Here is a really nice video I saw Tom Elish Jr. posted on YouTube for the Corner Field Museum and Hobby Shop.
Tom's description is "Here is video & pictures of B&O Baltimore & Ohio 1 Williams Powered & 1 Williams Non-Powered E7's Pulling A Total of 50 Freight Cars Which Is 212 Axles. This train is running on our Museum Display (Layout) at Corner Field Model Railroad Museum & Hobby Shop." "1 unit was only powered and the other a dummy non-powered pulling 50 freight cars. So actually counting because the 2nd unit is a dummy, it's actually 51."