Santa Barbara Dual Spectrum (SBDS), now a division of Kidde Technologies Inc, has been involved in the development, testing and manufacture of high-speed optical explosion/fire sensing and suppression systems since 1969 in co-operation with various US and foreign military programmes.

In addition to armoured vehicles these programmes include aircraft, helicopters and ships. The first USA production vehicle to be fitted with this system was the General Dynamics Land Systems M1 Abrams MBT followed by the United Defense LP M2/M3 Bradley armoured fighting vehicles.

These Infra-Red (IR) optical sensors with millisecond response plus thermal sensors provide the best protection for engine and auxiliary power unit spaces against both explosive fires and slow growth fires. They also have the ability to detect quickly, overheated conditions in these spaces.

The SBDS Fire Sensing and Suppression (FSS) systems product line is dedicated completely to developing and producing explosion protection systems which are highly reliable, of high quality and totally dependable for protection of life and equipment.

SBDS now has systems in quantity production for the M1 Abrams, M2/M3 Bradley Fighting Vehicle, South Korean K1 (which was originally called the Type 88), US Marine Corps AAV7A1 armoured amphibious assault vehicle, LAV-25 (8 x 8) vehicle and variants, Taiwanese M48H 105 mm MBT, C-5 heavy lift transport aircraft, Ariete MBT, South Korean K77 Fire Direction Control Vehicle, US M8 Armored Gun System (AGS) and the Italian Centauro (8x8) 105 mm armoured car/tank destroyer. In some cases, production of these vehicles has been completed although marketing continues. The M8 AGS remains at the prototype stage as it was cancelled by the US Army, but is still being offered on the export market by United Defense.

These programmes account for the manufacture of more than 100,000 sensor system components, which are contained in over 17,000 vehicle sets of production hardware, plus additional test and support equipment and spares.

The SBDS system proved to be effective on the battlefield during Operation Desert Storm, being credited with saving several lives of crew members of M1 MBTs and Bradley Fighting Vehicles under hostile fire.

The SBDS Automatic Explosion/Fire Sensing and Suppression (AEFSS) system is an IR Dual Spectrum optical system capable of detecting hydrocarbon fuel fires and explosions within tanks and other armoured fighting vehicles. The system is integrated with a compatible fire suppression system, utilising [high-- speed valvesand cylinders filled with the appropriate extinguishing agent. Complete sensing and suppression of an explosive fire can be achieved in less than 200 ms. The SBDS system is designed and qualified to meet the performance specifications developed by the US Army, the US Marine Corps and aircraft manufacturers.

The basic Dual Spectrum sensing system responds to explosive hydrocarbon type fires in under 3 ms with almost complete false alarm immunity. To produce an output trigger signal to the suppression system, the sensors must detect radiation within two IR spectral bands, each with radiation levels above pre-established thresholds.

The Dual Spectrum sensing systems are used primarily with high-speed cylinder/valve suppression systems. The cylinder/valve assemblies used for these applications typically contain a variety of suppressant agents depending upon the application, super pressurised with dry nitrogen to ensure rapid discharge over a wide range of temperatures.

Valve opening times vary from about 2 ms for squib' or protractor type valves to about 7 ms for solenoid type valves. The entire cylinder is discharged in 60 to 90 ms.

SBDS Dual Spectrum sensors operate according to a patented concept which monitors near and far IR spectral bands within pre-established thresholds to confirm a hydrocarbon fire and to exclude false alarm stimuli. SBDS IR optical sensors function effectively in engine compartments with little degradation from accumulation of dirt or oil on the detector windows.

Model PM-3 is the basic SBDS Dual Spectrum fire sensor which is standard equipment on the M1/M1A1/ M1A2Abrams, M48Hand Centauroand K1 production MBTs. This sensor has a 90° optical field of view and an operational temperature range from -67°F (-55°C) to +257°F(+125°C).

The Model PM-34 provides additional discrimination capability which prevents the suppression system from activating on the energy from Kinetic Energy (KE) or High Explosive Anti-Tank (HEAT) rounds when no hydrocarbon explosion or fire occurs. This equipment isstandard on the M2/M3 Bradley Fighting Vehicle and has been procured by the US Marine Corps for the AAV7A1 armoured amphibious assault vehicle. This has the same optical field of view and operational temperature range as the PM-3 model.

The Model PM-34CBEH is the newest advanced unit which incorporates the false alarm immunity and discrimination features of the other fire sensor models plus Built-in Test Equipment (BITE) and integral fast response optical heat sensing capability. This sensor has the same optical field of view and operational temperature ranges as the previous models.

The PM-5 is a stand-alone driver's module which is powered by standard 12 V (or 24 V) power sources. It can operate one extinguisher or may be interfaced with other PM-5s and extinguishers for larger zone sensing and suppression coverage. It has a 90° optical field of view and will operate over the temperature range of-67 to+212°F.

These provide the logic and control functions rapidly and reliably to process inputs from sensors, perform necessary analysis and comparisons and generate signals needed to activate extinguishers and status indicators. System control panels are tailored to each vehicle's operational needs for crew alerts and status indicators, plus controls for manual system activation.

The combination of non-shatterable steel bottles and fast acting valves, which are activated by either solenoid or protractor, provide the mechanism to store and release the fire suppression agent. Agent leakage rates of less than 1 ounce peryear ensure availability of the fire extinguisher when needed.

Electrical wiring and (components mounting brackets comprise the remainder of the system. They are designed to ensure reliable and durable performance in the vehicle operational environment which is typically characterised by vibration, shock and rugged use.

SBDS also manufactures test equipment for checking the Dual Spectrum IR sensors and the system as a whole.

Early in 1996 this company was sold by Hughes Aircraft to Kidde International Limited, a subsidiary of Williams Holdings PLC. It is now an operating division of Kidde Technologies, a business sector under Kidde International.

In production. In service with Italy (Ariete MBT and Centauro 105 mm tank destroyer), Taiwan (M48H), South Korea (K1 MBT and K77), the US Army (M1/ M1A1, M1A2, M2 and M3) and US Marine Corps (M1A1, MBTG and AAV7A1 amphibious assault vehicle). The V-22 Osprey aircraft, LAV (8 x 8) is in service with Australia, Canada and the Saudi Arabian National Guard. It has also been installed in many vehicles for trials purposes including the Bofors S-tank, M47 and M60 MBTs, M113 series APC, HSTV-L prototype, AAI automotive test rig, M48 MBTs (former Cadillac Gage Textron and General Dynamics Land Systems), Leopard 2, AMX-10P, AAI HWSTD, Italian VCC-80, US LAV-105 (8x8), South Korean Biho SPAAG, US Breacher, HAB and AAV - ATR vehicles.