Posted on 11/07/2005 4:46:54 PM PST by ElkGroveDan
The crew of a luxury cruise ship used a sonic weapon that blasts earsplitting noise in a directed beam while being attacked by a gang of pirates off Africa this weekend, the cruise line said Monday.
The Seabourn Spirit had a Long Range Acoustic Device, or LRAD, installed as a part of its defense systems, said Bruce Good, a spokesman for Miami-based Seabourn Cruise Line. The Spirit was about 100 miles off Somalia when pirates fired rocket-propelled grenades and machine guns as they tried to get onboard.
The subsidiary of Carnival Corp. was investigating whether the weapon was successful in warding off the pirates, he said. The ship's captain also changed its course, shifted into high speed and headed out into the open sea to elude the pirates, who were in two small boats, he said. He had no further details.
Device maker American Technology Corp. said earsplitting "bangs" were directed by trained security personnel toward the pirates. That, combined with ship maneuvers, caused the attackers to leave the area, the company said.
The LRAD is a so-called "non-lethal weapon" developed for the U.S. military after the 2000 attack on the USS Cole off Yemen as a way to keep operators of small boats from approaching U.S. warships.
The military version is a 45-pound, dish-shaped device that can direct a high-pitched, piercing tone with a tight beam. Neither the LRAD's operators or others in the immediate area are affected.
American Technology, based in San Diego, compares its shrill tone to that of smoke detectors, only much louder. It can be as loud as about 150 decibels, while smoke alarms are about 80 to 90 decibels.
The devices have been deployed on commercial and naval vessels worldwide since summer 2003, the company said.
Sound travels in waves through the air like waves through water. The higher the wave, the greater its power. The greater the number of waves a sound has, the greater is its frequency or pitch.
The strength of sound, or sound level, is measured in decibels (dB). The frequency is measured in Hertz (Hz) (cycles per second). The human ear does not hear all frequencies. Normal hearing ranges from 20 Hz to 20,000 Hz or, roughly, from the lowest note on a great pipe organ to the highest note on a violin. Our ears hear very low and very high pitched sounds more faintly than those sounds in our normal conversation pitch, between 300 and 4,000 Hz.
The decibel scale is logarithmic (based on powers of ten), not linear like a ruler. Therefore, a small increase in decibels represents a great increase in intensity. For example, while 10 decibels is 10 times more intense that one decibel, 20 decibels is 100 times more intense (10 X 10, rather than 10 + 10), 30 decibels is 1,000 times more intense (10 X 10 X 10), and so on. The sound intensity multiplies by 10 with every 10-decibel increase. The reason for such a scale is simply that the human ear is sensitive over such a wide range of acoustic energy that the numbers involved had to be compressed for convenience.
In some ways, the decibel scale resembles the Richter scale for earthquakes. A small numerical increase represents a great increase in intensity.
The ear can detect a very slight change in noise intensity. Even a small reduction in decibels then can make a difference.
I agree. I think this report is a crock of...
I have a boom-boxer in the condo next door.....
Guaranteed: 100W in a 2 or 3 mm dia beam @ 10.6µm wavelength would drive ALL thoughts of what they were going to do to the ship from their minds. And, with good aim, probably touch-off their munitions too.
I think a Ma Deuce (i.e. 50BMG belt fed) without a silencer would make a more effective noise.
You can skeet-shoot on a lot of those ships. I say just hand anyone who wants one a shotgun/AR-15/whatever you have handy, and tell them the pirates are the new clay pigeons.............
Classical music is supposed to work like a charm.
"This might be whole new spectator sport: Cruises that let you open fire on terrorists/pirates. If you can shoot skeet from a cruise ship, why not terrorists/pirates? The possibilities are endless."
I think skeet shooting has been abandoned on cruise ships since the aftermath of 911. If not , please inform as to which lines allow it .
I like it, all except for the "non-lethal" part. This way, the pirates live to pirate another day.
Maximum SPL tone : 146dB sustained 151dB burst at 1 meter
Normal Operation : 120dB at 1 meter
Me too. I suppose with real calm seas maybe. But we may be beyond the limits of Zodiacs fuel supply as in onboard fuel capacity. Yes you can strap on cans/bladders but you start to be a floating explosive. Mother ship? As posted by others already.
Who cares who allows it. It doesn't matter.
I'm not convinced of your numbers. I am aware of car stereo competitions that regularly exceed 148db. I witnessed one vehicle several years ago that was closing in on 160 db. Because of the danger, operators are not allowed to run the systems from within the vehicle, instead turning it on/operating it by remote.
It does seem unlikely that a hand-operated device could achieve such high db's, but then again, depending upon the frequency, it might very well be possible - I just don't know that the db would be so high at any distance.
"Neato. I want one. I bet it would work great to clear my neighborhood park of teenagers after dark.
I have GOT to get me one of those too!
One meter?
If this were true, I can't imagine it would be reported.
The "mother ship" is one possibility. Another is that the news reports on the ship's position are wrong.
Either way, I am sure that Zodiacs were not operating unassisted 100 miles off shore.
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