Denel Land Systems’ LEO leaps forward

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The development the 105mm LAV III Light Self-Propelled Howitzer (LSPH) has taken another leap forward with the certification of the system as safe for manned firing tests. To date, the system has been remotely fired. The LSPH is a joint project between General Dynamics Land Systems (GDLS), Denel Land Systems (DLS) and Rheinmetall Denel Munition (RDM).

Work on the development resumed last year after the cancellation of the US Army’s NLOS-C (non-line-of-sight, i.e indirect fire, cannon) programme the year before. DLS in a statement say the LSPH during the week of July 4 fired high explosive projectiles at a maximum range of 31km from a manned turret at Armscor’s Alkantpan Test range in the Northern Cape.
“This marks a significant advance in maturing the technology of this revolutionary artillery system,” the statement added of the weapon that has the logistic footprint of a 105mm howitzer but the range and terminal performance of a 155mm system, “but with better precision”.

Work on the 58-calibre LSPH started during the 1990s under Project Musuku, a South African Army/Armscor research and development programme, where a Denel/Armscor project team was tasked to develop a 105mm artillery system with range, accuracy and lethality similar or better than 155mm 39-calibre artillery systems. “This resulted in the Light Experimental Ordnance (LEO) gun [Advanced Multi-Role Light Artillery Gun to the SA Army] that achieved all these objectives.

Since its unveiling as the “LEO 105″ at the African Aerospace and Defence Exhibition (AAD) in 2000, the 105mm Artillery System continues to generate a considerable amount of international interest. At the request of the US GDLS, the LEO was repackaged into a Denel Land Systems-designed turret, and fitted on a GDLS [ex-Mowag] LAV III [Piranha] vehicle that was demonstrated to the US Army between 2004 and 2006, at Eglin Air Force Base in Florida and Ft. Sill Field Artillery School in Oklahoma.

The 105mm LSPH demonstrator has a crew of three (driver, commander/gunner and loader). As the system fires off its wheels (no outriggers necessary), it provides for faster in- and out of action times than comparable systems. The system weighs 18 200 kg with 36 rounds of ammunition on board and is air-transportable in a Lockheed Martin C130 Hercules aircraft. During combat the on-board ammunition could be increased to 60 rounds, depending on storage configuration.” It matches the strategic and tactical mobility and protection requirements of the Stryker Brigade Combat Teams (SBCT’s). The final configuration and weight of the system is still evolving.”

DLS adds that its turret is also be able to fire from the Patria AMV 8X8 vehicle chosen as the platform for the South African Army’s Badger family of armoured infantry fighting vehicles. “Studies will continue to establish turret compatibility with other 8X8 vehicle platforms.” Denel has also completed conceptual designs for a light towed howitzer (LTH), which will have the same ballistic capabilities as the self-propelled howitzer.

The LTH prototype has a mass of 3800kg, although the objective was 2700kg. In position the LTH is 6.9m long, 2.02m wide and less than 2.1m in height. The LTH would have a crew of five, who would be able to deploy the weapon in two minutes and take it out of action in three minutes. It would have a maximum rate of fire of six rounds a minute for eight minutes at maximum charge and a sustained rate of fire of two rounds a minute. Two LTH can be fitted into a single C130.

Some years ago it was reported the budget for Project Musuku was R134 million, with a project study report and specification for a towed variant due by February 2007. At the the system’s foreseen commissioning in the South African Artillery was 2012. This is now unlikely.

The turret currently incorporates a single semi-automatic chain-type push rammer, which rams the projectile and the charge; as well as a fully automatic laying and navigation system, based on the Denel Arachnida II Weapon Management System and the Selex Fin 3110 Inertial Navigation Unit.

The breech is a semi-automatic swing- and slide block type, similar to the tried and tested breech that is used in the Denel 155mm 52 calibre guns.

The system was man-rated with RDM XM24A42 uni-modular charge system, which is now cleared for manned firings. “With a minimum charge of two modules and a maximum of five, this charge system allows for more than the required 20% range overlap between modules. The charges are used in combination with the standard M82 percussion primers. No brass cartridge case, as used in traditional 105mm howitzers, is required.”

RDM also developed the Igala range of munitions for the LEO/LSPH. For this month’s tests, the M0125A2 IHE PFF (Insensitive High Explosive Pre-Formed Fragmentation) projectile and the XM2019A2 Practice round were fired in both the BT (boat-tail) as well as the BB (base-bleed) configurations. With the BT configuration, a maximum range of 24 km was achieved, while BB has a maximum proven range of 30km at sea level. “At the Alkantpan Test Range (which is 1000m above sea level), ranges of about 25km and 33km respectively, were achieved.”

The M0125A2 IHE PFF projectile has a lethal area of 1600m2, “which is 66% larger than the typical lethal area of the 155mm M107 projectile”. The safety distance for the XM0125A2 IHE PFF projectile is typically 50% smaller than that of the M107, which makes the 105mm PFF projectile more suitable for close fire-support. The M0125A2 IHE PFF projectile achieved US Army Safety certification in September 2008 as part of the Foreign Comparative Test Programme sponsored by the US Department of Defence. “Once the M0125A2 was Safety Certified, it was given the US designation M1130 for the fixed base bleed projectile, and M1131 for the fixed boat tail projectile. Both the M1130 and M1131 projectiles are in the final stages of Type Classification, a process that has taken almost a decade.”

The Igala range of projectiles also include a natural fragmenting HE and IHE projectile, a visual illumination carrier projectile, a bi-spectral screening smoke carrier projectile and an infra-red illumination projectile. “These projectiles are ballistically matched (as it fires with the same range tables). Although they have been fired from this system at maximum range, they are not currently included in the man-rating status of the system.”

DLS says the precision of the system is exceptional. “During the firings leading up to the man-rating of the system, a Probable Error (range) value of less than 0.3% for range was consistently achieved at maximum range with both BB and BT projectiles. This is substantially better than any other known 155mm or 105mm systems at the same, or their respective maximum ranges. The deflection error is typically less than 0.5mil. This kind of performance was achieved through the system engineering approach followed during development of the gun, with the charges and projectiles as an integral part of the system.”

The power of the direct firing capability was demonstrated on the final day of the man-rating at Alkantpan. Members of the South African defence community witnessed three shots that were fired through the same hole in a wall at one kilometre distance.



Pic: The LSPH firing at a RDM shoot at Alkantpan in April 2011