There is a resurgence of interest in the US Navy in long range artillery as a replacement for missiles due to the cost savings involved. That is, even though the missile launcher is normally cheaper than a gun of similar caliber, each missile is much more expensive than the projectile and propellant for the gun and this soon outweighs the extra cost of the gun system.
To obtain greater range, the gun barrels must be longer or the chamber pressure must be greater. A combination of these two factors, together with optimum projectile design, provides the best opportunity for long range firings. However, the protrusion of the barrel above the deck is vulnerable to detection by enemy radar, hence it is of interest to reduce this to a minimum.
To maximize the length of barrel for a given protrusion of the barrel from the housing module, there should be a minimum of recoiled components behind the chamber/breech, and also, the recoil stroke should be as short as possible. The optimum space utilization is to have only enough room behind the back of the cannon assembly for recoiling. For this to be effected, the chamber must be separated from the barrel to allow for loading of the projectile and charge. This also allows a reduction in time between shots as the charge may be loaded at the same time as the projectile.
The gun described herein embodies the necessary features to allow for compact stowage as well as providing improved performance. A 5 inch caliber smooth bore barrel has been assumed, however the design can be readily scaled up or down.
The invention provides a gun system that incorporates a two piece cannon assembly that is separated between the chamber and the projectile forcing cone. The gun described has no traditional breech. It has a removable chamber instead which has a plug at one end that can accommodate any type of ignition system that may be required. The other end is open and is attached to the barrel with a connection fitting that is clamped to the barrel by a threaded collar. The high pressure gases created by the propellant combustion are sealed with a high-pressure gas compression seal at the interface between the chamber and the barrel. The lower side of the connection fitting has a locking collar screwed into it. The internal diameter of this locking collar has a bayonet feature or interrupted thread to suit the top end of the chamber. A torque plate, which extends out beyond the edge of the connection fitting, is attached to the lower face of the collar. A slot in the torque plate aligns with the pin of a slide actuator that is attached to a frame cross-member. When the cannon assembly is in battery position, the actuator pin is located inside the torque plate slot.
The connection fitting also provides the attachment for the rear cannon bearing slide which rides on rails attached to the main support structure. This also reacts any torque induced into the barrel from the actuation of the chamber/barrel locking collar.
To provide adequate clearance to the loading mechanism, the recoil cylinders are mounted in front of (above) the chamber/barrel connection fitting. The lower end of the cylinders are attached to the connection fitting. The structure necessary to support the front of the recoil cylinders and hence transmit the recoil force to the main support, provides a suitable mounting for the front barrel slide. The resultant extended xe2x80x9cwheelbasexe2x80x9d between the front and rear slides ensures improved shot repeatability.
A turntable upon which are mounted two chamber elevating/support mechanisms and two projectile loader/rammer mechanisms is positioned around one of the main support structure legs.