MEOclassIIexamnotes

1) Cast iron is that the metal is filled with impurities. When you melt the metal the embedded dirt and sand contaminated the weld and tend to not mix well with the cast iron filler rod.What you end up with is not a fused intermixed metal bead but a porosity filled weld that can be easy to chip away with a chisel because it has not bonded to the base metal.  2) Pre heat & Post Heat required.And different as per its composition.Pre heat to stress relieve & post heat to control rate of cooling.  3) The large amount of carbon in the base metal tends to segregate itself along grain boundaries as the weld puddle solidifies and cools. What this does is lower the tensile strength even lower so that in the weld fusion boundary the shrinkage force pulls the metal apart as it cools, ie it tends to crack along the weld when cools.  4) Cracking. If it cools down too quickly you will get cracks along the weld.  5) Proper selection of filler rod & flux required as per the grade and compo

1) Cast iron is that the metal is filled with impurities. When you melt the metal the embedded dirt and sand contaminated the weld and tend to not mix well with the cast iron filler rod.What you end up with is not a fused intermixed metal bead but a porosity filled weld that can be easy to chip away with a chisel because it has not bonded to the base metal.  2) Pre heat & Post Heat required.And different as per its composition.Pre heat to stress relieve & post heat to control rate of cooling.  3) The large amount of carbon in the base metal tends to segregate itself along grain boundaries as the weld puddle solidifies and cools. What this does is lower the tensile strength even lower so that in the weld fusion boundary the shrinkage force pulls the metal apart as it cools, ie it tends to crack along the weld when cools.  4) Cracking. If it cools down too quickly you will get cracks along the weld.  5) Proper selection of filler rod & flux required as per the grade and compo

The cam for the air distributer serves its purpose only while starting the engine . Actually if you see there is no other requirement of this particular cam while the engine is continue in operation.  Therefore if a cam ( normal possitive ) is used then wear of this particular cam will be abviated and will be expensive to repair / replace this cam. So when the engine has started and the vessel is enroute a voyage , then this particular cam turns without any running gear touching it. It comes into play only starting

Boiler Turndown Boiler turndown is the ratio between a boiler’s maximum and minimum output. Depending on the burner’s design, it may have a turndown ratio between 4:1 and 10:1 or even higher.  A 4:1 turndown means the boiler’s minimum operating load is 25% of the boiler’s full capacity (100% capacity divided by 4).  A 10:1 turndown means the minimum operating load is 10% of the full load capacity (100% capacity divided by 10). Why is Boiler Turndown Ratio Important? Turndown ratio is important for boilers that are required to operate at a wide variation of capacities. A boiler with a higher turndown ratio will usually handle fluctuating loads more efficiently than one with a low turndown. A boiler’s burner will modulate or “turn down” as the demand for hot water or steam decreases, in an attempt to meet only the required load. The turndown ratio tells you the minimum output the boiler can handle before turning off and then cycling on and off frequently. If the demand goes below the bur

Hopper tanks are classified into bottom hoppers and top heavy wing tanks. For bottom hoppers, the main purpose is to take ballast, so as to rapidly increase the vessel immersion, simultaneous reduction in metacentric height, and a change in Centre of gravity. For top heavy wing tanks, the idea is to rapidly correct list of the vessel and act as active ballast tanks, for vessels such as Lakers where passages are narrow and cargo loading is often scattered. Except for this, they contribute in cargo loading also because the side slopes allow the cargo to slide off and collect at the centre, thereby making the cargo collection easier at the end Also, the hoppers are strengthened by additional transverse and longitudinal members, thereby supporting the port and starboard fuel tanks, and also distributing the cargo loading in a dynamic way to make sure the load is not concentrated at one point for higher loading speeds

 200 % load carrying capacity Phase failure alarm Short circuit trip Overload alarm ( no trip ) One motor connected to ESB Zero time delay after power recovery with auto start. Power failure alarm

  W - Manufacturer stamp/symbole + - fill 10% excess on psi ✬ - 10 years testing, if no ✬ then every 5years hydrostatic test. 2005/03 - year/month of manufacture 6831611 - serial number pw200 - cylinder pressure 5L- cylinder capacity Stamp for testing lab 

Reopening of the fuel valve after the main injection id terminated is secondary injection . The sudden closing of the injector needle cause a pressure wave to be setup which reflects from the delivery valve back to the injector needle . If the residual pressure and reflected pressure together exceeds the injector lifting pressure , secondary injection takes place.

