Ok, a little complicated to get too but…
Go to the link, go to about 1:15 in the video (if you don’t want to wait), notice the lumber car that is over stacked. That can’t be safe. Isin’t that just an accident waiting to happen being too top heavy? Oh, I guess you need the link. http://www.youtube.com/watch?v=Y0FpbQg9YPs
There is a possible danger of the load shifting, possibly minimized by the fact the the lower portions of the top bundles are below the top of the bulkheads. Also, this isn’t lumber, like the stuff in the car next to it–it’s manufactured flooring, which is considerably lighter in weight.
Having said that, we’ve taken precautions with loads of that stuff in our sandbox here in Illinois. Also, I’ve seen a number of bulkhead flats with extensions on their bulkheads (by a foot, maybe a little more), just for handling this stuff. That’s probably the best idea.