Development of Locomotive 27 



Many of the " singles " had inside cylin- 

 ders, such as the Midland, the later Great 

 Northern, the North-Eastern, and the Great 

 Central. In all cases they were beautifully 

 painted and kept in splendid condition. It 

 is generally agreed that the most pleasing 

 engines, as regards uniform and neatness, 

 were the famous 80 Great Western " singles", 

 which were built on the passing of the 

 broad gauge. The last of these disappeared 

 early in the war period. 



The " singles " gave place to the four- 

 coupled engine, usually with a leading bogie, 

 though there were scores without until 

 quite recent years. As a go-between the 

 ' singles " and the four-coupler, came the 

 ' double single " which flourished for a 

 time on the North- Western, and later, to 

 the number of six, on the South- Western. 



Here we have four large driving wheels, 

 that is two pairs, driven by separate sets of 

 cylinders, the idea being that the engine 

 will run with all the freedom of the " single", 

 with something of the greater power of the 

 four-coupled engine. On the North- Western 



