These rail crossing timbers are 7″ thickness x 10″ wide x 20′ long. You can see we custom saw the bottom triangle out of the pieces that are closest to the rail, so that they lay flat. Inside the “missing triangle” are the rail plates to hold down the rail. Different “weights” of rails have different thicknesses for Crossing Planks. We make 8″ thickness, 7″ thickness and 6″ thickness.