I'm pretty sure I know what they are, but not certain.
Electric train axle-truck was my guess too. It is weird though that Brazil has a different gauge. I'm guessing it's going to be narrower than our gauge to deal with the mountains they have there or the tighter confines of city streets.In California we have quite a rich railroad history, so I know a fair amount about railroading stuff. I've been to the California State Rail Museum in Sacramento several times as I only live about an hour's drive away. In fact, I can walk to it from my house, albeit indirectly. I live 5 blocks from an Amtrak hub, and the rail museum is about the same distance from the Amtrak station in Sac. Makes a great day trip on weekends for the kids. http://www.parks.ca.gov/?page_id=668
Interesting, didn't know that Brazil used a different gauge. I'm assuming they use a narrower gauge than us? BTW, the prototype I was referring to before is Thomas Edison's electric locomotive bogey, the first in North America. You can see it clear as day from Main St. in West Orange, NJ outside of the Edison Lab complex, right next to a replica of the first movie studio, the Black Maria. Some very nice pubs and restaurants right there if anyone ever decides to make the trip.........
That's pretty interesting. Most of what I know about railroads in California is from Dr SHeldon Cooper!