By using sound waves, ultrasonic antifouling can prevent the growth of algae, barnacles and slime on boat hulls and interiors, and can protect sea chests and box coolers as well.
The technology has been employed internationally from Europe to Australia, Japan, Chile and the Caribbean, and implemented on commercial, military and recreational vessels. More recently, these systems have caught on with yacht owners in North America.
Fouled, rough hulls can slow boats and increase fuel consumption, and antifouling paints — while effective — can release toxins when a vessel is in the water or when coatings are scraped off in dry dock. Usage of ultrasound has grown following the International Maritime Organization’s ban over a decade ago on organotin in bottom paints, and because of moves to limit copper as an antifouling agent. Ultrasonic systems don’t rely on chemicals that can harm fish and mammals or pollute the air, and they can reduce vessel lift outs for cleaning.
The cleaning abilities of sound waves have been recognized since before World War II. Starting in the 1950s, sound waves were utilized for this purpose in the food, agriculture, electronics, medical, aircraft and auto industries. While ultrasound’s marine applications have been acknowledged for decades, usage by commercial vessel operators has only gained traction in the past 15 years. To install a system, transducers are mounted inside a vessel’s hull, or on other internal features, along with a control box. Onboard generators or shore sources power the equipment.
“Wherever sea, river or estuary water touches a vessel or its internal equipment, biological organisms are at work, clogging pipe work, encrusting the hull and propeller, increasing fuel consumption and requiring expensive remedial work,” said Darren Rowlands, director of NRG Marine Ltd. in the United Kingdom. “Antifouling is therefore an essential preventative measure that all commercial, military or leisure operators use to maintain smooth, fouling-free surfaces to reduce running costs and extend service intervals.”
この記事は Professional Mariner の April 2017 版に掲載されています。
7 日間の Magzter GOLD 無料トライアルを開始して、何千もの厳選されたプレミアム ストーリー、9,000 以上の雑誌や新聞にアクセスしてください。
すでに購読者です ? サインイン
この記事は Professional Mariner の April 2017 版に掲載されています。
7 日間の Magzter GOLD 無料トライアルを開始して、何千もの厳選されたプレミアム ストーリー、9,000 以上の雑誌や新聞にアクセスしてください。
すでに購読者です? サインイン
Mariner's role still unknown as autonomous shipping gains speed
Mariners’ role still unknown as autonomous shipping gains speed
Piracy edges closer to home with wave of raids in southern Gulf
In the brief cellphone video recorded by a crewmember on the offshore supply vessel (OSV) Remas, the pirates walk back and forth on the deck of the ship, clenching their guns and using them to point as they order around the crew. Their faces are draped in clothing and bandanas.
Casualties
NTSB: Dredge hit Texas gas pipeline, causing fire that killed four
IMO emissions report raises new concerns about methane slip
A recent report from the International Maritime Organization (IMO) reveals that global shipping emissions increased nearly 10 percent from 2012 to 2018, with the industry facing a growing challenge concerning methane slip.
Bay State brothers find industry niche by making old into new
Zero non-conformities is what you want to hear when the U.S. Coast Guard inspects your tugboat. Once you’ve prepared your vessel, the inspectors come aboard to peruse your paperwork. They ask you pointed questions, to which they expect straightforward answers. Perusal completed, they then scrutinize all of the related safety systems, from bilge to antennas — even the ship’s bell.
Signals
A year into the pandemic, thousands ‘essentially indentured’ on ships
Analysis points to faulty loading, low ballast in Golden Ray rollover
While the salvage of the sunken vehicle carrier Golden Ray has been delayed for months due to COVID-19 and the hurricane season, analysis by the U.S. Coast Guard has determined a possible cause for the rollover: a combination of vehicles placed too high on the ship’s decks, and not enough ballast water gave the placement of the cargo.
Seastreak newcomer pushing through dip in demand
Two years ago, Seastreak LLC took delivery of Seastreak Commodore, a 600-passenger fast ferry, from Gulf Craft of Franklin, La. Designed by Australia-based Incat Crowther, the vessel is the largest of its kind in the United States and was built to meet the burgeoning demand for service in the New York-New Jersey market.
New year in a new world: Navigating COVID's maritime realities
In a matter of days, the decorative time balls will drop, “Auld Lang Syne” will fill the air, and ships at anchor will sound their horns as the world welcomes in the new year.
Advanced props, rudders provide new efficiencies below the waterline
It took a decade or two from the invention of the marine propeller in the 19th century for the technology to become widely accepted. Thereafter, adoption has been nearly universal, but progress toward improved efficiencies has come in fits and starts.
