MurrayM, as another rock and ice climbing catamaran owner - I'm afraid that Manyboats post has the same conclusion as I do, that as the vessel yaws first one anchor, then the other, effectively take all the load. As it swings through the 'centre' your diagram is (I am convinced) correct but most of the time you are effectively reliant on one anchor.
However the maximum loads on the anchor(s) are snatch loads, caused by yawing simultaneous with moving fore and aft as the wind eases and gusts. A bridle or 'V' anchor arrangement reduces yawing and this reduces the overall level of snatch loads.
So its not so much that the anchors (or bridle) share the load nor that each anchor or bridle arm only is stressed half the time but the 'V' anchor arrangement or bridle actually reduces the maximum loads because yawing is reduced. There are other ways to reduce yawing, a riding sail is a perfect example for a Trawler. Deploying one anchor as 'normal' and simply deploying a second such that it simply drags under the bow is another well recognised technique. Tying to trees (or rocks) is another.
But its all about what is best at the time, for you, the vessel and the location - its back to that compromise.
However the maximum loads on the anchor(s) are snatch loads, caused by yawing simultaneous with moving fore and aft as the wind eases and gusts. A bridle or 'V' anchor arrangement reduces yawing and this reduces the overall level of snatch loads.
So its not so much that the anchors (or bridle) share the load nor that each anchor or bridle arm only is stressed half the time but the 'V' anchor arrangement or bridle actually reduces the maximum loads because yawing is reduced. There are other ways to reduce yawing, a riding sail is a perfect example for a Trawler. Deploying one anchor as 'normal' and simply deploying a second such that it simply drags under the bow is another well recognised technique. Tying to trees (or rocks) is another.
But its all about what is best at the time, for you, the vessel and the location - its back to that compromise.