of oil at 15* but ur taking oil at 40-50* approx so with which formula will u calculate the density at the given temp213 how will u check trueness of shaft of centrifugal pphold d shaft in lathe.. fix a dial gauge(one which has magnetic base), so that its plunger touches the shaft. set it at zero in this position. turn the shaft 1 revolution with hand slowly and check for the deflection. repeat the same procedure at different points along the length of shaft..214Alarms,trips interlocks in incineratorflame failure ,sld temp high, sld temp low,combustion chmbr temp high, flue gas temp high,draught failure, low level sld tk for incinerator, thermal failure motor overload .. all thses alarms followed by trip stop incinerator .interlock- door will not open till the CCT reaches to 170'c & flue gas will will be running continoulsy till CCT temp drop below 170'c,215Type of burner in ur IGG? Draw it.pressure jet typemishra216Auto air start valve? Wht type it was? Difference between same for B&W and sulzer?http://www.marinediesels.info/2_stroke_engine_parts/Other_info/air_start_valve.htm http://www.marinediesels.info/Basics/air_start/automatic_valve.htm mishra217All Alarms in steering Gear?mishra218Steering gear test before departure, what all test and checks u do?12 hr before departure from port 1. communication between e/r, s/g room, bridge 2. main steering 3. auxiliary steering 4. emergency steering. 5.emergency power 6. Visual inspection 7. Rudder movement from one side 35 to other side 35 within 28 sec. 8. position of rudder with respect to position indicator 9. detail diagram of steering gear to be pasted in steering gear compartmentmishra219sea water pipe flanges leaky, how to make gasket and fit gasketTake inner dia, outer dia,pcd of flange and cut the gasket220what is the difference between windlass and mooring winchA winch is a machine usually powered by a hydraulic/electric power unit that is used to handle mooring ropes which are used too moor a ship while it is in port or to a buoy as in SBM/SPM operations. A windlass is a machine hydraulically actuated(steampowered in the olden days) used for letting go/hauling up of anchor. The power rating of the prime mover of the windlass is much higher when compared to the prime mover of the mooring winches. A ship will usually have 2 windlasses(for starboard and port anchor) and 5-7 (depending on the size of the vessel )mooring winches221from wer to take bottom end bearing clearance. of. generator..?Bottom shell when piston is at bdc222purifier fuel oil temp not coming up.reasonMay be 1) Settling tank temperature too low...2) Transfer of hfo is going on to settling tank & the respective bunker tank steam is closed/blank for any purpose...3)Heater is not working properly..4) Heater steam return line valve is shut. 5:)steam trap s not working properlyShirish223.what is the Lube oil pressure in refrigeration system.kamath224whats type of condenser on your ship and how is cooling water in/out arrangement in condenser ,cooling water enters from down side or upside.kamath225Suppose we will put evaporator in room then room will cool down or not.kamath226Why there is lube oil differential pressure in compressor and which pressure it is showing.Diff press is the press diff betwn suction and l.o press in comp. sump bcz suction is connected to the compressor there is aiways press inside the comp ,if l.o is finished then comp will damage bcz press is there inside so to knw the lo is there or not there is alway a diff. Press gauge and it is normally 2.5-4 bar.kamath227testing starting air vvif u want to test starting air valve with 30bar pr trassi nu keh we will close the air to distrubutor and keep all the indicator cocks open open starting air automatic valve and check from each unit indicator cock whether air is coming or not or use soap solution is u want to check minor leakage of starting air valve alsoTrassi228Function of chlorinator chamber in sewage treatment plant. Why we are adding tablets in sewage treatment plantWe want to killl aerobic bacteria before discharging in sea bcse if u are dischrging aerobic bacteria so its consumed oxygen and its harmful to our sea life thts why we kill bacteria in chlorination chamber229Why compressor is used in vapour comp. Cycle.what is lub oil pressure in compressoraccording to 2nd law of thermodynamics ,heat can only be transferred from a source at low temperature to a sink at high temperature if work is done on the system. .now compressor is used for this as it sets the refrigerant above critical pressure so that the refrigerant is in liquid form when it enters the condensor ...................................... to compress high pressure high temp gas into liquid, and maintaining the flow of refferigerent through the ckt, lube oil press 4-6 bar maintain 2-3 bar of differential presure refferigerent press inlet 2.5-3 bar and outlet 12-15bar230Function of deaerator.Undissolved gases...including trapped air can be released to expansion tank through a point highest in line for deaeration.....mishra231Types of expansion valves. TEV, is there any by-pass line for it. How does electronic expansion valve work.mishra232What will happen to interface if smaller size gravity disc is usedkamath233Types of Air Conditioning Systems and which type on your ship.Reheat system, Double duct system, Zone control systemmishra234Butt clearance of piston rings in aux engine..how to measureTrassi235in reference to nomogram chart why