US-led coalition operations in Afghanistan and Iraq in recent years have demonstrated the value of the 60 mm and 81 mm mortars and the US Army and US Marine Corps are investing in the development of new weapons, ammunition, fire control systems and associated equipment. In the war on terror mortars have proven to be reliable, responsive and lethal. In the mountainous terrain of Afghanistan mortars have been carried by helicopter or vehicle and then manpacked into positions inaccessible to artillery. In operations in built-up areas in Iraq, such as the 2004 battle of Fallujah, mortars have been a 'weapon-of-choice" particularly in situations where commanders have been reluctant to employ close air support or artillery for fear of causing unacceptable collateral damage.
Following Operation Iraqi Freedom in 2003, an after action review prepared by the US Army's 3rd Armored Cavalry Regiment stated, << Mortars were excellent in the counter-fire role. 155 mm howitzer fire cannot be employed within three km of the gun, and most attacks take place at or near this distance, making the 120 mm or 81 mm mortars the most effective counter battery weapon. >> The use of mortars in the 'close fight' allowed the field artillery to concentrate on 'shaping' the battlefield.
Reports from other units noted, << [the] 60 mm handheld was devastating in the close fight and excellent for marking targets. 60 mm is still the best option for a rifle company >>.
Members of the army's 75th Ranger Regiment stated, << Based on the situations that have been encountered during the global war on terrorism we always have a 60 mm handheld as convoy security. It is just as responsive as a machine gun and creates a unique psychological effect that is unmatched. During all of the ambushes we have encountered over the past few years the 60 mm has been the deciding factor for gaining fire superiority. It is the counter to the rocket propelled grenade and can suppress places that the M2 (.50 cal heavy machine gun)/Mk 19 (automatic grenade launcher) cannot. >> Both British and US forces have cited the deterrent value of using mortar illumination rounds.
Since 1978 the US Army and US Marine Corps have employed the M224 60 mm lightweight company mortar, of which more than 2000 are in service.
The weapon can be used in the handheld mode and also with a baseplate and bipod to achieve greater accuracy and a sustained rate of fire. The weapon has a minimum range of 70 metres and a maximum of 3500 using the bipod and 1340 in the handheld mode. A skilled three-man team can achieve a 30 round-per-minute rate of fire. The 21.11-kg weapon is broken down into two loads for carrying.
The M252 is the designation for the US version of the BAE Systems RO Defence L16A2 81 mm mortar. The British weapon was chosen by the US Army 30 years ago because of its maximum range of 5650 metres, which has since been extended to 5935 metres with the introduction of new ammunition. A 15 round-per-minute rate of fire can be achieved. Over 5000 examples of the L16 series have been produced for almost 40 countries. In several armies, including those of Canada, New Zealand and Britain, the L16A2 is the heaviest mortar in service and is used in both the light and mechanised roles. Canadian weapons have recently been shifted from tracked M113s to the General Dynamics Land Systems--Canada Bison 8 x 8 armoured personnel carrier, where they are mounted on the Wolf turntable developed by DEW Engineering and BAE Systems.
Under the US Army's new modular brigade structure the service will field more mortars. Heavy brigades will be equipped only with the self-propelled Israeli Soltam M121 120 mm mortar. These are currently mounted in tracked M1064 carriers (M113 series) but sometime in the next decade could be replaced by the Future Combat System non-line-of-sight mortar variant. Infantry brigade combat teams--light, airborne and air assault--will have two 60 mm mortars in each rifle company while battalion mortar platoons will be equipped with four towed Soltam M120 120 mm and four 81 mm mortars. Infantry battalions will thus operate four 120 mm, four 81 mm and six 60 mm mortars. Under the 'arms room' concept, copied from the 75th Ranger Regiment, light infantry commanders will choose which battalion mortar is most appropriate for a specific mission. When using an 81 mm mortar a crew will typically deploy with 80 rounds consisting of 56 high explosive (HE), 16 smoke, 4 white illumination and 4 infrared (IR) illumination rounds. When using a 120 mm mortar the crew will carry 25 HE, seven smoke, two white illumination, two IR illumination rounds and, in the future, five M395 Precision Guided Mortar Munitions (under development by ATK) for a total of 41 rounds.
