GWR Mixed Traffic: The Great Western Railways mixed-traffic classes revolutionised steam locomotive design in Britain. George Jackson Churchward, Chief Mechanical Engineer on the GWR from 1902 to 1922, successfully broke tradition with the introduction of his 43xx Class 2-6-0 moguls. They would go on to influence future locomotive design, not just on the Great Western network, but across the entire national network. Heavy Freight:Though passenger traffic came to play a huge part in the running of the railways, it was the movement of freight that first necessitated the laying of metals. As loads became heavier, the locomotives charged with hauling them grew accordingly. It was a trend that continued throughout the steam era, and one that produced some of the most powerful and rugged engines ever designed. BRITISH NARROW GAUGE: Narrow gauge railways have been employed in an enormous range of locations and for a brood variety of purposes. The locomotives that run on these lines come in all shapes and sizes. The Welsh Highlands Beyer Garratts are large in comparison to the Beyer Peacocks of the Isle of Man network. Nonetheless, both perform much the same duties hauling passengers along spectacular routes.