In spite of the latest advancements in maritime navigation technologies such as GPS, ECDIS, and several other satellite signaling systems, navigation lights still play an important role in navigation of ships at sea.

These signalling lights have been an integral part of the ship navigation procedures since decades and because of their frequent usage, are included in the routine maintenance procedures.

Navigation lights are used while navigating a vessel near coastal areas, in heavy shipping traffic areas, maneuvering at a harbor, or simply sailing out at the sea. They help in indicating the ship’s position, status, direction of course etc. to other nearby vessels for avoiding collision at the sea. This is the first form of non-verbal communication that is made by a ship to the nearby vessels during navigation.

 

Ship’s navigation and signal lights are located in those areas, which make  them easily noticeable even from a far distance. However,  when it comes to maintenance of these lights, such high locations are quiet dangerous to access especially when the ship is at open seas.

The three important locations for navigation lights on ships are

·         Fore mast

·         Main mast

·         Aft signal light station

Maintenance of Ship Navigation lights

Following safety procedures must be followed before doing any maintenance work on ship navigation lights

·         Prepare the work permit

·         Put the lock out tag and inform the officer who is on duty

·         Try to do the routine maintenance when the ship is in the port

·         Before climbing up the main mast, take the working aloft permit

·         Switch off the radars and take out the fuses

·         Disable the power supply of the nearby ship whistle

·         Switch off any other communication devices as the antennas, which are usually located near the mast, generate radiations harmful for humans

·         While working on navigation lights at sea, check the wind flow meter for wind speed and direction. If the wind is heavy avoid climbing on the mast

·         Check for rolling and pitching of the ship. If it’s too much, don’t climb the mast

Factors Affecting Navigation Lights and Procedure for Maintenance 

Maintenance of marine navigation lights is extremely important for safety of ships. These lights are located on the ship’s outside, at highest places of the vessel. The following factors thus affect these lights:

a) Water (sea and rain water)

b) Vibrations

c) Sun light and wind

d) Wire securing

Let’s understand how each factor affects the navigation lights.

A) Water (Sea water and Rain water)

Water is a major threat to all the electrical systems onboard. Water ingress can cause fire in the electrical systems because of short circuit. Since all the navigation lights are located outside on the ship’s deck, they are prone to harmful effects of seawater, rainwater and atmospheric moisture.

The navigation lights are thus placed in weather tight and watertight enclosures. However, even though these casings are weather proof, there are high chances of water penetration due to leakage in the system because of rust formation and frequent opening of enclosures for replacing bulbs.

Note: If the bulb of a navigation light is frequently getting fused, this is an indication of water ingress inside the circuit.

Points to consider:

·         Periodically check the light fittings for leakage of water

·         Ensure to apply water resistant material like silicon or putty whenever the light fitting is opened up for replacing the bulbs

·         Visually, check inside the casing for any salt formation. If salt formation is found, it means that the sea water has penetrated inside.

·         Take fine clothes and cleaners for cleaning the glasses of the light fittings for good illumination/signaling

·         Check the light holders inside the fittings for corrosion or fungus formation

·         Use the contact cleaners for cleaning purpose whenever the light fitting is opened up 

B) Vibrations

There is no place on the ship where vibrations generated from operating ship’s engine room machinery don’t reach. Since the navigation lights are located at the highest points of the vessel, they are always under the effect of vibrations when main engine is running. This is yet another cause of bulb failure.

·         Ensure to use vibration absorber material like rubber gasket material wherever possible.

·         While working on the navigation lights, check for any loose nut bolts and holders. Tighten and secure them whenever necessary.

·         Use washers where nut bolts are used in light fixtures to avoid loosening of the nuts

·         Clamp the structure where the light fixture is installed.

C) Sun light and wind

This is one factor affecting marine navigation lights wherein nothing much can be done.

Due to continuous sunlight, the life of the light fittings often get reduced especially if they are made of plastic. Thus it’s always better to install weatherproof brass material light fittings.

D) Wire Securing

More than often, the wires of navigation lights that are secured to the mast, get tangled or loosen due to weather exposure. Do check for any loose connections of the wire and secure the wires using cable wires. Keep a regular check on the condition of these wires.

All the navigation lights on ships are installed in pairs, i.e. two in numbers. If one fails, the other one replaces it. However, it is important that officers in charge perform routine maintenance checks on these lights and also check the light/ bulb failure alarms for the same.