Mast head crane

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bigdave
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Re: Mast head crane

Postby bigdave » Sun Nov 02, 2014 7:23 pm

I've gone for Chris W's tie-round-the-top-hole mentioned earlier. I filed the crane smooth all around where I thought the rope would go, and it seems to be doing fine. I had to move it once in about 3 months so far, sailing most weekends.

Bruce
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Re: Mast head crane

Postby Bruce » Wed Apr 08, 2015 12:19 pm

Hi,

So what was the final outcome of all these discussions? What is the current class recommendation? I tried to follow the Selden instructions on the website, but there is no way of getting the knot in there with the supplied Marlow 4mm line.

Here is my summary of what I have seen on this forum as possible solutions and my comments:
1) As shown on the website http://www.mustoskiff.com/sub-pages/S3-Carbon-Head-Crane.pdf - not possible with the supplied halyard
2) As website but tapering halyard (or replace entire halyard with D12) and then using tracer line to pull knot through. - Removing the outer protective cover concerns me when there are so many rough edges. Not feasible to have to go through this procedure every few weeks to move the knot along
3) Tie halyard around top of crane (like Chris Wright has shown) - does this add sideways load to the crane? Does the know slip down and rub against the other end of the halyard
4) Drill a hole through the top of the crane - this seems to be the most sensible, but has this been declared legal by the class?
5) Find an old mast head crane and use that instead ....

Any feedback on which of these work best would be useful.
Bruce
GBR534

EdWilkinson
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Re: Mast head crane

Postby EdWilkinson » Wed Apr 08, 2015 9:13 pm

I wouldn't trust any option which has a knot hidden on a notch inside the mast. My main fell down off the start in the first race of the nationals because the knot jumped out. It lasted a practice beat with cunningham on so it must have been fairly well engaged to start with. There is simply no way to guarantee this can't happen with a blind fitting. You might argue it was the technique of installing the knot, but a) if we are supposed to check it regularly there is a risk every time in putting it back that it doesn't lock securely and b) there is no apparent mechanism to keep it from working loose whenever the halyard is slackened.

Ed

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Re: Mast head crane

Postby johnr » Tue Apr 14, 2015 12:31 pm

Hi Bruce,

I have spiced a 1-2m length of 4mm un-covered dyneema (D12) onto the main halyard and this is located in the notch. This has done the entire worlds and a few sails in Britain now with no problem. I could not get the supplied halyard to go round the bend radius at the top without excessively wearing the outer core and the added problem was the wear between the two lines entering the top of the fitting. This would wear away the outer cover during hoisting of the main. I will take a picture if I remember tonight.

With this modification I will probably work with the fitting as if I only have to cut the halyard every 3 months or so, retie and thread and I can deal with this. At the Nationals pre modification it was every day it needed done and then the outer cover would be gone before the day was out.

bambam
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Re: Mast head crane

Postby bambam » Tue Apr 14, 2015 7:34 pm

I went and brought the ld style mast head crane, couldn't get the new style to work, all the methods stated by others seem like added faf.
I like the fact that you can inspect the knot and re tie easily if needed, the only reason i had to change the fitting was it was badly corroded and it broke.

Besty
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Re: Mast head crane

Postby Besty » Wed Apr 15, 2015 1:28 pm

I still have the old mast fitting, but, similar to johnr, I have spliced about 1m of D12 to the top of my halyard. This last much longer than conventional 4mm Excel Racing (or similar) as it can sustain small radius of curvature around the shackle and through the tie off point.
Jamie Hilton - GBR444
Datchet Water SC

campervan
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Re: Mast head crane

Postby campervan » Sat May 16, 2015 8:59 am

Yep, been having trouble, after about 12 sails with new halyard and mast crane.
Used Chris's tie round the top method, after filing off rough edges. Works ok, but there is significant wear on the rope, I think because its too close to the block and rubbing against the incoming loop.

About to splice 4mm Dyneema on and give that ago. To clarify, John, you are ending the dyneema in the notch, knotted inside the mast as originally supplied?
Must admit, not too keen on an internal knot which can't be inspected and mast separation to move it.

Kevin

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Re: Mast head crane

Postby johnr » Mon Jun 22, 2015 4:25 pm

Yes the dyneema is knotted and held internally. You have to splice in 4mm dyneema though as anything smaller will not grip.

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Re: Mast head crane

Postby johnr » Mon Jun 22, 2015 4:26 pm

I have never had to split the mast to move it as a poke down with a fid after you have removed the top pulley allows you to get the knot back out for a halyard trim and then a new knot back in.

campervan
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Re: Mast head crane

Postby campervan » Tue Jun 23, 2015 10:22 pm

Thanks.

I like this.

chriswrightlaser
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Re: Mast head crane

Postby chriswrightlaser » Thu Jun 30, 2016 10:10 pm

Hi all.
Just got my new mast and their is a hole drilled into the top of the fitting to put the rope through. Is this now standard for new boats from now on?

Chris 530

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paul manning
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Re: Mast head crane

Postby paul manning » Fri Jul 01, 2016 8:27 am

Hi Chris

Yes, that's the plan.
Paul Manning
MSCA Secretary

Phone 0044 (0)7843 269353
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chriswrightlaser
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Re: Mast head crane

Postby chriswrightlaser » Sun Oct 09, 2016 9:06 pm

Hi, Just some feedback on the hole in the top of the mast crane, been using mine now for months with the new hole and it great, no problems at all and the rope does not wear but does go hard, great job (-:

justo
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Re: Mast head crane

Postby justo » Sun Jan 15, 2017 4:32 pm

I got the final solution for the mast head crane. My heat crane with the hole make from ovington breaks, so I start to think in a solution.
I use a small piece 4 mm dynema to tide the halyard. I have been sailing for three months with full cunni a few days and the halyard and the dynema piece do not have any damage.
First picture is the damage head.
Image
Image

Image
Image

PaulM
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Re: Mast head crane

Postby PaulM » Sun Jan 15, 2017 7:53 pm

This looks like a good solution. Top marks from me...
Paul Molesworth
GBR582


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