…and I never knew that in some countries they used the apostrophe instead of a hyphen as the separator in the wheel arrangment descriptions - after 30 years of watching the railway scene ! [:)]
Tony
440cuin.
I think you mean MILW bipolars. They would be 1Bo+Do+Do+Bo1 
I was thinking of the Great Northern W-1. A big streamlined unit. I think all axles are powered.