tag:blogger.com,1999:blog-3569829691409436882024-03-15T18:09:01.467-07:00MEOclassIIexamnotesMarine Engineering exam notes for SeafarersmeoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.comBlogger613125tag:blogger.com,1999:blog-356982969140943688.post-53390230468596606902024-02-02T19:29:00.000-08:002024-02-02T19:29:55.244-08:00Insert plate in welding<p></p><ul style="text-align: left;"><li><span style="font-family: arial; font-size: medium;">An insert plate is used to replace any damaged steel plate of ship's hull. The insert plate must have identical characteristics with the original steel plate ( type /grade/thickness etc). The damaged part of the steel plate has to be cropped-out and renewed by welding using the same welding consumables. The minimum consumable grades. All ship's Class Societies consider the above mentioned requirements as permanent repairs for maintaining the ship’s Classification Certificates fully valid.</span></li></ul><p></p><ul><li></li><li><span style="font-family: arial; font-size: medium;">On the contrary, doubler steel plates which are welded on top of a damaged structure plate is considered as temporary repaired with a short limit date until the full permanent repairs are dealt with</span></li></ul>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-59898437999614065922024-01-01T18:51:00.000-08:002024-01-01T18:51:56.753-08:00How is engine frame attached to the ships shell plate<p></p><ul style="text-align: left;"><li><span style="font-family: arial;">For engine seating a plate floor is required every frame </span></li><li><span style="font-family: arial;">Main engine seatings are in general integral with this double bottom structure. </span></li><li><span style="font-family: arial;">Inner bottom in way of the engine foundation has a substantially increased thickness. </span></li><li><span style="font-family: arial;">Often the machinery is built up on seatings forming longitudinal bearers which are supported transversely by tripping brackets in line
with the double bottom floors, the longitudinal bearers being in line with the double bottom side girders. </span></li><li><span style="font-family: arial;">There are transverse plate floors at each frame. The thickness of the engine seating is governed by the power, weight, and length of
the unit
</span></li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-60242263719590661482024-01-01T18:45:00.000-08:002024-01-01T18:45:08.066-08:00What is dual class ? Why <div style="text-align: left;"><span style="font-family: arial;">A dual class vessel is one which is classed by two Societies between which there is a written agreement regarding sharing of work,
reciprocal recognition of surveys carried out by each of the Societies on behalf of the other Society and full exchange of information
on the class status and survey reports. <br /></span><ul style="text-align: left;"><li><span style="font-family: arial;">All the ships of "The shipping corportation of India" used to have dual class. </span></li><li><span style="font-family: arial;">Out of two, one classfication society was "Indian Registrar of shipping". </span></li><li><span style="font-family: arial;">Indian ships were required to have IRS as its classification society but as IRS was then not a member of IACS, ships were
forced to have a second classification society which was member of IACS. </span></li><li><span style="font-family: arial;">So in this case, these ships would have certificate of class from each classification society. </span></li><li><span style="font-family: arial;">In 2010 when IRS became the member of IACS, Indian ships were no more required to have Dual class. </span></li><li><span style="font-family: arial;">More than 50 classification societies. But only 12 are IACS members </span></li></ul><span style="font-family: arial;">A double classed vessel is one which is classed by two Societies and where each Society works as if it is the only Society classing the
ship, and does all surveys in accordance with its own requirements and schedule.
