If the mechanical and electrical equipment (main propulsion device, main power supply, emergency power supply, boiler, steering device) fails in the process of entering and leaving the port and channel with heavy water traffic, the ship's maneuvering will be limited, and it is very easy to cause dangerous accidents.
Since April 7, the Maritime Safety Administration of the Ministry of Transport has carried out a nationwide special action to prevent the failure of ship mechanical and electrical equipment, focusing on reducing the risk of ship mechanical and electrical equipment failure, and focusing on preventing and curbing water traffic accidents.
Some of the cases in the special action are representative and worthy of our reference.
Below, the editor introduces a recently discovered signal feedback failure of the ME main engine cylinder lubricating oil injector, hoping to arouse the vigilance and attention of relevant shipping companies and ships, draw inferences from one another, and strengthen investigation and self-correction.
One
Fault conditions
In April 2024, during the entry of a large container ship "M", the main engine suddenly failed to reduce its speed in the waterway in the port, resulting in the restriction of ship operation and the risk of collision with ships and terminals. The pilot immediately reported to the maritime department, and the local maritime administration immediately activated the emergency response and arranged for the tugboat to assist the ship to anchor at the anchorage in the port.
Two
Port State Control Inspections
During the inspection, it was found that the alarm "CCU1 032020 Failing Lubricator Feedback (Slowdown)" appeared in the engine room alarm monitoring system, that is, the lubricating oil feedback failure of the No. 1 cylinder of the main engine caused the main engine to slow down, and the oiler assembly was checked next to the machine, and there was no leakage in the appearance, and the relevant wires and cables were tried to be tightened, and the alarm was eliminated, but after further inspection for half an hour, the same alarm appeared again. Upon verification, the sensor-related line connector named "JB Lubricator Position Feedback" was found to be loose.
The law enforcement officers immediately reported the cause of the failure to the responsible crew, requested that the "JB Lubricator Position Feedback" sensor be repaired, and checked the electromagnetic signal feedback devices of the main engine to ensure that the main engine remained in good condition during the ship's navigation. The responsible crew then replaced the relevant equipment, and checked the working status of the main engine electronic control system circuit and joint in detail.
Case Study
In this case, the main engine model of the ship is MITSUI-MAN B&W 11S90ME-C10.5 type ME main engine, compared with the MC main engine, the mechanical parts are reduced, the electrical part is increased, and the electrical workload and failure rate are increased accordingly, and the main engine of the ME model is an ultra-long stroke machine, and the main engine has high burst pressure and large vibration, which is easy to cause the loosening and wear of the connecting lines.
The main engine cylinder lubricating oil is an important part of the marine two-stroke diesel engine lubrication system, and its main functions are:
(1) An oil film is formed between the piston ring and the cylinder liner, the piston ring and the ring groove to provide lubrication for the friction pair, reduce wear, and assist the cylinder sealing;
(2) Neutralize the acidic substances produced by fuel combustion and reduce corrosion;
(3) Clean the piston rings, ring grooves and cylinder walls.
Therefore, when the oil injection rate is too low and the oil film is incomplete, semi-dry friction will be formed between the piston ring and the cylinder liner, which will increase the excessive wear of the piston ring and the cylinder liner, resulting in gas leakage, and the leaked gas will destroy the oil film on the cylinder wall, and in serious cases, it may produce cylinder pulling and cylinder biting.
Security management recommendations
The stability and reliability of the operation of the ship's main engine directly affect the operation safety of the ship. In view of the preceding cases, we recommend the following three points to prevent the occurrence of host failures of the same type:
(1) Shipping companies should strengthen the maintenance management of mechanical and electrical equipment and shore-based support. Shore-based maintains good communication with the ship's crew, organizes regular training, improves the crew's familiarity with the operation principle of the ship's main engine and the operation status of each component, improves the crew's safety awareness and operation skills, and ensures the safe and stable operation of the ship.
(2) The crew should strengthen the learning of the main engine electrical equipment. The chief engineer and the chief engineer should actively participate in the management of the main engine electrical equipment, and when the main engine electrical fault occurs, the chief engineer and the chief engineer must analyze and solve it together with the electrician. Electricians or crew members who perform the duties of electricians should strengthen the regular maintenance and testing of mechanical and electrical equipment.
(3) The crew should strengthen the ability of fault analysis. The engine room alarm monitoring system of the ME main engine has a main engine alarm system, which will give fault diagnosis information and related suggestions when the main engine alarm, and the crew can make full use of this information for fault analysis and treatment.
Source: Zhejiang Maritime
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