ACT president Steve Barrett said the two purchase orders comprised 94 ActiveMine nodes to be placed in the active sections of the operations and would include all federally approved network equipment, handsets and tracking capabilities.

"Our new customer selected ActiveMine because of the productivity gains it makes possible," he said.

Barrett added that the orders complied with US Mine Safety and Health Administration regulations requiring emergency response plans for all underground coal mines in the nation by June 15.

Emergency communication and tracking plans were required to be included in all submitted ERPs.

Barrett expects ACT to further grow its customer base and orders as ERPs are approved by MSHA in the coming months.

In May, the company won a contract to expand a 1-month-old ActiveMine installation at a West Virginia mine, creating the largest federally approved wireless Wi-Fi mesh network in the US.

Barrett earlier told ILN the installation of seven additional nodes and associated network equipment for the undisclosed operation had been wrapped just weeks after the initial installation was completed.

The 57-node system was adjusted for the customer, ACT said, because the mine had both faces backed up with redundant nodes that covered both the primary and secondary escapeways.

ACT received federal approval for the final component of ActiveMine, the wireless Wi-Fi telephone units, in late April. The first regulatory approval for the system was for its RFID Wi-Fi Tags, which were deemed intrinsically safe in September 2008.