The Ministry of Defence intends to procure naval gun, five-inch or above for Indian Navy. It should be suitable for fitment onboard Indian Navy ships of 6,000 tonnes displacement and optimised for long-range surface engagement of vessels and shore bombardment (request for information (RFI) issued by the Ministry of Defence (MoD)).

Guns mounted on ships have been traditionally used to engage other ships or targets on land. With the advent of airpower, guns were also employed in the anti-aircraft (AA) role. Such guns can be termed as naval guns or naval artillery. As guns and gunnery developed, ships started to carry a smaller number of heavy, long-ranged guns rather than dozens of cannon. After World War II, the guided missile began to replace the naval gun as the principal surface-to-surface weapon and post 1945; no new ships were deployed using heavy guns; though a small number of battleships and cruisers continued in service. Today, many destroyers and frigates carry a single gun of three inches to five inches in calibre, which is capable of a mixture of fire-support, anti-surface and anti-air fire missions; but it is not regarded as the principal weapon system. Currently, one of the major roles of naval guns is to provide short-ranged anti-air and anti-missile defence, one example of which is the popular 20mm Phalanx CIWS system.

4.5-inch Mark 8 British naval gun

The 4.5-inch Mark 8 naval gun system currently equips the Royal Navy’s frigates and some ships sold to other countries. The 4.5-inch gun has been the standard medium-gun calibre of the Royal Navy for use against surface, aircraft and shore targets since 1938. The current 55-calibre Mark 8 gun replaced the World War II era 45-calibre QF 4.5-inch Mk I-V naval guns. Like all British 4.5-inch naval guns, it actually has a calibre of 4.45 inches (113mm). The gun was designed in the 1960s with a longer 55-calibre barrel for the new classes of frigates and destroyers. The gun, built by Vickers, was developed from the ordnance, QF 105mm L13 of the Abbot self-propelled gun and focused on providing a lighter, single barrel mounting and ammunition of a one-piece design. It has a combination of electrical and hydraulic components, is semi-automatic, has a rate of fire of about 25 rounds per minute, and a range of 12nm (22 km; 27.5 km with the newer high explosive extended range round). The gun entered service in 1971 with the Iranian frigate Zaal in 1971 and the Royal Navy in 1973 on the new destroyer Bristol. The first major modification to the mounting, the MOD 1, was developed in the late 1990s; replacing the gun house with a reduced radar cross-section assembly and replacing the hydraulic loading mechanism with an all electric system. It is still in service with some of the Royal Navy’s frigates and destroyers. It was used in Iraq in 2003 and recently in Libya.

155mm Variant

BAE Systems had proposed to “up gun” the 4.5-inch to accept the 155mm (6.1-inch) gun barrel and breech from the AS-90 self propelled gun. Holding of a common gun calibre with the Army and Navy would make ammunition logistics simpler and encourage joint Army-Navy development of extended range and precision-guided shells. The first study phase involved fitting AS90 self-propelled howitzer ordnance onto the existing 4.5-inch Mk8 Mod 1 gun mounting structure.

Advanced Gun System

The advanced gun system (AGS) is a naval gun system under development by BAE Systems Armaments Systems (formerly United Defense) for the Zumwalt class destroyer of the US Navy. Originally designed for mounting as a vertical gun, this 155mm calibre gun has since been slated for mounting with a more conventional turret arrangement. As a vertical gun system, it would only have been capable of firing guided munitions; the turret mounting will allow the use of unguided munitions as well. The AGS is designed to offer a weapon system capable of delivering precision munitions at a high rate of fire and at over-the-horizon ranges. The AGS uses the same 155mm calibre as most US field artillery forces, although it is unable to fire the same ammunition and a new range of ammunition has been developed for it, called long-range land attack projectile (LRLAP). The LRLAP is claimed to be highly accurate, with a circular error of probability of 50 m (160 ft) or less, guidance system of GPS/INS, a maximum range of 100 nautical miles, length of gun barrel of 62 calibres and a average rate of fire of ten rounds per minute. The AGS is to be mounted in a turret specifically designed for the Zumwalt class destroyer with fully automated ammunition supply and operation. A primary advantage of the AGS over the existing Mark 45 5″ gun which equips most major surface combatants of the US Navy is its increased capability for supporting ground forces and striking land targets. With a 10 round per minute capacity, it offers the ability to deliver firepower close to that of a battery of six 155mm howitzers. The AGS is currently planned only for inclusion on the Zumwalt class destroyers.

OTO Melara 127/64 lightweight (LW) Naval Gun

Oto Melara’s 127/64 LW naval gun mount is a rapid fire gun system suitable for installation on large and medium size ships for providing surface fire and naval gunfire support in the main role and surface-to-air as secondary role. The compactness of the gun feeding system makes possible the installation on narrow section crafts. The gun can fire all standard five-inch ammunition including the new Vulcano long-range guided ammunition. Modular automatic feeding magazines allow the firing of up to four different and immediately selectable types of ammunition. Digital and analogue interfaces are available for any combat management system, also according to Corba protocol. The 127/64 LW naval gun mounts include a Vulcano module, which acts as:

• Programmer for ammunition’s fuse and guidance system.
• Mission planning and execution for naval fire support action in a standalone mode or integrated with the ship’s network-centric system.