There's a saying that goes something like: "Any idiot can build a bridge. It takes an engineer to build a bridge that is just strong enough to stand given the weight it's meant to bear".
A lot of older structural "engineering" was figuring out how much material was required, then multiplying it by 80 just in case.
A lot of older structural "engineering" was figuring out how much material was required, then multiplying it by 80 just in case.