Weapon Options for M-113

The March/April 1994 issue of JDSM looked at the wide ranging options for upgrading and enhancing the M113 family of vehicles. The article referred to the vehicle family as "ubiquitous" and, with 80000 vehicles produced to date, there are few who would argue with that assessment. In this issue, Scott R. Gourley considers the equally-widespread options for adding firepower to the basic M113.

While avoiding the debate over roles and missions between armoured personnel carriers (APCs) and infantry fighting vehicles (IFVs), this article will look at the spectrum of add-on weapon options for the M113. The article is not designed as a compendium of all weapon options available but, rather, a representative sample of some current M113 armament upgrade programmes.

These armament upgrades range from 5.56mm machine guns to 25mm automatic cannons supported by TOW missile launchers. The weapons are carried in everything from pintle mounts to dedicated turret systems. The simplest add-on armament for M113 vehicles involves a pintle/ring-mounted weapon located at the vehicle commander's cupola. Weapons frequently utilised in this configuration include the M2 0.50in (12.7mm) machine gun and the Mk19 Mod3 40mm grenade launcher.

Some level of ballistic protection for the weapon operator can be provided through the installation of so-called "gun shields", consisting of armour panels arranged around the cupola. One example of this configuration can be seen on Brazilian M113s which have been upgraded to include the Moto Pecas Gunner's Shield. The kit carries an M2 0.50in calibre machine gun and provides the gunner with side protection against 5.56mm and 7.62mm small arms ammunition.

The operator can also be protected through the use of remote weapon stations in which the operator remains inside the vehicle and uses externally-mounted sights to direct weapons fire. At one end of the remote station spectrum is the turret-mounted 5.56mm NEGEV light machine gun from TAAS-Israel Industries Ltd. Although originally designed to be part of their "Tankpak" upgrade, TAAS representatives indicate that the mount could be easily adapted for use on the M113. Features include light weight, simplicity of mounting/ dismounting and a lethal machine gun capable of firing at rates up to 950 shots per minute.

Rafael also offers customers a broad range of remotely-operated weapon systems for application to M113s. According to company representatives, Rafael has worked closely with Israel's Defence Forces (IDF) to develop the firepower upgrades ranging from 7.62mm to 25mm.

The smallest of these kits is the 7.62mm Overhead Weapon Station (OWS). The lightweight gun mount allows observation, laying and firing the weapon from either inside the carrier's compartment or as direct fire with the hatch open. The mount was designed to accept the FN M240 7.62mm machine gun but can also be adapted to other weapons.

Installation of the OWS requires a 430mm diameter clearance hole, fastening holes and connection to the vehicle's electric power supply. The weapon, ammunition feed belt, gunner's overhead sight and infra-red searchlight are all mounted externally to the vehicle. Located inside the vehicle are the gunner's control handles, the day sight and the ammunition magazine. An external ammunition box, for use instead of the interior box, is an optional mount attachment.

Up to three 7.62mm OWS can be installed on the top deck of an M113 with each weapon assigned a separate sector in traverse and elevation. A separate commander's day/night periscopic sight (CPS) can also be added to the forward part of the top deck to permit the commander to control acquisition and engagement of targets.

Rafael also offers an OWS for the 0.50in heavy machine gun (with option for 7.62mm co-axial machine gun). It has been designed to fit into the original well of the M113 commander's hatch.

The 0.50in OWS is electro-mechanically and manually driven in traverse (360 ) as well as manually driven in elevation (-15 to + 50 ). As with the 7.62mm OWS, the system can be operated in either closed hatch or head-out mode.

The system is designed to accommodate a variety of sighting subsystems. One suggested package includes the M28C (T46) periscope sight, a charge-coupled device (CCD) day camera, a colour monitor and an optional Improved CCD night camera. Three other sighting options reportedly include: a thermal imaging (FLIR) module positioned externally on the cradle with video information transmitted to the monitor; an externally-mounted searchlight; and a zoom option for the day camera.

As the high end of the scale, Rafael offers a one-man OWS consisting of both 25mm cannon (M242 or government-furnished automatic cannon) and 7.62mm co-axial machine gun. Three smoke grenade launchers are mounted either side of the turret.

The system includes two structures: an upper structure with weapons, mounts, smoke grenade launchers, and operator's hatch; as well as a lower structure with turret cage, turret drives, weapon control assemblies, sighting system, and ammunition. It can be operated in both open and closed-hatch modes. Turret drives are electro-mechanic with manual backup. The system can traverse 360 and elevate from -15 to +45 .

The standard optical sighting package contains a Rafael image intensified sight with day magnifications of x1 and x8 and night magnifications of x1 and x7. Options include a laser rangefinder or thermal imaging night sight offering x1.6 (9.6 x4.8 field-of-view: FOV) and x5.5 (2.8 x1.4 FOV) viewing.

In addition to these dual-mode (open hatch/closed hatch) weapon stations, the M113 can also carry a wide range of closed-hatch weapons turrets. Many of these turret installations would require some modification of the vehicle top plate to accommodate the supporting turret ring.

The Cadillac Gage Textron T-50 machine gun turret is one weapon station option that is currently mounted on a large number of international M113s. The one-man manually-operated turret can be equipped with a combination of 0.50in and 7.62mm machine guns. The basic turret provides the operator with ballistic protection against 7.62mm AP projectiles.

Several upgrade efforts are currently being directed toward existing T-50 turret systems. One of these activities, involving Australia's proposed upgrade to more than 350 of their T-50 turrets, was described in our May/June 1994 issue.

A second T-50 turret upgrade effort was reportedly accomplished by the New Zealand Army Support Command. The unspecified upgrade was conducted on 20 New Zealand Army M113s that were recently delivered to Split, Bosnia, for use in the UN contingent force.

