"My understanding is that the bulkhead in question is not structural to the boat per se, rather it just gives the the requisite strongpoint"
In other words, it's an essential structural element... if you want to use that sail as intended
I think it would have been a very hard repair to effect at sea in those conditions. It's the roughest part of the boat, and bailing wire and duct tape won't do when carefully laid up carbon fiber and epoxy are called for...
No matter what other drivel we might read on here, this comment is right on. There is just no way that Groupama or even Tele would have turned around and taken all that mileage on the chin. No way. They want to win too goddamned much to just fork over free miles without a fight. Cammas is an engineer and they would have gotten out the duct tape and bailing wire and made do.
My understanding is that the bulkhead in question is not structural to the boat per se, rather it just gives the the requisite strongpoint, via a strop up to the deck, to mount the tack of the much-desired-on-this-leg J4. Yes, it sucks that it popped out. But for thousands of years sailors have jury-rigged stuff at sea. Worst comes to worse, carry the J4 on the regular jib tack -- it's only 3-4 feet forward of the J4 tack -- while the epoxy dries. Yes, ADOR would have gone a little slower with their sail rigged incorrectly for those hours. They were not in physical danger as a result of the failure (which would always be cause for heading for port); the boat just wouldn't go as fast without the J4 set up correctly. And yes, the boat is hugely bouncing around and effecting a repair up in the bow would have been a huge pain in the neck.
But for crying out loud, they have just given up 600 MILES!!! That is insane. It's not even yacht racing. I don't know what to call it. I mean, literally, why even bother?
As one of the other posters said, they could have used another tack fitting. The J4 tack fitting is a couple/few feet back from the stem. They could have used the fitting right at the stem, and hoisted the J4 from there. Sure, it is not the correct way to fly the sail and it will be angled back a few degrees and the lead position has to be moved forward somehow, but you have to be kidding if they thought it was worth 600 miles. If they lost one knot of boat speed and used the J4 constantly, 600 miles is almost a month of sailing. Additionally, they have several other sails to choose from. Anyhow, surely there would be at least one relatively smooth day and they could have glued the bulkhead back in. To your question, the boat doesn't need one of those bulkheads in order to stay together, it just transfers the load for the tack fitting there into the hull. I realize this is a pretty scary leg, but that's just hyperconservatism on Abu Dhabi's part -- not even close to a good enough reason to turn back and lose so much mileage.