Stryker Brigade Combat Teams operate the General Dynamics Land System Stryker Mortar Carrier Vehicle version B (MCV-B), of which the first of 241 vehicles was delivered in mid-2005. The MCVB mounts a 120 mm mortar at the battalion level or an 81 mm mortar at the company level that fire through an open hatch. Each vehicle also carries a second mortar to provide dismounted fire. The battalion's four MCV-B vehicles each carry an 81 mm mortar while the two vehicles in each rifle company carry a 60 mm mortar. A Stryker battalion has a formidable indirect fire capability with four M120, ten M252 and six M224 mortars.
The US Marine Corps has 315 M224 60 mm and 280 M252 81 mm mortars fielded with its 24 active and nine reserve battalions, although these figures will increase with the formation of two new battalions this year. These will be reinforced from 2008 with the General Dynamics Expeditionary Fire Support System that consists of the TDA SAS RT 120 rifled mortar towed by an American Growler Internally Transportable Vehicle.
Improved Fire Control
Led by the Army's Project Manager for Mortar Systems at Picatinny Arsenal, both services are seeking to introduce digital fire control systems, improved ammunition and Lighter mortars. The new M32 Light Weight Hand Held Mortar Ballistic Computer (LHMBC) is being fielded to replace about 1400 1980s-vintage M23 computers now in service. The LHMBC consists of the Rugged Personal Data Assistant-55, manufactured by Talla-Tech of Tallahassee in Florida, and fire control software that uses a Windows graphical user interface thus making its operation more intuitive to soldiers. Weighing less than one kg the M32 is about one-quarter the weight of the M23 and includes a tactical modern and an embedded global positioning system (GPS) receiver. The LHMBC can be used with 60 mm, 81 mm and 120 mm mortars. In mid-2004, 32 prototype XM32s using Version 1 software were sent to Iraq for field testing while engineers at Picatinny continued to develop Version 2 software. In early 2005 the army asked for funds in the supplemental request to the fiscal year 2005 budget to procure sufficient M32 LHMBC units to support 20 infantry brigade combat teams. Additional orders are planned to follow for both the army and the US Marine Corps.
In 2005 the army also requested funding to field another five brigade sets of the M95/M96 Mortar Fire Control System to its heavy forces. According to PM Mortars the MFCS, << provides Paladin-like (M109A6) fire control capability that greatly improves mortar lethality, responsiveness and crew survivability. MFCS links mortar fires with the digital battlefield. It integrates a fire control computer with an inertial navigation and pointing system, allowing crews to fire in less than one minute >>. The MFCS uses the same computers, displays and software in the tracked M577 fire direction centre, the M1064 mortar carrier and the Stryker MCV-B. Honeywell is responsible for the hardware interface involving Militope's Pentium-based ruggedised computers, Rockwell Collins Precision Lightweight GPS Receivers and Honeywell Talin inertial measurement units mounted on individual mortar barrels. Fielding of the M95/96 should be completed in FY08. In a second increment the army plans to field a Mortar Fire Control System-Light (MFCS-L) using the M32 as the computer. The system can be used by dismounted platoons equipped with 81 mm mortars and possibly 60 mm types. With the fielding of the Future Combat System in the next decade it is planned that mortar units will use common FCS software for all applications.
