A responsible solution to a sensible requirement
Defence journalist John Reed examines the requirements and development processes that have contributed to the growing success of Royal Ordnance’s ARWEN Law Enforcement Weapon System.
ARWEN 37 MULTI is a lightweight law enforcement weapon with a highly-accurate capability for up to five shots in a combination of natures of ammunition at ranges out to 100m. It is also available in single shot short barreled and vehicle mounted versions as the basis of a complete internal security weapon system which extends to include a comprehensive range of projectiles.
The ARWEN system has its origins in a 1977 British Army requirement for a Crowd Control Projectile System which acknowledged the tactical and technical lessons of its recent experience in Northern Ireland and elsewhere. The existing L67A1 38mm Riot Gun was no more than a conversion signal pistol with a short effective range making it virtually impossible for its user to put a safe distance between himself and a rioting mob – and indeed even if he was able to do so the likelihood was that any advantage would be lost as he came out of the aim to reload his break-action single shot weapon. Moreover the operational usefulness of what had already become an outdated weapon was further limited by the unsatisfactory ballistic performance of the PVC baton round which had replaced the dangerously inaccurate “rubber bullet” five years earlier. These baton rounds were produced in short (25-60m) and long range (60-80m) versions, but quite apart from being adversely affected by changes in the ambient temperature, both were of such a primitive design that they tumbled in flight, and were likely to hit their target side-ways-on, if at all, with an unpredictable terminal effect – and nightmare implications in sensitive political situations.
From Concept to System
Undoubtedly ARWEN’s lengthy development period has owed much to the decision to opt for an entirely new system comprising both weapon and armament rather than for say a single new multipurpose weapon using inadequate existing ammunition. The requirement called for combinations of weapon and projectile capable of incapacitating a rioter with a low probability of serious injury at ranges between 20-100m in situations in which the use of high velocity firearms was unacceptable. No less important was the intention that the firer should be given an enhanced chance of hitting his target thus reducing the likelihood of injuring individuals who were not at the heart of the disorder.
The outcome is today’s ARWEN 37 MULTI. A rifled 37mm barrel with 5 grooves at a pitch of 1 in 540mm and a matched family of projectiles provides the desired superlative improvement in accuracy, whilst the revolver action with a cyclic rate of fire of 60rpm and a sustained rate of 12 aimed shots per minute offers a solution to some of the more pressing tactical problems. However it also incorporates other features which reflect both the design team’s extensive experience and the considerable investment in trialling. First and foremost ARWEN is a weapon which combines accuracy and reliability with ease of use. It weighs only 3.8kg when loaded with five baton rounds, has a notably low recoil and in addition to its adjustable stock (which gives the weapon six optional lengths between 760-840mm) its adjustable front pistol grip offers the firer a choice of radial adjustment. A proper concern for safety is evident in the manner in which in addition to the customary safety catch, which positively locks the breech block firing pin and trigger, the weapon becomes fully cocked only after the fire has taken up first pressure on the trigger, and reverts to a safe mode should he subsequently release that pressure.
The ARWEN weapon was developed in parallel with a family of five projectiles each of which is propelled by charge contained in a modified .44 Magnum cartridge secured into the base section of the rimless main cartridge. The AR1 Kinetic Energy Baton Round is based on a specially-designed aerodynamic polyurethane baton and, developed as it was against the requirement to “discourage” a rioter at 100m has the necessary stability to achieve a nose-on hit at that range. The RE (Reduced Energy) version of the AR1 offers comparable performance at close ranges yet retains its characteristic low lethality. The AR2 Multi-Source Irritant Smoke Round – a practice version is available for training – is an airburst projectile incorporating four CS-filled canisters within a plastic sabot which disrupts after one second’s flight time. The individual canisters disperse, burning over an area of approximately 5m in radius at a range of 90m (20m in the case of the short-range AR2SR) and emit irritant smoke for a period of around 12 seconds. The AR3 Frangible Nose Baton Round fires a baton with aerodynamics similar to those of the AR1 but is fitted with an expanded polystyrene-styrofoam nose cap containing 2 grammes of CS powder which is dispersed on impact. It has no fire risk and is therefore suitable as a means of effecting individual arrest in or near buildings. The AR4 is a Smoke Screening Round similar in constructions and performance to the AR2, whilst the AR5 Barricade Penetrating Irritant Round deploys an aerodynamic higher velocity projectile with a cutting edge around a hollow nose containing micronised CS powder which is dispersed after the projectile has achieved penetration. It is intended for use against such targets as car windscreens/windows, interior doors and plywood in thicknesses up to 13mm – albeit at lesser ranges. Naturally there is a practice version available.
The ARWEN system concept was subsequently carried a stage further with the development of the ARWEN 37 MULTI S close quarter 5-shot revolver weapon which has no stock and a shorter (165mm) barrel and the optically-sighted stockless ARWEN 37 MULTI V installed within a ball mounting for use in Internal Security vehicles. Finally although the revolver principle – with its facility for changing the load to suit rapidly changing tactical circumstances by indexing the rotary magazine without having to fire – was seen as one of ARWEN’s strongest selling points its designers recognized that there were potential users who sought accuracy but who would not find a multi-shot weapon politically or financially acceptable. To meet their requirements, RO developed a single shot version known as ARWEN ACE weighing only 2.3kg loaded. This weapon being of a non-break action is simple and highly effective, achieving as it does the same sustained rate of fire as the five-shot version.
ARWEN in the marketplace
Arguably the fact that the 1977 requirement document originally foresaw a 1987 in-service date was rather more a recognition of the timeframe in which the British Army saw itself as being able to afford to re-equip, than of operational urgency. Eventually that target date was altered to 1983.
Ironically whilst ARWEN was still undergoing evaluation the Provisional IRA – whose sympatisers’ activities had promoted the requirement – was able to cite the demonstrable inaccuracy of the in-service weapon to secure a considerable propaganda success – but in much the same timeframe the UK authorities decided to defer a decision to actually procure any weapon which might have been perceived as “more efficient”.
It was a turn of events which placed Royal Ordnance in the unenviable position of being a state-owned manufacturer whose principal customer had decided for reasons quite unconnected with technical merit to withhold a procurement decision. However the initial response to ARWEN had been sufficiently good to encourage RO to proceed with its development on what was in effect a private venture basis. In 1984 it secured the all-important breakthrough with a sale of ARWEN to the Kentucky State Police and was soon winning plaudits from other US Law Enforcement agencies who were quick to appreciate and experience its usefulness as an alternative to lethal firearms in situations other than civil disorder. This interest was confirmed in orders for more than five hundred weapons from the US during the four years following the first sale, whilst further afield there was a major order from Singapore where ARWEN was selected for use by the Republic’s Gurkha Police Contingent.
Current development work is concentrated primarily on value engineering the weapon and providing it with an optical sight. This sight will have an illuminated graticule to enhance accuracy in poor light and in combination with the ongoing ammunition development programme seems certain to maintain ARWEN’s technical supremacy over its competitors. The changes in production and marketing which followed Royal Ordnance’s acquisition by British Aerospace saw responsibility for ARWEN transferred from Enfield to the company’s modern production facility at Nottingham. Much of the machining – but not that of the all-important rifled barrel – was subcontracted to a leading AQAP 1 – approved specialist as part of an aggressive drive to ensure ARWEN the most competitive of positions in a price-conscious market. In the process ARWEN’s status in the RO product line has changed from that of a “private venture” in an organization that was not structured to support such projects. By early 1989 its technical features, its quality and its reliability are clearly seen as competitive attributes marking it out as a potential leader in a sector of the market which has historically been slow to accept change and places a premium on operational reliability.