I seem to remember that someone involved in the design of the power cars disliked the original front design (show in the first of the two pictures earlier) and changed it at the last minute hoping it would be too late for anyone to object.
What ever the cause of the redesign - much prefer "version 2" that we have today.
The front of the prototype power cars was based on an streamlined nosecone made by
BR▸ 's Plastics Development Unit at Derby and attached to an AL6 electric locomotive (now Class 86) E3173 in the late 1960s for high speed aerodynamic testing. This locomotive was also used for the trials of the Helicoil secondary suspension, used for the
HST▸ power cars (and used in airbag form in practically every bogie ever since) and so earned the name Zebedee after the TV Magic Roundabout character.
After construction of the prototypes
ASLEF» (not the
RMT▸ which didn't exist then) 'blacked' the trains for a year because the locomotives were not designed for two man operation. Finally test running started under a special agreement which saw the production trains equipped with two proper seats in the cab.
Before the locomotives went into production the nose was re-styled for several reasons. Firstly to meet ASLEF's demands that trains still had to have a fireman so the seating and window arrangements needed to be changed; development made it possible to manufacture larger sheets of armoured glass for the windscreens and the BR Design Panel thought that the trains need a more impressive appearance than the prototypes. The Chief Mechanical Engineer was persuaded that this was good idea and BR engaged Kenneth Grange (
http://en.wikipedia.org/wiki/Kenneth_Grange) to re-work the frontal appearance.
The rest, as they say, is history!