I’m pretty sure if I developed a business plan that called for the construction of a remote controlled underwater bulldozer I would be laughed out of any and every bank that would let me through the doors. Chalk this idea up to one that is crazy enough to work as the Japanese heavy equipment giant Komatsu perfected such a machine decades ago.
The D155W was the worlds first commercially marketed amphibious bulldozer. Large air intact and exhaust stacks allowed the dozer to operate via remote control in water as deep as 23 feet. The original production run saw nearly 36 D155W models constructed and sold to a variety of customers around the globe. Today at least five still exist in their home country of Japan and were in use as late as 2012.
The natural question that comes to mind is why? Surely the cost to build, operate, and maintain such a unique contraption negate the intended benefits. Could not the same job be performed buy a dredge or a land based excavator with a long reach boom? Perhaps the advantage lies in their small and compact size relative to large floating barges. In 2011 the Great East Japan Earthquake washed away sediment used to support bridge foundations spanning the Natori River. A group of D115W’s were used to replace this soil with pinpoint accuracy.
The video below shows you exactly how this bizarre concept looks in the real world. Operators stand on the shore watching the exhaust towers move through the water. Occasionally the machines surface for one reason or another. A team of divers are usually on hand to assist with repairs and guiding of the dozers in this uniquely Japanese application.
Thanks to Mark for sharing!
Continued Reading: Komatsu December 2013 Newsletter