Limitations of remote-control operation of Marine Power plant and Auxiliary machinery

All the remote-control limitations satisfy SOLAS and IACS (international Association Classification societies) standards. The requirement may differ according to class notations. But basics remain common to all ships.

Remote control limitations mean shortcomings with the systems

Limitations of remote-control operation of Marine Power plant.

1. AE can start automatically any time which can lead to accidents if somebody is not careful while working in the close proximity of the generators.
Hence to prevent that following need to be observed.
a) That Warning signs are displayed near AEs that, “AEs can start any time”.
b) All rotating parts to be covered properly.
c) No safety to be bypassed.
d) It is essential to isolate, lockout and tagout the AE properly whenever any maintenance is carried out on them.

2. Any water leaks in combustion space will not be noticed and if AEs start in this situation from remote may lead to major damage to the AEs due to water hammer. Hence as a best management practices the AEs are always blown through first and started locally to avoid damages.

3. AE’s remote operation is dependent upon the input of various parameters. These parameters are measured with the help of various sensors. Malfunction of any of the sensors can lead to sudden stopping of AEs or render it in inoperable condition. That can lead to dangerous situations when vessel is navigating in narrow waters. Hence keeping such situations in mind two AE’s are run in parallel when navigating in narrow waters. And running generators are checked time to time physically to ensure their trouble-free operation.

4. The operator may not come to know about the fuel oil or lub oil leaks immediately and by the time alarm sounds or safety system actuate a shut down, might be too late by that time.

5. Any unusual sound in AEs may not be observed immediately if the AE’s are stared from remote. Hence as A best management practice the AEs are started from local and switch over to remote once insured that all is well.

6. Malfunction of any safety or shut down device may cause sudden stopping of AEs or AEs cannot be stared at all.

7. If excessive water in the starting air system AE may failed to start in remote starting. When AEs are stared from local sand, it is normal practice to drain the water from the starting air system. This is related to maintenance issues where the remote operation fails due to badly maintained water separators, automatic drains traps and dryers in the system.

8. The remote-control systems are Sensitive to vibrations and heat and dust hence required utmost attention for maintaining in good health.

Limitations of remote-control operation of Auxiliary machinery
1. Aux. Machinery can start automatically any time which can lead to accidents if somebody is not careful while working in the close proximity of the standby machinery.
Hence to prevent that following need to be observed.
a) That Warning signs are displayed near machineries, “machinery in standby mode can start any time”.
b) All rotating parts to be covered properly.
c) No safety to be bypassed.
d) It is essential to isolate, lockout and tagout the machinery properly whenever any maintenance is carried out on them.

2. Actual health of the running auxiliaries may not be assessed when the machinery is operated from remote station.

3. Remote operation of various pneumatically operated deck valves or dewatering valves or other machineries like pneumatically operated winches and davits may fail to operate in cold weather as moisture in the air tends to freeze in the system and may clog tiny orifices of control valves on main decks or in mast houses. To deal with this the effectiveness of dryer lubricator in the systems to be checked time to time. In this situation System may require additional heaters and or regular draining of air from the system.

4. Similarly, if the systems are hydraulically operated the oil become thick in cold weather and causes unusual leakages and rapturing of pipes if system is not warmed up before put in use. Hence the remote starting of system must be done with care and system must be put in circulation for a while which is generally done by manually operated valves. For example, the hydraulic system for hatch covers and mooring winches is put in recirculation in cold weather before operation.
Any kind of oil leakage may not be noticed till the time low level alarm sounds by that time system can lose a large quantity of system oil.

5. Power operated ventilation louvers and operation of fire dampers: the remote operation doesn’t ensure whether the louvers are completely closed or completely open. Same to be insured during the periodic inspection of the system.

6. Where machinery has more than one control station it become difficult to trace out the fault and sometimes, a fault at one control station render the whole system inoperable hence the effectiveness of the control system is checked time to time by operating the machinery from all operating stations.

7. Some remote operations of machineries required proper communication failing to do so may lead to severe accidents.
Remote starting of heavy machinery requires engine room to be informed for the requirement of extra power from DGS. Starting of such machineries from remote without proper preparation may lead to over loading of generators and eventually the blackout. For example, before starting ballast/De-ballast operation, Engine Room to be informed though todays latest automation systems can take care of such situation and can start another DG if load demand increases beyond a certain limit.

There are other issues related to maintenance of aux. system which may impair the remote operation of aux. machineries.

1. In steering system Excessive play in the linkages, leakages in hydraulic system and play between rudder stock and rudder cannot be identify by the control system which may impairs the accuracy of the steering system and may lead to accidents.

2. Inaccurate Remote level sensors and wrong indications of remote operated valves often cause problem in bilge and ballast operation and sometimes may lead to pump damage due to dry running of pumps. To deal with this the manual sounding of tanks is carried out and the valve open/close position is ensured manually. Wrong indication of sensors and valves sometimes may lead to overflow of tanks and severe stability problem if not crosschecked in time.

3. Lifeboat davits, bunker davits, provision cranes, gangway winches control systems are provided with various limit switches to safeguard the systems/machineries. Any malfunction of these limit switches may lead to accidents or make the system inoperable. As a safeguard the correct functioning of these limit switches is insured before putting the machinery in use from remote.

There are many other aspects related to limitations of remote operations of aux. machineries. Remote operations are unsafe without the proper knowledge of the system and it’s operation and need proper communication, monitoring and maintenance for trouble-free services. For further quarry please contact us on support@marinetecs.com we will be happy to answer you.

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