Giat Industries is another manufacturer offering several turreted machine gun and cannon weapon systems that could be adapted to M113s. The DRAGAR turret, for example, can be armed with a 25mm cannon and co-axial 7.62mm machine gun.

As might be expected, FMC Corporation element of United Defense LP, designer and manufacturer of the M113 family of vehicles, has spent decades developing its own options for adding armament to the M113. As examples, options developed during the 1970s included a one-man enclosed weapon station with 40mm grenade launcher, a one-man enclosed weapon station with 20mm cannon, and a one-man enclosed weapon station with 0.50in and 7.62mm machine guns.

Much of the current armament effort involves a One-man Electric Drive Enclosed Weapon Station with 25mm cannon and coaxial 7.62mm machine gun. Identified as SHARPSHOOTER, the turret has reportedly been demonstrated in Pakistan, Korea, Egypt, Singapore and Turkey. Major advantages of the SHARPSHOOTER system include firepower, ballistic protection, and light weight.

The primary weapon in the SHARPSHOOTER turret is a 25mm M242 cannon with a dual feed system allowing both armour piercing (AP) and high explosive (HE) fire. Prototype systems also carry a coaxially mounted 7.62mm MAG 58 machine gun. However, designers stress that any 7.62mm weapon can be utilised. An all-electric power drive system - with manual backup - provides smooth control of guns and sights while an optional stabilisation system allows firing-on-the-move. The current primary sight is the M36E3 image intensified day/night sight, although United Defense has developed alternative fire control systems.

Company sources stress that SHARPSHOOTER offers excellent ballistic protection with minimum weight. Specifically, it provides the operator with 14.5mm protection at a total weight of 3100 lb (1406kg). They note that the light turret weight is extremely important since it also permits the installation of 14.5mm add-on protection to the exterior of the M113 without significant degradation to suspension, chassis, and overall vehicle performance.

At present there are two prototype SHARPSHOOTER systems, with at least one system being readied for shipment and demonstration in the Republic of China (Taiwan). Moreover, it is reported that the company's joint venture in Turkey, FMC-NUROL, is going to work on upgrades to the turret electronics.

Another one-man 25mm cannon turret that will soon be available for installation on M113s is the T25 low profile design from Italy's OTO Breda (formerly Breda Meccanica Bresciana SpA). The turret design includes a dual feed 25mm Oerlikon-Contraves KBA cannon with a coaxially-mounted 7.62mm MG3. Three multi-purpose grenade launchers are located on either side of the turret.

Other one-man turret options for M113s include a combination of both point and area-fire weapons. For example, United Defense LP has experimented with installation of its "40/50" turret on an M113. The turret, originally designed to satisfy the USMC requirement to upgrade the turrets on its AAV7A1 Amphibious Assault Vehicles, carries both Mk19 Mod3 40mm grenade launcher and M2 0.50in machine gun.

Chartered Industries of Singapore (CIS) has also developed a "40/50" turret option. The turret reportedly carries a CIS 40mm AGL grenade launcher and 0.50in CIS 50MG machine gun.

Delco Electronics, a subsidiary of GM Hughes Electronics, also offers some impressive two-man turret options for the M113 APC. Not surprisingly, these two-man designs are somewhat larger and heavier than the options cited above. The basic LAV-25 turret weighs 4000 lb (1815kg).

Close to 1000 LAV-25 turrets have reportedly been produced to date with "almost an equal number" on order. The combat-proven turret has been installed and demonstrated on a number of wheeled and tracked vehicles, including the USMC Light Armoured Vehicle (LAV), the Alvis Stormer, and the Canadian M113A2.

The turret carries a stabilised 25mm M242 cannon with 7.62mm M240 co-axial machine gun. Externally mounted grenade launchers can be used to provide quick smoke obscuration. Fire control sub-systems include two DIM36 sights (x1 and x7 magnification) with image intensifiers for night viewing (The turret can also accept an optional thermal vision module). The basic ballistic steel turret structure reportedly provides "95% protection against 7.62mm ball ammunition at zero meters" although this can be upgraded to 14.5mm protection.

The LAV-25 systems being delivered today feature an electro-hydraulic drive. However, Delco representatives emphasize that the turrets now being built for Canada's wheeled LAV reconnaissance vehicle, with deliveries beginning in early 1995, use electric drive. Moreover, the electric drive will be the LAV-25 baseline design from that day forward.

The 25mm cannon and 7.62mm machine gun are sufficient to defeat an estimated 80% of all targets likely to be encountered on the battlefield. However, for users desiring even greater lethality, Delco offers the LAV-25 turret with TOW option.

The TOW option places a single TOW anti-armour missile launcher on both sides of the LAV-25 turret. Additional missile displays and controls are then integrated into the turret panel for access by both commander and gunner. Delco representatives note that the critical hardware for the launcher, missile guidance set and aiming device is all in production and that the total additional weight added to the turret is 475 lb (216kg). The TOW option can be fitted as either new production or an add-on to existing LAV-25 turrets.

Egypt has been identified as "one country of principal interest" for the LAV-25 turret. In addition, programme representatives note interest among a number of current users of M113s in the Middle East and the Asia-Pacific region.

Although this article set out to avoid debating the line between APCs and IFVs, at some point, however, that line was approached and crossed. Many potential users will likely cross the same line as they face the worldwide array of armament options. One company official noted that his international customers specifically "want to make the M113, the troop transport, into a fighting vehicle."

Whether or not users want to cross the line between APC and IFV, in the final analysis the myriad of available M113 weapon options only reinforces the fact that the "ubiquitous" M113 will continue to play a vital role in defence inventories for decades to come.