Gentlemen:
You do realize that nearly every green built in the last thirty years has been built on sand with some soil amendments, don't you?
Do you have any reason to believe that the same thing wouldn't work on a fairway, or wall to wall?
We made significant soil amendments at Pacific Dunes and Barnbougle (and Lost Dunes and Sebonack and Ballyneal), but we certainly didn't truck in topsoil or anything like that ... that would make a mess of the percolation rate. What you need is enough starter fertilizer to get the turf going ... chicken manure and fish guts are often used for this.
Minimalism helps. You don't need nearly as much fertilizer in the areas you haven't torn up and re-graded, because the soil biology is still intact in those areas, but when you have to cap sandstone with three feet of dune sand, it does require a fair amount of chicken poop. Fescue, of course, responds far better to these lean conditions than other grasses might.
As to the question of why three feet, Dave Wilber could answer this technically much better than I can, but I do know that the depth of sand cap can vary significantly depending on the materials and the exact makeup of the sand. If you are sand capping an entire rocky or clay site (such as in Bend, Oregon), you will lay herringbone drainage under the whole fairway, so you only need 12-18 inches of sand for a growing medium. (Most developers can't stomach the $$ for more than 12 inches, and may even try to go less, but they sometimes get wet conditions as a result.) At Pacific Dunes, though, we weren't doing herringbone drainage underneath ... we just drained the pockets ... so we needed enough depth for the water to freely drain down into the profile a ways before it sat on rock.
David E: Probably that was Greg Ramsay's "early budget" at Barnbougle that you're referring to. Greg was trying to make the numbers fit what he could raise himself. I can assure you that Dave Wilber and John Sloan and Bruce Grant all told Richard Sattler exactly what it would take to grow grass there, even though he might not have believed them to begin with. And, Chip, that 18th fairway was as close to pure beach sand when we built it as anything I've ever worked on; I spent a couple of nights out there shaking my head thinking what Walter Woods would have told me our chances were, but there's grass after all.