Technical
Main Engine Failures and Blackouts
a. Introduction In the recent past the shipping industry has noted an increasing number of blackouts and main engine failures, which can result in a total loss of propulsion and steering capability. The risks to the vessel and crew become critical and may result in a major casualty when they occur while maneuvering in restricted areas (traffic lanes, channels), entering or leaving port or navigating close to a coast during heavy weather.
b. Consequences of Propulsion Loss The most serious consequences of a blackout or propulsion loss are contact, collision and/or grounding.
c1. Possible Causes of Main Engine Failure The main possible causes of main engine failure are as follows: • Starting failures • Fuel supply issues • Improper fuel changeover procedure when entering or exiting ECA areas • Mechanical failure • Control equipment failure • Blackout • Human error • Other causes
By Yiannis Pantos, Director/Technical
c1.1. Starting Failures Difficulty
Fig. 1: Collision
Possible Cause
Remedy
The pressure in the starting air receiver is too low.
Start the main air compressors. Check that they are working properly.
The valves on the starting air receiver or the starting air distributor are closed.
Open the valves.
There is no pressure in the control air system.
Check the pressure (normally 7 bar). If it is too low, change over to the other reducing valve and clean the filter.
The main starting valve is locked in the closed condition.
Lift the locking plate to the working position.
The main starting valve does not function due to the activated turning gear locking device.
Release the turning gear locking device.
The pistons in the starting air distributor are sticking.
The starting air distributor is to be overhauled.
The starting air distributor is wrongly adjusted.
Check the timing marks. Re-adjust the starting air distributor.
The control valve for the starting air distributor is sticking.
Overhaul the control valve slide.
The starting air valves in the cylinder covers are defective.
Pressure – test the valves. Replace or overhaul the defective valves.
Fig. 2: Grounding
Furthermore, a significant number of claims for third party property damage, many of which were enormously expensive, could be attributed directly or indirectly to main engine failures or electrical blackouts.
c. Possible Causes of Propulsion Loss According to a detailed analysis of claims related to propulsion loss by UK P&I Club for a period of five (5) years, the main causes of propulsion loss are as follows:
Insufficient or ineffective maintenance
Equipment failure
Human error
Fire
Other
It is worth mentioning that blackouts and main engine failures tend to occur when the vessel begins maneuvering in confined waters or enters and leaves port. Under these operating conditions, the stable electric load during the sea passage is replaced by variable electric power requirements i.e. additional electric load of steering motors, deck machinery etc.
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Issue 71-March 2020
The main engine fails to turn on the starting air after the START order has been given.
It should be noted that an excessive number of main engine starts / stops while maneuvering will deplete the pressure in the main air bottles. This may lead to main engine starting failure. It is, therefore, very important to monitor the main starting air pressure while maneuvering and for the pilot and bridge team to be aware of the maximum number of consecutive engine starts they can demand.
