The lightweight ICCL has been approved with a number of optional communication devices, including a PED pager to receiver text messages from a through-the-earth PED transmission system.

MST said installation at many of the underground coal mines in the US would be straight forward because the ICCL can be used with Koehler's Mark V headpiece, meaning only minor electrical modifications are required for some of the existing charging racks.

The ICCLs and PED systems will be supplied to eastern US coal mines by CSE Corporation. CSE's Chuck Edwards said the introduction of ICCL technologies offers mines an option to meet their responsibilities under the MINER Act.

On-going developments and approvals will allow the ICCL to include an IS Radio module and a two-way PED module, allowing through-the-earth signalling between people underground and at the surface.

"This complementary set of communications systems available, and the inherent redundancy they achieve, should ensure very high quality emergency communications at many times," Edwards said.