Causes and emergency preparedness.
There are several incidents of main engine failure during vessel movement in or out of harbour or in narrow channels, nevertheless this is the time where engine reliability is required most. On the basis of experience and reports we have summarised various causes of engine failure and required emergency preparedness to counteract this situation.
STATISTICS – Increasing numbers of main engine failure related incidents and accidents have been reported to UK P&I Club’s. More than 700 such claims which has given cause for concern.
CONSEQUENCES – Extensive Damage to third party property e.g. berths, locks, bridges, dolphins, navigational marks, loading arms, cranes and gantries, damage to other moored ships, collision and grounding and damage to own ship structure. These damages, directly or indirectly attributed to main engine failures are enormously expensive and in some cases amounted to millions of dollars.
Time between the fault occurrence, fault identification and rectification to bring back the control to NORMAL is utmost important. Hence quick evaluation of the situation and right decision making is what is required from crew. How can this time be reduced? Engineer’s proactive measures can reduce the time to bring back the control to NORMAL. Good understanding of the main engine control, safety systems, associated systems and their interlocks is must for quick response and preparedness. Besides this good understanding of ship’s power management system is also a must for the crew in this regard.
Primary reasons : Associated with Main engine and its systems.
Secondary reasons : Associated with the Auxiliary system feeding to Main engine, e.g. Loss of Power.
Among Primary Reasons below are commonly reported;
- ME Remote Control System Failure
- Loss of Starting Air pressure. Failure of Mechanical system
- Loss of Fuel Pressure.
- Electrical failure or faulty alarms and sensors
- Human error, lack of monitoring and supervision
FEW COMMON FAULTS & REMEDY
Main Engine cannot be started in Ahead and Astern from Bridge Control.
- Any of the start interlock active in main engine safety system
- Solenoid valves for remote starts are not energized or Stuck in one positionLoss of speed setting air pressure. (in case of pneumatic system.)
- Output from bridge telegraph to governor is missing
- Switch for bridge control to safety system missing.
- ME REMOTE CONTROL SYSTEM FAILURE
- In all such cases, it is advisable to change to local stand and manually operate valves and Fuel Lever.
- In case of remote control system failure, it is always advisable to change to local (engine side) control directly rather than changing first to ECR remote control and then to local control.
- Many of the electro-pneumatic valves are common for bridge & engine remote control system.
- Reversing Failure
- Loss in control air pressure to reversing actuators.
- Reversing solenoids are not energized or pneumatic valve leading reversing air to main manifold stuck.
- Reversing actuator for Fuel pump piston is stuck.
- Start air distributor stuck (does not change the cam profile)
- Check for any control air leak in reversing system
- Identify the Ahead & Astern pilot and main valves and check whether energized or moving.
- Check all fuel pump actuator in desired position.
- Check start air distributor pilot valves free and moving
2. Loss of Start Air Pressure, Main Engine start blocked
- Too frequent air kicks while positioning the Vessel
- Excessive air consumption during each Kick;
- Faulty air starting Shutoff valve, not Closing even after start signal is OFF
- Leak in starting air system ; through flanges/gaskets, Safety Disc
- Poor start air comp pumping rate
Action (Immediate) :
Start air block to be bypassed only if start is confirmed below that level (Chief Engineer’s decision). Else need to wait for Pressure to come up. Bridge to be informed immediately about the situation.
- Check and rectify start air leak /
- Start air comp to be overhauled and kept ready always for manoeuvring.
Proactive measures: 12 starts on one air bottle reserve, 6 Ahead & 6 Astern from shaft standstill, Chief Engineer to verify upon joining vessel and to be carried out as a routine on regular basis.
3. Failure of Mechanical System
- Pipe Rupture, causing loss of pressure in fuel lube or air system.
- ME moving parts failure or Stuck. Immediate bypassing the pipe ruptured; else bridge to be notified regarding unavailability of main engine. Proactive measures: special tools to be ready near engine all time.
- Immediately go for emergency operation by cutting out the moving me parts, (e.g. Exhaust valve, fuel pump, turbocharger etc.) :
Action: (quick evaluation and decision making by Engineers)
4. Loss of Fuel Pressure
- Suction filter clogged.
- Supply and circulating pumps failure.
- FO Service piping ruptures or leaks. FO rail leak (as case may be)
- FO pressure regulating valves malfunctioning
- Immediate by passing the ruptured pipe, if possible, else bridge to be notified regarding unavailability of ME.
Proactive Measure: Stand By supply & circulating pump to be checked frequently for real stand by operation. Usually it is carried out on monthly basis.
5. Electrical Failure or Faulty Alarms and Sensors
- In most of the cases , some faulty feedback sensors, Switch , Transmitter in the Safety System block the remote Start
- Broken Cables in Electrical System
- Persisting Earth Faults in distribution of ME Control System
- To find out the faulty sensor and replace /bypass (Time Permitting)
- Proactive Measure: Important faulty feedback sensors, Switch , Transmitter in the Safety System to be identified and marked for quick action
6. Human Error / Lack of Monitoring and Supervision
- All the faults (mentioned previously) can be observed and rectified at its premature state by proper Monitoring of Engine Parameter and Engine Side.
- Lack of Clear understanding on ME Control & Safety System and its other associated System
- Lack of familiarity with the equipment and its emergency running.
- Engineers to read and understand ME control & Automation system (Similar for engine specific to be made for quick reference)
- Proper monitoring of engine parameters and engine side is important.
- Knowledge and familiarity with the equipment is important.
7. LOSS OF ELECTRIC POWER //BLACK OUT
Probable reason (Aux engine trouble):
- Automation failure
- Auxiliaries load control or sharing failure.
- Control equipment failure (eg. governor failure, defective trips for high temperature cooling or low luboil pressure etc)
- Electrical failure (eg. overload, reverse power trip, preferential trip device failure etc)
- Lack of fuel (eg. blocked filters, water in fuel, fuel supply piping and pump failures etc)
- Mechanical failure(eg. lack of compression, engine seizure, loss of lubrication, overheating etc)
- Human error
- In case of an inevitable Black out, Tie line from MSB to ESB to be manually taken off so that Emergency equipment’s start to get power from Emg Gen through ESB.
- Proper Monitoring of engine parameter and engine side so that faults can be observed and rectified at premature stage.
- Quick evaluation of the situation and time to revive normal power to be intimated to bridge for seeking outside assistance.
- Main generator other than the tripped Generator to be started immediately.
DONOT GET PANIC.
Contributed by – Saroj Kumar Ojha, Chief Engineer and presently working as technical Superintendent. The views are his own and do not represent his employer.