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Old 14 November 2009, 13:03   #21
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If your D-ring is breaking it must have in inherent design flaw. I assume the D ring proper is not actually breaking but being wrenched from the stem as the hull itself is not sufficiently reinforced where the D-ring is located?
If you need more holding power, in lieu of a samson post why not fit two D rings similar to those used on the SR 4-point bridle arrangement, instead of the D ring being either side of the bows inside the boat have them either side of the bows on the outside of the boat. Essentially a D ring on a stainless steel backing plate for example 5" or 6" square through bolted (Sikaflexed etc) through the hull with a similar backing plate in way of a large "washer" inside the boat.
You can then also use them to secure your boat to your trailer & in a bridle arrangement if you ever need to tow your boat.
Quite the opposite - the hull there is over 1" thick - it's the stainless that fails!!!

Looking at the motion today it is very violent - snubbers on the ropes would help but they are nylon anyway. With the forces involved I really wouldn't want to attach ropes to the console!!!
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Old 14 November 2009, 13:11   #22
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Quite the opposite - the hull there is over 1" thick - it's the stainless that fails!!!

Looking at the motion today it is very violent - snubbers on the ropes would help but they are nylon anyway. With the forces involved I really wouldn't want to attach ropes to the console!!!
With a well setup spring there wouldn't be that much force.
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Old 14 November 2009, 13:33   #23
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With a well setup spring there wouldn't be that much force.
Or movement.
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Old 14 November 2009, 13:44   #24
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Well, its obviously the shock load thats doing the damage.
If your boat is tied to a floating pontoon & there is no height difference between boat & pontoon then all lines need to be tight such that the inertia from the bow being kicked by the wind does not cause a sufficient acceleration force to break the D ring. That is why ships lines are bar tight.
Alternatively, the lines need to be long with a catenary in them to dampen the acceleration forces, the catenary can be from long lines, heavy lines or lines with a weight attached to them, a section of chain for example.
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Old 14 November 2009, 14:00   #25
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Went out this morning for a bit this morning; was supposed to be picking an outboard up from Bembridge. Was gusting 40 knots at the time. Probably the biggest swells I've ever seen at the mouth of Portsmouth harbour. Didn't stay out too long - turned for home rather quickly. Was more worried about flipping over rather than anything else, and that was in 9m RIB. Fun times
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Old 14 November 2009, 14:08   #26
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So far I think all the comments and advice are assuming it's the wind that's the problem. From what Codders says, it's the waves that are the trouble. In those circumstances, adding springs will not stop the movement, tight lines will just tear the fittings out of the boat as well as shred the tubes on the pontoons. The pitching and rolling periods of the pontoons and a RIB are never going to be in synch., so sudden shock loads are inevitable.

In heavy weather, i.e when wave tops squirt up through the gaps in the planking, like they do here at times, pontoons are the very worst places for small boats to be. It's much safer, if you have to be afloat, on a swinging mooring.

Those stretchy rubber mooring thingys might help with the problem a bit, but I fear the real answer is to move the boat.
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Old 14 November 2009, 14:10   #27
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So far I think all the comments and advice are assuming it's the wind that's the problem. From what Codders says, it's the waves that are the trouble. In those circumstances, adding springs will not stop the movement, tight lines will just tear the fittings out of the boat as well as shred the tubes on the pontoons. The pitching and rolling periods of the pontoons and a RIB are never going to be in synch., so sudden shock loads are inevitable.

In heavy weather, i.e when wave tops squirt up through the gaps in the planking, like they do here at times, pontoons are the very worst places for small boats to be. It's much safer, if you have to be afloat, on a swinging mooring.

Those stretchy rubber mooring thingys might help with the problem a bit, but I fear the real answer is to move the boat.
Ah I was taking it was in a gated marina, not sure why I jumped to that conclusion.
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Old 14 November 2009, 14:13   #28
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Ah I was taking it was in a gated marina, not sure why I jumped to that conclusion.
Posh git!
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Old 14 November 2009, 14:18   #29
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Posh git!
Here on the west coast the marina's are more refined than your eastcoast crap
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Old 14 November 2009, 14:19   #30
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Here on the west coast the marina's are more refined than your eastcoast crap
40 a year mate, you can keep your gates.
Refined eh, hows Maryport these days....
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