Burlington Northern sixteen wheel depressed center flatcar in Anchorage on August 1983.  According to the ARR switch crew, the load was "a pump for the oilfields, worth about one million dollars".  For the HO modelers, a few years ago Walthers had a kit for a similar car, and it was available painted for BN.  The load could be shaped from balsa wood, then wrapped with thin black plastic to give the tarp effect.