</span></div>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-63407798193452979062024-01-01T18:39:00.000-08:002024-01-01T18:48:25.082-08:00Pressure testing of DB tank<h3 style="text-align: left;"><span style="font-family: arial;">Both Leak & Structural test </span></h3><h4 style="text-align: left;"><span style="font-family: arial;"><b>Test head</b>: </span></h4><p><span style="font-family: arial;">The greater of – </span></p><p></p><ul style="text-align: left;"><li><span style="font-family: arial;">Top of the overflow</span></li><li><span style="font-family: arial;">To 2.4m above top of tank </span></li><li><span style="font-family: arial;"> To bulkhead deck </span></li></ul><p></p><h4 style="text-align: left;"><span style="font-family: arial;"> <b>Procedure:</b></span></h4><p style="text-align: justify;"></p><ul><li><span style="font-family: arial;">Fill tanks by gravity to sea level.</span></li><li><span style="font-family: arial;">A ballast pump can be used if the vessel wishes, but is not recommended.</span></li><li><span style="font-family: arial;">If there are scuppers, then block scuppers as would be required for bunkering operations. </span></li><li><span style="font-family: arial;">Close sounding pipes tightly if these are at deck level. </span></li><li><span style="font-family: arial;">Open, or take off, air vent tops. </span></li><li><span style="font-family: arial;">Top up tank through air vents by fire hose until (assuming stern trim) water level is close to top of aft air vents. </span></li><li><span style="font-family: arial;">Ensure that fire hose can be stopped quickly as water level nears top of air vent. </span></li><li><span style="font-family: arial;">Check by sounding or ullage through the air vent, that water level in forward air vents has also risen towards top of air
vents.</span></li><li><span style="font-family: arial;">Hold level for 30 minutes minimum and check if level in vent is falling or steady. </span></li><li><span style="font-family: arial;">Look for leaks. </span></li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-74326205410105423762024-01-01T18:32:00.000-08:002024-01-01T18:49:32.758-08:00Why Gross Tonnage should be measured <p><span style="font-family: arial;"> Used to determine things such as </span></p><p></p><ul style="text-align: left;"><li><span style="font-family: arial;">Ship's manning regulations </span></li><li><span style="font-family: arial;">Safety rules,
o registration fees</span></li><li><span style="font-family: arial;">Insurance premium
.</span></li><li><span style="font-family: arial;">Port dues</span></li><li><span style="font-family: arial;">Canal- and pilotage charges </span></li><li><span style="font-family: arial;">Fleet- and traffic statistics </span></li><li><span style="font-family: arial;">Technical equipment</span></li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-79743412764497997172024-01-01T18:27:00.000-08:002024-01-01T18:27:32.956-08:00Rudder clearances<p><b> Pintle </b></p><p></p><ul style="text-align: left;"><li>For a ship in service, Maximum allowable clearances between Pintle and bush is 6 mm. </li><li>IF the actual clearance exceeds 6mm, the bush should be renewed. </li><li>Measured using the thickness gauge. The clearance is taken in four sides: forward, aft, port, and starboard. </li><li>The measurements are taken through the inspection cover, usually on the port side. </li><li>The normal clearance is about 1 to 2 mm. </li></ul><p></p><p><b>Neck bush clearance</b></p><p></p><ul style="text-align: left;"><li>Between the rudder stock and the neck bush (rudder stock upper side) is measured using the thickness gauge. </li><li>The clearance is taken in four sides: forward, aft, port, and starboard. </li><li>The measurements are taken from top of the rudder. </li><li>The normal clearance is about 1 to 2 mm. </li></ul>
<p></p><p><b>Jumping Clearance:</b></p><p></p><ul style="text-align: left;"><li>The designed clearance is 2.0 mm maximum. </li><li>If the clearance measured is found to be large, it can be concluded that the rudder has moved down.</li><li>The clearances can be taken from rudder trunk – between the stopper and carrier bearing</li></ul>
<p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-72871078782737341522024-01-01T18:23:00.000-08:002024-01-01T18:23:20.710-08:00Drydock 50 hz supply, ship 60 hz .What should be done<p></p><ul style="text-align: left;"><li> 50 Hz will make motors run slower. 50/60=83% that will have the effect on the efficiency and the connected load . </li><li>If we supply a reduced frequency then we also need to reduce the voltage accordingly to prevent the motor to draw more current. </li><li>Voltage/frequency of ship equals to Voltage/frequency shore. That’s gives us a calculated voltage of 366 volts, which closer to the standard 380 volts 50 Hz,
that can be accepted. </li><li>By doing so the through put of the pumps will be reduced, and we definitely have to keep an eye on the temperatures of the motor
