He also envisioned a fast breakthrough tank, similar to the British cruiser tank, which was to be armored against enemy anti-tank weapons and have a large 75-millimeter (2.95 in) main gun. Lastly, Germany would need a heavy tank, armed with a massive 150-millimeter (5.9 in) cannon to defeat enemy fortifications, and even stronger armor. Such a tank would require a weight of 70 to 100 tonnes and was completely impractical given the manufacturing capabilities of the day.[14]