During this same time-frame in the 1970s the Imperial Iranian Army was making several advancements and placing massive orders to keep up with other divisions of the military. To reinforce the ground troops the Iranians ordered 500 M109 howitzer's, 455 M60 Patton A3 tanks were ordered from the Americans. The largest order was placed from the British for 2000 Chieftain tanks, which had been specifically designed for the Iranian Army. Some other major equipment on order included hundreds of Russian BMP-1 outfitted with anti-tank missiles. In addition the Iranians sought to strengthen their position in the Strait of Hormuz by setting up missile sites in the close vicinity.