If anyone in charge of people's lives is watching... please check these
websites...

for buying time when the air is thin, or blackdamp situations:
http://www.submersiblesystems.com/

Gives some extra time for evac...
in a "trap" situation, not much one can do, as the problem is getting the
air scrubbed of CO2 and CO or whatever other gas is about.

for Mine/cave radio system stuff:
http://www.infomine.com/index/suppli...y_Limited.html
and
http://bcra.org.uk/creg/

rb



"Alien" wrote in message
...
In article ,
"Brenda Ann" wrote:

"Alien" wrote in message
...
In article ,
mike murphy wrote:

In article ,
"Hamguy" wrote:

KC8VKZ

very sad situation:

Kind of strange they don't have any kind of decent ( even primitive)
comm system in place in the mines

Each miner should be carrying personal communications like
firefighters.

The problem with that being that when they are two miles deep in the
mine,
radio comms are all but worthless. To get comms for the rescue workers,
they
had to relay by radio from two points, then by wire from the last relay
point to the command center. One might suggest repeaters every so often,
but
these could easily be damaged or destroyed during an explosion or
cave-in.

I thought there were some freq which would pass thru rocks and earth to
great depths. LF perhaps, but that would present other problems. There
must be some way for them to reliably communicate other than by wire.