THERMAL SIGHT FOR SHERIDAN

The 82nd Airborne Division, wanting to upgrade the night vision capabilities of their M551 Sheridan Vehicles, decided to replace the M44 periscope with the M60A3 Tank Thermal Sight (TTS). This presented a problem with the reticle system in the TTS since it was designed to aim a single weapon system (the 105 mm cannon). The M551 vehicle has two weapon systems that interface with the periscope: the 155 mm cannon and the Shillelagh Missile. ARDEC was given the assignment to make the necessary changes to the TTS to meet the M551 system performance. ARDEC tasked Decilog to design TTS modification kits to make the necessary reticle changes with minimal impact on the existing hardware. Decilog developed a concept which would require the design of two kits; one for the gunner's display unit of the TTS and one for the vehicle dimmer box. This concept was approved and Decilog was given the go ahead to design the kits and fabricate 3 prototypes. These prototypes were installed in vehicles and successfully tested at Anniston Army Depot and Ft. Bragg, resulting in a Government decision for Decilog to produce 80 systems.