Since 2001 US forces have been using 60 mm (M677), 81 mm (M816) and 120 mm (M983) infrared rounds which are filled with a new 'candle composition', which illuminates targets in the near IR wavelengths of the electromagnetic spectrum and is thus only visible to soldiers wearing passive night vision equipment. Feedback from users indicates that a much clearer target image is achieved with IR rounds than with white light. As there is no light to illuminate friendly troops the round is ideally suited for special operations. The rounds are produced at the army's Pine Bluff Arsenal in Arkansas and, under current plans, production will continue until at least the end of the decade.
Ruag's 60 mm Mortar Anti-Personnel Anti-Materiel (Mapam) round, under the designation XM1046, is being evaluated in comparison with the US M720 60 mm HE round. The explosion of a standard mortar bomb produces different numbers of irregular fragments that fly at different speeds. What differentiates the Mapam is a unique composite warhead body made of a matrix of 2400 steel balls bound in epoxy that provides increased lethality by rendering a predictable and consistent dispersion pattern. This means that in the required area, the Mapam has a lethality that is at least equal to that of a convention 81 mm bomb. Product qualification testing of the XM1046, which uses the Ruag matrix in a round made with US components, began in December 2005. PM Mortars plans to leverage Mapam technology for future 81 mm ammunition, although Ruag demonstrated an 81 mm Mapam version round in 2005--three years after it first demonstrated the 60 mm--and is also working on a 120 mm Mapam. The 81 mm Mapam scatters 4800 balls.
Picatinny is evaluating new electronical timed fuzes that will offer better timing accuracy and safety than the current mechanical fuzes. The XM784 fuze will be compatible with the 60 mm M721 and M767, and the 120 mm M930 and M983 illumination rounds. The XM785 will be compatible with 81 mm M853A1, M816 and M819 smoke and illumination rounds. The new fuzes will allow the time to be set in 0.1-second increments from 5 to 99.9 seconds. The time can be set by hand without special equipment or fuze setters and the display will be backlit to eliminate the need for external illumination.
The US is developing a lightweight 81 mm mortar. The M252 weighs 93.25 lb (42.3 kg) with a 35-1b (15.88-kg) barrel, 27-1b (11.25-kg) bipod and 26-1b (11.79-kg) baseplate. The "threshold' target is a 63.91-1b (28.99-kg) weapon with a 24.5-1b (11.11-kg) barrel, 18.9-1b (8.57-kg) bipod and 18.2-1b (8.26-kg) baseplate. The more ambitious 'objective' target is a 54.78-1b (24.85-kg) weapon with a 21-1b barrel (9.53-kg), 16.2-1b (7.35-kg) bipod and a 15.6-1b (7.08-kg) baseplate. In order to reduce weight the army is evaluating the suitability of Inconel 718, a nickel-based alloy, for mortar tubes, carbon fibre reinforced composites for baseplates and a lightweight material for a new bipod. Although Inconel 718 has never been used before to produce a gun barrel, tests to date have shown its ability to retain high strength at high temperatures. Over 1600 rounds have been fired from the Inconel 718 tubes in total and during one trial 141 rounds were fired from four tubes heated to maximum operating temperature. Programme officials state, << nothing was noted to preclude the use of Inconel 718 in future mortar designs, >>. Tests have recently begun on a 60 mm tube made from Inconel 718. The 81 mm tube is currently undergoing qualification in preparation for the production in FY06.
Two baseplate designs are being evaluated: a carbon fibre reinforced thermoset composite design that offers a 40% weight reduction, and a high strength forged aluminium baseplate that is 25% lighter. A carbon fibre reinforced thermoplastic baseplate was eliminated at early stage of the test process. An aluminium matrix composite prototype baseplate will also be tested. The L16/M252 'K-mount' bipod design will be replaced with a more conventional 'A-mount' design. Two designs made of composites, plastics and lightweight metals have undergone initial firing tests, and in December 2005 a rough handling and user evaluation took place.
