Дэвид Джонс и развитие локомотивов в Шотландии

David Jones (1834–1906) was locomotive superintendent of the Highland Railway between 1870 and 1896. He was credited with the design of the first British 4 6 0, which was strongly influenced by the Scottish locomotive design for Indian Railways. The 4 6 0 wheel arrangement that appeared in 1894, quickly became the most common locomotive for main line passenger and mixed traffic work in Britain. Although Jones was a fervent disciple of Alexander Allan, Jones' new designs tended to break away from the Allan tradition, which had lasted so long in Scotland. One Allan feature that Jones did not perpetuate in his 4 6 0s was double framing around the outside cylinders. Allan's straight link valve gear was, however, retained; this was basically similar to the corresponding Stephenson gear, but the link was easier and therefore cheaper to make and imparted a constant lead irrespective of cut off. The "Drummond" Castle class was, mechanically, Jones’ personal design, although the Drummond stamp of chimney, cab and 'water cart' bogie tender was unmistakable. A dubious asset, without which none of the younger Drummond's locomotives was complete, was the provision of a reversing gear, a troublesome mechanism if it were not well maintained. With the introduction of the 4 6 0, Highland Railway had thus obviated the 0 6 0 type employed by practically every other British railway, except its most intense competitor, the Great North of Scotland Railway. A 0 6 0, however, would have meant a crank axle, and crank axles did not have a place in Jones' designs. Jones’ new designs also tended to break away from the Allan tradition, although he continued to use the Allan link valve gear.

In 1892, the opportunity was taken to purchase two 4 4 0T engines which had been built by Dübs and Company for the Uruguay Eastern Railway but not delivered due to a financial hitch. These were known as the Yankee tanks.