Any indication Gary of a possible cause? It looked to be a fairly gentle day weather-wise so I guess it came as quite a shock when the break occurred. Annie's comments about loads on these camber panel sails are very true. I need to use a winch on the luff hauling parrel on Footprints to get the creases out of the sail. I have already bend the alloy yard I had and am now back to my old timber yard, but I wonder if it is a bit of a time bomb, just waiting to break. I really do need to investigate a carbon yard for Footprints.

Woops, sounds exciting!

I guess we have to make the yards of our cambered panel sails a bit stronger in the vertical plane than when using flat sails. This is because most of the vertical loads have moved out to the luff and leech.

Here is my “yard experience”:
Soon after I had rigged my Johanna with the braced aluminium yard (the first yard, of fir, was way too heavy), we took her out in a strong breeze. We deliberately pressed her downwind with too much sail up. Then an inferior weld, holding the brace to the yard, snapped. What then happened was that the yard bent about 20°  at the slingpoint. This flattened the top panel which then took over the role as yard. Thanks to the strong fabric, this top panel prevented any problems further down the sail. We were in other words still operational and could limp home (well reefed). The yard was straightened (more or less) and rewelded, and is still in use, 12 years later.

The aluminium’s ability to bend before breaking makes me think that it is particularly well suited for yards.

Cheers, Arne

Here Johanna's - almost straight  -  braced yard can be seen. Click on it to zoom in...
(Photo: Peter Manning)

It's a bit raw and shaky but I like it.

http://youtu.be/8r_7eLouUPI