Here are some pictures of my new 8x8x6 bin. I built it out of 3/4 plywood bolted to pressure treated 4x4s. It should hold about 9.6 tons minus the area for the auger's doghouse. Having automated feeding via the auger to the boiler is a beautiful thing! One side is supported by my concrete foundation; but, I was a little concerned about the other three sides---so I added three rows of 2x6 lumber to the base on the unsupported sides. I also ripped 12" wide 3/4 plywood and screwed this plywood to the joint between the 4x8 plywood and 2x8 plywood.
Loading the bin was interesting. I have a JD 4310 compact utility tractor w/430 loader w/6 foot bucket. I fabricated a "funnel" out of two sheets of 3/4 plywood; and, dumped the coal into the bin via the chute through my garage. I didn't take any pictures of this part of the job... I was too busy getting it done! We're all set for winter now!! Bring it on winter!!!