Harald
Sorry for the late reply to this topic.
The plan in Steven's post comes from a book called British Military Architecture, From Airships to the Jet Age by Paul Francis. The book is out of print, but sometimes comes up for sale online.
Unfortunately the book does not include drawings of the other types of dispersal pens. I suspect copies of original Air Ministry plans may be held by the RAF Museum at Hendon.
The accompanying text mainly deals with the later types with splayed pens as illustrated by Steven.
There is a thread on the same topic at another modelling site here:
http://www.scale-models.co.uk/threads/e-shape-bob-dispersal-pen.19557/The link in Steve's post on that thread does not seem to be working, but try this one:
http://archaeologydataservice.ac.uk/archives/view/greylit/details.cfm?id=18051This will take you to the download page for the report, which is one I prepared…
Regards
Andrew