Follow the Light: Novel Illuminated Rope Could Revolutionize Diving Safety and Rescue

Scientists design a long-lasting low-power glowing rescue rope of unprecedented brightness

Divers use rescue ropes to secure return paths underwater. To ensure visibility in turbid and deep waters, LED-powered side-emitting optical fiber ropes have begun to be used. But, attempts to maximize the brightness of these ropes have hit a roadblock. Now, scientists from Korea have attempted to clear the road, opening the path to the future of marine activities.

Wet suit: check; oxygen supply: check; lifeline: check; and… diving in!

Whether it is to experience schools of fish, explore the deep sea, save corals, or execute a covert naval operation, diving is at the core of marine activity. To help return to the surface or assist their surface buddies in keeping tabs on their condition, divers carry an unwinding rope as they go deeper into the water. This is the lifeline or the “rescue rope.”

In recent decades, researchers engaged in finding ways to improve diver safety have created illuminated rescue ropes for better visibility in turbid or deep, dark waters. These are optical fibers―flexible glass or plastic hollow channels through which light travels―with LED light sources at their surface end, designed for controlled emission of light from their sides. But even with the best existing illuminated rescue ropes, while the optical fiber material takes care of water damage and insulation, when higher power LEDs are used to make the rope brighter, the heat on the LEDs damages the rope at its contact point, lowering it effectiveness.

Now, a group of scientists from the Korea Maritime and Ocean University, led by Professor Gyung-Suk Kil, has fabricated a rope that does not have this problem!

Prof Kil explains, “By applying a light concentrator between the LED light source and the optical fiber, the light emitted at the rope surface increased by 180% at half the driving current compared with previous prototype ropes.” Details on their device can be found in their paper published in the Journal of Advanced Marine Engineering and Technology.

The light concentrator is a combination of lenses that separates the LED and the rope, preventing damage to the latter, while causing all of the light from the LED to converge into the opening of the rope instead of some of it spreading out.

The scientists also added specialized transparent jackets at regular intervals, called auxiliary jackets, that reduced the loss of light while maximizing emissions at those intervals. And a “reflector” at the water end of the rope to keep the light flowing within the rope helped this process.

Prof Kil says, “The auxiliary jacket increased the light emitted at the surface by 280% compared with previous prototype ropes. The reflector raised this number to 430%.”

Excited by these incredibly glowing results, Prof Kil continues, “A lifeline as well illuminated as this one can, of course, massively help divers and rescuers save lives, but its applications go beyond: it can be widely used for exploration, investigation and leisure activities on land and in water; it can also be used in ship collision prevention devices.”

Have we finally learnt the ropes of marine activities? This study surely does seem to indicate so!

DOI: https://doi.org/10.5916/jamet.2020.44.3.236

*Corresponding author’s email: kilgs@kmou.ac.kr

About the author

Dr Gyung-Suk Kil received B.Eng., M.Eng., and Ph.D. degrees from Inha University, Korea, in 1984, 1987, and 1996, respectively, after which he found his way to becoming a professor at the Division of Electrical and Electronics Engineering, Korea Maritime and Ocean University. He has also been a visiting professor at Cardiff University in 2003. His research interests span high voltage and discharge engineering, lightning protection, asset management of electrical power facilities, and illumination engineering.