Agreed, Sam. I posted as I did to try to explain two things to newbies:

1. No matter how good you think you are at guessing, you're not good enough. Calculate it, get it checked, and file it, then if something goes wrong you can still sleep at night.

2. If you recommend that something be calculated, and management disagrees, you can whip what I posted above out of the third brain cell from the left and impress the hell out of them in about 30 seconds, using numbers appropriate to your particular problem. This sort of argument is almost foolproof in meetings - nobody wants to go on record as saying the ice is not too thin for skating. And as the piper, you're the only one with a ruler for that particular measurement.