[Juha]

Hello Kutscha
I have read the same years ago fromNoble Frankland's Bomber Offensive (Purnell 1969) and from semi-official Richards' Royal Air Force 1939-1945 Vol I (1953). I don't know if it is in Davis' book but already by July 41 Air Staff knew that oil plants were too small to be found with the equipment and training level at the time, so Peirse was informed that targets were morale and marshalling yards.

But Tony's point was that COS could not control Harris, that's a different thing than Air Staff. IMHO power grid targets were not feasible for night bombers before late 43 when there was enough H2Ss and some ecperiences on their use and Oboe was established itself. IIRC Germans jammed GEE much earlier than British had anticiped but still had its function because it was working over North Sea and navigators could check their calculations against GEE positions for first couple hundred kilometers, so they saw for ex how exact was the forecast for winds etc and it also helped them during last couple hundred kilometers on way back.

And one should go through the British reports on effects on LW bombing to see how British power grid coped, that surely had its effects on how vulnerable target British saw the Germany's grid. I'm rather sure that there are books on the target selection and at least memorandums and service's own internal studies, for ex that on Photo recon was opened to general readers at PRO in 1978.
Juha