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Re: Chainplate bolt failure

Posted: Fri Jan 29, 2010 10:12 am
by paul manning
Chainplate fixing method and possible failures

The chainplates (stainless steel bent plates fixed to the deck which hold the wire rigging port and starboard sides) have been fixed to the deck in two methods.

1. The first method used a black anodised solid round alloy bar with two threaded holes in it. The chainplate on the top of the deck was then bolted through the deck and into the threaded holes.
This method of fixing was dropped, as although the bolts were coated in an electrolysis barrier paint the bolts still corroded in the alloy bar making replacement less easy.

2. The more recent boats have replaced the round alloy bar with large curved washers. This stops the corrosion problem.

Chainplate fixing bolt shearing

A small but regular failure is that the bolts can shear. One bolt fails, and the rig then looses tension.
The class technical committee and Ovington Boats discussed this problem, and Ovington Boats now supply all new bolts with a higher grade bolt.

This bolt is available directly from Ovington Boats.

Re: Chainplate bolt failure

Posted: Wed Feb 10, 2010 7:24 pm
by Rick

Re: Chainplate bolt failure

Posted: Sat Jul 02, 2011 12:50 am
by Peiler
Hey all - I bought a chainplate bolt replacement kit last week (after the classic rear bolt failure), but am having troubles installing it. The bolts have a 20mm thread length, which seems to be a little bit short as I can't quite get the bolt to fully engage with the nylock part of the nut - even doing it up as hard as I can I end up about 2-3mm short. The installation seems pretty straight forward (starting from the top of the bolt head, there is the small washer, the chainplate itself, the deck, then below the deck is the bent washer then the nylock nut).

Am I missing something obvious here? :? Any thoughts are welcome...

Thanks,
Chris

Re: Chainplate bolt failure

Posted: Mon Jul 04, 2011 12:08 pm
by paul manning
Ovington Boats part number 64025 is the chainplate bolt kit.

This is a replacement set of machine screws, nyloc nuts and formed washers.

Following a working party in liaison with Ovington Boats, it was decided to increase the DIN number of the supplied fittings. This made them capable of working at a higher shear loading.

Re: Chainplate bolt failure

Posted: Mon Jul 04, 2011 12:30 pm
by Rick
20mm dosn't sound long enough; perhaps Ovis have put the wrong bolts in the bag ... give them a ring and see what they say ...

Re: Chainplate bolt failure

Posted: Thu Jul 07, 2011 8:59 pm
by paul manning
I agree with Rick, 20mm sounds a bit short and I don't have one handy to check.

Give Peter a call and I'm sure he can help.

Re: Chainplate bolt failure

Posted: Fri Jul 08, 2011 12:28 am
by Peiler
Thanks for the replies - have confirmed that 25mm is the correct length (almost perfect - just a little bit of thread visible beyond the nylock nut). I have the correct length bolts on there way.

Cheers,
Chris

Re: Chainplate bolt failure

Posted: Sun Aug 28, 2011 8:32 am
by ThomasD
griff_323 wrote:A slightly disturbing variation on this; I have the washer arrangement on my boat (#323) yet at the weekend one of the bolts sheared off (about mid way up the bolt) with no warning.


The same happened to me now. Same setup, no warning. #332

Re: Chainplate bolt failure

Posted: Fri Sep 02, 2011 2:59 pm
by paul manning
I think it is important that everyone checks their bolts, and replaces them with the latest specification :!:

Re: Chainplate bolt failure

Posted: Mon Sep 05, 2011 10:08 am
by Emilien
I'd like to change mines, will you bring some kits at Portoroz ?

Re: Chainplate bolt failure

Posted: Tue Sep 06, 2011 1:43 pm
by paul manning
Yes I will :D

Re: Chainplate bolt failure

Posted: Wed Jan 25, 2012 3:24 pm
by Popeye
Just replaced mine and its a good job I did as the port side bolts sheared with minimum effort removing them!