A computerized safety tracking and proximity warning system for personnel (10-20, 68-78, 92, 94, 96), plant and equipment (22-24, 60-66, 96, 98) operating both above and below ground and moving between above and below ground, the system comprising: a plurality of transponders carried or worn by the personnel (10-20, 68-78, 92, 94, 96) and attached to the plant and the equipment (22-24, 60-66, 96, 98); a central computer in wireless communication with the plurality of transponders via one or more wireless communication protocols; and a visual display; wherein an alarm is triggered upon determining that the distance between any two of the personnel (10-20, 68-78, 92, 94, 96), plant and equipment (22-24, 60-66, 96, 98) carrying transponders is below a predetermined value; wherein the central computer is adapted to: wirelessly receive position information from each of the plurality of transponders and process the received position information to determine relative positions of each of the personnel (10-20, 68-78, 92, 94, 96), plant and equipment (22-24, 60-66, 96, 98) carrying transponders, to each other; and display the relative positions of each of the personnel (10-20, 68-78, 92, 94, 96), plant and equipment (22-24, 60-66, 96, 98) carrying transponders in real time on the visual display; characterised in that the system further comprises a sensor configured to detect any sudden deceleration or change in direction by the personnel (10-20, 68-78, 92, 94, 96) indicative of possibility of a fall, or if there has been no movement by the personnel (10-20, 68-78, 92, 94, 96) over a predetermined period of time; wherein the alarm is also triggered upon detecting one or more of the sudden deceleration, the change in direction or no movement by the personnel (10-20, 68-78, 92, 94, 96) over the predetermined period of time; and the alarm continues to be triggered as pulses in a power saving mode until extinguished or switched off to enable detection and/or location of the personnel (10-20, 68-78, 92, 94, 96) who are required to be rescued over a period of time. a plurality of transponders carried or worn by the personnel (10-20, 68-78, 92, 94, 96) and attached to the plant and the equipment (22-24, 60-66, 96, 98); a central computer in wireless communication with the plurality of transponders via one or more wireless communication protocols; and a visual display; wherein an alarm is triggered upon determining that the distance between any two of the personnel (10-20, 68-78, 92, 94, 96), plant and equipment (22-24, 60-66, 96, 98) carrying transponders is below a predetermined value; wherein the central computer is adapted to: wirelessly receive position information from each of the plurality of transponders and process the received position information to determine relative positions of each of the personnel (10-20, 68-78, 92, 94, 96), plant and equipment (22-24, 60-66, 96, 98) carrying transponders, to each other; and display the relative positions of each of the personnel (10-20, 68-78, 92, 94, 96), plant and equipment (22-24, 60-66, 96, 98) carrying transponders in real time on the visual display; characterised in that the system further comprises a sensor configured to detect any sudden deceleration or change in direction by the personnel (10-20, 68-78, 92, 94, 96) indicative of possibility of a fall, or if there has been no movement by the personnel (10-20, 68-78, 92, 94, 96) over a predetermined period of time; wherein the alarm is also triggered upon detecting one or more of the sudden deceleration, the change in direction or no movement by the personnel (10-20, 68-78, 92, 94, 96) over the predetermined period of time; and the alarm continues to be triggered as pulses in a power saving mode until extinguished or switched off to enable detection and/or location of the personnel (10-20, 68-78, 92, 94, 96) who are required to be rescued over a period of time. wirelessly receive position information from each of the plurality of transponders and process the received position information to determine relative positions of each of the personnel (10-20, 68-78, 92, 94, 96), plant and equipment (22-24, 60-66, 96, 98) carrying transponders, to each other; and display the relative positions of each of the personnel (10-20, 68-78, 92, 94, 96), plant and equipment (22-24, 60-66, 96, 98) carrying transponders in real time on the visual display; characterised in that the system further comprises a sensor configured to detect any sudden deceleration or change in direction by the personnel (10-20, 68-78, 92, 94, 96) indicative of possibility of a fall, or if there has been no movement by the personnel (10-20, 68-78, 92, 94, 96) over a predetermined period of time; wherein the alarm is also triggered upon detecting one or more of the sudden deceleration, the change in direction or no movement by the personnel (10-20, 68-78, 92, 94, 96) over the predetermined period of time; and the alarm continues to be triggered as pulses in a power saving mode until extinguished or switched off to enable detection and/or location of the personnel (10-20, 68-78, 92, 94, 96) who are required to be rescued over a period of time.