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Onboard interference from LED lights called ‘huge safety issue’ for mariners

Nov 30, 2018 03:55 PM

Courtesy U.S. Coast Guard

Light-emitting diode (LED) lighting on vessels can interfere with radio transmissions and navigation systems and must be replaced before a tragedy occurs, said a pioneer producer of many such systems used universally on ships today.

“I’ve told the Coast Guard that this is a tsunami waiting to break over the United States and we don’t even know we have a problem,” said Ross Norsworthy, a contractor and senior subject matter expert with the Coast Guard since 2003.

Norsworthy produced the ROSS radio used on Coast Guard and Navy vessels, and owned a marine electronics company after working for industry giants like Raytheon and Bendix. After “retiring,” the Coast Guard hired him full time.

Norsworthy, who wrote a safety alert that the Coast Guard issued on Aug. 15 to warn mariners about the LED issue, explained the problem: “Everybody’s been changing out their halogen bulbs with LED lighting. They reportedly last forever and use less power, so why not, right? But we’re seeing problems. Our friends in France did an investigation after trying to contact a ship by radio. The AIS (automatic identification system) was tracking, but the ship radio was not receiving. When they boarded the ship, they found out that it was LED navigation lights up top and in the galley below that were desensitizing the radio. It’s a huge safety issue when you can’t receive communications.”

The Coast Guard is just starting to explore the problem and is asking for help to understand interference variables and experiences, said Derrick Croinex, chief of spectrum management and telecommunications policy.

“I can tell you that there appears to be no specific type of vessel affected,” he said. “It seems that it can affect anyone (who) has installed LED lighting.”

A request in the August safety alert seeking more information about LED interference experiences has yielded only about 10 responses thus far, he noted.

“We have a lot of questions at this point,” Croinex said. “We’d like more information about what type of radios people experiencing problems are using. How far is their lighting from antennas? Is it lighting from certain manufacturers? Is it the quality of the radio? The lighting? A combination of both? We’re trying to track this down.”

He said that the Coast Guard Research and Development Center in New London, Conn., is looking for volunteers willing to have their vessel systems and LED lighting analyzed. To report an issue or to volunteer, contact the Coast Guard Navigation Center (www.navcen.uscg.gov).

One big problem is that mariners may not even realize they’re not picking up signals that they should, Croinex said. He urged mariners to make use of the simple test described in the safety alert (see sidebar) to detect the presence of LED lighting interference.

Norsworthy said he spent much of the past year trying to get the word out about the potential risks of LED lighting, and encouraging adoption of standards for the Coast Guard that have been used for years by other industries.

The International Electrotechnical Commission, which publishes standards for electrical, electronic and related technologies, already has standards to ensure that LED lighting systems in automobiles do not interfere with radio and GPS systems, Norsworthy said. And there’s a standard for broadcast services as well.

To ensure safety, manufacturers of LED lighting for the maritime industry should be held to such standards as well, he said.

“Why reinvent the wheel for marine services? Automotive and broadcast services already have a standard for manufacturers — why don’t we just adopt it?” he asked. “If a ship is interfering with itself because its LED navigation lights are too close to antennas, for example, you’re in a heap of trouble. We need new standards for ships.”

Norsworthy said LED interference is rearing its head in many realms. For instance, “The FCC (Federal Communications Commission) ... is trying to put clamps down on manufacturers of billboard lights,” he said. “LED lights also can interfere with Wi-Fi in homes and businesses.”

The National Marine Electronics Association is concerned about the problem, too, said Executive Director Mark Reedenauer. He noted that in the coming year, the NMEA will update its standards for installing electronics equipment on vessels to include sections on LED lighting.

“It’s kind of in its infancy on our side of things, but we are definitely addressing this, and we feel manufacturers should be, too,” Reedenauer said. “We need to do our homework and get it right — to learn more about this so that we can say that LED lights should not be mounted within X-number of feet from VHF antennas, etc. It’s an absolute must.”

He said the NMEA has sent the safety alert to its members, and knows that some were already aware of interference issues caused by installing LED lights on various types of boats.

In the meantime, besides testing for interference, what can mariners do to ensure their ship systems operate without interruption? One option is to go back to the lighting that was installed before the LEDs, Croinex said. And mariners can spread the word about this issue, added Norsworthy.

“Safety has to trump everything else,” he said. “If you take your family out on your boat and you can’t bring them back because your navigation system goes out, nothing else matters. I’m going to continue (publicizing) this issue and force the bureaucracy to take action. Everyone who owns or operates a boat needs to know that LEDs can cause big problems.”

Feb 19, 2019 10:23 pm
 Posted by  DStirling

Hello again Patricia,

I also have an independent report from FLIR that was recently published and discusses the issues with EMI from LED products.

They go on to recommend Hella marine LED lamps after testing and finding other LED products from different manufacturers are causing issues on their boats.

In fact the issue is not only because of LED lights. Any electronic device can cause EMI by raising the noise floor at a specific frequency (between 156 MHz and 165 MHz) and will effect VHF and AIS systems.

I would be more than happy to share these reports if you get in touch. I can also introduce you to our electrical designers who are extremely experienced in this topic. They could explain the compounding effect multiple devices can have if they each create a little noise and how in remote locations, like at sea where radio signal strength is low, this can have a significant effect.

Duncan Stirling
Duncan.stirling@hella.com

https://www.hellamarine.com/en/blog/news/us-coast-guard-alert-leds-and-emi.html

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