The Automatic Fire and Explosion Detection and Suppression System (AFEDSS) was developed by Spectronix to meet the requirements of the Israel Defence Force following their experiences in the 1973 Middle East war. Many Israeli tank crews were killed or injured when their vehicles caught fire, following penetration of the tank armour by High Explosive Anti-Tank (HEAT) and Kinetic Energy (KE) weapons.

The main Israel Defence Force requirements were to increase crew and vehicle survivability and to provide for an add-on modular design, enabling interchangeability and commonality between vehicles.

Following extensive trials, series production of the AFEDSS commenced in 1981 and the Israel Defence Force now installs it on all new production Merkava MBTs. It has been retrofitted to earlier production Merkavas as well as Centurion, M48 and M60A1/ M60A3 MBTs. It is probable that the AFEDSS is fitted to the specialised APCs developed by Israel based on converted MBT chassis.

These heavy APCs include the Puma (Centurion chassis), Achzarit (T-55 chassis), Nagmachon (M48 chassis) and Nakpadon (Centurion chassis). It is possible that the Classical M113 based armoured personnel carrier, (which is illustrated in the entry for the RAFAEL explosive reactive armour package for the M113 in the earlier Armour systems section), may also have this system.

The AFEDSS has also been exported and other vehicle types in which it has been installed include the Leopard 1 and Russian Federation and Associated States (CIS) T-series MBTs, the M113 APC and M109 155 mm self-propelled howitzer.

The Spectronix Crew System is an automatic, instantaneous, detection, control and suppression system with a normal and combat mode of operation. Its primary function is to protect the crew from secondary effects of a projectile penetration, namely, restricting skin burns to first degree levels and preventing lung damage which results from pressure shock. The system detects an explosion or fire within 3 ms and suppresses it within 100 ms. It consists of a number of key subsystems:

(1) detection subsystem. This consists of a suitable number of optical fire detectors which effectively cover the entire volume to be protected. It is capable of detecting HEAT or KE round penetration within 2 ms, as well as fuel fires and vapour explosion, without false alarms

(2) logic and control subsystem. This provides automatic control and status indication of all components, has a dual-operation mode selection (normal/combat), a manual override capability, automatic back-up in case of cylinder or system malfunction and built-in testing features

(3) dispersion subsystem. This consists of a suitable number of Halon 1301 * cylinders with a double shot capacity, capable of instantly discharging their contents and effectively suppressing fire or explosions.

The Spectronix Engine System is based on the need for an automatic, reliable, rapid and durable detection, control and extinguishing system, the primary duty of which is to prevent damage to or destruction of the engine and transmission. It consists of the following subsystems:

(1) detection subsystem. This is a thermistor type overheat wire detector which detects rises and falls in temperature and is employed to ensure full coverage of the engine compartment. The detector has two levels of detection, an overheat level wherej indication warnings are given that the preset overheat level has been reached and the higher fire condition where the system automatically activates the dispersion subsystem

(2) logic and control subsystem. This provides automatic control and status indication of all components, has a manual override capability and automatic back-up in case of cylinder or system malfunction and has built-in testing features. The system features /dual-shot performance. The second shot is manual and shuts down the engine (in order to extinguish engine-fed fires). Since it is a manual activation it engine in combat situations, in contrast to automatic shut down systems

(3) dispersion subsystem. This consists of a suitable number of Halon 1301* cylinders, capable of instantaneously discharging their contents through piping and discharge nozzles to the various areas in the engine compartments. As an option the system can also incorporate various

add-on features some of which are:

(1) external independent manual activation

(2) activation of the vehicle's ventilation

(3) audio or audio/visual alarms

(4) systems energiser unit (for vehicle storage situations).

• The extinguishing cylinders are also available with a Halon alternative such as FM 200 or PFC 410.

In series production since 1981 for the Israel Defence Force and many other undisclosed customers. More than 7,000 systems are in field use. Known customers include Austria, Canada, Greece, Israel, Spain and Taiwan.