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move chain plates to sheer

  • yes and why

    Votes: 4 40.0%
  • no and why

    Votes: 6 60.0%
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Discussion Starter #1
hi, ok you rigging guys. I have a 72 ranger 33. Thinking of moving the chain plates to the outboard sheer. I understand the effects on windward performance but i already use inside sheeting track for close hauled weather work. planning on island hopping in the Caribbean and don't plan for more than three or four days off shore at a time. Please let me know the effects on rig strength good or bad. thanks
 

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Marginal if any increase in strength. It requires input from a qualified NA to determin what additional reinforcement is necessary at the new attachment point! and all new standing rigging, and new spreaders. Assuming it is done correctly you can get a reduction in the compression loads of the mast, but unless the outboard move is dramatic it doesn't make that much difference.

Unless you are replacing the mast with a different section I can't see the point.
 

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I agree with Stumble. You can't just bolt the new plates to the hull, it will have to be strengthened on the advice of a NA. And you will need new spreaders. I don't think that the Ranger 33 has had an issue with poor mast support.

What is your reason - leaks and maintenance issues?
 

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Discussion Starter #5
thanks for the reply, yea leaks and maintenance. I now think I will just re-bed and keep what mr. mull designed.
 

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I would suggest that while leaks and maintenance can be costly repairs if you are not careful, hiring a nautical architect and doing all necessary modifications will probably be a lot more expensive, not to mention the costs of machining new chainplates new spreaders, and you will lose some performance.
 

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well you can, but you have to be smart...if your hull is cored and is flexy(this used to be something I did to boats while dock walking, tap tap or push) and or is simply soft like a lot of plastic flyers in the 80, 90s then you could benefit from reinforcment...

your ranger 33 is a nice racer cruiser but I cant remember where your plates are...I had a friend in fl who had one

if going outboard you can bend a new t-shaped backing plate on the inside...
you can create a strengthened knee
you can layup some plywood and stringers
you can add a mini bulkhead if space is available
you can add a permanent stay inside if the angle is available

hiring a NA? you must be kidding...$$$ unless he is your brother have a nice day...

there are plenty of books on boatbuilding, restoration and riggers apprentice type books that go massively into detail on how to make modifications and fixes without detroying structural integrity, more often then not improving over stock.

other sources like james baldwin´s atom voyages site are also good as they are real world mod sites that show how beefing up certain parts of production boats make them better for intended purposes...

another good site is jean du sud site of his alberg 30

does your boat have 1, or 2 or 3 plates per side?

Im reinforcing my aft lowers on my islander 36 as we speak as this is an issue with some islanders, with inner stays(cheap galvanised wire and eyes) and beefed up deck underside...

cheers
 
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Here is the chainplate configuration on the Ranger 33:



The uppers are in line with the main bulkhead:



The best solution I can suggest if they are leaking is to re-bed them with a raised section of the deck where they enter to keep water from pooling there. Done properly chainplates should not leak. Here is a link to a series of pics showing what I mean.
https://plus.google.com/photos/+JeffLovett/albums/5665170238138437761?banner=pwa
 

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thats almost exactly like my islander 36 except the angles of the main plates are not straight like mine...Im elongating my main plates btw by about 6 inches or 2 extra bolts...unnecessary in reality but since Im doing new bulkheads spacing out the load over more area will result in less point loading etc...

which stays are you planning on moving? if ALL then you do have to modify the spreaders and possibly elongate all stays...this can get expensive...and uneccesarily complex for a simple solution like more "deck space"

I have grown to like either setup inboard or outboard plates that is

on inboard plates and stays you can swing between them and the lifelines etc...

on outboard plates and stays you usually just duck under a bit and can rest against them while tending other stuff inwards of them...

there are many production boats like older pearsons that owners have mounted their plates outboard

one thing to notice is that a lot of older boats have very thick overly layed up glass that like it or not does allow for modifications wthout ANY detriment to structural integrity etc...usually on these boats all that is done is to use old plates as backing plates, OR some straps are glassed into the hull.

examples of these boats to look at on google images and the like are the

alberg 30
pearson triton, electra, vanguard, invicta

some bristols like the 27, 29

etc...

good luck
 
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Moving chains OUT to the hull will reduce rig stress so I doubt an N/A would need to be involved.

Moving them IN is an entirely different matter - rig compression can go up significantly, depending on how narrow you make the base.

Having said that, I can't see any reason for moving them out - they still have to be sealed and maintained, the rigs performance will be degraded, it will cost $$ and gain no benefit that I can see.

Make sure the existing ones are in good shape and seal them properly.

'Nuff said.
 

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Moving chains OUT to the hull will reduce rig stress so I doubt an N/A would need to be involved.

Moving them IN is an entirely different matter - rig compression can go up significantly, depending on how narrow you make the base.

Having said that, I can't see any reason for moving them out - they still have to be sealed and maintained, the rigs performance will be degraded, it will cost $$ and gain no benefit that I can see.

Make sure the existing ones are in good shape and seal them properly.

'Nuff said.
This is true, assuming there is somewhere outboard that is strong enough in the vertical to handle the loads of the chainplates. Sure you could just bolt them to the side of the boat, but how do you know if they are strong enough in tension? Sure there are some boats that it would be fine on, on others you could rip the side of the boat off.

Your boat, your choice. But before moving major structural elements I want someone to run the numbers.
 
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