Quigly, What you saw was what is known as a culvert emplaced ied. Jam as much homemade bulk explosives into a culvert and then det. on intended target. Our mission over in the "Sand Box" was Route Clearence. One of our jobs was culvert denial, ie. plugging them up with concrete. OBTW the first US KIA's In a Buffalo was last year. The Buffalo was completely destroyed by such a device.
