Emergency Stopping the Diesel Generator
Running a diesel generator on board can be dangerous if not handled properly. For safety, it is essential to know when to turn off the generator in an emergency.
When using a diesel generator, it is crucial to know the 10 emergencies that must stop the generator immediately. Failure to do so could result in severe damage or even injury. Train operators must be aware of the 10 emergencies in which their diesel generators must be turned off immediately. These include fuel leaks, overloads, overheating, and other potentially dangerous situations. Awareness of these situations and quick action can ensure the safety of everyone on board.
This article describes 10 emergencies that require an immediate shutdown of diesel generators on ships. It will provide helpful information on the importance of being aware of such situations and taking appropriate actionwhen they arise.
Abnormal/ Obnoxious Sound

A ship’s generator engine is a complex system of many heavy oscillating and moving parts. The attached auxiliaries, such as turbochargers, pumps, etc., are also high-speed machines that produce a good amount of sound; however, sometimes, a strange sound can come from the engine, indicating something is wrong. This abnormal sound can be caused by damage or wear of any part or part of the engine. It is essential to identify this particular sound so immediate steps can be taken to repair or replace it before it leads to more significant problems.
The abnormal noise fault refers to the regular operation of the diesel engine because of the moving parts in the process of uncommon damage (such as part clearance being too large), the reason such as the abnormal state and abnormal noise.
Including the diesel engine cylinder, cylinder, the supercharger surge, the valve mechanism knock, diesel engine attached mechanical fault that made the abnormal sound.
The emergence of abnormal noise indicates that the diesel engine has a potential failure and the fault is deteriorating.
In the daily operation and management of the Marine Diesel Engine, The duty Marine engineer must watch, listen attentively, and frequently smell and touch.
And one of the more practical and effective means is to listen attentively. Because any machine in the process of work sends out the voice of the inherent frequency, and when the sound length parts, quality, intensity, duration, and other changes, its sound or frequency will change the abnormal noise.
Even the slightest noise should not be ignored. If abnormal noise occurs, immediately stop the engine and troubleshoot.
Wrong Approach by Engineers
The engine room is equipped with hundreds of engine systems. Abnormal noise can be suppressed by noise from other machines during operation of the power plant. If you hear something strange coming from your generator, you might think it’s coming from a nearby machine or machine. Don’t ignore even the slightest noise. Get a second opinion and stop the engine for checking.
Smoke

If smoke comes from the generator or near the generator, the generator should be shut down immediately. There is no need to unload the generators as the situation has already exceeded the danger level. Use the emergency stop button provided on the local station or remote station. Smoke can be caused by friction between moving parts, overheating, etc.
Abnormal smoke from a ship’s engine can indicate a severe problem. If you notice smoke coming from your engine, you must act quickly. The first step is identifying the smoke source and determining whether the problem is minor or significant. Depending on the severity, it may be necessary to stop the engine and seek help. If it’s minor, you can troubleshoot it yourself and adjust accordingly. It’s also essential to look for other visible signs of damage or wear causing the smoke. These steps will help ensure your safety and keep your marine engine running smoothly.
Wrong Approach by Engineers
Never panic in such situations. Use the remote start button on standby generators that charge near-instantaneously (usually on-site) and stop running generators in an emergency. Panic is the first thing that strikes you when you see smoke or fire. It reduces the engineer’s thought process and can ultimately slow down the approach.
Abnormal Lubricating Oil Parameters

Abnormal marine engine lubricant parameters can be a cause for concern. If the lubricating oil temperature rises above normal levels or the oil pressure drops below a suitable level, immediately shut down the generator and identify problems such as dirty lube coolers and clogged filters.
Take action as soon as you notice a parameter change: high oil viscosity or low oil pressure. Taking precautions is critical to keeping your marine engine running smoothly and efficiently.
Wrong Approach by Engineers
When you notice a pressure drop, the first thing that comes to mind is switching to the standby filter. Air pockets can seriously damage the bearings if the spare filter is not primed and does not come into working condition during operation. It is recommended to stop the machine and switch to the standby filter only after priming.
Higher Lube oil Differential Pressure
Effective monitoring of higher differential lubricant pressure parameters is essential for the safe and efficient operation of marine engines. Differential pressure is a term used to assess the condition of lube filters by providing a pressure reading across the filter. A pressure gauge indicates the difference in pre-filter and post-filter pressure. If the differential pressure is higher, stop the generator and switch to the standby filter.
Wrong Approach by Engineers
It has also been confirmed several times that the generator operates when the differential pressure alarm sounds during the manoeuvring. Engineers usually don’t want to risk replacing filters during a run, as they can cause power outages if they aren’t working correctly. Therefore, they plan to change it after the maneuvering is finished. However, this further increases the differential pressure, which can lead to a sudden drop in oil pressure and shut down the generator during the manoeuvring operation. When opening the filter for cleaning, you may find particles of bearing metal. Metal Particles in the filter indicate that engineers are primarily aware of filter issues but are not seeing the big picture.
Overspeed
Generators are high-speed machines, and over-speeding of generator motors has historically caused explosions and consequences.
Generator over-speeding is mainly caused by fuel system problems, especially regulator malfunctions. If the generator runs above its rated speed but does not stop the engineer should stop the generator immediately to avoid a severe accident. Then inspect the crankcase and replace the bottom end screw.
Over-speeding a ship’s engine can have severe consequences for the machinery and the safety of the crew and passengers. It can cause excessive wear on engine parts, leading to premature failure and damage. Therefore, it is crucial to ensure that all engines operate within their specified RPM limits to ensure optimum performance and safety.
Wrong Approach by Engineers
During the commissioning of the generator after overhaul, the governor droop is changed to achieve the desired RPM specified in the manual. Incorrect settings or stuck firing frames can cause the generator to over speed during this time. Failure to inspect the crankcase and replace the bottom end bolt is a common cause of bearing failure.
Cooling Water Supply

