The RDM Assegai 155-mm ammunition family consists of three low-sensitivity ammunition options, including (from left to right) the M0121A1 shrapnel with a tapered tail, a range of 30 km, a 40-km pre-fragmented M0603A1 PFF BB projectile and a 60-km VFF-LAP1 fragmentation projectile extended range with tail bottom gasifier / rocket booster
The latest successful tests give rise to hope that the Rheinmetall Waffe Munition (RWM) company will soon be able to begin serial deliveries of the DM121 high-explosive fragmentation artillery ammunition to the German army.
Under standard conditions, the active projectile DM121 with a tapered tail, also known as Rh30, when fired with six modular charges DM72 / DM92 from the 52-caliber barrel of the German army's PzH2000 self-propelled howitzer or any other L52 caliber weapon has a maximum range of 30 km. RWM has a bottom gas generator option in its lineup, designated Rh40 (or DM131), which can reach ranges over 40 km with the same charges.
In addition to meeting modern standards for low-sensitivity ammunition (STANAG 4439), the DM121 will give the German army better concrete-piercing capabilities compared to the 155-mm high-explosive fragmentation projectile DM111 supplied by Rheinmetall as an intermediate solution. The DM111 is a development of the L15A1 / A2 HE (Composition B explosive) projectile, which first entered service in the 70s for 39-caliber howitzers. barrels L52 at a distance of 30 km.
According to an RWM representative who spoke at the Rheinmetall Defense Day held in South Africa at the end of April 2015, the latest tests of a prototype batch of DM121 shells, conducted at the Alcantpan test site in March 2015, confirmed their "high accuracy."
He also said that a new batch of DM121 shells is currently being manufactured and they will soon undergo further qualification tests. Completion of tests is scheduled for mid-2016; this should allow RWM to begin fulfilling a serial contract for 30,000 rounds, which it received from the German army in 2009.
The Rh30 shell was originally chosen by the Bundeswehr at the end of 2004 in order to fulfill its HE Mod 2000 / DM121 requirement. It was preferred over the LU211LM projectile (with fused filler XF13-333 EIDS - TNT / nitrogen tetroxide / aluminum) of the French company Nexter and the XM0121 projectile, an insensitive (with a pressed-in plastic substance PBX) version of the Assegai M2000 variant with a tapered tail section proposed by Diehl, in collaboration with South African Denel. For budgetary reasons, the Bundeswehr did not enter into a contract with RWM to complete the development and initial production of the DM121 projectile until 2009. In the meantime (in 2008) the Rheinmetall group bought a controlling stake in Denel Munitions and subsequently moved its long-range ammunition firing tests and shell production to South Africa.
The warhead of the Assegai family of projectiles ballistically coincides with their high-explosive fragmentation counterparts, so they have the same characteristics: (from left to right) smoke M2002A1 (red phosphorus), illuminating M2003A1 and illuminating infrared M0263A1 (black light). The latter has a gas generator (pink), which can be replaced in the field with a narrowed tail section (its neighbors are equipped with this)
Dutch army experience
The delay in the program for testing and evaluating the DM121 projectile is to some extent related to the experience of the Dutch army with its analogue Rh40 in Afghanistan. It was filled with the same type of Rh26 proprietary low-explosive high-explosive mixture (PBX vulcanized plastic filler), patented by Rheinmetall, which was originally chosen for the DM121, but fundamentally differed in the gas generator built into the tail section. Although the installation of a bottom gas generator reduces the mass of the explosive (explosive), it makes it possible to reduce the bottom resistance at the initial segment of the trajectory and thereby increase the range to more than 40 km.
Although the Rh40 was never adopted by the German army, it has been the subject of preliminary safety and type tests (like the DM131) conducted since 2005 at the official German test center WTD91 in Meppen. They were carried out in the interests of the alleged foreign customers of the PzH2000 howitzer, primarily Greece and the Netherlands.
In September 2006, in Afghanistan, the Dutch army urgently deployed three recently delivered PzH2000NL howitzers. This happened before the scheduled commissioning date for these howitzers, and at that time the certification of the Rh40 had not been completed.
As a result, the Dutch army had only traditional M107 high-explosive fragmentation projectiles and cartridge charges for firing, which initially limited the practical range of the PzH2000NL howitzers to about 17 km. This meant that the Dutch army could not provide optimal coverage of the terrain between its forward bases in Afghanistan, which were separated by a ridge and were 40 km apart.
As an urgent measure, RWM delivered a number of pre-production Rh40 rounds to the Dutch army by the end of 2006, along with the ballistic software needed to update its artillery fire control system. (The German army also took up the supply of smoke and lighting shells to the Dutch). In April 2007, at the Woomera training ground, additional safety and compatibility tests between the PzH2000NL and the Rh40 were completed, carried out in conjunction with the Australian army (which was evaluating the PzH2000 at the time), after which the Dutch army was given permission to fire Rh40 shells from their howitzers during military operations.