windings.</li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-35258334895230196952024-01-01T18:17:00.000-08:002024-01-01T18:17:23.031-08:00Hull roughness measurement<p></p><ul style="text-align: left;"><li><span style="font-family: arial;">Hull Roughness Analyser </span></li><li><span style="font-family: arial;">Computer is connected to the hand held carriage having a stylus measuring head. </span></li><li><span style="font-family: arial;">Stylus head is moved around the hull surface to measure and record the hull roughness profile. </span></li><li><span style="font-family: arial;">One traverse of the head at any point on the hull will collect information from 10 samples having length of 50 mm. </span></li><li><span style="font-family: arial;">For each 50 mm sample, the micro processor will assess the mean gradient through the peaks and valleys to give highest peak to
lowest valley measurement for that sample. </span></li><li><span style="font-family: arial;">This measurement is known as Rt (50). </span></li><li><span style="font-family: arial;">Approx. 100 selected locations which must include bow, stern, mid ship, and boot topping area (area between load line and ballast
water line). </span></li><li><span style="font-family: arial;">A number of traverses for stylus will give ‘n’ readings, hence the Mean Hull Roughness (M.H.R) at that station is average of Rt (50) </span></li><li><span style="font-family: arial;">There will be ‘m’ stations around the hull of the ship. Hence Average Hull Roughness (AHR) will be average of Mean Hull Roughnes</span></li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-3536707558814893682023-12-31T07:39:00.000-08:002023-12-31T07:39:38.525-08:00Mooring winch Brake holding capacity<p></p><ul style="text-align: left;"><li> Determined at the design stage based on vessel size, number of mooring lines , wind area and tidal conditions and the mean braking load of mooring lines.</li><li>After selection of the MBL of the mooring line, the winch heaving load will be set to a lower value than MBL to prevent the winch motor from applying excessive loads</li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-58086833545037577832023-12-31T07:31:00.000-08:002023-12-31T07:34:02.135-08:00Working of a Chain Block<p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgmLO6MkgO8Kkyqi_o7d4SEt0JnaswaHktemTfD3tck-4fZv0xWEzvIFYqU-1KbazBF2IQxUqUzdGIrf9wh-qFJlU79gpg1hSpTKtSQqjTieS2kyl3cTZX8EUh0gila7DC1ARCk-7Tg85_bRvjpns0TADRJEzmBdXEQaRFJjm0J4ThpiJdyRvSUxYQW0AY/s503/image_2023-12-31_210024850.png" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="317" data-original-width="503" height="202" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgmLO6MkgO8Kkyqi_o7d4SEt0JnaswaHktemTfD3tck-4fZv0xWEzvIFYqU-1KbazBF2IQxUqUzdGIrf9wh-qFJlU79gpg1hSpTKtSQqjTieS2kyl3cTZX8EUh0gila7DC1ARCk-7Tg85_bRvjpns0TADRJEzmBdXEQaRFJjm0J4ThpiJdyRvSUxYQW0AY/s320/image_2023-12-31_210024850.png" width="320" /></a></div><br /><div><br /></div><ul style="text-align: left;"><li><span style="font-family: arial; white-space-collapse: preserve;">The chain block contains two cogs or gears in which the chain is wrapped around. </span></li><li><span style="font-family: arial; white-space-collapse: preserve;">Both electric chain blocks and manual chain blocks have the same fundamental functions - when the chain is pulled, it wraps around the wheels which adds torque to the lifting mechanism, pulling the item that is on the other end of the chain (usually with a strong hook) and lifting it off the ground - the wheels inside the block are how they are able to lift heavy loads - even when operated manually. when the chain is release a braking mechanism kicks in and holds the load where it is until the chain is pulled again.</span></li><li><span style="font-family: arial;">A chain block has a strong chain for lifting objects and attaching hooks to, manual lifting blocks have a hand chain which can be used for pulling by hand to bring the load up (these are powered by motors in electric chain blocks), they also have a grabbing load hook for attaching the load</span>. </li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-59834776172116717062023-12-31T07:25:00.000-08:002023-12-31T07:25:48.469-08:00Aspect ratio of Rudder<p></p><ul style="text-align: left;"><li>Dept of rudder / width of the rudder.</li><li>High aspect ratio is used in large vessels where depth is not a constraint. </li><li>Higher aspect ration reduces the astern torque considerably</li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-78268078830743925312023-12-31T07:23:00.000-08:002023-12-31T07:23:13.014-08:00Rudder Trunk<p></p><ul style="text-align: left;"><li>Rudder stock is carried in the rudder trunk which as a rule is not made water tight at lower end , but water tight gland at top of the trunk ;ie, where the stock enters the intact hull.</li><li>Trunk kept short so that the stock has minimum unsupported length. </li><li>Watertight opening for inspection</li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-33711951080045306202023-12-31T07:19:00.000-08:002023-12-31T07:19:24.873-08:00Bedplate alignment - Piano wire method<p></p><ul style="text-align: left;"><li> A 0.5 mm diameter piano wire is stretched along each side of the bedplate.