Ammunition management/resupply for the light infantry mortar

Infantry Magazine, Summer, 2002 by Brian A. Hamm

The integration and effectiveness of the light mortar is only as good as the ammunition plan, management, and resupply procedures. The amount of ammunition available is an important consideration in the attack of targets. When this is low, missions should be limited to those that contribute to mission accomplishment. When the controlled supply rate (CSR) is high, missions fired may include targets that require the massing of fires without adjustment. The CSR is designed to limit the number of rounds per weapon per day.

CSRs are imposed for two reasons--to conserve ammunition and to avoid a shortage for a tactical operation. During the fire support planning, ammunition requirements must be considered. Thus, it is very important for the mortar section leader to be present to recommend the types and amounts of ammunition that will be required. Combat experiences in World War II and Korea have shown that an on-hand mix of 70 percent HE, 20 percent WP or smoke, and 10 percent illumination ammunition is the most flexible. The basic load of a light infantry company should be approximately 245 HE, 60 WP, and 45 illumination, for a total of 350 rounds, which can be in any combination to best support the mission. The percentage of ammunition used by the unit should be modified by the commander on the basis of the mission. The expenditure of mortar ammunition must be based on the tactical priorities and ammunition availability.

How do we manage 60mm ammunition at company level (that is, How do we know what we have on the ground at any one time.)?

It is difficult for the commander to keep track of the availability of on-hand mortar ammunition. The primary responsibility should fall on that section sergeant and the FSO/FSNCO for knowing exactly how many rounds are currently carried by the company, where in the company, and what type of rounds. To make it easier for the commander to know what is on the ground, recommended ammunition breakout is as follows: 1st and 2nd squads carry HE pure (2 rounds per man = 36 HE per platoon), and 3rd squad carries illumination and WP (A Team illumination [8 rounds], B Team WP [8 rounds]. This amounts to a basic load of 60mm--not carded by the mortar section--as 108 round HE, 24 rounds illumination and WP. Using a very basic tracking card updated by the FSO/FSNCO, the commander can keep track of the availability of 60mm ammunition within the company and realistically plan future operations.

AMMUNITION RESUPPLY

Even as good as it sounds by doctrine, we know a light infantry company cannot carry a basic load of 350 rounds of mortar ammunition. Companies at the Joint Readiness Training Center (JRTC) routinely begin rotations with as few as 40 to 60 rounds of 60mm mortar ammunition and almost never get a resupply. When executing the defense, it is with a very small amount of ammunition. To keep the company resupplied with mortar rounds, the company executive officer (XO) and the first sergeant and mortar section sergeant must work together on a daily basis. They must forecast the appropriate number of rounds to be fired daily and make it a standard part of logistics. If the number resupplied is more than the number fired, the ammunition can be kept in the combat trains or carried in the company vehicle until needed. This allows the company to maintain its initial load of ammunition on the basis of the SOP or the current tactical mission. When defense sectors are identified, another basic load can be brought forward.

Although units generally manage to get mortar ammunition onto the battlefield, getting it to the mortar firing positions has been the problem. The fix to ammunition management and resupply must be obtained through a detailed company level control procedure (SOP) for the distribution, drop-off, and retrieval of mortar ammunition. Target suppression is a common task for the mortars. Field Manual (FM) 7-90, Tactical Employment of Mortars, recommends firing five rounds from each tube against a platoon-size enemy element, which should inflict 20 percent casualties. This means that the fire for effect (FFE) should never be less than 10 rounds and will often require much more. This is only one example for one mission. A 60mm mortar section can fire 350 rounds in approximately 9 to 10 minutes at a sustained rate of fire.

How do we get the ammunition to the mortar section?

* Line squads drop when called for ammunition: Using his quick reference card, the mortar section sergeant and the FSO/FSNCO can call for the squads or teams that carry the required ammunition to be dropped off at the mortar firing point location. This works well in the defense, as well as air assaults and airborne assaults as units require time to assemble and thus will have time to drop ammunition with the mortars. This can be chaotic if the landing plans are changed.

* Co-locate ruck drops with mortar firing point: The most success I saw at the JRTC was when in the attack, co-locating the company (or a platoon) ruck drop with the mortars. This allows the mortars direct access to the ammunition they might require. It works very well when mortars are supporting an attack from an established company tactical assembly area, where platoon ruck drops can be established. Thus, mortars have three mortar round caches, in effect. This allows them to shoot, then displace to the next ruck drop, which in most cases would be 150 to 250 meters away from the last firing point. This gives the mortars greater flexibility in supporting the attack. The driving constraint in this method is the maximum range of the 60mm mortar, especially if older, non-ballistically matched lots are issued, where WP and illumination have a maximum range of 950-1500 meters. This method can also succeed when the mortars are task organized under a platoon for security purposes, and establish a mortar firing position in the vicinity of that platoon's objective release point (ORP).