This is really troubling.  My vang hasn't broken (H400) but I did notice one problem this summer:  there was no bearing washer between the bottom surface of the end fitting of the vang and the top surface of the fitting attached to the mast.   As a result the vang was wearing a "notch" in the mast fitting which would tend to make it hard for the vang to rotate on that fitting, and someday perhaps it would have "stuck" and broken.

I've added a washer to fix this, and probably most people already have a washer there but I thought I'd mention this in case, because I can see how this could have eventually caused a failure....



You might also notice in the photo that I have a shackle on the bottom of the pin that goes through the vang and mast fitting.  This isn't of much use on the bottom of the pin but I can't put it at the top because there isn't enough clearance between the bottom of the mast fitting and the deck to insert the pin from that direction.   This seems to be different from other installations I've seen on the forum.

Thanks for the photo Johan.  I do think my pin is upside down but as you point out I would need to lift the mast to invert it and then I won't be able to take it out again without lifting the mast again.   Maybe I should have a pin with holes at both ends instead of a "cap" on one end-then I could remove it and still put a shackle on top.

I own a 470 from 2009. The fixing of the vang with the mast is ok so far. Anyway I have noticed that the fixing is a little bit loose and in light wings the vang moves. I have nevertheless a problem with the fixing of the vang with the boom. Just a week ago I noticed a crack on the steel piece that goes into the rail in the boom. I have comunicated to the Hanse dealer and I am waiting for their response. I have nonetheless not sailed yet in maximum force 6 winds and for a short period of time.

On our boat (4 y.) the holding plate at the boom broke (s. pic, Sparcraft rig). On a today Selden rig the situation is different, but it is the weak point. We don't race and we tend to reef the main rather too early than too late going up-wind (1st reef at 15-18 kts, 2nd at 18-25 kts) with no significant loss of speed . On a reaching course the vang is on full load and tighened very hard to avoid the main of twisting and touching the spreaders. We rarely go downwind. It is important that you check the vang reguarly and that the boomvang line (10mm) has a certain streching capability to compensate the hits on the boom ( no Dyneema-type rope).
 

I too had some weld fracturing on the same part on my 400... Wouldn't it be fantastic if someone at Hanse could/would actually compile this type of info and make some changes accordingly. Imagine the impact to quality and customer experience.