</li><li>The wire is loaded with 40 KPa horizontal force.</li><li>At the centre line of each cross girder , the distance is measured between the wire and the machined faces of the bedplate top outside oil grooves</li><li>It will thus be revealed whether the later has changed compared with values during engine installation.</li><li>The measurement are taken by micrometer with laser light when touches wire.</li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-24270270760851253162023-12-28T18:19:00.000-08:002023-12-28T18:19:39.855-08:00Sewage checks by PSC inspector<p></p><ul style="text-align: left;"><li>Chlorine content on effluent</li><li>STP is operational or not</li><li>Corrosion or hole on the tank holding to tank</li><li>Aeration blower working and checking the pressure</li><li>Overboard valve locked and sealed. Seal number recorded on logbook</li><li>Validity of international sewage pollution prevention certificate</li><li>Proper air lift from settling tank to aeration chambers</li><li>Working of high level alarms and auto cut off</li><li>Presence of Chlorine tablets or UV lamp </li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-74639969031224874452023-12-27T05:50:00.000-08:002023-12-27T05:50:51.646-08:00Why Full Astern Power is usually less than Full Ahead Power <p></p><ul style="text-align: left;"><li>Propeller blade system is designed for maximum efficiency in ahead direction</li><li>In astern direction angle of attack is high on the back of the blade.</li><li>Propeller will absorb very little available power. Severe eddying occurs on face(efficiency is low)</li><li>Hence if 80% of Full ahead power is available for astern then boosting it to 100% will have minimal return in thrust</li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-2938337280511424822023-12-17T23:32:00.000-08:002023-12-17T23:32:55.164-08:00Difference between air coolers for shipboard reciprocating main air compressor and Large slow speed two stroke Marine diesel propulsion engines <p><br /></p><p></p><ul style="text-align: left;"><li>In both cases the air coolers are for increasing the efficiency of the compressors by inter cooling. </li><li>Both T/C and Reciprocating compressors are meant to increase pressure , however to a different degree ( T/C : 4 for single stage , and 10 bar for 2stage turbo chargers) </li><li>During the compression the air temp raises when the pressure is increased, and need to be cooled. </li><li>Cooling is by fresh water / sea water / air in the Main Air Compressors and Either Sea water or Fresh Water(LT)</li><li>Cooling is controlled in Engine Coolers to maintain the Air Temperature to the required value, to reduce water impingement on to the liners. Cooling is not controlled in air coolers of Main Air Compressors ( the lower the temp is better for the efficiency), hence there will be control valves for Engine Air Coolers and no control valves for Air Compressor coolers.</li><li>Engine Coolers are very large in comparison to Main Air Compressors as the air flow is very large ( depend on the Engine power rating)</li><li>Engine coolers are difficult to remove and maintain and hence there will be a system installed to clean the coolers by using the chemical, where as air compressor coolers are not fitted with cleaning arrangement.</li><li>Engine Coolers are not required to be fitted with any pressure safety devices, as the pressure is lesser and safety can be achieved by the construction itself. However for Main Air Compressor coolers each and every cooler must be fitted with safety valve to relieve excessive pressure which can be due to leakage of interstage valves.</li><li>Both Engine Coolers and Main Air Coolers are fitted with water ( condensate from air ) separators.</li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-82665175373258153402023-12-17T23:17:00.000-08:002023-12-17T23:18:22.036-08:00Types of keys used in keyed propellers<p><br /></p><p><b>Parallel Keys</b>: These keys have a rectangular cross-section and are used in straight keyways. They provide a simple and effective means of transferring torque between the shaft and the hub.</p><p><b>Sunk Keys</b>: Also known as rectangular keys, these keys fit into keyways that are cut into both the shaft and the hub. They have tapered sides that fit tightly into the keyway, preventing movement.</p><p><b>Woodruff Keys</b>:These keys have a semi-circular shape and are often used in applications where axial movement of the propeller on the shaft needs to be prevented. They fit into a curved keyway on the shaft and a corresponding slot on the hub.</p><p><b>Tapered Keys</b>:Tapered keys are used in tapered keyways, providing a wedging action that helps secure the propeller onto the shaft tightly.</p><p><b>Gib Head Keys</b>:Also known as feather keys, these keys have a projection, or gib head, that fits into a slot in the hub, preventing axial movement.