Donor Mechanism: N scale Kato 11-109 Drive This locomotive is a fully freelance narrow gauge boxcab, rooted in typical construction and design of early industrial switchers and interurban equipment. The ALW 20-ton boxcab shares lots of design characteristics of other units in the 28-ton series, including a cast frame and a steel cab with large pilots. This version includes two removable couplers designed to accept most HOn30 and OO9 rolling stock and two sandboxes that are shared with the 28-tonners. The shell is designed to click over a Kato 11-109 chassis and the removable cab gives easy access to the interior.