A3 0-4-0 Switcher (PRR US)

The Pennsylvania Rail Road (PRR) A3 Switcher is an 0-4-0 tender switching (shunting) locomotive designed by Kenzo Hiraoka. He has covered 3 1/2" gauge, and 7 1/2 & 7 1/4 inch gauges in a single construction book titled " The Pennsylvania A3 Switcher, ISBN 0-941653-62-5, which also contains full drawings. The construction series was originally printed in Live Steam (US) magazine. The only castings needed are for wheels, all other items can be fabricated.

The design can be adapted to 5" gauge by simple scaling, but the boiler would require redesign.

Finished 12 spoke driving and coupled locomotive wheel diameters are as follows: 3/4 inch scale, 3 1/2" gauge = 3 1/4 inches over tread 1 1/2 inch scale, 7 1/4 or 7 1/2" gauge = 6 1/2 inches over tread