Underground safety communication technology

Sydney company Tiller + Tiller has developed an underground communications technology for the mining industry. The technology is for use on the integrated communications cap lamp (ICCL), which is a lightweight cap lamp developed to incorporate a range of communications and safety technologies.

The PED (personal emergency device) System is an ultra low frequency 'through-the-earth' communication, control and blasting system. It is the only commercially available and proven, through-the-earth mine communication system available.

The system provides a fast and reliable method of informing underground miners of emergency situations, making it an extremely effective emergency system. The ability to transmit actual messages allows a warning to be issued, along with specific information regarding the situation (such as where a fire is and which evacuation route to take).

The use of low frequency (ULF) electromagnetic frequencies enables the PED signal to propagate through several hundreds of metres of rock strata. The signal can therefore be received at any location throughout the mine with either an antenna on the surface or a small underground antenna.

The PED pagers (BeltPEDs and ICCLs) are fitted to the miner's cap lamp battery. The PEDs will display any message up to 32 characters in length.

On reception of a valid message the cap lamp will flash (full to half brightness) and a buzzer will sound. The message is displayed on a backlit LCD.

The units will store two messages and the pagers can be paged individually or in groups.