Chainplate bolt failure

Use this thread to share technique tips or ask questions of the experts. Also discuss boat modifications and rig tuning.
User avatar
paul manning
Posts: 2008
Joined: Tue Oct 09, 2007 10:02 am
So I know you are a real person not a spambot please enter the middle number from the below list (i.e. 3): 3
Contact:

Re: Chainplate bolt failure

Postby paul manning » Fri Jan 29, 2010 10:12 am

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.
Paul Manning
MSCA Secretary

Phone 0044 (0)7843 269353
Fax 0044 (0)1621 785735
paulsmanning01@gmail.com
http://www.mustoskiff.com

User avatar
Rick
Site Admin
Posts: 3160
Joined: Tue Nov 01, 2005 3:48 pm
So I know you are a real person not a spambot please enter the middle number from the below list (i.e. 3): 3
Location: Millbank, UK
Contact:

Re: Chainplate bolt failure

Postby Rick » Wed Feb 10, 2010 7:24 pm

Rick Perkins. GBR

Peiler
Posts: 7
Joined: Tue Feb 01, 2011 5:35 am
So I know you are a real person not a spambot please enter the middle number from the below list (i.e. 3): 3

Re: Chainplate bolt failure

Postby Peiler » Sat Jul 02, 2011 12:50 am

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

User avatar
paul manning
Posts: 2008
Joined: Tue Oct 09, 2007 10:02 am
So I know you are a real person not a spambot please enter the middle number from the below list (i.e. 3): 3
Contact:

Re: Chainplate bolt failure

Postby paul manning » Mon Jul 04, 2011 12:08 pm

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.
Paul Manning
MSCA Secretary

Phone 0044 (0)7843 269353
Fax 0044 (0)1621 785735
paulsmanning01@gmail.com
http://www.mustoskiff.com

User avatar
Rick
Site Admin
Posts: 3160
Joined: Tue Nov 01, 2005 3:48 pm
So I know you are a real person not a spambot please enter the middle number from the below list (i.e. 3): 3
Location: Millbank, UK
Contact:

Re: Chainplate bolt failure

Postby Rick » Mon Jul 04, 2011 12:30 pm

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 ...
Rick Perkins. GBR

User avatar
paul manning
Posts: 2008
Joined: Tue Oct 09, 2007 10:02 am
So I know you are a real person not a spambot please enter the middle number from the below list (i.e. 3): 3
Contact:

Re: Chainplate bolt failure

Postby paul manning » Thu Jul 07, 2011 8:59 pm

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.
Paul Manning
MSCA Secretary

Phone 0044 (0)7843 269353
Fax 0044 (0)1621 785735
paulsmanning01@gmail.com
http://www.mustoskiff.com

Peiler
Posts: 7
Joined: Tue Feb 01, 2011 5:35 am
So I know you are a real person not a spambot please enter the middle number from the below list (i.e. 3): 3

Re: Chainplate bolt failure

Postby Peiler » Fri Jul 08, 2011 12:28 am

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

ThomasD
Posts: 11
Joined: Fri Sep 25, 2009 11:14 am
So I know you are a real person not a spambot please enter the middle number from the below list (i.e. 3): 3
Location: Thun, Switzerland
Contact:

Re: Chainplate bolt failure

Postby ThomasD » Sun Aug 28, 2011 8:32 am

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
Thomas
SUI-517

User avatar
paul manning
Posts: 2008
Joined: Tue Oct 09, 2007 10:02 am
So I know you are a real person not a spambot please enter the middle number from the below list (i.e. 3): 3
Contact:

Re: Chainplate bolt failure

Postby paul manning » Fri Sep 02, 2011 2:59 pm

I think it is important that everyone checks their bolts, and replaces them with the latest specification :!:
Paul Manning
MSCA Secretary

Phone 0044 (0)7843 269353
Fax 0044 (0)1621 785735
paulsmanning01@gmail.com
http://www.mustoskiff.com

User avatar
Emilien
Posts: 119
Joined: Tue Oct 12, 2010 8:04 am
So I know you are a real person not a spambot please enter the middle number from the below list (i.e. 3): 3
Location: Nantes, France
Contact:

Re: Chainplate bolt failure

Postby Emilien » Mon Sep 05, 2011 10:08 am

I'd like to change mines, will you bring some kits at Portoroz ?

User avatar
paul manning
Posts: 2008
Joined: Tue Oct 09, 2007 10:02 am
So I know you are a real person not a spambot please enter the middle number from the below list (i.e. 3): 3
Contact:

Re: Chainplate bolt failure

Postby paul manning » Tue Sep 06, 2011 1:43 pm

Yes I will :D
Paul Manning
MSCA Secretary

Phone 0044 (0)7843 269353
Fax 0044 (0)1621 785735
paulsmanning01@gmail.com
http://www.mustoskiff.com

Popeye
Posts: 55
Joined: Mon Jan 02, 2012 7:11 pm
So I know you are a real person not a spambot please enter the middle number from the below list (i.e. 3): 3

Re: Chainplate bolt failure

Postby Popeye » Wed Jan 25, 2012 3:24 pm

Just replaced mine and its a good job I did as the port side bolts sheared with minimum effort removing them!


Return to “Coaching, Technique & Technical Area”

Who is online

Users browsing this forum: No registered users and 2 guests