J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Mast Base Halyard Blocks

I am considering getting rid of the mast base halyard blocks and install a custom made stainless steel collar to attach new blocks to similar to the collar in the pictures below. The question is if this falls within the parameters of permitted alternatives as described under paragraph 5.9.1.2 of the Class Rules?

Note: Edit made to display pictures in this post

[This message has been edited by whk (edited 12-19-2007).]

Koos asked me about this via email and I suggested he post it in the forum so Larry Christy could comment and people could see it. I believe this just fits into the category "relocation of deck blocks" for the halyards in the referenced rules paragraph as Koos has described it. It merely takes the sheaves that swivel at the base of the mast and relocates them a couple of inches, using blocks that attach to the stainless steel plate instead of the mast. It does not materially change the running rigging on the boat. Just my opinion, but thought we should get an official reading.

Bill

I would prefer to discuss this type of question under the Class rules section of the forum. Since I am notified of new posting, you will get a faster response.

I am going to refer this one to my rules committee for a decisiion.

However, I have two issues with his idea.
1. The rules allow four sets of pad eyes for blocks, etc. The addition of the plate could be viewed as a "multiple" pad eye and not permitted under the rules.
2. Perhaps of more concern is the affect it will have on the deck. After I lost a mast 3 years ago I considered doing this. I was advised by 2 riggers not to do it. This will shift the halyard loads from the mast to the deck and the deck of a J30 in this area was not built to carry these loads. I suggest this be discussed with a rigger and boat builder before proceeding. I will provide a decision from a rules stand point ASAP.

Larry Christy
J30 Class Measurer

It seems that the coach roof would also need modified at least on my J-30 since there is a raised lip around the entrance for the mast on my J-30. While on the subject of turning blocks I want to remind everyone that they should remove the turning blocks and inspect thier mast in this area. My mast had a crack 3/4ths of the way around it in this area. The crack went from one turning block mounting bolt hole to the next - to the next etc. It was hidden by the hardware and I only discovered it when I removed the turning blocks to paint the mast. I can't believe I am the only one that had this problem!

I don't think there is a good case under 5.9.1.2, for turning blocks attached to the mast to be considered halyard 'deck blocks' that could be relocated. I'd put this in the category of "impossible to foresee" and "not within established practice" thus a measurers ruling. I'm unclear if this gizmo gets bolted to the mast as well as through the deck and if the tie rod shown is then attached back to the mast or elsewhere. There is the issue of whether the J/30 deck was designed for such loads. 22-28 years of experience has shown that, not withstanding cracks, the mast can.

I am curious what type of anti-skid do you have?

This is someone elses boat, I have no idea what type of non-skid it is. I used to build windsurfers years ago, the best and cheapest non-skid is coarse salt or sugar sprinkled over wet paint. Once the paint is completely dry the salt or sugar is washed off, the inbedded granules desolve and leave small indentations that have a vacuum effect.

I looked at doing something similar to this on Koesh, but found that the pattern got so spread out by the time I cleared the collar for the mast boot that it presented a major trip hazard and took up WAAAY too much deck space. A friend had a similar setup on his Kalik 40 with a matching ring inside that tied back into the mast, but his was an old early IOR configuration with a massive telephone pole, not a bending spar. If this were duly tied back into the mast to keep the deck from lifting I'd worry about pointloads on the mast and the possibility of losing the flex we need to maintain rig tune.

As indicated in my earlier comments I asked the rules committee to provide some input on this proposal. The committee unaminously ruled that this is not a legal modification under the current J30 Class rules.

Larry Christy
J30 National Class Measurer

Larry, thank you for your time reviewing the proposed change. I removed the vang plate and halyard blocks this weekend. After 28 years, no cracks or indication of excessive wear at rivet holes, other than corrosion/oxidation that left a pitted surface where the wang plate used to be, all looks good for another 28 years. Thank you.