Cooling water supply is an integral part of a marine engine as it helps it run smoothly and efficiently. Failure of the cooling water supply can have severe consequences for the engine. Cooling water starvation can cause the engine to overheat, damage components, or even fail. Insufficient cooling water supply due to prolonged exposure to high temperatures can also lead to corrosion of metal parts and other components within the engine. It is, therefore, crucial for ship technicians and operators to ensure that the cooling water supply system is always functioning correctly.
Wrong Approach by Engineers
If there is no cooling water pressure in the line, the engineer may try to bleed air from the bleeder cock near the generator expansion tank line. Suppose the water supply is unavailable (due to failure of the supply pump). In that case, this will further increase the temperature, and later the generator will shut down, leading to the seizure of moving parts. Always stop the generator first before troubleshooting. The flywheel should be barred when the generator stops due to a lack of water to avoid seizing of parts.
Piping Leakage
Leaks in marine engine piping are hazardous and should be repaired immediately. Suppose leaks are found in the fuel, lubricant, or cooling water lines. In that case, they should be repaired after the generator has stopped only because these leaks can lead to pressure loss in the system, which can seriously damage the engine and its components.
Leakage should not be taken lightly because fuel, oil, and coolant leaks can be lost and affect engine efficiency. It is essential to regularly inspect all piping for signs of leaks and take appropriate action if necessary. The best way to prevent leaks is to use quality plumbing system materials and follow the manufacturer’s instructions for proper installation and maintenance.
Wrong Approach by Engineers
If a small amount of fuel oil or water is leaking from a pipe joint, it is possible to stop the leak by tightening it. However, if the joint is over tightened, it may cause further leakage and even damage the pipe. Hence the leakages should be repaired after the generator has stopped only
Loose Parts and vibrations
Vibration is one of the most common causes of wear on moving parts. Parts can come loose, reducing efficiency and performance. Loose bolts are also a significant source of vibration. To prevent this, it is essential to regularly inspect all moving parts for loose bolts and other signs of wear. Additionally, regular maintenance should ensure that all components are adequately lubricated and tightened to prevent excessive vibration while the engine is running. If the bolts loosen or vibrate excessively while the engine is running, immediately stop the generator motor, investigate the cause, and repair it.
Wrong Approach by Engineers
On board ships, it is not customary to check the tightness of generator foundation bolts and attached accessory units such as turbochargers. It turns out that PMS at many shipping companies do not incorporate foundation bolts and other bolt tightness checks into their routines.
Non-functional Alarms and Trips
Alarms and shutdowns are essential to your generator set’s safe and reliable operation. The generator should be shut down immediately whenever an alarm is detected due to a running generator not working. A non-functioning alarm can damage equipment and cause dangerous situations such as fire. Additionally, operational failures can occur, which can result in high costs. Therefore, checking alarms and trips regularly and replacing malfunctioning alarms as necessary is essential.
Wrong Approach by Engineers
Crews on many ships tend to ignore alarms they consider unimportant. Port State Control (PSC) often observes generator alarms and trips not functioning or set correctly. In such a situation, the generator cannot be saved from disaster. Check all alarms and trips weekly.
Lube oil Contaminated with water

Water leaking into the oil will reduce the oil capacity and damage the bearings. The generator should be stopped when the moisture content becomes too high in such cases. Find leaks immediately and change/clean the sump oil before operating the generator again.
Wrong Approach by Engineers
Several cases have been found where generator lubricant tests were not performed regularly, and generators were run with water in the oil. The effects of small amounts of water are not immediately noticeable, but in the long run, they corrode and damage critical parts of the crankshaft and bearings.
Blog Conclusion
We hope you enjoyed our blog on emergency stopping your diesel generator. Please let us know if you have any questions or comments. We would love to hear from you! If you would like to learn more about emergency stopping your diesel generator, you can visit our website at https://www.marinediesel.co.in/. Thank you for reading, we are always excited when one of our posts is able to provide useful information on a topic like this!