Mine Exposition 2012 (http://www.minexpo.com/) in Las Vegas filled up the Las Vegas Convention Center, the same place that fills up for the more famous Consumer Electronics Show. A feature of Mine Expo is that large equipment manufacturers bring examples of their equipment that will later be shipped to mines. Caterpillar had such a large booth that they put a complete EMD locomotive in the middle of the booth, where it was hard to see from outside since sightlines were blocked by other mining equipment.
Looking up can describe the equipment industry, since they provided generally optimistic views of overall up-coming demand. Given that advertizing growth at a show like this is required, I focussed on a different kind of thing by looking up at Mine Expo.
Several equipment suppliers brought mining trucks that haul the loads away from the face being mined. These huge trucks have beds (or bins or trays, depending on your mining dialect) well above my head. But looking up at the underside, you start to get a feel for the range of possible welding designs. Some were stiffened by I-beams, others by channels and still others by tubes or T’s. Replacement beds are supplied by other industry participants.
Why aren’t these varied designs being winnowed down? I think that the wear of the top surface can dominate the lifetime of a well-used bed. While stiffening is required to bring the strength and weight into balance, the rapid wear of the upper surface can dominate the lifetime. Indeed, one of the builders of replacement beds talked about the upper surface in his conference presentation rather than the under-side surface.