[Tom in SFCA]

And building the Ark as described out of wood with the tools of the time would take 3000 man years.

But Jesus looked at them and said, “With man this is impossible, but with God all things are possible.”

[HeadOn]

Estimates range from 120 years on down, based on the Biblical account in Genesis. One common estimate is about 70 years.

Noah didn’t work on his own - we know he had three sons. And nothing says he didn’t hire a crew, either. So, if we go with 3000 man years, a crew of 43 men is 70 years. If 120 years, only 25 men.

(With modern tools and crew, it only took 3 years for the full-scale model in Kentucky...)