There was a time in the mid-1980s, when the main battle tank was still 'King of the Battlefield', when the 'unmanned' turret (remote controlled weapons station is a better description) for these vehicles was seen as a way forward, but later lost its way. In the last ten years the concept has seen something of a renaissance, albeit with a slightly different slant as the focus is now on the lighter armoured fighting vehicles.
While still seen as a necessity, the place of the main battle tank as an army's main weapon has reduced in importance. Consequently, the perceived need for externally mounted larger-calibre 'unmanned' turrets for main battle tanks has taken a lower priority.
The main benefits of an 'unmanned' turret or externally mounted weapons station can be summarised thus: a reduction in the vehicle profile, making it harder to acquire and hit, a reduced combat weight so savings can be reapplied as additional armour, a reduced crew size by replacing the loader with an auto-loader mechanism, relocating the crew and ammunition within the hull to increase the protection factor, improved logistics and an easier upgrade path for the future.
A major catalyst in the development of this turret genre has been the advance in electro-optical technology. This allows day/night vision of the outside world, via image intensification, low-light level television or thermal cameras, to be delivered to the gunner in the comparatively more secure environment of the lower hull.
This category has produced a list of differing descriptive titles for products (or an acronym) that enhance promotional copy. Thus, one may see such turrets varyingly described as Remote (or Remotely Controlled) Weapons Stations (RWS/ RCWS) or Overhead Weapons Stations (OWS). Turrets in this category are the most numerous.
Typical of the breed is the range of RWS/RCWS/OWS from Rafael (covering the medium and light categories). Designed for use with 7.62 mm light machine guns, the company's OWS 7.62 is modular and can either be installed as a retrofit kit on older armoured fighting vehicles or as a new-build item. It is in service with the Israel Defence Force on a number of platforms including the modified M113 series, the Puma (converted from a Centurion tank chassis) and the Achzarit infantry armoured vehicle (a T-54/T-55 chassis modified by Nimda). It also equips Turkish Army Otokar Akrep reconnaissance vehicles and has been trialled on a Chilean-built Piranha.
The main features of the OWS 7.62 include a day/night sight assembly, weapon cocking from inside the vehicle, an internal (within the vehicle) ammunition feed (with 250 ready-use rounds) and electrical firing. The optics comprise a periscope sight with a x1 magnification day window and collimated aiming circle, a x8 magnification day channel with ballistic reticule, a x1 magnification night window with collimated aiming circle and a x7.5 magnification passive image-intensified night elbow. With a rotating seat, +/-170[degrees] traverse is possible with a 360[degrees] option available--elevation is from -15[degrees] to +45[degrees].
Rafael's OWS 12.7D/DE/DI series is designed for use with 12.7 mm (0.5-in or 50 calibre) heavy machine-guns, specifically the M2 HB model. The features and specification mirror the OWS 7.62, although only 100 ready-use rounds are carried. These are in service in static border defences with the Israel Defence Force.
The Katlanit RCWS (with a 7.62 mm machine-gun) was developed by Rafael as a private venture and has already been adopted by the Canadian Army under the name Protected Weapon Station (PWS). It is, to all intents and purposes, the OWS 12.7D system, except it uses an uncooled micro-bolometer thermal camera (or low light level television) in place of the image-intensified night elbow.
The production of the Katlanit by Oerlikon Aerospace began in mid-2000 and will be installed on the Recovery/Fitter variants of the stretched M113 (the Mobile Tactical Vehicle Light--MTVL), plus some M113A3 series. In addition, it will arm pioneer versions of the new Light Armoured Vehicle III being built by General Dynamics Land Systems--Canada and about 60 8 x 8 Bisons and 40 Armoured Vehicle General Purpose (6 x 6) that are being upgraded and re-roled. It is also in service with the Israel Defence Force on some Dingo and M113 vehicles. AEI in Britain is manufacturing 333 RCWS under the name Enforcer for the new British Army Alvis Vickers (now BAE Systems Land Systems) MLV.
An improved RCWS, launched in 2004, is able to mount a variety of 7.62 mm, 12.7 mm, 25 mm and 40 mm weapons including the XM312, XM307 and GAU17. It will be equipped with a stabilisation system, day/night sight, laser rangefinder, fire control system, auto-tracker, round...