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Showing posts from January, 2020

Generator fuel oil system

Oil record book (ORB) codes

Generator evaluation of readings regarding combustion condition


Scuffing is a form of micro-seizure of Piston Ring when LO breaks down.  Scuffing is caused due to;  Bad Cylinder Lubricant  Defective Cyl. Lubricator  Insufficient LO Points  No oil groove in liner  Absence or wrong Scraper Rings.

Turbocharger cutting-off procedures:

» When it is necessary to cut-off T/C due to heavy vibration, bearing failure, etc. cutting  procedure should be done as per engine maker’s instruction.  » Cutting-off operation depends on number of T/C installed and number of T/C damaged.  Following procedures are in accordance with Sulzer RT engine practice:  Case I: Failure of one T/C, with Exhaust by-pass piping: Lock rotor as per T/C manual.  Remove blank flange in by-pass exhaust piping. Open covers of scavenge air trunk.  Auxiliary blowers must be running during operation.  If casing is cracked, stop T/C cooling.  If T/C is supplied with external lubrication, shut L.O. supply.   Output 25%: RPM 60% at MCR.  Case II: Failure of one T/C, of two T/C engine: Lock rotor of damaged T/C.  Remove expansion joints of both exhaust inlet and air outlet of damaged T/C,  and put blank flanges.  If casing is cracked, stop T/C cooling.  If T/C is supplied with external lubrication shut L.O. supply.   Output 50%: RPM 80% : Running T/C rpm must

Precautions before Entry into Empty Tank:

1. Gas freeing is essential before entering empty tank.  2. Manhole doors to be opened for at least 24 hours before entry.  3. Forced ventilation with air duct, to be done with electric blower, for at least 24 hours.  4. With forced exhausting system, minimum of 2 air changes should be completed during  that time. [For every dangerous space, 10 to 20 air changes are necessary.]  5. After thorough ventilation, tank atmosphere tested for any toxic or explosive gases, by  invited Chemist or with Safety Lamp before entering. [Flame will burn clearly, if free  from foul gases. Faint blue cap will show presence of explosive gases. If burning black  or flame goes out, it shows presence of CO₂ gas, which is fatal to life].   When tested by Chemist, TLV must be taken as a standard.  6. When the tank is gas free, following LSA to be carried or kept ready, when entering.  a) Lifeline or harness to be put on.  b) Spark proof hand torch to be brought in.  c) BA set to be kept ready.  d) Resuscitati

Crankcase Relief Door: SOLAS Regulation and Requirements:

An IC engine of over 200-mm bore or crankcase volume of 0.6 m³ and above,  shall be provided with crankcase relief door with sufficient relief area.(Regulation)  Opening pressure = 1/15 bar (0.07 bar) above Atmospheric pressure, but ≯ 3∼7  bar of explosion pressure.  Free area of each relief valve ≮ 45 cm².  Combined area of relief valves ≮ 115 cm² per m³ of crankcase volume.

Fire control plan

Fire control plan:  » General arrangement plan must be permanently exhibited onboard, for the guidance of  officers.  » Positioned outside the deck house [opposite to gangway of both sides] in a permanently watertight enclosure for assistance of shore fire brigade.  » Fire Control Plan includes:  Fire control stations.  Various fire sections, enclosed by both Class A and Class B divisions.  Particulars of fire detection and alarm system.  Sprinkler installation and fire extinguishing appliance.  Means of escape.  Ventilation system, including positions and numbers of fan controls and dampers.  Fire Fighting Appliances, FFA:    All portable and semi-portable extinguishers: Good working order ensured, properly

Types of detector

Smoke detector: 1. 2. 3. 4. 5. 6. Installed at stairways, corridor, escape route within Accommodation Space.  Also used in Cargo space and Machinery space  Maximum floor area per detector = 74 m².  Max. distance apart = 11 meters.  Max. distance away from bulkhead = 5.5 m.  Photocell or light scattering types.  Heat Detector: Maximum floor area per detector = 37 m².  Max. Distance apart = 9 meters.  Max. Distance away from bulkhead = 4.5 m.  Used Bi-metal strip.  Fitted in boiler room, laundry, Control Room, Galley.  Flame Detector: Ultra Violet or infrared.  Fitted near fuel handling equipment.  Combustible Detector: Fitted in galley, ER fwd bulkhead adjacent to p/p room under floor plate.

