P-385-63 Range Safety Pamphlet Download

Chapter 9 Mortars 9–1. Firing conditions a. Firing mortars over the heads of unprotected troops by Army units is not recommended. Mortar ammunition must be certified for overhead fire of unprotected troops. The senior commander may approve overhead fire of unprotected troops with certified overhead fire mortar ammunition on the basis of acceptable level of risk. Procedural controls to prevent human error (for example, dedicated observer-controllers with the unprotected troops and firing mortars with dedicated communications) will be included in the risk management process. b. Firing mortars over the heads of troops by Marine Corps units is not authorized except when firing the Expeditionary Fire Support System (EFSS) M327 120mm rifled towed mortar. For the Marine Corps, mortars must be fired at the edge of a high hazard impact area. Requirements for overhead fire using the 120mm rifled towed mortar can be found in chapter 10. c. Overhead fire is allowed when Soldiers are in tanks with hatches closed 100 m or more from the line of fire. d. All personnel who take part in mortar firing will wear, for the Army, a minimum of IBA and helmet; for the Marine Corps, PPE Level 1. Refer to table 2–2. At the commander’s discretion, the gunner may remove their protective helmet while sighting the mortar. All personnel within the hearing hazard zone for the mortar, cartridge, or charge increment used will wear approved single hearing protection. The hearing hazard zone is usually defined in the manuals for the mortar or cartridges. If the hearing hazard zone information cannot be determined, single hearing protection will be required within 200 m. e. Propellant increments removed from rounds before firing will be placed in metal or wooden covered (water- proofed) containers located outside the firing vehicle or positioned a distance of at least 25 m from the firing point when firing dismounted. Unused powder increments must be safeguarded and handled in accordance with installation range and environmental regulations. f. M720, M721, M722, and M888 cartridges will not be fired above propellant charge 2 in the M2/M19 (60mm) mortar. g. No mortar cartridges will be fired in the hand-held mode with a charge greater than charge 1. h. No 800 series cartridges may be fired in the M29 (81mm) mortar except the M880 short-range target practice round. This also applies when using the M303 insert. i. When firing the 120mm mortar from the carrier, all crew members and personnel inside the carrier must wear double hearing protection. Double hearing protection is required regardless of the carrier ramp position (opened or closed). Double hearing protection is defined as any approved earplugs plus either a CVC helmet or a communication aural protective system/artillery communication aural protective system with personnel armored system for ground troops helmet. Personnel outside the carrier within 200 m must wear single hearing protection. j. Crew members and all personnel within 5 m of the 120mm mortar must wear double hearing protection when firing. k. When firing the 120mm ground mount and carrier mount configuration, using the M933E1 HE cartridge, all personnel within 5 m of the mortar are required to wear double hearing protection. Exposure is limited to 140 rounds in any 24 hours. l. Firing restrictions and limitations in TM 43–0001–28 apply to all cartridges and fuzes. Marine Corps fires will observe restrictions in TM 08655A–10A for light armored vehicle-mortar variants. m. The target engagement distance will not be less than the distance required for Area B of the respective caliber of mortar to be fired, unless fired from protected positions. 9–2. Surface danger zones a. SDZ requirements for 60mm, 81mm, and 120mm mortars are provided in table 9–1 and figure 9–1. b. Distance X is the maximum range of the weapon system at a given charge. Distance X will not be less than the maximum range of the greatest charge to be fired. Distance X may be past the downrange edge of the target area. c. Basic dimensions of the impact area will be computed as specified in table 9–2. d. Firing table probable errors corresponding to the maximum range of charge employed will be used for this computation. These basic dimensions are based on standard conditions. They do not compensate for errors or nonstandard conditions. e. To compute the probable errors in range and deflection, multiply the constant (listed in tab 9–2 and fig 9–1) by the data found in the tabular firing tables. These data are drawn in meters from the downrange edge of the target area for deflection probable errors (PE D) and from Distance X for range probable errors (PE R) . f. When firing ammunition with explosive warheads at distances equal to or less than the lateral hazard area (Area A), the angle between the weapon target line/lateral limits and the firing point will increase by the width of Area A. 107 DA PAM 385–63 • 16 April 2014