National 12

General Boards => General National 12 chat => Topic started by: tp00 on 01 Sep 2022, 12:15

Title: Rudder failure
Post by: tp00 on 01 Sep 2022, 12:15
I recently suffered a total failure of a wing rudder on a Paradigm 2 while sailing on a broad reach in F5, the boat was flat and planing and no helm applied at time of breakage, could anyone suggest a reason, could it have been that too much wing was applied.(https://onedrive.live.com/?cid=1341EB655C11F81F&id=1341EB655C11F81F%213858&parId=1341EB655C11F81F%211513&o=OneUp)
Title: Re: Rudder failure
Post by: Chris Troth on 01 Sep 2022, 03:19
I also had an accident with my wings in similar weather. The bow was starting to head south, so I let off the rudder control. As I did so, BIG bang, and we were in the drink.
Photo of the rudder here - https://www.flickr.com/gp/23450051@N03/Sy0Z6ioE00 (https://www.flickr.com/gp/23450051@N03/Sy0Z6ioE00)
The stock and transom are fine. The wings themselves are solid. Did I let things off too fast? Did I generate too much 'downforce' too suddenly? Was there a weakness in the foil? Thoughts welcome!
Title: Re: Rudder failure
Post by: tp00 on 01 Sep 2022, 11:46
https://onedrive.live.com/?cid=1341EB655C11F81F&id=1341EB655C11F81F%213858&parId=1341EB655C11F81F%211513&o=OneUp

https://onedrive.live.com/?cid=1341EB655C11F81F&id=1341EB655C11F81F%213859&parId=1341EB655C11F81F%211513&o=OneUp

Pics of failed rudder
Title: Re: Rudder failure
Post by: darebarry on 03 Sep 2022, 11:00
Looks like a Lack of carbon. Talking to Andy Patterson of Bloodaxe foils many years age I asked how do you know how much carbon to use. Answer was a bit less each time until it breaks then a bit more next time. The pics would seem to show a lack of the black stuff where the stress was. Remember carbon only breaks, it does not give. Thats my take.