Don't get me wrong - love the C38s! But streamlining in the case of the LNER was a genuine desire to reduce horsepower required at higher speeds. The smoke deflection part of the design was not entirely accidental however. It is true the chimney "thumbprint" was added to the model in the wind tunnel. However the bit that actually makes the smoke lift up and away is the bugatti front end and the complex curves around the smokebox. If you look at the A4 head on you realise just what a complex shape it is. Far more complex than the LMS equivalent (which in absolute fairness, was still a good solution to the "streamlined" problem - but approached from a different perspective). Totally agree. One can state however that it is integral to the design. It's not just an A3 with a casing on top - it's far more complex than that. It really is a case of perfecting a design over a fifteen year period.