Webbing Anchor around boulder

There's a route where I climb with a large boulder at the top of the route about 5-10 feet back from the ledge. By large, I mean size of a volkswagen bug large. I've climbed this route with a couple of different people who have both used pro plugged in a crack below the boulder to build a TR anchor. When I set it up for myself yesterday, I plugged a couple of cams and tied a large webbing sling around the afore mentioned boulder- all equalized out. My question involves anchors and redundancy- Luebben, in his book, suggests that it is alright to tie two separate slings around 1 large boulder like this and consider it redundant- does anyone else practice this, or other points of anchor a necessary addition? If you were setting up on this route, how would you approach it?

If the boulder is bomber, not sitting on gravel or precariously perched, it is fine. Two runners or two cordalettes around that boulder would be a fine anchor.

I believe one or two slings around a car size boulder is enough. No need for pro below it. Recently climbed a route where the FA slung a large tree and nothing else. Webbing was in great shape and tree was solid. I had no concerns with extra protection.

Yeah, its definitely bomber. A relatively severe earthquake would be required to move it (and in that case, I'd be F'd anyway). Thats what I thought, and seeing Luebben write it was definitely comforting, but I wanted to check again and make sure I hadn't misread anything

Totally valid.

Triple check what the consequences of the boulder shifting even a little bit will be. Will a small shift send it hurtling down onto your follower/you/everyone else? I've only ever climbed on one unsafe anchor... I was following my partner who had slung this giant ass boulder that was perched on the edge of the down sloping top out and had about a one inch contact point wth a crystal in the ledge.

Needless to say I was pissed, so don't be that guy!

I downclimbed off a pitch once when I saw that the guy's TR anchor was a single loop of webbing (1" tubular) around a big ass boulder. What scared me was that the webbing was pinched in a rather sharp fissure on the back side of the boulder. No redundancy if it were to cut. Making it worse, the loop was really tight around the boulder, and the rope therefore pulled outward on it at a rather large angle. It's easy for tension in the webbing to be greater than the applied load in a situation like this; that whole tangent(theta) thing.

Otherwise I'm fine with a BFB as the anchor.

Totally OK. I prefer to do this as much as possible. Why mess with a tiny nut in an 'iffy crack, two or three more of the same, equalizing knots, etc. to set a toprope anchor? When you have THE immovable object such as a tree 10 inches thick or a car sized boulder,,you use equalized slings and you have made a redundant anchor. I intentionally have almost all of my anchor slings tied in lengths of exact size,to the half inch or less, for this purpose of using them together on the same massive anchor. Saves soo much time in set ups, saves lots of money as slings are cheaper than another 2 nuts or a cam. Luckily my 'home' climbing area has enough huge boulders and big trees for me to use them for over 90% of my set ups. Fast and easy,solid, and what I learned in my anchoring systems classes in 'old school' days of 70's. Still works fine. Never a failure .

Woodchuck ATC wrote: Saves soo much time in set ups, saves lots of money as slings are cheaper than another 2 nuts or a cam. Luckily my 'home' climbing area has enough huge boulders and big trees for me to use them for over 90% of my set ups. Fast and easy,solid... .

That's essentially how I felt, but again, as a newish climber wanted a little bit more assurance. My home area's the same- big boulders and decent trees. I feel so comfortable equalizing slings with water knots and have a lot of webbing, so the less time I have to spend setting up a solid anchor, the more climbing I can get in (and the more confident I feel dangling from said anchor). And as I don't have an extensive rack yet, double-slinging a single massive boulder may allow me to climb in a couple of places I otherwise couldn't set an anchor.