The objective weapon should have a unit price not exceeding the $ 70,500 cost of an M252. The objective weapon requirements are similar to the M252 in other respects--the same 83-metre minimum and 5935-metre maximum ranges, the same 30 round-per-minute maximum and 16 round-per-minute sustained rate of fire, and a tube life equal too or greater than the present 10,000 rounds. A complete system firing demonstration is scheduled for the fourth quarter of FY06 and a portability test will compare the weapon with the M252. In the future the army is seeking an FCS Non-Light of Sight Lightweight Dismounted Mortar System that combines a 50% weight reduction with greater range and lethality. The target date for the first unit equipped is FY14.
On 29 December 2005 the US Army awarded General Dynamics Ordnance and Tactical Systems a $19.4 million base contract with four option years to produce 60 mm, 81 mm and 120 mm mortars. The contract, along with the EFSS project, makes GD-OTS the sole supplier of mortars to the Department of Defense and, if all options are awarded, would be worth $194.5 million. Barrels, including Inconel 718 barrels for the M252 81 mm mortar, will be supplied by Watervliet Arsenal and GD-OTS will source other components and assemble the compete weapons at the Huntsville, Alabama facilities of Tec-Masters. The Mistral Group and its partner Soltam Ltd will supply many of the components and assemblies.
The British Army's 81 mm mortar midlife update focussed on the "system' rather than the weapon by introducing new Target Locating Equipment (TLE), Gun Locating System (GLS) and Mortar Fire Control System. The British TLE is now the LH40C laser rangefinder produced by Eloptro, a member of the South African Denel Group, used in conjunction with the Rockwell Collins Specialised Personal GPS Receiver. The LH40C provides range, azimuth and elevation data to a target and when integrated with the GPS provides ten-figure grids of the mortar fire controller's position, the enemy position and the fall of shot. The PLGR also issued to every mortar crew as a GLS. The final element is the Fire Control Application developed by LogicaCMG that runs on a ruggedised MBM LT 456 laptop computer. The combined effects of these systems, demonstrated during recent operations, is the ability of mortar crews to achieve a second-round hit on target if not a first-round hit. As with the United States, Britain is buying additional quantities of 81 mm illumination ammunition. The service does not intend to replace its handheld BAE Systems Royal Ordnance 51 mm Light Mortars used at platoon level, as their role is partially fulfilled by the recently fielded Heckler & Koch 40 mm under-barrel grenade launcher, but is instead considering introducing a lightweight 60 mm or 81 mm mortar at company level and a 120 mm weapon at battalion level. No tenders have yet been issued for these requirements.
The Irish Army bought 54 LH40C rangefinders for use by its MFCs. The LH40C is a key component of Denel's Integrated Mortar System, although the mortar fire controller could also be equipped with Denel's recently developed Eagle Eye target location binoculars. The Eagle Eye combines a long-range laser rangefinder, observation binocular, GPS, digital compass, digital camera and digital voice recorder into a unit of less than two kg. Other elements include the Marine Air Systems Morfire fire control system, a CSIR-designed digital sight fitted to the mortar and Denel's 60 mm M6 and 81 mm M8 Vektor long-range mortars. The M6 has a total weight of 24 km and a maximum range of 6000 metres, while the 43-kg M8 has a maximum range of 7263 metres. The barrel of the M6 is manufactured using carbon-fibre composite material. To enhance the mobility of either weapon CSIR designed a modular mortar mount that can be affixed to vehicles such as the 4 x 4 Bat Mk II air-droppable light utility vehicle in service with South African airborne units. Denel produces a complete family of long-range 60 mm and 81 mm mortar ammunition.
The Australian Army has recently bought 81 mm Denel ammunition for use with its M252 mortars (locally designated the F2). Denel will no doubt be hoping to interest the service in its MS, as the ammunition is intended to be compatible with a new long-range 81 mm mortar. The army plans to replace the F2 in both the dismounted and mounted roles. A request for tender is expected to be published by the time this issue of Armada goes to press.
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|Title Annotation:||Infantry: mortars|
|Date:||Apr 1, 2006|
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