CO2 calculation

CO₂ Quantity Calculation: (by Regulation):    For cargo space, CO₂ quantity shall be sufficient to give a minimum volume of free gas,  equal to 30% of gross volume of largest cargo space so protected.  For machinery space, CO₂ quantity shall be sufficient to give a minimum volume of free gas,  equal to 40% of gross volume of machinery space so protected excluding the casing.  Weight of CO₂ / bottle = 45 kg / bottle.  Free gas volume of CO₂ = 0.56 m³/ kg.   

Sludge content onboard is high, what to do?

Sludge, waste oil or oil and water mixture up to 25% of water content could be  burnt in incinerator.  Sludge can be disposed from ship to shore reception facility through International  Discharge Connection, provided at discharge side of Sludge Pump.  Transferred to another (other) tank. (Indicate tank and total content of tank)  Incinerated amount, total time of incinerator operation, disposal of oil residue  (sludge), quantity of retention, tank no. and its capacity, port name, item no. and  letter code are to be recorded in ORB. (See page 164)  Reception Certificate attached with ORB.

SOPEP requirement

SOPEP Requirements: Oil spill kit inside Oil spill Locker: Can be grouped into: Solvent Absorbent Cleaning Plugging material.  1. OSD 200 litres.  2. Chemical splash suit 10 nos.  3. Goggle 10 pairs.  4. Boots 10 pairs.  5. Nitrile gloves 10 pairs.  6. Sawdust and cotton rags.  7. Oil seals 30 nos.  8. Oil coushions 40 nos.  9. Oil scoop (non-spark) 1 no.  10. Deep pan shovel (non-spark) 1 no.  11. Disposable bags 10 nos.  12. 29 ft³ Container 2 nos.  13. Bucket (non-spark) 1 no.  14. Brooms 6 nos.  15. Scupper plugs  16. Cement for plugging  17. Submersible pump (Wilden)  18. Bilge and Ballast Piping Diagram.  19. Fuel and LO system Piping Diagram.  20. HO responsible address.  21. Port Authority Address.  22. Agent Address.

Generator load test

  1. After priming the AE, start and run under no load, low speed condition for about 3 to  5 min.  2. Then stop and checked externally for overheating. If no overheating, crankcase doors  to be opened and checked temperature of bearings and running gears.  3. If satisfactory, restart the engine at full speed, no load condition for about 30 min.,  then stopped and recheck again.  4. If satisfactory, restart and load-shared with running generator engine. Load sharing  should be gradually increased in small steps, taking about 6 to 10 hours to reach at  full load condition. While running in full load, another generator to be run in stand- by for possible emergency use. Synchronising or load sharing steps: 25%, 50%,  75%, and 100% within 6 to 10 hrs.  5. All necessary items checked, during load increasing steps.  6. Then peak pressure indicator and other performance data, taken for each cylinder and  compare with test results.  7. Load test should be done, until preferential trip initiate

Sounding pipe requirements

Used to determine the dept of liquid in a tank.  Should be as straight as possible.  If it is not possible, pipe curvature should allow easy passage of sounding rod or  chain.  Normally, bore of pipe must be not less than 32mm.  Striking pad of adequate size and thickness placed under the pipe

Condition for freeboard and its important

Efficient means of protection must be provided for all openings to hull and  superstructure, for protection of crew in heavy weather, and for rapid freeing of water from weather deck.  2. Condition of Assignment must be maintained, at all times in satisfactory condition.  3. Annual Inspection to be made by assigning authorities, to ensure that they have been  maintained in satisfactory condition for continued validity of Load Line Certificate.

Reed valve

Reed valves  are a type of check valve which restrict the flow of fluids to a single direction, opening and closing under changing pressure on each face.  Modern versions often consist of flexible metal or composite materials  Reed valves  are commonly used in high-performance versions of the two-stroke engine, where they control the fuel-air mixture admitted to the cylinder.  As the piston rises in the cylinder a vacuum is created in the crankcase beneath the piston.

Crankshaft deflections

Crankshaft Deflections And Wear Down Gauge Readings In order to prevent crankshaft failure and serious breakdowns, it is absolutely essential to maintain the main bearings of an engine in true alignment.  The alignment must be checked as per the maker’s instructions, with the main bearing bridge gauge, and the crankweb deflection gauge. In taking these measurements, extreme care must be taken to see that the journal is bedding on its bearing.  The thickness of the lower half main bearing shells must also be measured and recorded. If the reduction in thickness of individual bearing shells is not uniform then the differences will be a true record of misalignment. A chart is provided by the engine manufacturer that gives the various tolerances which may be allowed. Inspections : Cylinder Liner Gauging: The gauging of the cylinder liners must also be taken and recorded on the appropriate form. Abnormal wear rate must be investigated and reported to the superintendent. Cyli

Hull efficiency

Hull Efficiency is defined as the ratio of the effective power for a hull with appendages to the thrust power developed by propellers.

