Thought you might find this of interest.

The present system involves CW sent by a hammer against rocks. <grin>
By the way, the surviving miner, Randal McCloy  is a ham.
 

-- forwarded article --



Pittsburgh, Pa.
Friday, June 9, 2006

Initial two-way tests for wireless mine communicators show promise

Improvements sought in methods for contacting the surface

Friday, June 09, 2006
By Steve Twedt, Pittsburgh Post-Gazette

The head of the nation's mine safety agency said initial tests of wireless two-way communication systems for underground mines have shown promising results.

   

RELATED STORY
U.S. calls UMW lawsuit over emergency oxygen pack inspections 'a stunt'
  
 

   


One prototype system produced a cell-phone quality signal more than two miles underground, according to David G. Dye, acting administrator of the Mine Safety
and Health Administration.

That system, made by Kutta Consulting of Phoenix, uses medium frequency radio signals relayed through the mine's metal infrastructure.

TeleMag, made by Pittsburgh-based Transtek, was the only system to transmit a voice signal through the earth at 270 feet. It uses very low frequency magnetic
fields.

"We are hopeful that the systems being tested will provide long-sought solutions to the daunting challenge of communicating miles into the earth to help
miners safely evacuate during an emergency," Mr. Dye said in a statement released yesterday.

The need for effective two-way communications in U.S. mines became tragically evident Jan. 2 when 13 miners were trapped inside Sago Mine No. 1 in Upshur
County, W.Va.

After making at least one attempt to escape, the miners tried to barricade themselves from the carbon monoxide atmosphere while awaiting rescue. Only one
of the miners, Randal McCloy Jr., survived.

Many now believe mine rescue officials on the surface could have talked the miners out to safety if they could have communicated with them.

On Wednesday, Congress gave final approval to the Miner Act, which calls for underground mines to have two-way wireless communication within three years.

Testing has already begun on both communication and tracking systems.

Beginning in late March, MSHA officials tested six systems at two mines owned by Consol Energy Inc., paying particular attention to systems that have the
best chance of working after a catastrophic event like a mine fire or explosion.

The Kutta system successfully produced a cell-phone quality transmission at 11,600 feet, according to MSHA. No other system went beyond 1,679 feet.

Kutta's low-frequency, one-way text signal worked at 900 feet underground, and its two-way text worked at 631 feet.

TeleMag was the only voice system to get a through-the-earth signal at 270 feet.

Additional testing will be done in coming months. MSHA officials say they've received numerous proposals for new systems from manufacturers and distributors
and "additional proposals continue to come in on a daily basis."

(Steve Twedt can be reached at
[log in to unmask]
or 412-263-1963. )


M

Mark Senk | [log in to unmask] 
412 386-6513
http://www.cdc.gov/niosh/npptl/