The T64 had the advanced feature of automatic canon loading, that eliminated the requirement for a loader, reducing the crew from four men to three. The T-64 tank; however, proved to be unreliable due to its complicated mechanics, and this led to the development of the T72 tank. The T72, despite its close external resemblance to the T-64, was created in an attempt to simplify the overall design; improve its maintenance capability; and to also enhance productivity. The refined type 2A46 125mm gun with its auto-loading system is capable of firing high explosive or hollow-charge, armor-piercing ammunition. The powerplant is a type V-46, V-12 cylinder, multi-fuel engine. The standard production designated T72M1 uses reinforced frontal armor and incorporates a laser range finder. This versatile tank, which began service a the beginning of the 1970s has been in production for many years, and had been license produced in many of the Warsaw Pact countries. Even during the 1980's when a new T80 main battle tank was introduced to replace the aging T-64, the T-72 series continued to be the centerpiece of the Russian armed forces.