By Paolo Valpolini
Announced in August this year, the new 60 mm mortar designed by Rheinmetall, known as RSG60, made its first public appearance at DSEI.
The work on this new project started two years ago, Rheinmetall engineers aiming at developing a system that would be different from what was already on the market. The company wanted to leverage the full range of ammunition which was part of its inventory, also through its South African joint-venture Rheinmetall-Denel Munitions.
The key design elements were the reduced weight and the ease of deployment. Two teams, entirely made of company personnel, were created, in order to get two different proposals, one team asking Special Forces operators to provide comments since the early stage of the project. Rheinmetall objective was to have a weight saving of 25% compared to the lightest competitor, however the final result was even better as it turned out to be about 30% lighter, reaching 15.8 kg for the infantry weapon.
The extensive use of carbon fibre is definitely a key element in weight reduction, this materiel being used for the baseplate as well as for over-wrapping the steel barrel; the latter is about 700 mm long, the use of composite materiel to increase stiffness having led to a 30% reduction of the barrel weight.
The RSG60 is not fitted with a bipod, the typical solutions for 60 mm long barrel mortars; Rheinmetall engineers designed a system that allows quick trimming of the elevation; on the right side of the mortar a table allows to mechanically input the required range, providing the data for the different charges. On the left a compass fitted with a level; while the compass is used to orient the mortar at the right azimuth, once range data have been input, it is sufficient to zero the level in order to attain the right elevation. Firing can be done either in drop mode or trigger mode. With charge 6 the maximum range attainable is 3,200 meters; however a 300 mm extension of the barrel can be screwed on, allowing to reach 3,700 meters using charge 6+. The baseplate is fitted with small spikes allowing to fix it to the ground, however these can be replaced with different elements, i.e. rubber pads, depending on the surface. To transport the RSG60 on foot infantrymen can easily collapse the mortar at 0° elevation and fix it to a frame that allows carrying it comfortably on the back, the whole mortar and carrying system weighing 23 kg.
Unscrewing the mortar from the baseplate and extracting a bolt that fixes it to the elevation mechanism, it is possible to separate the barrel obtaining a Commando mortar, the weight dropping to a mere 6.8 kg. Considering recoil forces and the reduced baseplate diameter, the RSG60 in the Commando configuration cannot be used with the more powerful charges; the maximum range currently declared is of 2,000 meters, however the maximum charge that can be used is still under evaluation. As the RSG60 baseplate can be fixed on a vehicle flatbed, the easy split of the barrel from the mount allows soldiers, when needed, to quickly debus the vehicle, average disassembly time is 30 seconds, carrying with them with a shorter range but very light indirect fire weapon.
The RSG60 has undergone numerous firing trials, and Rheinmetall has delivered some weapons to the German Army, which is conducting comparative trials before selecting its future light mortar.
Photos courtesy Rheinmetall and by Paolo Valpolini