Safety of Single-strand of Webbing anchor?

I had a question about the safety of tying a TR anchor off of 2 trees with limited webbing. Ideally I know I should get static line. However, would it be safe to use a single strand of webbing like in these following examples? I have Freedom of the Hills Vol8 but could not find anything about this.

Let's assume the trees are solid but about 6" in diameter, so two trees would be ideal.

This first system is essentially tying a figure8 on a bight on each of the trees and throwing a master point in the middle of the single strand that is going between the two trees. This uses one piece of webbing for the whole system (I would back it up somehow - how would you back it up?)

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This second system is for when a really long extended TR anchor is needed:

Pretty much tying two figure8s on either end of the single strand of webbing, around each tree. Would use two locking biners opposite and opposed.

I reason that with the single strand, there is a similar amount of security using an equalette on a multi pitch climb. What are your thoughts MP?

Webbing is plenty strong but very vulnerable to abrasion/cuts; it has no 'sheath' like a static rope or even a simple cordellette... if you're going to use it as shown in your diagrams better be darn sure it's not going to be rubbing on anything sharp.

before you even think about setting this up, ask yourself how big are the trees?  if they are 12" diameter or larger, no need for all this mess...

How solid are the trees.  Often, one tree is more than adequate.  But, if you feel the need for two trees:

What is the first master point?  One strand or two.  

A bfk or two separate eights on a bight would make redundancy there.

The second setup is fine.  

What exactly is your question?

Greg D wrote:

The second setup is fine.  

Tri-loading a single biner on the master point should be avoided...

Edek Falkowski wrote:

 Would use two locking biners opposite and opposed.

curt86iroc wrote:

Tri-loading a single biner on the master point should be avoided...

I take it you didn't read the op's text.

nope, just looked at the image and included text.

curt86iroc wrote:

Tri-loading a single biner on the master point should be avoided...

Fine, use a delta quicklink. Problem solved.