[CINC] Did you know?

[Ron Dreher]

Ear to the water 


Bob Kieding 






 


 


 

June 4, 2008 7:36 AM

The Santa Barbara Channel and its islands encompass many diverse activities
- fishing, shipping, research, yachting, resource extraction, and many more.
One operation not well known by the public is underwater acoustic research.

Underwater acoustics include the process of monitoring or using undersea
sound for a variety of applications. The sound can be natural or created.
During the Cold War and beyond, underwater acoustics projects were
significant activities that took place on the back side of Santa Cruz
Island. General Motors, followed by its successor Maripro, conducted a
variety of operations that ranged from top secret defense work to those of
pure academic interest.

Many of us were captivated by the film "The Hunt for Red October," an
exciting cold-war yarn about the search for a dangerous Soviet spy
submarine. The tracking technology in the film was based on using
hydrophones (underwater microphones). This was the same cornerstone
technology that was being used at the Santa Cruz Island acoustic facility.
Basically, the Santa Cruz Island range consisted of a number of submerged
hydrophones, located at considerable depth, and connected by cables running
ashore to computers that accumulated data for a variety of uses.

There were several reasons for collecting underwater sound data. The most
dramatic was the "Red October" mission. Underwater sound monitoring systems
located at various strategic locations in the oceans of the world were used
to track Soviet submarines and warships to determine their location as well
as what mischief they might be up to. Despite great care to minimize it, all
submarines and ships generate a unique acoustic "signature" that allows
identification. It is assumed that the Soviets were also monitoring U.S.
vessels for similar signatures.

A second use of underwater acoustics for defense purposes is to try to make
your own vessels as immune as possible to identification and detection by
other nations. This was a major activity at the Santa Cruz Island facility.
U.S. submarines were driven through the acoustic range, and data was
evaluated to determine if they were as "quiet" as possible and if they had
tell-tale signatures. With tracking range data, the vessels could then be
modified to reduce any detected problems. I can recall a number of cases
where the entire 22-mile back side of Santa Cruz Island was declared
off-limits to all vessels because a super secret U.S. submarine was being
run through the range.

Another major application of underwater acoustic tracking is for weapons
testing and evaluation. The premier location for such activities is AUTEC
(Atlantic Underwater Test and Evaluation Center) which is located near the
Bahamas Islands. It can evaluate both in-air and underwater weapons using
above-water technologies such as radar and photography, as well as
underwater acoustic tracking arrays. A classic application would have an
aircraft fly down-range and launch a weapon that would fly a portion of its
mission in-air and then enter the ocean as a torpedo type delivery system.
The Santa Cruz Island tracking range conducted underwater, but not in-air
testing and evaluation.

The Santa Cruz range also operated two unique vehicles. One was POP (for
Perpendicular Ocean Platform). This was a long, tubular ship over 100 feet
in length. When partially filled with seawater, POP would sink at one end
until it was in a vertical position with only a portion above water level.
With almost a hundred feet of the POP under water, the above water portion
was as steady as a rock - even in rough winds and seas. This made it an
ideal at-sea scientific platform for the conduct of motion sensitive
projects. One night, POP came loose from its mooring and was carried up the
island by ocean currents. Next day, the Coast Guard received a radio call
that there was a vessel aground in mid-channel between Santa Cruz and Santa
Rosa Islands. The position given had the vessel in over ninety feet of
water. This seemed impossible until it was learned that POP in its vertical
position had a draft of over ninety feet.

The second unique vehicle was DOWB (for Deep Ocean Work Boat). DOWB was a
two-person, deep water submarine that was capable of operating over a mile
beneath the ocean. It had remote-controlled "arms" to perform underwater
tasks, and was used at various locations around the world as well as waters
off the back side of Santa Cruz Island.

In addition to defense related applications, the Santa Cruz Island range was
also used for scientific research. Sound is continually being generated in
the sea by geological, weather, creature related, and other sources. In
addition to defense projects, much pure science was studied and evaluated on
the range

The Santa Cruz Island facility was closed down several years ago. It was
dismantled with great care to ensure that both the island and its
surrounding waters were returned to their original condition. That is not to
say that underwater acoustics is no longer a prime activity elsewhere. Our
government continues to operate several acoustic ranges at various locations
for defense and scientific applications. Technology is ever-changing, and
our oceans continue to be one of the major areas where new science and
discoveries occur.

SEA TERMS

Hydrophone - An underwater microphone that has been designed to be immune to
damage from water and extreme underwater pressure.

Acoustic - Pertaining to the hearing, to sound and its transmission; worked
by sound or echoes. Acoustics - a branch of physics that studies sound.









Draft - The distance from the waterline to the bottom of a boat. Important
to know when operating in shallow water to avoid running aground.

 

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