Cavitation of propellor and cavitation number

Pressure distribution in a blade element is shown below As the pressure on the back of a propeller falls lower and lower with the increase in a propeller’s n, the absolute pressure at the back of the propeller will eventually become low enough for the water to vaporize and local cavities form. This phenomenon is known as cavitation. (     , vapor pressure of water  Cavitation on a propeller Lower the thrust of the propeller, & thus decrease its efficiency Cause vibration of hull & the propeller and generate uncomfortable noise, &cause erosion of the propeller blade. Cavitation number   The cavitation is most likely to occur at the tips of blades where the relative velocity is the largest and the hydro-static pressure is the lowest when blades rotate to the highest position.  It can also occur near the roots where blades join the boss of a propeller because the attack angle is the largest.

“Quasi-propulsion” coefficient

“ Quasi - propulsion ”  coefficient   defined as the ratio of the effective horsepower to the delivery horsepower.  The division of the  quasi - propulsive coefficient  are 1) understanding the  propulsive  problem  2) in making estimates of  propulsive  efficiency for design purposes.

Deck fire extinguishing system

Slot welding

A weld between two members, one containing an elongated hole through which the other member is exposed The hole is completely or partially filled with weld metal, thereby joining the two members; one end of the hole may be open

Parts Of A Compressor Suction And Discharge Valve .Overhaul procedure

1. Loosen The Castle Nut By Suitable Spanner. 2. Take Out The Split Pin. 3. Remove The Nut Washer. 4. Remove Buffer Plate. 5. Remove 3 Spring Plates. 6. Remove Damper Plate. 7. Remove Valve Plate And Guide Washer. 8. Remove Locating Pin(it Keeps The Valve Aligned ).Now All The Plates Are Checked For Proper Seating , If Valve Plate Does'nt Seat Properly, It Is Lapped By A coarser And finer Paste, Making A Figure Of 8 On A True Surface Plate. A Figure Of 8 Is Made Because An Even And Continuous Lapping Can Be Done Only By A Figure Of 8.

Main Air Compressor ( safeties, unloader, bumping clearances )

Discharge Unloader And  Its Operatiom  One Of The Most Important Component, An Unloader Is Used For Unloaded Starting Of Compressor And Draining At Continuous Intervals.  An Unloader Is Fitted At The End Of Drain Line From Inter And Aftercooler. It Is Basically A Solenoid Operated Spring Loaded Valve Arrangement.  Unloader Has Two Lines Drain From Above And Delivery Air Pressure Of 1st Stage From Below. When Compressor Is Shut And Delivery Air Pressure Is Zero, The Drain Opens The Unloader Valve Against Spring Pressure, Thus It Is Always Open. When Started, Slowly The Delivery Pressure Rises And Tries To Shut  The Valve, During This Time The Actuated Solenoid Valve Overcomes The Air Pressure And Keeps The Valve Open.  The Solenoid Valve Is Operated By A Time Delay Circuit As The Time Span Of 10-15 Sec Gets Over The Solenoid Is Deactivated And The Unloader Valve Shuts.  After Every 20-30 Mins., It Is Activated Again And Clears The Drain For 10-15 Secs, Then Deactivates. If Th

Firing order of IC engine

The order in which the ignition take place in various cylinders of a multi cylinder engine is called firing order. Every engine cylinder must fire once in every cycle. Three factors must be considered before deciding the firing order in IC engine. These are Engine Vibrations :  Load on the bearing should not be imbalanced due to firing order of cylinder so firing order should be kept in such an order that the load is equally distributed on bearings. The imbalance load on the two bearings would result in severe engine vibrations. Engine cooling :  The firing should be in such an order that the cooling system should work in an effective manner. The cooling position should not change its position with time otherwise the task of the cooling system becomes very difficult. Development of back pressure :  There should be sufficient time and space for the exhaust gases to travel in the exhaust pipe otherwise the danger of back flow will rise. The commonly used firing orders for eng

