Page 88: of Marine News Magazine (November 2016)
Subchapter M: the Devil is in the Details
Intelligent LED Commercial/Military (CM) series navigation lights are ready to meet the challenge.
ith the long-awaited, much anticipated Subchap- ter M towboat RULES now upon the towing in-
Wdustry, there are many details to address. None, perhaps, is more important than the need to maintain com- pliant and safe running lights. And, navigation light up- grades have been added to the list. That said; navigation/ running lights may be about as gratifying a purchase as put- ting tires on your car or a new roof on your house. Neverthe- less, all three are absolutely crucial aspects of everyday life.
Sub M requires all towing vessels over 20 meters (65’) to have navigation lights certi? ed to UL 1104. Towing vessels larger than 26’ and less than 65’ are required to have lights certi? ed to ABYC A-16. The Coast Guard is generously al- lowing vessels two years – until July 2018 – to upgrade the lights to the new standards, but that deadline, like many others, will be here before you know it.
Although ‘SubM’ only requires a basic certi? ed UL 1104 navigation light, many seagoing towing vessels, depend- ing on the type of inspected vessel, will require additional safety equipment, including: • Redundant back up lights; • Dual power feed; • Navigation light monitoring (w/alarm panel.
Beyond this, manufacturers of UL 1104 LED naviga- tion lights for inspected vessels are required to comply with the International Maritime Organization (IMO) Resolu- tion MSC.253 (83) Performance Standards for Navigation
Lights. These standards stipulate, among other things, that the luminous intensity of LEDs gradually decreases while the electricity consumption remains unchanged. The rate of decrease of luminous intensity depends on the output of
LEDs and temperatures of LEDs. To prevent shortage of luminous intensity of LEDs, (a.) an alarm function should be activated to notify the Of? cer of the Watch that the luminous intensity of the light reduces below the level re- quired by COLREGs; or (b.) LEDs should only be used within the lifespan (practical term of validity) speci? ed by