![](http://upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/30px-Commons-logo.svg.png)
Wikimedia Commons has media related to B′B1′ locomotives.
Four-coupled Mallet articulated steam locomotives with a trailing truck, classified B′B1′ under the UIC classification of locomotive axle arrangements.
- The equivalent Whyte notation of locomotive axle arrangements is 0-4-4-2T.