A long-range truck-based artillery effector by Rheinmetall
By Paolo Valpolini
Visiting the Unterlüß premises means witnessing the manufacturing of some of the key elements of the new Rheinmetall artillery system that is being proposed to the Bundeswehr and, of course, to potential export customers.
The remaining key element, the 10×10 truck chassis, is produced by Rheinmetall MAN Military Vehicles (RMMV), the joint venture between Rheinmetall (51%) and MAN (49%), specialised in trucks design and production, from white fleet trucks to fully militarised tactical trucks, which main production facility is based in Vienna.
The new artillery system is based on the new HX3 truck chassis, the new family of vehicles ensuring better protection, better ergonomics, a new electronic architecture, simpler human-machine interface, increased stowage space for soldiers’ equipment, as well as innovative mechanical solutions. The new Euro 5 engine is fully multifuel and can therefore employ either diesel fuel or F34 jet fuel, a key capability when operating downrange. A Euro 6 engine is also available, however in that case the silencer must be replaced to allow it using the F34.
As said a key issue in the design phase was protection, both ballistic and against blast. Customers can select their preferred protection solution, maximum level remaining classified. Rheinmetall inaugurated the new Unterlüß protected cabin assembly hall in 2014, and since then in late April this year 1,380 such cabins had been produced. A new welding robot was acquired, being the only one in Germany capable to weld ballistic steel, according to the company. The robot is used to weld the main parts of the cabin, the structure, the floor panel, the rear panel and the doors, while smaller items are welded by hand, which is considered more cost effective. Welding is checked using paint, UV rays and magnetron, faulted welding being restored by hand. Once finished the most protected cabin weighs around 2,200 kg, the Rheinmetall Unterlüß plant being able to produce eight cabins per week.
The Rheinmetall Weapons & Munitions (RWM) plant is also in charge of the automated artillery turret that will equip the 10×10 HX3 in the self-propelled artillery version. At Eurosatory the company exhibits the truck with a mock-up turret, as during the show the real demonstrator is being assembled at Unterlüß, EDR On-Line was told. Increasing the range was a key requirement, hence the development of a 60-calibre barrel, which means a 9.3 meters long one. The Unterlüß plant is the one where all 120 mm and 155 mm barrels are produced, the average time since the raw barrel coming from Buderus, a company based in Wetzlar, arrives at the Rheinmetall facility till it is ready to be sent to KMW in Munich, where both the Leopard 2 and the PzH 2000 are assembled, is around six months. The production is made of 24 steps, however the long time is not due to machining but to the resting time between operations, which allows tensions in the materiel to decrease. To give an idea of the precision work involved in barrels production, in a 120 mm 55-calibre barrel, which means a 6.6 meters length, the tolerance on the centre of the bore at the breech end and at the muzzle end must be lower than 0.08 mm. Until now the longest barrel produced was that of the PzH 2000, slightly over 8 meters, however the new 60-calibre artillery barrel requires new tools to be produced, therefore RWM has recently installed new machines. Among those the one used for rifling; in the past the barrel was kept still, the rifling being made by rotating tools that were machining the inside of the barrel. The new grooving machine works with the opposite principle, machining tools remaining fix while it is the barrel that rotates. According to Rheinmetall the new gun will be able to shoot 155 mm boattail, base bleed or V-LAP projectiles at over 75 km, new long-range rounds allowing reaching targets at even greater distances
. More than one 60-calibre barrel could be seen on the production line, at different stage of completion, the company aiming to start the testing of the whole system in late 2022.