As you know, I love heavy equipment. This digger is a John Deere 410G loader backhoe, belonging to the Falls Church city maintenance department. I drew it while sitting on my car's tailgate at the recycling center. This annoyed some of the visitors to the center who complained that I was blocking traffic. That's plein air art, folks. The industrial area around the recycling bins has been a longtime source of inspiration for me.
The digger reminds me of the mechas that I've been drawing. Many mecha artists use industrial equipment as a design source for their robot warriors. The articulation of the front digging arm is ultimately a biomechanical design, with metal shapes and pistons as joints and muscles, and electric cords as nerves. Were this for warfare rather than construction, some of the more vulnerable structures would be concealed under plates of armor. Also if this were a war machine I'd use tank tracks rather than wheels or legs.
Brown technical pen on sketchbook page, 5" x 4 1/2", November 1, 2013.