The 4 Largest Tanks Ever Built (And One That Remains A Twisted Dream)

The problem with the Heavy tanks was just that,,, they were heavy,, too heavy to be practical. The major players in tank development realized that the light and heavy designs were impractical. Medium tanks or as they are dubbed now Main Battle tanks were the best solution,
German Tigers were too heavy for bridges, hard to recover when damages and wore out quickly. Even the US foray in heavy tanks the T-26 Pershing was outperformed by the Sherman as far as reliability in Korea.

Back in the late '80s and '90s. The Artillery branch was developing a replacement for the M109 Self Propelled Howitzer. I think it was called Excalibur, weighed around 110 tons. The program was eventually cancelled.

The Rat definitely was a huge chunk of iron.