Bill:
For the structural integrity of various aspects of golf course architecture, particularly the upswept sand surfaces of various bunkers, the "angle of repose" (as well as the coefficient of friction), is massively important and very likely one of the fundamental aspects of the endurance of features like that.
The thing that occurs to me is that many of the early architects, and particularly some of the most dramatic and respected of the earlier architects, may not have had any idea of the limitations of it if they were even aware of it at all.
Put in "angle of respose" into the search feature of GOLFCLUBATLAS and you will find around Sept 2004 that in that argument I had with Tom MacWood over the bunker restoration of Aronimink that the "angle of respose" was an important topic of the discussion and one that a guy like MacWood probably had little idea about or little idea about the significance of it.
All he did is keep harping on the fact that the bunker sand upsweeps did not look the same on the restoration by Prichard as they did back when the course was first built. He just kept saying they should look the same as those old photos but did he even consider the maintenance aspects and the cost of maintaining that look?
I very much doubt it. However, I don't think that was the problem in our argument about the bunker restoration of Aronimink. I think the problem was he was relying on the type of early photographs that did not show the reality of those old bunkers and the other problem was he'd never even bothered to go to Aronimink to look at the bunkers of the Prichard restoration project as the rest of us had.
A good example is the green fronting bunkers Crump designed on the 2nd, 10th and 18th holes at Pine Valley. There was no way in the world those sand faces could endure since the sand surfaces on the upswept areas were so far beyond the angle of repose and the coefficient of friction. Matter of fact, on one or two of them they were so excessive when they collapsed they took a significant portion of the front of the green down with them.
MacWood was all for original aesthetic purity and restoration and such but I doubt the guy had the slightest idea of some of the physics problems ("angle of repose" and "coefficient of fricton") involved in the look of some of that old architecture. Either that or he just didn't care. Well, golf clubs and their maintenance departments sure as hell care.