List of certificates and documents carried onboard

Certificates: Certificate of Registry International Tonnage Certificate International Load Line Certificate International Load Line Exemption Certificate International Ship Security Certificate Intact Stability Certificate Minimum Safe Manning Document Certificates For Masters Officers Or Rating International Oil Pollution Certificate Document Of Compliance Safety Management Certificate Damage Control Booklets Oil Record Book Garbage Record Book Cargo Securing Manual List of additional certificate for PASSENGER SHIP Passenger Safety Certificate Exemption Certificate Special Trade Passenger Ships Special Trade Passenger Ships Space Certificate Search And Rescue Co-Operation Plan List Of Operational Limitations Decision Support System For Masters List of additional certificate  for CARGO SHIP Cargo Ship Construction Certificate Cargo Ship Safety Equipment Certificate Cargo Ship Safety Radio Certificate Cargo Ship Safety Certificate Exemption Certific

International safety managment (ISM ) code

seafarer identity document

SOLAS requirement for low and high expansion foam system

SOLAS requirement of Low Expansion foam firefighting system Foam system should be approved by the administration Foam monitors should have the capacity to discharge 3litres/m 2 /minute. The system should contain five times the volume the of largest space Expansion ratio should not exceed 1000:1 The main control station should be located away from the cargo area, adjacent to accommodation space. The system shall be capable to discharge foam, in no more than 5 minutes, the quantity should be sufficient to form a foam blanket over the largest single area over which oil fuel is liable to spread. The system shall be capable to supply foam not less than 20 minutes on tanker fitted with inert gas system and not less than 30 minutes on tankers not fitted with the inert gas system. The rate of supply of foam shall not be less than the greatest of following 0.6  l /min per square meter of cargo tanks deck area, where cargo tanks deck area means the maximum breadth of the ship multipl

Why we use low expansion foam on deck and high expansion foam in the engine room?

Low expansion foam is having a more weight to volume ratio as compared to high expansion foam.  If we use high expansion on deck, then wind effect will blow away the foam.  The low expansion foam having sufficient weight to counter the wind force effect. So, it is easier for low expansion foam to form a blanket over fire properly. In the engine room, wind effect is not present only we need to suppress the flammable gases and to give a cooling effect in the large volume of the engine room. So high expansion foam is good to cover more space in a short time

Main Engine Fuel oil system

Fresh water generator

Starting First, check if the engine speed is running above 50 RPM. The reason for this is that at low RPM the temperature of jacket water is around 60 degrees, which is not sufficient for evaporation of water Check if the drain valve present at the bottom of the generator is in closed position Now open the suction and discharge valves of the sea water or ejector pump, which will provide water for evaporation, cooling, and to the eductor for creating vacuum Open the sea water discharge valve from where the water is sent back to the sea after circulating inside the fresh water generator Close the vacuum valve situated on top of the generator Now start the sea water pump and check the pressure of the pump. The pressure is generally 3-4 bars Wait for the vacuum to build up. Vacuum should be at least 90% which can be seen on the gauge present on the generator. Generally the time taken for vacuum generation is about 10 minutes When vacuum is achieved, open the valve for feed water

Cargo operated pump turbine (COPT)

Cargo operated pump turbine (COPT) is required on tanker ships for discharging of loaded cargo to the port. COPT is steam driven centrifugal pump operated by steam produced from the ship’s boiler. STARTING Check the lube oil sump level Start the lube oil priming pump and check the pressure Operate the vacuum condenser seawater pump suction and discharge valves to obtain a flow through the condenser Switch on the breaker for vacuum condenser pump Start the pump and check sea water pressure Open the lube oil cooler seawater valves Check the level for vacuum pump water supply Check the water level in the condenser Operate drain valve of turbine casing and remove the water Operate the steam inlet and exhaust valves opening gland Steam valve to provide sufficient steam pressure to the gland Start the vacuum pump and check the vacuum pressure Operate the condensate pump suction and discharge valves and then start the pump Press the turbine rolling button and star

Quick closing valve

A quick closing valve is an important part of the engine room fire fighting system. During emergencies, it cuts off one of the main sources of fire prominently present in the engine room - fuel oil. The quick closing valves are installed in all fuel tanks in the engine room. They can be closed from a remote position outside the engine room, normally from fire control station. These valves are spring loaded and are normally operated by following methods: Wire-pulley system Pneumatic system Hydraulic system Wire pulley system operation: Check for any slackness in the wire Ensure all the wires are seated on the pulley From the remote station, first release the required lever from its seat Pull the lever with a jerk to operate the required quick closing valve Once the quick closing valve is operated, the wire will be slackened Pneumatic system operation: A pneumatic cylinder with piston is fitted in the quick closing valve housing which operates the spring to

