Convex Rails With the NGL-60 Prototype Railgun

At the French-German Research Institute of Saint-Louis (ISL), railguns are investigated with respect to military scenarios. Currently, different railguns installed at ISL use rails with a flat contact surface. For lateral guidance of the armarture, the barrel is equipped with guiding bars made of reinforced plastic mounted on the sides of the rails. This solution is prone to damage of the guiding bars. In this investigation, rails with a convex-shaped contact surface are installed and used in a 2-m-long railgun. It is experimentally shown that using these modified rails, the guiding bars can be eliminated from the barrel setup, thus simplifying the barrel. Furthermore, in a comparison to launches with flat rails, the convex rail implementation is more efficient, resulting in a higher armature velocity at the same primary energy. Additional improvement was obtained by an armature modification.