I need to replace the pulley attached to the front of the wishbone that is for the choker. (The sheave on the block seems to have completely failed and disappeared. The 1/2" rope is riding on the axle pin.) Looking at the Harken Element block for example a 60 mm block has a SWL of 1100 kg (2400 lb) and the 80 mm 2200 kg (4850 lb). Do I need the 80 mm or will a 60 mm be adequate? The 80 mm is more than twice the price of the 60 mm.
Blake
According to Harken, the overall lengths of their basic single sheave swivel blocks are 121mm for the 60mm size and 171mm for the 80mm size. I would think that variations in sail cut and age (stretching) would affect the range of movement needed when adjusting the choker. And using the larger size would reduce your choker range by 50mm or about an inch. When you’re sailing, the clew of the sail is pulling forward on the wishbone and the choker is holding against all of that force. If you have the extra 50mm available, the 80mm size will turn with less effort and the extra strength seems like it would be worth the $40 extra.
Blake,
I’m not aware of a factory list of running rigging blocks for the N33s. A safe approach would be to use their recommendations for the N36s, which can be found at the back of your 2024 Registry from the INA.
The factory recommended safe working load for the N36 wishbone choker block is 3750 lbs. This would knock the 60 mm Harken Element block out of contention, and make the 80mm a better choice. For some reason, this block on an N36 is listed as a snatch block, rather than a block with shackle like the other boats. I don’t know why that is, or whether that advice applies to the N33s.
If you don’t like Harken prices, take a look at Garhauer Marine. Their high-load single block with shackle that would meet the criteria sells for about $75 USD: https://www.garhauermarine.com/shop/blocks-mast-boom-blocks-hardware/single-blocks-blocks-mast-boom-blocks-hardware/single-blocks-with-shackle-single-blocks-blocks-mast-boom-blocks-hardware/single-block-with-shackle-50-13-ushl/
If you had to go with their snatch block, now you’re talking a lot more money – close to $200 USD: https://www.garhauermarine.com/shop/blocks-mast-boom-blocks-hardware/single-blocks-blocks-mast-boom-blocks-hardware/snatch-blocks/snatch-block-70sn/
I can see the advantage of a snatch block in that particular location because it would certainly make life a bit easier for rigging and un-rigging. Not sure why it’s spec’ed that way.
All of this is the kind of question the INA has former Nonsuch rigger Mike Quill on retainer to answer, so you might also consider asking him.
– Bob
Me Gusta
Nonsuch e26U #233
Looking forward to seeing folks in Toronto:
https://nonsuch.org/2024-INA-International-Rendezvous-Status
I agree with Bob that the 60 Harken will be too small.
The Garhauer has a 10 year no questions warranty. Not sure what the Harken has.
The high load Garhauer 60-13 is about $95 USD and has a safe working load of 5000 lbs. Max line size is 5/8”.
Mark Powers
I think that Garhauer blocks represent the absolute best value out there. They don’t break and the company is very helpful.
Ernie A. in Toronto
Thanks for all the replies. After I posted my original post I remembered about the " Ask Mike Quill a question" service from the INA. I sent him the question and he replied “Use the 80mm” within 3 hours, I have now installed a Harken Element 80 mm block. While running the new choker line I noticed the block with the becket has bent cheeks and the pulley is starting to crack, looks like another block is in my future.
I did not look at the Garhaur blocks since I did not have the luxury of waiting for mail delivery and for that matter the marina will not accept packages.
Thanks for the replies. I did ask Mike Quill through the INA service and he replied quickly and said “use the 80mm”. I have the Harken Element 80 mm on the boom now.
I did not look at obtaining a Garhauer since I needed the block yesterday as we are leaving the marina today.
Garhauer are by far the best option
Blake, for future reference, Pro-Tech Yacht Services in North Vancouver carries Garhauer products.
Mark Powers