Radicals Distort Facts on New Navy Sonar

The U.S. Navy has made great progress in developing a new sonar system to detect enemy submarines, and to no one’s surprise, radical environmentalists are on the warpath.

Surveillance Towed Array Sensor System (SURTASS) consists of a surface ship towed long acoustic array, outfitted with hydrophones that can detect underwater sound signals with environmental sensors and other electronic components. It’s what our hotshot engineers developed when the Soviets actually began to quiet their submarines following the John Walker spy scandal in 1985.

Until then, their subs were so noisy that finding them was the least of our worries. Once they discovered how quiet our subs really were, and how well we could track and even follow their boats, they undertook a crash program to quiet their subs. The results were pretty impressive.

Stealth had arrived underwater. To keep the books balanced, our subs also got quieter, so much so that they became virtually undetectable, so that the balance of stealth remained essentially unchanged.

It became a race between our own SURTASS developers and our sub designers to see whether we could continue our uninterrupted string of successes in detecting state-of-the-art Soviet sub technology.

The hands-down winners were the sub designers – they created a stealth design so effective that the SURTASS detection range shrank close to zero. By the mid-1990s, our submarines were virtually undetectable – by anybody.

There is a way to overcome this, however. We all have watched World War II movies about submarine warfare, accompanied by the eerie warbling of active sonar and the resulting ping echo. Sonar was developed during World War II and was instrumental in helping the Allies win the war against the underwater menace of enemy submarines.

Active sonar, as it is called, has two limitations, however. By using it, a ship, and particularly a submarine, gives away its location. Furthermore, even with the enormous power levels developed in the 1970s, active sonar is severely range limited. Seawater is a powerful sound absorber.

Ingenious designers developed methods to overcome some of the range limitations by taking advantage of the very characteristics of seawater that limited range in the first place. Using refraction caused by increasing pressure at depth and density differences caused by temperature and salinity variations, they were able to extend active sonar ranges into the tens of miles, and when conditions were just right, sometimes even farther.

But that was it – sound simply couldn’t go any farther. That is, sound in the frequency ranges that had been used up until then.

Enter LFA – low Frequency Active.

By shifting the frequency well down into the very low sonic range, if you can pump sufficient power into a pulse, you can send sound for very long distances in seawater. The key was finding a way to put sufficient power into the pulse, and to aim it in some fashion, so that the power went where it was intended.

Navy researchers had always been aware that active sonar affects marine mammals. From the beginning, their sonar research projects took this into account. The effects they observed were dramatic at close range, but dissipated with increasing distance from the transmitter.

With the increasing sophistication and power of the new LFA, questions began to arise about the safety of marine mammals exposed to these increased power levels. The Navy was determined to develop LFA, but not at the expense of significant damage to marine life.

Since July 1996 the Navy has spent over $16 million in preparing an environmental impact statement for the SURTASS – LFA. The Navy plan was guided by five underlying principles:

* Conduct a study on the potential effects of low frequency sound on marine life and human divers.
* Maintain scientific rigor throughout the study.
* Use an independent scientific team to review and edit the statement.
* Preserve an open process with public engagement.
* Ensure funding is available for scientific research to address critical data gaps and to furnish a meaningful and understandable document to the public.

The study involved nine steps:

1. Literature review and determination of data gaps.
2. Scientific screening of marine animal species for potential sensitivity to low frequency sound.
3. Scientific research on the effects of low frequency sound on humans in water.
4. Scientific research on the effects of low frequency sound on marine mammals.
5. Development of a method for quantifying risk to marine mammals.
6. Analytical acoustic modeling of representative cases for the deployment of SURTASS LFA sonar.
7. Estimation of marine mammal stocks potentially affected.
8. Estimation of potential effects on fish and sea turtles stocks.
9. Establishment of mitigation and monitoring to reduce potential effects to a negligible level.

The Navy set up its tests in three phases. The details of these tests and their results are reported in detail at the Navy’s SURTASS-LFA website. The bottom line is that there were no serious consequences to any sea life. In fact, some species of whales seemed to enjoy the high intensity low frequency sounds, even blending their songs into the LFA transmissions.

Despite these somewhat unexpected results, the Natural Resources Defense Council (NRDC) initiated a lawsuit against the Navy, alleging widespread marine mammal injuries resulting from the Navy’s tests. In association with Greenpeace and other radical environmental groups, the NRDC has created a series of websites purporting to demonstrate the alleged damage.

Most of these sites can be found by entering the words “SURTASS LFA” and “NRDC” or “Greenpeace” in a web search engine (such as Google). Universally, these sites contain distortions, misinformation, and outright lies. The authors of these sites typically haven’t a clue about how the universe really works, and apparently are too ignorant to do their homework before “publishing” their information.

I discovered during my research for this article, that many of the current crop of environmental naysayers were active about a decade ago in trying to prevent the launch of a series of space probes from Cape Canaveral – probes containing RTG power sources, radioactive thermal generators. These small, long-lasting power sources contain a tiny pebble of plutonium; it was this that these folks were protesting against. Apparently they were concerned that these probes might contaminate the pristine deep space environment. They had not the slightest comprehension that deep space is a boiling cauldron of radiation and other active ionizing particles, or that anything humans might add would be like a drop in the ocean.

So they are at it again, but this time, their high-powered attorneys, paid by donations from little old ladies conned into donating their nickels, dimes, and hundred dollar bills, are making advances in court. The result is that the Navy has been restricted at least temporarily from operating its LFA equipment anywhere but in a remote area of the Pacific.

Remember that this research is vital to our being able to detect state-of-the-art enemy submarines before they can launch missiles against our homeland.

The Navy took full account of the potential damage from LFA to marine life, and is maintaining this careful attitude throughout current testing and future deployment of this vital tool. We simply cannot let misguided eco-fascists use our courts against the common good of our entire nation.

It is time for men and women of reasonable perspective to explain the facts of life to these misanthropes who place the welfare of animals before the safety of human beings.

Robert G. Williscroft is DefenseWatch Navy Editor

Submariner, diver, scientist, author & adventurer. 22 mos underwater, a yr in the equatorial Pacific, 3 yrs in the Arctic, and a yr at the South Pole. BS Marine Physics & Meteorology, PhD in Engineering. Authors non-fiction, Cold War thrillers, and hard science fiction. Lives in Centennial, CO.

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