In 2009, at a conference on the prospects of artillery, Dutch Army inspector Colonel Peter Froling spoke about the experience of the combat service of PzH2000NL howitzers in Afghanistan. He noted that it proved to be "very" accurate at ranges up to 22 km. However, the overall accuracy of the system did not allow hitting any targets at ranges of more than 32 km (achievable only with Rh40 ammunition), at which the dispersion in some cases exceeded 1 km or the observer did not see the fall of the projectile at all. There was also a case of premature firing and the Rh40 projectile was therefore taken out of service.
At the same conference, Froling noted that a follow-up study of the Rh40's characteristics, including extended ranges and high temperatures, was planned at an artillery range in Turkey.
Ultimately, these tests were carried over to the Alcantpan proving ground in South Africa. No details about their results were published in the mass media. However, it is clear that some of the characteristics that negatively affected the fate of the Rh40 could be attributed to its insensitive explosives, while others could be due to the fact that the shells of the pre-production batch were hastily modified for mass production. Subcontractor Eurenco later filled the last batch of DM121 projectiles with another explosive, resulting in good results in this year's firing.
The successful outcome of the Rheinmetall program for the 155-mm Rh30 / DM121 projectile means that the PzH2000 howitzers of the German army will finally receive a low-sensitivity projectile with a range of 30 km with improved concrete-piercing characteristics.
Dutch admiration
Trials in South Africa gave the Dutch army the opportunity to evaluate the locally produced Assegai family of extended-range ammunition developed by Rheinmetall Denel Munitions (RDM). It includes projectiles of natural fragmentation with an insensitive pressed-in PBX-4, which have an interchangeable tapered tail and a bottom gas generator, which allow you to get ranges corresponding to the ranges of Rh30 and Rh40. An improved version of the M0603A1 with ready-made striking elements is also being produced, which, according to the manufacturer, forms 20,000 fragments. This is four times the number of fragments in a standard (American M107) projectile, and its plastic explosive PBX-4 gives the fragments three times the speed.
At a conference on the prospects of artillery in March 2015, the head of the Dutch army's expert center revealed that his army decided to select Assegai shells, with which, as he put it, his army is currently "very happy." A spokesman for Rheinmetall confirmed that the Netherlands is in the process of qualifying Assegai, but this process will only be completed by mid-2016 for the M0121Al projectile and by mid-2017 for cluster projectiles (and not in 2015 as previously reported). The delivery of several thousand M0121A1 projectiles in versions with a bottom gas generator and with a tapered tail section will also be completed by mid-2017. He noted that the M0121A1 will be able to receive both conventional fuses and deeply embedded fuses, such as the Orbital ATK M1156 PGK (Precision Guidance Kit), GPS-based course correction fuse.
Qatar became the first purchaser of the Assegai ammunition family. The first deliveries will take place at the end of 2015, the shells will be used with the PzH2000 self-propelled howitzers, which this country ordered from Krauss-Maffei Wegmann in 2013. The Qatar order includes a hybrid active-jet version of the M0256A1 V-LAP with a range of 60 km, whose pre-fragmented hull allows for a total of 13,000 fragments. However, the contract from the Dutch army is considered more important, since this is the first order received from a NATO member country.
According to a representative of the RWM company, the decision was made at the level of the group of companies. It is that RDM's Assegai family should be the future preferred solution for all export requirements for 155mm ammunition, including NATO countries. RDM officials say the Assegai high-explosive fragmentation variants are now not only compatible with the low sensitivity standard, but also show low dispersion at increased ranges, thanks in part to their internally and externally machined hulls.
Compared to the Rh40 projectile, the V-LAP variant allows you to shoot at targets located at significantly longer ranges. The entire family, including the Rh30 / 40, was created in accordance with the provisions of the joint memorandum on ballistics adopted by the NATO countries. Consequently, the Assegai difference is that smoke and lighting projectiles can reach the same maximum range as their high-explosive fragmentation options, respectively active (with a tapering tail) and active-reactive (with a bottom gas generator).
A comment
Not only German ammunition developers fought for the introduction of a new generation of insensitive artillery ammunition.
British plans to produce 105mm and 155mm low-sensitivity ammunition were stalled for several years while scientists investigated the cause of several explosions in the barrel of an experimental 105mm XL50 projectile, the predecessor to the larger caliber.
BAE Systems currently expects to begin production of the modified high-explosive 105-mm projectile XL53 with a warhead ROWANEX 1100 IM in 2017, but the plan for the 155-mm projectile has not yet been announced. It is reasonable to assume that there could be a combination of British and German efforts to develop the 155mm projectile; not least because Germany is in the process of making a decision, and also due to the fact that BAE Systems and RWM have previously worked closely together (although mainly in the field of propellants).
The Rheinmetall group chose to consolidate all shell production in South Africa for commercial reasons, although strategically it would be better if the British and German governments continue to rely on production in Europe.
