[aerohead]

I forgot this and had meant to include it.Darin had posted the other day a citing by Hucho regarding the back of trains.In Hoerner's book,he reports that the actual boundary layer thickness around trains,at the time of publication,could not be accurately deduced from formulas and would have to be established empirically from observation.

Trains were exhibiting boundary layers of areas greater than 10 X the base area of the tail car.

And as Darin has reported,with the tail of the train embedded within all this noisy air,the aftbody shape might not have the significance one might presume.

What strikes me,is that in 2005,the Shinkansen began tests of two experimental 52-foot-long aerodynamic nosecones ( tails ),and by 2006,were running the form essentially established by Jaray/Klemperer in 1922.It also looks suspiciously like the inflatable/extensible bus boat-tail depicted in Hucho's text.What's old is new again.