Course it's true. If materials that could deliver 100,000 trucks to the parking lot of the vehicle factory are consumed getting 930 to the end-user (probably close if you include all the fuel/transport/escorts/their fuel and losses etc) then the useful supply ratio is about 1%.
To the recipient 930 are received, out of 1000 expected, but the sender needs a far higher effort to get those vehicles delivered. One lost ship is hundreds/thousands of 'trucks', and a ship carrying trucks can't be used for anything else till it is back after the round trip, and needs fuel/crew/escort etc..
What were the merchant loss rates on the North Cape convoys? Escorts? We lost at least one Carrier up there. How many ships were lost to U-Boats.
Not saying there was any alternative, or that it was a bad choice... just that 1 truck costs a damn sight more than in peace time, or the cost of building that 1 truck.
(Mind you the trucks were useful, the 'tanks' we sent, plus assorted small-arms ~ less so though the quality did improve towards the end of the war - things that were useful also included AA guns, radios, radar and similar 'tech').
Looks like we shall agree to disagree. I cannot understand the point, or even if it made sense to me, how you would even attempt to calculate a loss/delivered rate, factoring in not only ships/men lost en route, but now you are suggesting escorts AND transports - even if not lost as they are being used for supply to USSR purposes and not for something else
BTW what carrier did "we" lose?? I assume you mean American, but I can't think of one, and the British certainly didn't (unless my memory is fading in my frail dotage)....
22nd November 1944 - The British Pacific Fleet is born (temporary avatar changes to commemorate the ships and aircraft). HM Ships Formidable, Illustrious, Victorious