Staff Writer (Updated: 7/12/2016):
To compensate for the mounting losses, German authorities called for improved tanks - particularly where armor protection and penetrative weaponry were concerned. The response eventually yielded the Panther Medium Tank as well as the highly respected Tiger I and Tiger II Heavy Tanks. To counter the German counter, the Soviets moved to designing family of tracked vehicles with their own increasingly effective armament arrangements and one of these creations became the "SU-100" tank destroyer.
The SU-100 originated through the plain and simple need from the Soviet Army needing to combat the latest generation of German tanks now being fielded across the Eastern Front. Soviet engineers responded by developing a new gun based around the existing - and proven - B-34 naval gun utilized on Soviet warships of the time. To help improve development time, the natural selection of the T-34 chassis was made to ensure the gun could be mounted onto a readily available and proven tracked system. Nearly three quarters of the new vehicle would be made up of the T-34 while the remaining quarter would be largely unique to the new tank destroyer. Design and development of the tank destroyer - designated as the SU-100 (the "100" is derived from the caliber of the main armament) - began in early 1944. The gun was itself designated as the "D-10" in its basic form and, became the D-10T when fitted to a tank while becoming the D-10S when fitted to a self-propelled artillery vehicle. Despite their associated designations, the guns were differentiated largely by the choice of mount required for each installation - tank versions fitted into traversing turrets while self-propelled forms fitted into fixed superstructure hulls. Two pilot vehicles - the "SU-100-1" and the "SU-100-2" - was made ready for testing in March of 1944.
After successful evaluation, the vehicle was quickly accepted into frontline service with the Red Army under its well-known and general "SU-100" designation. Its overall design was rather conventional which much of the hull appearance of the T-34 left largely intact. The key differentiating feature of the SU-100 was its fixed superstructure hull which housed the needed gun mount for the 100mm main gun. The 100mm main gun protruded from the front facing of the vehicle and held limited traversal and elevation, requiring the crew to face the entire tank in the direction it needed to fire. The crew, applicable internal facilities and the engine were all housed under the enclosed armor structure. The driver sat at the front left with the gun to his immediate right. The crew of four also included the tank commander, gunner and an ammunition handler. The glacis plate of the vehicle was efficiently sloped for basic ballistics protection while the sides of the hull superstructure were angled inwards with the hull roof left flat. There was a raised cupola to the right side on the hull roof for the commander and completed with useful vision slots. Another hatch was set to the cupola's left, just aft of the driver's position for the loader. The hull superstructure only ran up to the midway point of the design to which the lower engine compartment was fitted to the rear. The engine exhausted through a pair of pipes at the rear facing which was also sloped inwards, giving the SU-100 its distinct all-around shape. As the T-34 before it, the SU-100's frame made use of five large, rubber-tired road wheels to a track side with the requisite track idler and drive sprocket at either end. The chassis was suspended by a conventional Christie-type suspension system for improved cross-country performance. SU-100s were commonly seen with two or four external fuel drums hooked up to the upper sides of the hull rear - this helping to extend the operational range of the vehicle in keeping up with the main force. All told, the SU-100 was an imposing looking battlefield system - built of Soviet expertise and war time experience.