I am planning on putting blocks on our reefing lines at the leech and luff reef cringles (hopefully the correct terms) to try to ease the friction. I want something fairly light for obvious reasons.
I am looking at blocks which have a safe working load of 1540 lbs and a breaking load of 3080 lbs. These are a 2" block and can handle 1/4" to 1/2 " lines, our reefing lines are 3/8".
Just wondering if those would be strong enough for the single line reefing lines at the sail? I have difficulty relating loads to pounds, hopefully someone else with more experience can advise me on this.
Hi Bud,
I have the same thought, check this link:
[url]http://books.google.ca/books?id=lI71GXRPELsC&pg=PA47&lpg=PA47&dq=harken+...
Look at pages 47 and 48 - he suggests a Harken 1754 but I guess it is a discontinued model as I can't find it listed on the Harken site. You will see that this is a minimal sized block, a little digging should turn up the spec's for it.
BTW, this is a great book and the authour, Bill Seifert, has serious experience and credibility.
Cheers,
Graham
Graham Mackey
SV Nostromo
1989 C36 908
Tall Rig/Wing Keel
Toronto, Canada
Interesting.
I have those eyes and nylon webbing sewn into the cringles on the front reefing points but not the back, I'd never seen that before and wondered what they were intended to do. Now I know. I was going to attach the blocks to them at the luff and make some more for the leech. Thought it would eliminate chafe totally at least on the sail. I can't find a reference anywhere to specs for that Harken block though. Also found interesting their solution to the leech being too high with a deep reef.
I've emailed Harken to see if they can tell me what the current equivalent to the 1754 is, that book was published in 2002.
Update: Harken replied, they still have the 1754 and don't forsee replacing it- I guess I just couldn't find it in their catalogue.
Graham Mackey
SV Nostromo
1989 C36 908
Tall Rig/Wing Keel
Toronto, Canada
Does it give the load specs for that block? I went all through their pdf's and couldn't find any reference to it at all.
Edit: On Harken's website they have a pdf that details their add-on single life reefing system which is pretty close to what we have except external blocks on the boom and 5/16" line whereas we have 3/8" line. The blocks they use in this at the mast and deck are #168 Big Bullet blocks. That block shows safe working load of 300 lbs breaking load of 2000 lbs,, so they must be figuring max loads at less than 300 lbs. The breaking strength of 3/8" dacron/polyester is 3700 lbs. So I'm thinking the blocks I'm looking at are going to be fine with lots of safety factor even at double load for the 180 degree angle factor if Harken's numbers are accurate.
I couldn't find that pdf; only thing I found was a #430 Medium Single Line Reefing kit for boats < 27 feet. Do you per chance have a link to that PDF? I'd be interested in seeing it?
Thanks.
Gary and Cathy Price
1997 C36 Mk II Tall Rig/Wing Keel Imagine...
Hull # 1617
Worton Creek, Md.
Northern Chesapeake Bay
Gary, no, I don't have a link to it. I was just surfing around on their website and came across that pdf. I thought their 300 lbs number was light but the blocks I am looking at have a SWL of 1540 lbs, so even if that setup was for 27 foot boats I think that a 1540 lb block would be strong enough for a 36 footer?? 300 lbs on a 27 foot, 1540 on a 36 footer sounds about right to me.
But I clearly don't know for sure or I wouldn't have started this thread!!
It sounds like you'd be safe with those blocks, but it would be nice to know the load.
I'm curious about how you plan on rigging the block at the forward/luff cringle. The stock configuration has the reefing line going up one side of the sail, through the eye and down the other. I'd planned on having the block and line on one side of the sail, eg., up through the fairlead on the mast, through the block at the reef cringle, down and into the internal roller at the gooseneck,all on the same side of the sail ( say 1st reef on starboard, 2nd reef on port). How do you plan on doing this?
Gary and Cathy Price
1997 C36 Mk II Tall Rig/Wing Keel Imagine...
Hull # 1617
Worton Creek, Md.
Northern Chesapeake Bay
Absolutely, I'd really like to know the load. Maybe Catalina would know?
I was going to use a shackle and shackle the block to the webbing pieces with rings in them that are already in the luff cringles. Have to make a couple more of them for the back of the sail. That puts the shackle directly in front of/behind the sail so the lines run pretty much as normal. I believe that will minimize chafe on the sail. I'm not sure yet if that will work, will depend how close the cringle is to a slide at the luff and how the shackles will hang at the leech. But I think it will work.
I submitted this question to Garhauer, they told me to call and talk to Guido which I did. I explained what I was doing and he said a Series 25 block would be fine. That's rated at 1150 lbs SWL. So that's what I'm going to order.