The worlds biggest and heaviest bulldozer ever made is the Acco. It is a non production custom " one-off " that was built by the Italian Company Umberto Acco  in 1980.

The Acco was constructed mainly of Caterpillar parts, many other components however were specially adapted, like the big shovel blade that's bigger than anything Caterpillar make.  This Acco bulldozer is amazing, it is truly one of a kind.



The Acco has a colossal weight of one hundred and eighty three tons! and is powered by two 675 horse power Caterpillar engines.  The engines are placed horizontally opposed and deliver a total combined power output of 1350 horse power.

It can be assumed that the drive train mechanism shares the power of the combined engines, rather than being divided to drive a particular set of drive wheels.  This would of course be the easier and less expensive option.



This amount of shear horse power drives both the upper and lower rear mounted drive sprockets, having two drive sprockets maximizes torque, delivering fantastic pulling and pushing power.


Photo courtesy of Robert Frino


The " teeth " that run along the surface of the tracks are quite deep, and  greatly assist traction by digging into the soft earth and sand and providing maximum grip.



Robert Frino the modeller from Genoa, Italy, who made the scale model of the Acco that features on this page stated that it took him over 500 hours of hard work to complete the model, this includes the painting of it.

He used such materials as plastic-styrene, aluminum and brass.

The model was entirely handmade without the use of molds and is hence a rare and unique Acco model. Robert added that the scale of the model is 1/87 and is hence quite a small model.

I would like to add that it looks like a super-fantastic model, keep up the great modelling skills Bob!

Visit his website by clicking on the image below.


The Acco has a blade that is twenty three feet wide and nine feet high, whilst the total length of the bulldozer is over forty feet, from  the tip of the blade to the ripper on the rear.  As the picture below relates, the ripper alone is about ten feet tall! powered by huge hydraulic rams.  This is total earth manipulation at its best!



The Acco was initially built to be exported over to Libya, North Africa in the early 1980's, to help in land development, but as the President of Libya, Col Gaddafi was allegedly involved with International Terrorism at that time, the United Nations endorsed and sanctioned huge trading embargo's on that Country.  


Photo courtesy of Robert Frino


As a direct consequence of these trading restrictions, the completed Acco bulldozer was never shipped to its intended destination, but remained redundant in Italy where it was built.

Later with the sad death of Mr Umberto Acco, the directors of the company decided not to continue with many of Umberto's innovations and  along with a few other machines, the dozer of which had never been put to any operational use, was sadly put into storage where she remains today.



The above picture shows a guy standing at the rear of the Acco bulldozer to give some idea of the size of this truly enormous machine.

The twin upper and lower drive sprockets can be seen in this image too and that is some serious metal harnessing power.  It would be great to see this Acco bulldozer in action.


Photo courtesy of Robert Frino


The future of this massive dozer is uncertain, it could become an attraction at some possible sight seers venue or it could be cut up for scrap metal value. I hope its not the latter as it would be a great shame.


The Acco bulldozer has also been miniaturized in the same light as the Roberto Frino model.  Expert model maker Don Campbell from Otsego County, Northern Michigan, U.S.A has also created a full metal scale replica of the Acco bulldozer. The scale model is super detailed, right down to the last nut, bolt and rivet.



This model is truly remarkable and just shows what can be achieved if you have the enthusiasm and the know how. This model is thought to be a " one off " just as the real bulldozer is.


Don Campbell has a website featuring more of these wonderful models that he has built and you can visit by clicking on the above image.



The latest news is that the enormous Acco bulldozer has luckily been saved by a wealthy collector.  The  bulldozer, that will remain in Italy, has been moved to a permanent location for display.



She was worked on by mechanics to get her up and running and driven onto a low loader.  She has now been transported to Vivai Bejaflor, Portogruaro, a new location in Northern Italy.  Here she will be fully restored and put on display for thousands to see and enjoy.



This is excellent news and I am delighted that she will not be cut up for scrap and sold off in little pieces. Somebody obviously realized that this, the worlds biggest bulldozer was worth saving.

There is a YouTube  video of the Acco bulldozers arrival at her new destination, after her transportation...see below...




For further information please check out these links: More photos  and an enthusiasts facebook page offer some great new photos. Also there is an extra YouTube video for you to enjoy. Courtesy of  Marco Castellan, Italy.


Page created February 13th 2008. Updated  March 16th 2013