do we prefer smaller diameter of gravity discs for higher specific gravity of liquid....if the specfic gravity of the bunker to be treated is high ,the oil component higher specific gravity will tend to go far away from the center of rotation ,so the interface will shift outwards and the oil will start overflowing from water outlet ..so we will use a smaller dia gravity disc to maintain the interface inwards ...............coz in the purifier in order to maintain interface the pressure on either side of interface should be same if rho increses that will be compensated by decreasing size of disk236Why lip clearance is given? Why cant we fit relief valve on boiler?how to measure lip clearanceWith the help if lip clearance we are incresing the area of a seat so more force acting on a valve so we acheive d/ 12 witg the help of lip seal and clearance we are measure frm feeler gauge.. We dont use relief v/v bcoz we want to release the excess stm press. And to attain blowdown effect which is not possible in relief v/v........... Lip clearance is not measured by filler gauge..it is measured by lead ball at least 4 in no. And tighting the bolts at required torque..then measuring the compresion by vernier caliper of micrometer..237do we have air distributors on 4 aux engines.... arent dey air motor started???.. and how to adjust compression pressure of a running engine...larger generators in yanmar are started by air start valves and air distributor ie. same as how the main engine is started .. My previous ship had air distributor .. but most of them are air motor started. compression pressure of a running generator can be increased by either removing the turbocharger felt filter ( or changing if choked ) to increase the air intake OR by throttling the air cooler cooling water so that the temp of the turbocharged air is decreased even further to increase the density and thereby increasing the air intake ...238explain how air distibutor worksthere are 3 types of air distributors ... radial , in line and rotary . the generaotors and most of the newer main engines in MAN B&W have rotary type, where two plates , one rotating with the camshaft and one stationary , have holes , and these match to send air to a particular unit .. the diagram of this type is very complex and not easy to understand...... the older ones have either in line or radial , its explaination is quite simple239what is the difference between expansion valve of a.c. and refer system?in AC AKV (Automatic) type expansion valve used...these are pulse modulated....electronically PI controlled valve. in reefer we are using the normal Superheat control thermostatic expansion valve.240What is the use of umbrella sealIt is a seal, actually like a leap seal leaded from inside by spring to prevent the mixing and thereafter contamination of cam lub oil by fuel oil.It was introduced due to failure of sealing ring at high temperature and losing its elastic sealing property..........help the lube oil contamination from fuel in the MAN engines241what are the washer springs, where used in aux engine?In rotocap..To rotate spindle242Function of hunting gear1. Hunting gear floating lever mechanism is required to bring the rudder to the ordered position. 2. Also this mechanism is required to position the rudder in its ordered position when the action of water waves or propeller force displaces the rudder from its ordered position.243What is the difference between fuel valve opening pressure and fuel injection pressure?300 liftng pr 950 injctng pr... its mre coz back pressure will also be there...244what is blow down ring in safety valve?its present in the safety valve just besides the valve seat to direct the flow of steam and prevent any unnecessary loss of steam !!245What is propeller push up??Propeller push up means push our boss frm zero point to given distance by the maker with the help of dial gauge and pilgrim nut or hydraulic jack.... or by skf system Initially while fitting propeller a marking is made,then as said by virendra wth help of hyd pump pilgrim nut 70 bar pressure is given to push the propeller..and the distance to be observd..this difernce in initial mrking and new distance is push up............. before putting hub we do reference marking and then we put 70 bar pressure on hub and try to push the hub till tht point after reaching tht point again mark 40 mm frm hub to shaft after making calculate the distance btween two points so u got ur zero points then we use makers recommendation values for accoto temp of hub and tail and pressure given by makers............ First a fall we put hub on a tail shaft with a pressure of 65 bar with pilgrim nut then maake ref mark 25 mm frm fwd end of the hub then put dial gauge on hub and then apply full oressure and finalky reach tht point and again second mark of 25 mm frm fwd end of the hub and after pushup measure distance between two reference marks noted...246if a pump is used to pump 2 cargos with different SG and pump trips wen pumping the higher SG one... wat 2 do.. other than heating or cooling of cargo.by decreasing the speed of pp247how will u assemble overhauled fuel pump? How the barrel is fitted? How it is ensures that rack is fitted properly? What is the speciality of delivery valve?the delivery valve is a non return type there is a collar below the smal valve disc which wil release the presure of the delivery line before closing the valve..bt that delvry line wil remain primed without