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Kicker load on an Ent

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PeterG View Drop Down
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Post Options Post Options   Quote PeterG Quote  Post ReplyReply Direct Link To This Post Topic: Kicker load on an Ent
    Posted: 02 Apr 19 at 10:50am
I once got caught under the boom of my Contender and tried straightening up a little and snapped the 4mm dyneema, which made getting out a lot easier. OK, it snapped at a knot, so effective bs probably only around 1000kg, but it taught me a thing or two about the loads that can be generated by an 18:1 kicker.
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Sam.Spoons View Drop Down
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Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 02 Apr 19 at 9:11am
I'm getting older but I do have a pretty good idea how strong I am (a couple of different jobs and hobbies over the years). 60kg I can lift and pull on a line in a favourable position. I could not pull that much from the side deck but we have to take into account the max loads when speccing rigging. Good quality snap shackles will have a SF of 3 but cheaper Chinese stuff likely no more than SF = 2. The shock loads possible on a kicker are likely to be at least 2 x static load so a strong crew setting up the kicker while leaving the beach and a strong wind gybe will probably exceed the breaking load of a 1000 kg rated shackle. 99 times out of 100 the l tonne shackle will be fine, the OP wanted to know what to use for maximum confidence. 
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Post Options Post Options   Quote Neptune Quote  Post ReplyReply Direct Link To This Post Posted: 02 Apr 19 at 12:37am
I think some people here should go to the gym and recalibrate how strong they think they are... 
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Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 01 Apr 19 at 11:48pm
It shouldn't be too difficult to have a coarse and fine adjustment with a cascade kicker, take up the slack with the coarse and use the fine for power?
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Post Options Post Options   Quote Eisvogel Quote  Post ReplyReply Direct Link To This Post Posted: 01 Apr 19 at 7:09pm
Originally posted by ChrisJ

And if the boom is still the original, then the fitting on the boom could easily be in the wrong place. When new, it had a complex highfield lever system on the boom for the top of the kicker, to allow a coarse as well as a fine adjustment on the kicker lever. I suspect this was all replaced with a proper cascade system years ago!

Not sure if the boom is original; it could well be. And yes, it has a cascade kicker which is attached to the floor.

My problem is that the kicker is already maxxed out before I get the right setting for stronger winds, so ideally I need to move the attachment point on the boom further back (obvs in line with class rules), but that makes it even worse with the centreboard interference.

I think the consensus here is that the 1000kg ought to be enough, but might be borderline; and the 2000kg would be a safe bet. Thank you for all the useful comments!
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Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 01 Apr 19 at 5:09pm
Originally posted by Granite

I think that 1000kg will be more than enough. Sure there is a lot of purchase, but do you think you could feasibly lift 60kg, equivalent to a small adult with one hand using 4mm control line? Also think about the strength of other components in the system. Look at the final line strength, or final block type they will give you a good steer for strength of the system.



Good point about the block types, they will indeed be the weakest link (most likely) but I reckon I could pull 60 kg onto my kicker line so, with a 16:1 cascade 960kg less friction losses (which will be a fair percentage) but it's the additional shock loads in a windy gybe that will be the issue and they could easily be double or triple the static load.
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Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 01 Apr 19 at 3:36pm
I've bent 1 tonne ones before,(they distort enough that they no longer meet) but never a 2 tonne one, and the pressures cannot be that different between Ents and Minisails in the great scheme of things. My other boats have always used either closed shackles or keys.

Moving the boom take off point forward would reduce leverage, but mostly take out the forward component. It would create more crew room, too. But the big draw back it it shortens the length of travel for the last purchase. Do Ents have strict rules on the length of handle the centreboard needs?
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Post Options Post Options   Quote ChrisJ Quote  Post ReplyReply Direct Link To This Post Posted: 01 Apr 19 at 1:06pm
Enterprise 20361: When new, that had the lower kicker attachment as a U-bolt, bolted through the hull, with a backing plate underneath. It would take a lot of rotten wood and close to a complete boat failure for that to pull out! 

And if the boom is still the original, then the fitting on the boom could easily be in the wrong place. When new, it had a complex highfield lever system on the boom for the top of the kicker, to allow a coarse as well as a fine adjustment on the kicker lever. I suspect this was all replaced with a proper cascade system years ago!


Edited by ChrisJ - 01 Apr 19 at 1:08pm
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Post Options Post Options   Quote Granite Quote  Post ReplyReply Direct Link To This Post Posted: 28 Mar 19 at 2:16pm
I think that 1000kg will be more than enough. Sure there is a lot of purchase, but do you think you could feasibly lift 60kg, equivalent to a small adult with one hand using 4mm control line? Also think about the strength of other components in the system. Look at the final line strength, or final block type they will give you a good steer for strength of the system.


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Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 28 Mar 19 at 2:07pm
The weakest point in an older Ent kicker system is probably the lower fixing. Not sure how your's is fixed but mine were both screwed into the hog (early wooden boats, I can't remember but I imagine the kicker was no more than 4:1 TBH).

Edited by Sam.Spoons - 28 Mar 19 at 2:08pm
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