Which is Britain's favourite type of steam locomotive? Flying Scotsman is clearly the most famous, but as a sole survivor of the A3 Pacifics, it is out of the running.
The Gresley A4 Pacifics have an obvious appeal, and fortunately it is still possible to see several of them lined up together, but with their streamlined casings they do not conform to the pattern of the archetypal steam locomotive. The same applies to the unrebuilt Bulleid Pacifics, the appearance of which was a successful attempt to get away from that archetype at a time when it was commercially necessary to update the image of steam.
Surprisingly, LMS Class 5s, with the most survivors of any class, have more of a following than in the days of steam, when they were commonplace, neglected and ignored. Looking at the type in their present-day immaculate condition, however, their elegance and perfectly balanced appearance is evident.
Then there are the Great Western classes, which survived in large numbers thanks to the good fortune of having been sent to Barry. Here of course the obvious candidates are the Kings and the Castles. The former are imposing but the design pushed the GWR's four-cylinder 4-6-0 formula to the limit and they originated in a desire for publicity as much as for the needs of the traffic; the huge boiler sits uncomfortably and the inside/outside framed (and initially troublesome) bogie is an oddity which was the result of having too much to squeeze in. Which of course leaves the Castles, another class which has survived in large numbers. The single chimney variant is as nearly visually flawless as any practical machine can be. To judge by the number of Youtube videos of simulations which bring Castles to such improbable routes as the West Highland, and the West Coast Main Line north of Carlisle, one wonders if the type is not now at the top of the list.