of pressure..kamath248How do you perform Cyl Head pressure test (Aux Engine)?First a fall take ouut cylinder head and remove all valves frm the head and then clean ur head with emry paper and after cleaning we will put wooden plug or teflon plug in water inlet side and then cover water outlet side with flanges and connect pressure gauge and water prividing plug in one flange for testing then apoly 1.5 times pressure of a working pressure then u chck any leakages so u will easily one main precaution u will tke before leak use alwayss tested chain block and put cylinder head akways on wood for avoiding surface wear down ....249Refrigeration charging @ high pressure side .why?Bcse bro when u charge a liquid so we will charge frm high pressure side and if gas will go in tht line so no prb but if u are charging gas frm low pressure side and at a time of charging if liquid go on low pressure side so chances of compressor damage thts why we always charge at high pressure side250action if oil comes in evaporatorU can bring lp setting to below atm pr so that oil gets sucked by compr. Clean the oil separator Hot gassing by increasing ref temp by throttling condr sw Nitrogen purging of full coil251shipside valve is leaking in engine room, what actions to be taken??inform company,keep energency bilge suction stand by... manage wit out pumping out for the maximum time... if not under control wit informing administration approvel we can pump out.. if leak is small and manageable wait for company to arrrange drdock.. and get repaired...(not to open sipside valves at sea or port * unsafe practice)252In parallel operation 1 gen taking more load than other....reason??1.governor wrong setting, or malfunction (less rpm)2.avr problem, less exitation voltage , diodes damaged 3.loose connection in gen terminal box or in bus bar connection 4.less insulation in windings 5.walt metter showing wrong reading ...253what all checks to be done before fitting new stud..??Check the thread.pitch of the thread..size and length of the stud should be same. Before fitting clear inside with WD 40 or with any rest remover,or clear the thread with proper size of Tap...using check nut fit the stud.254Why we blow through engineThis water in incompressible..and can cause a severe damage to liner ..to remove ths we blow through and observe the content coming out255what is steering system safety?SWITCH LEVEL 1:The steering system has two lube oil tank system with 2 rams functioning on each system. Thelevel switch 1gives an initial alarm following a loss of oil from either system. In normal operation one power unit provides hydraulic power to all four rams.The causes for the loss of oil is mainly due to broken hydraulic pipes and damage in the ram, thus the leakage oil drains to the bilge well.SWITCH LEVEL 2:When no action is taken immediately upon the previous alarm, the loss of oil continuesand over a period of time this loss of oil intiates one or both of the level switches 2. This leads to the energization of a solenoid operated servo valve causing a combined isolating valve and bypass valve to operate. Thus splitting the system such thateach power unit supplies power to 2 rams only .At the same time this switch automatically starts the other standby helesaw pump to assist the turning and building up the pressure in the rams.SWITCH LEVEL 3:This switch will get activated when there is still no further improvement in the loss of oil on the faulty side. In such a situation thesteering continues un-interupted if one unitis stopped and thus the rudder is turned with the help of the other unit system of 2 rams only, isolating the faulty one, and this is called as emergency steering.Thus the steering system is designed to work at half of the maximum torque on thesteering system.The defective system is put out of action and isolated.RELIEF VALVE:A relief valve is fitted in the system to prevent over pressure in the hydraulic system due to shock loading of rudder. Shock loading of the rudder could occur in a variety of cases such as bad weather.MANUAL BY PASS VALVE:This valve is only operated when there is a failure of the one of the systems and the rudder stock has to be turned mechanically, so that the ideal fluid can flow from the high pressure side to low pressure side.LOW PRESSURE VALVE :Low pressure valve is a NON RETURN VALVE fitted in the main hydraulic pressureline, which opens for oil filling from a header tank if a low pressure situation occurs in the system .ELECTRICAL STOPPER:It stops the hydraulic pump when the position of the rudder turning is at an angleof 36o. It automatically cuts of the supply because it is the maximum turning angle ofrudder. (It normally operates at 35oangle).MECHANICAL STOPPER:In case of electrical stopper fails, the mechanical stopper is provided so that it stops the tiller arm after 36oangle of rudderElectrical motor overload alarmWhen ever hydraulic motor or helesaw pump motor draws excessive current during bad weather, the steering should not fail. Instead it gives an alarm about excessive current being drawn by the motor. Continued recurrence of this alarm could mean that the electrical motor might burn up.POWER FAILURE ALARM:The full power failure alarm will be raised if the power fails in black out condition. Emergency power should be arranged with in 45 seconds and the emergency generator must be capable to give power for at least 30 minutes for a big ship and 10min in case of small ships (ships