Learned of it on http://semitrckn.tumblr.com/ but the images are originally from http://www.vincelewis.net/accograder.html and all the known info about it can also be read there.
In a nutshell, an Italian company, ACCO, made this for Libya, but due to political issues it was never delivered, and wasted away for 30 years in Italy, until eventually, they got tired of storing it and dismantled it.
Weighing 160 tons, it had 2 engines, a 1000 hp in back, and a 700 hp in front, and the dual tires were needed to support the weight. The blade was 30 feet wide