# Chapter 22: Remote Firing Systems ## Learning Objectives - Explain remote firing systems and their purpose. - Describe the components and basics of a remote firing system. - Describe how to use a remote firing system. - List the general safety precautions for working with remote firing systems. --- ## Overview Remote firing systems allow blasters to initiate shock tube or electric detonators from a remote location. The remote-control technology in these systems allows blasters to increase their distance from blasts to help ensure safety. As a result, blasters are free to move around to achieve both the safest firing position and the preferred viewing position. A remote firing system is a set of electronic initiating devices for a shock tube assembly set-up or an electric initiation system. The blaster of record must have an endorsement for remote firing systems on their blasting certificate, as well as an endorsement for the initiation system being used. --- ## Components and Basics A remote firing system is made up of electronic initiating devices that contain no explosives. One or more remote units are placed at the blast site. A shock tube or firing cable (shot line) runs from each remote unit to the detonators. The controller is placed at a distant, safe position. The devices communicate with two-way, digitally encoded radio signals. When it's time to initiate the blast, the blaster uses the controller to send a firing signal to the remote units. These systems are designed to have highly reliable communications. This helps ensure successful full-scale testing, programming, and firing of blasts. Users need to be fully trained and understand the capabilities and limitations of these systems. Distance limitations, weather conditions, line-of-sight requirements, RF interference, and other factors all play roles in communication reliability. The blast site should be cleared of all workers before connecting a remote unit. ### Controller The controller is responsible for initiating all communications with the remote units. The controller fires the remote units and reports that blast movement was detected. ### Remote Units When firing, the remote unit's shock tube circuit develops a high-voltage spark to initiate shock tube lead-in line. Each remote unit includes shock tube igniter tips and an antenna. The igniter tips are designed to be rugged and to perform a rated number of shots before they need to be replaced. Some remote units may also fire electric detonators. The remote units are normally positioned at protected locations relatively close to the blast site. --- ## Using a Remote Firing System ### Setting Up the Controller When setting up the controller, do the following: - Ensure the controller is sufficiently charged and tested according to the operation manual. - Make sure the controller's antenna is installed correctly. - Ensure the controller key is removed (if applicable). - Do not turn on the controller near electric detonators. ### Setting Up a Remote Unit When setting up a remote unit, do the following: - Ensure the remote unit is sufficiently charged and tested according to the operation manual. - Position the remote unit at a safe location but close to the blast site. - Make sure the remote unit's antenna is installed correctly. - Turn the remote unit to the "power on" position. Then confirm that the battery light is steady and not flashing. - Ensure the battery reads the minimum required voltage. - Make sure that: - The shock tube is firmly connected into the jack on the remote unit, or - The electric detonator wires are connected properly to the binding posts. - When inserting the key into the remote unit, ensure the indicator light shows the key is active. - Select the electric detonator or shock tube firing circuit. - Close and fasten the lid on the unit. - Repeat these procedures for each additional remote unit to be fired. ### Firing the System To fire the system, do the following: - Check the system's status light on the controller. Does it show that the system is ready? - Insert the controller key (if applicable). - Arm selected remote units. - Wait for lights to indicate the remote units are armed. - Fire the system when ready. - When the status light shows that the action has been completed, turn off the power. - Remove the controller key (if applicable). ### System Operation Notes The system can be used repeatedly throughout an operation. The blaster can use the controller to check the status of any or all of the remote units. Most remote units can usually be held in the standby (disarmed) mode for 12 or more hours and still maintain the energy to initiate the shot. In most systems, if the remote units do not receive a properly addressed firing signal within two minutes of being armed, the system will automatically return to the disarmed state. Controllers and remote units are typically housed in rugged, watertight cases with vents to equalize pressure. The electronics are specially mounted to help prevent damage from shock and vibration from blasting, transportation, and mishandling. --- ## General Safety Precautions - Remote firing systems can pose additional challenges when clearing an area. For example, visibility may be an issue in some situations, such as underground blasting. - Remote firing systems should be tested and verified before connecting them to any blast circuit. - Do not touch the shock tube tip or output jacks when arming or firing, as contact may result in serious injury or death. For tip-handling procedures, always refer to the manufacturer's operation manuals. - Prevent debris and moisture from entering the shock tube tip or tube.