Flooding in engineroom

Engine room flooding as the name indicates, means filling up of the engine room space with water. Engine room flooding can affect the watertight integrity of ship. Action to be taken During Flooding Call for maximum manpower to tackle the situation The sooner you find the fault the better Start the other circulating system and isolate the leaking pump, pipe, cooler etc. Close inlet and outlet valves of the affected system to stop the leak Inform chief engineer regarding the leak and follow the instructions from him Put a notice or placard regarding leaking equipment or system and trip the breaker until repairs have been done In case of any tank leakage, start transferring the excess content from that tank to any other tank and try to minimize it as much as possible Tank should not be used until cement box or welding has taken place or repairs have been done 2) In case of leakage from Overboard Valve If the leakage is after the valve and if the val

Boiler fire

There are three main stages of boiler fire: Stage 1: Normal Soot fire Stage 2: Hydrogen fire Stage 3: Iron fire Stage 1- Normal soot fire: Soot is deposited in the water tube of the exhaust boiler. When the ship is at slow speed, the exhaust temperature of main engine may vary from 100 to 200 °C . This temperature is enough to ignite “wet soot” whose ignition temperature is around 150 °C . If the soot is “dry”, it will not get ignited at such low temperature (150 °C) but when the engine is running at higher speed and the temperature of gases reaches to above 300 °C , then in the presence of excess oxygen the deposits of combustible materials will liberate sufficient vapor which can be ignited by a spark or a flame. The above type soot fire is called small or normal soot fire because the heat energy is conducted away by the circulating boiler water and steam. Also the sparks remain inside the funnel or diminish while passing through the flame arrestor in the funnel top. Stag

Boiler furnace blowback

Cause of Boiler furnace Blow Back Main cause of boiler furnace blow back is accumulation of hydrocarbons inside the furnace. Hydrocarbons may exist as vapours or liquid form inside the boiler furnace. Accumulated fuel vapours inside furnace catches fire and develops high pressure inside the furnace thereby resulting in dangerous explosion. It is a usual practice that when there is frequent flame failure, operator try to fire the boiler in manual mode. In manual mode pre purging is not automatically controlled. Hence an attempt is made to fire boiler with insufficient pre purging time and eventuality may be catastrophic explosion. Preventive Actions Allow sufficient time for pre purging the furnace with dampers full open to ensure all the accumulated vapours are expelled out. Purging to be carried out 5-6 times the furnace volume for effective expelling. Never try to reduce purging time or bypass it. Carry out boiler burner and swirler routine as per planned maintenance system

Corrosion and Erosion

Both corrosion and erosion happen due to certain external actions on a surface. Corrosion means the destruction of materials through chemical reactions whereas erosion means the carrying away of the topsoil from the surface of the earth. Corrosion normally happens because of chemical reactions. Erosion occurs by chemical reactions and by certain forces of nature.  Corrosion also means the loss of electrons from the metals when it comes in contact with the moisture and oxygen in the atmosphere. Erosion happens because of natural forces like water and wind. Other factors such as acid rain, salt effects and oxidation of materials are also known to cause erosion. In terms of the process, corrosion is an electro chemical process whereas erosion is a physical process. The corrosion of metals is often referred to as rusting and it is evident in the material itself. Erosion is a natural process that removes or carries away materials from one place to another.  For instance, when sand i

Hunting gear mechanism

The floating lever movement to the left pulls the pump control lever also to the left with the pivoting taking place at the bottom point. When the tiller arm turns it pushes the hunting link to the right, which in turn pushes the pump control lever inwards and to mid position with pivoting taking place at the top point. At mid position the pump is at ‘no stroke’ and thus the rudder is stopped at that helm angle. For the rudder to be brought back to the midship position the telemotor receiver cylinder will have to move to the left, the floating lever top to the right pushing the pump control lever further in. Pump will start and the tiller will move in the opposite direction, pulling the hunting link to the left. This will in turn, will pull out the control lever of the pump back to the mid position, pivoting about the top floating lever point.

VIT and Super VIT

Inclining experiment

Purpose Ship’s stability calculations not only rely on the ship’s geometry but also on the knowledge of where the ship’s centre of gravity (G) is positioned. Although the distance of G from the keel can be ascertained for various conditions that the ship may be in, it is essential that it is accurately known for one specified ship condition. To this end, the need to carry out an inclining experiment becomes necessary and from this, two facts should become known the displacement; and the position of G in a known ship’s condition. The inclining test is carried out to find the lightship KG at the lightship displacement. It is sometimes known as a ‘ controlled list experiment ’. By conducting the experiment by means of a series of weight shifts, the GM of the vessel can be ascertained under the test condition. This GM value can then be compared with the ship’s KM to obtain the vessel’s KG value: KM – GM = KG The environment of the dry dock is ideal for performing such a stabilit