BR Class 21 Pug 0 4 0ST 51207 Era 4 Length 85mm Period Era 3 (1923 - 1947) Operator/Livery Early BR Black Class Class 21 'Pug' Designer Sir John Aspinall Entered Service 1893 Minimum Curve R1 Age Suitability 14+ Motor Type 7 Wheel Configuration 0-4-0ST Everyone loves a steam train and no model train set is complete without an engine heartily puffing its way along a branch line or nestling in an engine shed. Hornby steam locomotives are exquisitely built to our famous, exacting standards and all the authentic detailing from logos to rivets are meticulously executed to complement your layout.