Con rods during operation are subjected to buckling loads Buckling strength is directly proportional to moment of inertia. So , I section is having maximum area moment and least weight. Hence introduce the vibration of conrod and also reduce side thrust acting on the cylinder. I section can be easily manufactured

Shroud ring is a component in turbocharger which forms a part of the inner exhaust gas casing adjacent to the turbine The area around the turbine is always in contact with highly corrosive exhaust gas. If no shroud ring is fitted , the turbine inner casing will be slowly wasted and complete housing to be renewed for repair . Otherwise only shroud ring can be replaced with new one

Manufactured using Pot casting method , producing a short cylinder of oval cross- section from which the rings are machined in a cam turning lathe. This produces a balanced and homogenous casting around the entire circumference of the ring. The lathe is equipped with an interchangeable copying cam , which controls the cutting tool By changing the shape or ovality of the cam , the circumferential pressure distribution at the ring can be altered

Ability of the bearing material to accommodate geometry misalignments of the bearing , its housing or journal

Effective stroke  It is the travel of plunger in mm from beginning of injection to termination of injection Idle stroke It is upward travel of plunger during which fuel is pressurized but not injected

They have a low inertia of moving parts and good flow characteristics. It is highly efficient at higher rotational speed. Concentric valve is compact and a combination of suction and discharge valve , which make it compact and space saving with the lowest possible clearance volume. Plate type suction and discharge valve , whose larger diameter and small lift after the least resistance to the flow of gases

The FIVA valve feedback signal is not valid . ie outside 4 -20 mA FIVA valve feedback signal indicates a too high speed Indicates a position not allowed outside a window around TDC The fuel booster position feedback signal indicates that the fuel booster is moving during the compression stroke 

 Incase if there is any fault of signal received from CCU or signal range is outside 4 -20 mA then FIVA will automatically open the exhaust valve as per fail safe mechanism and will raise an alarm

The possibility of fire aboard the ship or elsewhere within the dockyard complex is always unwelcome, but the fact remains it is a possibility at virtually any time of day or night. In the event that the possibility becomes reality, common sense and past training should automatically come into the equation.  As with any other fire incident the alarm should be raised as soon as possible after the discovery of the fire and the following procedure is suggested. Assuming that the crew have remained on board and the fire is on board the vessel, after the alarm has been raised:  Muster an emergency fire party and attempt to contain and extinguish the fire immediately following its discovery. Non-essential personnel should be evacuated to the shore and the fire brigade should be contacted. A gangway watch should be set to ensure that the access to the vessel is not blocked which as such would deny accessibility to fire fighters. The minimum water volume should be used when tackling fires in d

  VEC (Variable Exhaust - valve Closing ): Adopting compression pressure to keep the firing ration (Pmax / Pcomp) within permitted range during injection. VEO ( Variable Exhaust - valve Opening ): Keeps the exhaust gas pressure blowback constant by earlier valve opening at higher speed for fuel economy and less deposit at piston underside

 

It involves matching of reciprocating engine to rotary compressor and turbine of Turbocharger. Impellor of compressor is chosen to provide desired airflow at engine power 80 - 90% MCR , thus taking into account.ie ( a ) Operating temperature and Engine room pressure ( b ) Pressure drop across air cooler. Once impellor output is fixed , diffuser is chosen which will provide compressor efficiency high , but ample surge margin. When compressor side design is final , turbine power requirements are known. The main variable on the  turbine side is nozzle size and this is matched to provide required compressor work and minimum restriction to exhaust gas flow. Smaller nozzle area: ( a )Work output increase   ( b ) T\C speed increase ( c ) Air delivery pressure increase

 In air compressors requirement is to discharge the maximum amount of compressed volume of air out of 1st stage cylinder so that maximum cool fresh air should come in. If the bumping clearance is more then air left inside stage will be more and at higher temperature after discharge so less mass of air will get inside in the suction stroke now due to this there will be increased suction temperature of air and consequently less work done and reduced efficiency of air compressor. Where as in Aux Engine we need maximum air to remain in cylinder head at TDC for better and efficient combustion of the fuel . Thats why enough clearance is provided between piston top and underneath of cylinder head . No danger of contacting or banging of piston to cylinderhead.

A wind vane is an instrument that measures wind direction while anemometer measures wind speed.   PRINCIPLES OF WIND VANE AND ANEMOMETER The measuring principle of anemometer is simple: the stronger the wind blows, the faster the half-open plastic cups turn. The speed of the cross rotation determines the wind speed. The cup anemometer records the number of rotations per minute and thus the wind speed very accurately. Information obtain by wind vane and anemometer are converted and can be read directly form ship’s bridge.   HOW THE DATA IS CONVERTED                                                     Information generated by wind vane and anemometer are converted and can be read directly form ship’s bridge. Through advance technology, wind speed and direction can be seen directly through a display unit in the ship’s bridge and no need for manual calculation.

 

 

Power supply : The electrical supply to the pump room must be protected by over-current devices, and the wiring must be properly installed and maintained. Lighting : Adequate lighting must be provided in the pump room, with emergency lighting available in the event of power failure. Equipment : Electrical equipment in the pump room must be approved by a recognized testing organization and properly maintained. Earthing and bonding : The pump room must have a proper earthing and bonding system to prevent electrical hazards. Fire protection : Fire protection measures must be in place, including automatic fire detection and fire suppression systems. Ventilation : Adequate ventilation must be provided in the pump room to ensure proper functioning of electrical equipment and prevent hazardous buildup of gases. Accessibility : The electrical equipment and wiring must be easily accessible for maintenance and inspection. Testing : The electrical equipment in the pump room must be regularly test