Hi. New member here. Please excuse me if I screw up the proper format for posting since this is a new forum software that I'll have to learn how to use yet.
I've been building a 1:72 scale U-boat and had been searching for trunking and piping detail under the casing, since it's all going to be accessible in my model, and when I found NZSnowman's drawings they just blew me away. He's got exactly the data I've been looking for all this time and his drawings are terrific!!!!
Anyway, so much for introduction. Now to take a stab at answering a recent question.
NZSnowman asked: "I was laying in bed this morning and wondering why are the models 1:72 scale, why not 1:70 or 1:75 scale? Anyone know why 1:72 scale."
And dougie47 replied: "Aircraft model scales tend to be in 24th, 32nd, 48th, 72nd, and 144th scale. All numbers that we can divide by 8. This allows Airfix's new 1/24th Mosquito (with 617 parts by the way!) to be exactly twice the size of a 1/48th Mosquito. If 1/72nd had been rounded off to 1/75th we wouldn't be able to make such a comparison."
I think dougie is on the right track when he said that all the aircraft scales can be divided by 8. It was simply that in the early years of commercial model kits, (at least the ones that were mass marketed in the English speaking world and thus became well known, that they were all measured in inches and the full size item was measured in feet. It's much easier to divide inches by 1/4, 1/8, etc. than it is to divide by 10s, and this also works out easily with a foot.
Even though metric is used in most places now and measurements divisible by 10 make more sense, the scale standard had already been set in the largest model-making countries of the time.