Foil box failure - fatigue

Hi all,
I'm 70 kg. 175cm tall. Intermediate. Winging for nearly 3 years. Been careful with all my gear. Never had any high speed hits with the foil.
Been using an Axis BSC 1060 for all that time, plus for the last 18 months a PnG 1300. Bought a Konrad 118L board about 2 years ago (brand new) and have run this as my go-to with those and other foil combos. I've loved the design and durability of the board. 18 months ago also got a carbon 86cm mast. About 9 months ago bought a Hi Mod Carbon 1020 mast from Axis. It's been amazing feeling the responsiveness of that mast with all foils. There's almost no flex at all in the mast despite the 1+m length. When I've foiled with the Hi mod and 1300 in choppy waters, I have felt very unstable as the wide wingtips provide massive feedback which has the board moving around under me a lot. In hindsight, the combo has put huge load on that Konrad foil box.
Last week, I was out at our local spot foiling in 15 knots with some 0.5m wind waves. Had been swapping back and forwards between the 1060 and the 1300 in that session. After an hour of chopping and changing those 2 front foils, I was out on the 1060 riding toeside and rolled downwind into a wave preparing to gybe - something I've done literally thousands of times before. I crashed mid turn, having the foil hit me in the head (which has never happened before) and me slightly confused as to why the gybe went so wrong. Luckily wearing a helmet spared me more damage than a black eye. When I came to the surface I tried to remount the board and couldn't as the foil box had failed meaning that the foil was now NOT attached to the board. Looking around I could not see the foil or anything that I could have hit causing the box to fail. I quickly triangulated my position so I had some idea of where the foil went down. I managed to self rescue.
On getting back on land I worked out what had happened. The box had broken out sideways with the sideways load when I was going into the gybe. I didn't hit anything - no loss of speed and no feeling of hitting anything when I crashed. I fell off the board sideways, not off the front. The foil also hit me in the head when I fell off, which means it broke out sideways, rather than flying off out the back of the board. The photo here shows how the box on the left has torn out completely, but on the right hand side, it's rolled out leaving parts of the box behind.


I contacted James from Konrad to discuss the issue. Initially he reckoned there was no way it could fail in the way that I described, saying all the failures he'd seen had been from forward hits. When I showed him the photos and described what had happened he could see my point. I also attributed the failure to being fatigue related and due primarily to the very long Hi mod mast and the 1300. I believe that combo puts a huge amount of force directly into the box - despite my scrawny weight. There's no mast flex to absorb any of the sideways forces and the extra length of the mast and width of the 1300 wingtips means that a much greater force is at work compared to most other combinations. He could understand what I was saying.
The board being out of warranty meant I pretty much knew he couldn't do much for me. James and my discussions were very respectful and he agreed to supply me with a new custom board at a heavily discounted price, to which I have gratefully accepted. He also said that the newer board he's making are stronger, lighter and have upgraded boxes.
As for the fate of my foil, it went to the bottom of a 6-7m deep bay. A very kind friend (thanks Simon!!) got his boat and side-looking depth sounder out to try to find it the next morning but no luck due to poor conditions. Super fortunately, the 15 knots sou-wester that blew all the next day had the mast and foil combo blow up on the beach outside the pub where another very kind foiler (thanks Alex!!) found it and returned it to me. Talk about bloody lucky! Someone said I should buy a lotto ticket.

I don't want to create a storm in a teacup, but my take home messages out of this:
- Have you bought a second hand board without knowing it's history? Perhaps be concerned about the integrity of the box?
- Do you run long stiff masts with big front foils? Maybe think about securing the foil to something like the board?
This may not be relevant for many of you but for some, it may be. If I can spare any of you the huge concern I had about not ever seeing my loved gear again, then it's been worth posting this. While I'm sad about the Konrad being damaged, I think I can get it professionally fixed.

I've also checked the foil combo to see why it moved so far underwater from where it busted off to where it washed up. Turns out it's BARELY negatively bouyant, which would likely mean that even sitting on the sandy sea floor it would be easily disturbed by currents - hence why it got washed up on the beach 500m downwind of where I lost it the day before.
I checked the bouyancy with a short fuse instead of a standard, and the combo BARELY floated. Regardless, I'm now employing a tether wrapped around the throat of the mast and clipped off to the board. The tether has a tendency to slide down the mast and create drag, so I've taped it up to the top of the mast. Have used a 4mm spectra.

Maybe with more guys progressing to longer masts and bigger waves we will see more track box failures and a trend back to tuttle boxes?

We may also see board makers use rail boxes specially engineered for the forces of foiling, and not mere surfing boxes.

I know Gong in 2023 has now its own reinforced boxes (also to have the double entry to put and remove the mast without unscrewing to totally the base), but I guess most companies has gone or will go this way too.

I wonder if some Windsurfing mast rail boxes are stronger and could be a solution.

FYI - I wouldn't touch a foil sup with any type of track box. YMMV

I've had a Naish Hover that i broke the foilbox out in a similar manner , nearly 2 years ago. 2000cm2 low aspect Foil set sunk to the bottom, never to be seen again. Self rescued home. Heard some similar stories about this board. Dealer was great about it and repaired the board for free. Was able to take some money out of insurance for the foil.

I think at the start a lot of boards were produced in a very short amount of time, that might have been the issue - and development of the sport is very rapid and therefore the requirements of all fittings / fixtures are constantly changing.
It's the reason I keep going back to a great surfshop. You pay a little more maybe, but if there's anything going on they'll be able to help out.

Thanks for the post, new to foiling, Naish 5.0 hover and foil mounted. Starting in Lake Mead. Wondered about the mount, seems like a lot of intense vector tension is placed on that surface. Since Lake Mead is so deep recovering the foil after a mount failure would be a lost cause. So took a que from your photos and tied a small nylon rope around base of the foil and hooked to leash mount on board. Thinking of drilling a small hole in the mast and using a small wire rope for this purpose. Anyone doing this, my mast is aluminum.
thanks,
Joe