Thumper, an acoustic signaling and locating system, is being developed by the Ohio-based firm and partners Pacific Scientific Energetic Materials and GeoSonics/Vibra-Tech.

It comprises a vibrating pulse through-the-earth signal generator and surface deployed receivers.

It leverages hardware developed for the military, where millions of dollars have already been spent in achieving state-of-the-art technology advancements.

“It generates ten times the energy that a healthy man with a sledgehammer could create when striking a rail to help rescuers pinpoint location,” according to research leader Jim Reuther and principal research engineer Rick Givens.

With a design based upon a series of propellant cartridges surrounding a center barrel, similar to a Gatling gun, Thumper will be a gas-driven impacting device that will generate a seismic pulse signal – even possessing special impact cycles to impress specific codes to assist rescuers in locating miners – for multiple days via replaceable magazines.

While the system is designed to create the “ping” via ignition of small propellant devices arranged around an internal chamber, Reuther and Givens stress that the system’s gasses will in no way serve as an ignition source with potentially elevated levels of methane gas following an emergency event.

“It is a very tiny charge, very safe,” Reuther said.

Thumper, which is envisioned to be a last resort system when there is no other means of escape and all other communications have been destroyed, will operate with the thumper itself (“feet”) and receivers (“ears”) which will be pre-deployed in small surface drill holes to improve reception through the strata.

Thumper is in the development phase and testing dates have already been set for 2012 when Battelle will be examining the system’s capabilities at different mine depths.

Published in the December 2011 Coal USA Magazine