</p><p><i>The type of key used depends on factors such as the design of the propeller hub and shaft, the torque requirements, the axial movement tolerance, and other specific requirements of the application. Proper installation of the key is essential to ensure the propeller remains securely attached to the shaft during operation. Additionally, routine inspections and maintenance are important to check for any signs of wear or loosening of the ke</i>y.</p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-53973717631998827812023-12-17T23:12:00.000-08:002023-12-17T23:12:24.046-08:00Safety features and considerations for windlass operations in hydraulic systems<p><b>Emergency Stop Button</b>: Install an easily accessible emergency stop button that immediately halts all windlass operations when pressed. This allows operators to quickly stop the system in case of emergencies or unexpected situations.</p><p><b>Pressure Relief Valves</b>:Hydraulic systems should be equipped with pressure relief valves that prevent the hydraulic pressure from exceeding safe limits. If the pressure reaches a dangerous level, the valve will open to release excess pressure and protect the system from overloading.</p><p><b>Pressure Gauges</b>: Install pressure gauges at appropriate points in the hydraulic system to allow operators to monitor hydraulic pressure. This helps ensure that the system operates within safe pressure ranges.</p><p><b>Limit Switches</b>:Use limit switches to automatically stop the windlass when the anchor chain reaches its upper or lower limit. This prevents overextension of the chain or damage to the equipment.</p><p><b>Flow Control Valves</b>:Flow control valves regulate the flow rate of hydraulic fluid, ensuring smooth and controlled movement of the windlass components. Proper flow control prevents sudden movements that could pose safety risks.</p><p><b>Check Valves</b>: Check valves allow fluid flow in one direction while preventing backflow. They ensure that the hydraulic system maintains pressure and prevents unexpected movement due to backflow.</p><p><b>Manual Override</b>: Provide a manual override option that allows operators to control the windlass manually in case of hydraulic system failure or emergencies.</p><p><b>Hydraulic Fluid Safety</b>: Use appropriate hydraulic fluid that meets the manufacturer's specifications and safety standards. Regularly check fluid levels and ensure proper maintenance of the hydraulic fluid to prevent leaks and contamination.</p><p><br /></p><p><br /></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-70477149389678515312023-12-17T23:04:00.000-08:002023-12-17T23:04:39.297-08:00 Why stainless steel not used for cylinder liners<p></p><ul style="text-align: left;"><li>SS is Difficult to machine for high finish</li><li>Galling or friction welding when moving up and down(like piston & cylinder; valve stem & gland etc)</li><li> Most of the engines work in the range 400 to 900°C and it is called Sensitization zone and SS will lose Chromium and SS becomes steel and start rusting and cracking.</li><li>Stainless steel has high thermal expansion(1.6times steel/CI) and low thermal conductivity(SS has low thermal conductivity , 25% of CS. The bore area will have high temperatures and high thermal expansion and distortion and mis-alignment of cylinder piston and engine bore are expected.</li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-75664843694861032023-12-17T23:01:00.000-08:002023-12-17T23:01:37.576-08:00Power to weight ratio. Explain<p></p><ul style="text-align: left;"><li>The power-to-weight ratio represents the ratio between a vehicle's power and its total weight. </li><li>The higher the PWR, the faster the vehicle will accelerate. It is for this reason that motorbikes accelerate quicker than most cars. </li><li>PWR calculations are commonly used to predict vehicle speed. </li><li>It's very easy to calculate a power-to-weight ratio. Simply divide the power output of a vehicle by its weight. </li><li>If you have a car that weighs 2000 pounds and has 250 hp, the PWR will be as follows: 250 / 2000 = 0.125 hp for every pound of car.</li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-67904444459277174572023-10-19T08:15:00.003-07:002023-10-19T08:15:45.761-07:00 Sulzer fuel pump timing adjustment<p></p><ul style="text-align: left;"><li>Engine should have run 30 mins of diesel oil before stoppage</li><li>Open the indicator cocks, shut the main air starting valve and engage the turning gear</li><li>close the fuel supply and ruturn valve on the fuel pump</li><li>Drain the remaining fuel from the fuel pump</li><li>Inspect the cams and rollers</li><li>The stagnation pressure control valve has to be dismantled</li><li>Note the valve desiganation S-suction , D- delivery and U- for spill valve</li><li>Remove the valve cover and the springs</li><li>Pressure bushes are released using special wrench</li><li>The vavles are removed using a withdrawal device</li><li>Examine valve seats and contact surfaces. Defective should be reconditioned or replaced</li><li>The valve contact surface in fuel pump block should be in good condition.Damaged surfaces must be reconditioned</li><li>After cleaning the fuel pump block throughly the suction and spill valves are cleaned in diesel