The Raids on the Vemork Heavy Water Plant in WWII

Okay, what with all the talk of us bombing Iran because they might have a nuclear weapon at some point in the future, I found my mind drifting back to the raids the Allies made on the Norwegian dam to keep the Germans from getting enough heavy water to build a bomb. I did some googling to see if I could pull up anything on it to refresh my memory of the kind of effort we (as in the Allies) put into blowing the thing up and I came up with some contradicory information. According to Global Security

This conflicts with what Wikipedia says

Now, the Wiki account seems more plausible (from a number of planes standpoint), but Wiki’s not always right, and one would think that a website dedicated to military info would be the definitive source, but dang, that just seems like an awful lot of planes for a single mission. (And yes, I do know how vital we felt it was to keep the Germans from building nukes. I can well imagine that many planes being used over a period of days, just not all at once, as it were.)

Paging 633 Squadron

Both accounts are correct. At least according to a third account

388 planes took off, 147 B-17s bombed the plant.

Huh. I wonder how that compares to other bombing raids of the war? Where’s David Simmons? He’s got first hand experience with such things.