Dory Halyard/Downhaul Ideas For Block/Cleat

I'd like to have lines led aft for halyard and downhaul on my Dory.  Idea is to add square blocks to the top of the mast partner on each side of the mast to provide large flat surfaces (block to fit between the stiffiners), then mount a turning block and a cam cleat on each side, one for each line.

Has anyone seen a combo unit with both a turning block and cam cleat? 

Here's an example of the idea, but the turning block roller is too small and I want a cam cleat not a clam/jam cleat.

Roller Fairlead Mk1 Racing Junior

Or other ideas?

Thanks!

Curt


2 replies:

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RE: Dory Halyard/Downhaul Ideas For Block/Cleat

   Curt, I havent done this so this is not coming from experience. but I have thought about running those lines back to where they can be accessed right from the main sitting positon of the middle thwart. and I have looked at a fair number of rigging options from all the NE Dorys one can find on YouTube.

 

I wont do this right away, but if I do, I am thinking I would drill two holes in the mast thwart one on each side of the mast hole. the lines would go through those holes to the bottom of the thwart and into a turning block there to run aft. my thinking is that all the pressure on those lines will then be compression stress only on the thwart and i dont have to worry about something pulling out there, which could happen if you are pulling from the top. and then once below it can run to cleats on the side of the daggerboard housing.

 

But you should consider that (whether or not you put your lines into the bottom or onto the top of the thwart) you are doing two things that the boat may not have been designed for. so consider this carefully. first you are putting al lot of pressure on the attachement point of the mast thwart to the hull. upwards pressure and a lot of it sometimes. My guess is the the knees can take it but I dont know that. and there is pressure on the bolts too.  Btween the haylard and the downhaul all that tension is being taken in by the attachement in the knees.

Second you are putting a lot of pressure now down there on the spot where the mast bottom contacts the hull. given enough tension on the downhaul or haylard you could theoretically push the mast through the bottom of the boat. ( I have no idea how hard or easy that might be)

 

Note that nether such stresses occur when those line run to cleats on the mast since all that pressure is taken up by the mast.

My own feeling is that as long as the pressure is not leveraged, in other words, I dont put a block and tackle on the downhaul, it probably is within the tolerances of the boat. but if you want to get some mechanical advantage into your downhaul you should be careful. I am guessing that if I want anything it will be to leverage up my downhaul to harden up my leading edge and luff, but not this.

 

right now I am going to see if it works just fine the way CLC designed it. If it does I will likely leave it alone. On the big racing boat I used to sail everything led right to where it was needed. but I've left that world behind.

 

David

 

RE: Dory Halyard/Downhaul Ideas For Block/Cleat

   David,

Thanks for the great write up, I totally get all your points.  I also agree about the mast compression on the hull.  To your point about leveraged purchase, I had not intended to do any purchase, just straight one for one loads.  An advantage in leaving the securing point on the mast is that should you ever capsize and want to float the mast out while righting, fastening to/through the mast partner would interfere with that.....so... I was looking at the Duckworksbbs web catalog and had an idea about mast mounting instead of mast partner mounting, something like this maybe...one of these would be mounted on each side of the mast where the horn cleats are now...not sure they would work with the "sideways" pull on the fairlead?   Maybe just two flat mounted cheek blocks and two flat mounted regular cam cleats would be better....oh and the reason I want this set up at all is to tweak the sail shape (yes) but also to be able to douse or raise the main without crawling forward, especially with people in the boat.

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