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American Lighthouse Foundation, Inc.
P.O. Box 565
Rockland,
Maine 04841
Phone: 207-594-4174
Fax: 207-596-1091
info@lighthousefoundation.org
The American Lighthouse Foundation is a
Non-Profit 501(c)(3) Organization dedicated to the
preservation of America's historic
lighthouses & lightships and
their heritage.
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Coast Guard Loans Mechanical “Keeper” to
Lighthouse Museum
By Bob Trapani, Jr.
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After standing silent sentinel at a lonely Maine
lighthouse for a number of years, a faithful “keeper” has been retired
for good by the United States Coast Guard – a mechanical “keeper” that
is.
During a recent American Lighthouse Foundation benefit
dinner held in Rockland, Maine, U.S. Coast Guard Chief Charles Petronis,
officer-in-charge of the USCG Aids to Navigation Team (ANT)
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Photo by Bob Trapani, Jr.
BMC Charles Petronis, officer-in-charge
of USCG Aids to Navigation Team Southwest Harbor, Maine, explains how a
Videograph "B" Fog Detector works during ALF's benefit dinner in
Rockland
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in Southwest Harbor, and Captain Stephen P. Garrity, Commander, Sector Northern New
England, presented the nonprofit lighthouse preservation organization
with a valuable piece of America’s modern lighthouse history in the form
of a loaned Videograph “B” Fog Detector.
This little-known piece of equipment may have outlived its usefulness at a
lighthouse but the fog detector will now embark on a new life as a unique
educational artifact on display at the Museum of Lighthouse History in
Wells, Maine, which is owned and operated by the American Lighthouse
Foundation.
So just what is a Videograph “B” Fog Detector one might ask? You could say
it was technologies’ replacement for the human eyes of a lighthouse
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Photo by Bob Trapani, Jr.
A close-up view of a Videograph "B" Fog
Detector "on watch" at Goat Island Light Station in Maine
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keeper. Though the United States Lighthouse Service began the process of
automating the lights in our nation’s lighthouses as early as the 1920s
through the use of compressed gas and devices that could sense light and
darkness, foghorns were an altogether different challenge.
When mariners could not see the shining light of a lighthouse during times
of thick weather, warning them of coastal dangers, they listened intently
for the bellowing sound of a foghorn to save them from life-threatening
hazards such as rocky ledges and sandy shoals. No matter how experienced a
ship captain and his crew were, they
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would be quick to say that the approach of fog – and its sinister ability to
completely shroud the seascape in a dangerous grip of a murky wet mantle,
was their most dreaded nemesis.
Science would remain mystified for many years in the wake of automatic
beacons when it came to developing machinery that could sense fog and
immediately activate a foghorn at a lighthouse. Until both an automatic
light and reliable fog sensing equipment could be combined at a light
station, human personnel would still be required at key lighthouses. This
gap in technology is primarily responsible for many lightkeepers enjoying an
extended reprieve of more than sixty years following the introduction of the
automatic light before nearly every Coast Guard keeper was finally removed
from lighthouses by the end of the 1980s.
Technology would eventually overcome this dilemma in the 1980s when the
Coast Guard introduced the Videograph “B” Fog Detector to light
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stations
prone to being obscured by fog. Not only did this equipment save the Coast
Guard money by the removal of human keepers; the Videograph “B” Fog Detector
had a “soothing” effect on nearby communities as well. Prior to this
advancement, some foghorns sounded 24-hours a day once the keepers were
removed, regardless of weather conditions. Naturally, not every person
living along coastal communities thought the ceaseless deep drone of a
foghorn was romantic, and thus yearned for the time it could be silenced.
Visitors to the Museum of Lighthouse History will be fascinated at how the
electronic “eyes” of a Videograph “B” Fog Detector work. According to a U.S.
Coast Guard document describing the function of the |
Photo by Bob Trapani, Jr.
The Videograph "B" Fog Detector, which is
located in the window at the base of Goat Island Lighthouse, acts as the
tower's automated "eyes" as it monitors for foggy conditions
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equipment, “The Videograph “B” is made up of two principal parts, the projector and the
receiver.” Essentially, this mechanical “keeper” is constantly sending out
strobe-type flashes of light into the atmosphere from its projector. As the
light is projected it encounters air particles such as dust, smoke, snow,
rain and fog. Once the light hits these particles, it refracts in many
directions – including back to the fog detector where the receiver monitors
what is called back scattered light.
The Coast Guard document goes on to note, “During a light fog, only a small
portion of back scattered light is returned to the fog detector. This small
portion of light is converted to a small amount of electricity. As the fog
becomes thicker or denser, the amount of light increases and the level
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Photo by Ann-Marie Trapani
(L to R) Tim Harrison, ALF president,
Captain Stephen P. Garrity, USCG
Commander, Sector Northern New
England, BMC Charles Petronis, USCG
ANT Southwest Harbor and
Bob Trapani, Jr., ALF executive director
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of electricity increases until finally it reaches a point that will exceed a
setting in the fog detector, and turn on the sound signal (foghorn).”
The Videograph “B” Fog Detector served the Coast Guard well over the years,
having been supplanted by similar but newer technology called the VM-100 fog
detector in the last decade. Though its days in service are numbered, its
place in America’s lighthouse
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history has been firmly established. Its legacy will now be perpetuated and
interpreted for the public’s benefit at places like the Museum of Lighthouse
History in Wells, Maine, for generations to come.
Posted: 7/17/06 |
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