oils and fitted back respectively without their springs</li><li>The pressure bushes are tightened to 300Nm</li><li>The dial gauges should be inspected before mounting it to their holes</li><li>Start the oil pump for bearings and crossheads and adjust pressure to normal operation </li><li>set reversing lever on emergency control stant to ahead</li><li>The fuel lever is removed from remote position and engaged to position " 8 "</li><li>The shutdown servo motor is set to its working position</li><li>The piston of the shutdown servomotor is locked in position by means of spacing tube and tensioning bolts</li><li>The control air shut off valves are closed and then system is vented</li><li>The fuel quality setting lever is to Zero . Note its position befor mixing</li><li>Replace the VIT cam with a circular running in disc</li><li>Set the fuel lever on the emergency control stand. So that the pointer on adjusting scale is on 8. Specified on the accepatance record</li><li>Make sure the VIT indicator is at 0(zero) and the roller is in contact with the circular disc and no spaces are there to reduce the fuel delivery</li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-86750741007339702682023-10-19T04:51:00.010-07:002023-10-19T04:51:50.480-07:00 Shaft earthing device<p></p><ul style="text-align: left;"><li>A turning propeller is electrically insulated from the hull by lubricating oil film in bearings</li><li>Electrical potential is generated between the shaft and the hull </li><li>As a result the cathodic protection of the ship will not protect the propeller</li><li>Electrical potential can cause currents in the bearigngs resulting in pitting of the bearing surfaces</li><li>Problems can be avoide if the shaft is earthed with a propeller shaft slip ring</li><li>This shaft earthing assembly comprises a pair of high silver content\graphite compound brushes mounted in a balanced brush holder, running on a copper slip ring with solid silver track</li></ul><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-11232456352511533922023-10-19T04:50:00.001-07:002023-10-19T04:50:38.574-07:006 stages of SCR<p></p><ol style="text-align: left;"><li>Standby</li><li>Heating </li><li>Reactor ready</li><li>Dosing enabling</li><li>Dosing (SCR active)</li><li>Flushing</li></ol><p></p>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-34288319624698567312023-10-19T04:48:00.001-07:002023-10-19T04:48:19.514-07:00Overboard valve regulation<p style="text-align: left;"></p><ol style="text-align: left;"><li>Should not be of cast iron</li><li>Must be Class approved</li><li>Fitted at easily accessible location as far as practicable readily visible</li><li>Indicators are to provided local to the valve ie ,showing whether they are open or shut</li><li>Valve spindle are to extend above the lower platform.</li><li>Valves and distance pieces extended for the installation on the ship side below the load water line are to be tested by hydraulic pressure not less than 5 bar.</li></ol><p></p><div><br /></div>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com0tag:blogger.com,1999:blog-356982969140943688.post-55383737216121030512023-06-09T13:00:00.000-07:002023-06-09T13:00:00.136-07:00Problems associated with welding cast Irons:<div>1) Cast iron is that the metal is filled with impurities. When you melt the metal the embedded dirt and sand</div><div>contaminated the weld and tend to not mix well with the cast iron filler rod.What you end up with is not a</div><div>fused intermixed metal bead but a porosity filled weld that can be easy to chip away with a chisel because it</div><div>has not bonded to the base metal. </div><div>2) Pre heat & Post Heat required.And different as per its composition.Pre heat to stress relieve & post heat</div><div>to control rate of cooling. </div><div>3) The large amount of carbon in the base metal tends to segregate itself along grain boundaries as the weld</div><div>puddle solidifies and cools. What this does is lower the tensile strength even lower so that in the weld fusion</div><div>boundary the shrinkage force pulls the metal apart as it cools, ie it tends to crack along the weld when cools. </div><div>4) Cracking. If it cools down too quickly you will get cracks along the weld. </div><div>5) Proper selection of filler rod & flux required as per the grade and composition of the cast iron. </div><div>6) To improve weld performance can be achieved by application of several special techniques. These include:</div><div>Joint design modifications. Groove face grooving Studding. Peening. Special deposition sequences and</div><div>electrode manipulation. </div><div>7) Some cast irons can not be fusion welded. </div><div>8) Some Cast irons can not be effectively welded.( white Cast Iron)</div><div>9) Some Cast iron you shall have to utilize special Ni coated Electrodes. </div><div>10) When welding a large casting expansion and contraction of the casting should be allowed for , maybe</div><div>removal/ loosening of foundation etc could be required,</div>meoclassIIexamnoteshttp://www.blogger.com/profile/07432536475317098168noreply@blogger.com2