Why are my adjustable blocks where they are?

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Mike

I have owned my O'day 23 for two years, and I have given up trying to figure out why O'day put the adjustable stand up blocks where they did. On my boat, I have fixed stand up blocks on the side decks about half-way back from the bow; I route my jib sheets through these blocks back to the winches in the cockpit. However, O'day also installed larger stand up blocks on adjustable tracks on either side of the cockpit. These tracks extend from the stern up to just in front of the winches. If the blocks are placed at their extreme forward setting, jib sheets can be run through these blocks as well before wrapping around the winches. However, I don't see any advantage to doing so. Why are these adjustable blocks there? Are they placed for outsized genoa sheets to be anchored farther astern and then run forward to winches? For spinnaker sheets? Neither makes much sense to me as I have a 150% genoa, and the sheets still don't need to be run that far back. Am I missing an opportunity to more efficiently or effectively control my sails? Any theories?
 
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Eric

I have the same question

I have always wondered the same thing on my 1980 Oday23. I have never used them- I run all sheets exactly the way you describe.
 
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Don Evans

Oday's Intent

Similar set up on the 25 Mike. I believe the intent was to use the stand alone, forward block for a working jib, or smaller (storm jib). Having the ability to adjust the angle of the larger genoa is critical for headsail shape. Thus moving the adjustable lead car back to the curved gunwhales of the pushpit offers ability to adjust draft depending on wind speed and angle. For any given size genoa having the block to far forward on the track will cause a baggier foot because the leech will be too taught. Having it too far back will spill wind from the sail. In addition the block on the adjustable track behind the winch gives purchase to the genoa sheet, thus reducing the power required to adjust the sheet. Ideally a right angle should be formed between the angle of the forestay and the angle of the jibsheet as it comes away from the clew (ya got to draw it to see it). A further aid to sheeting angles can be made by rigging a barberhauler. This a second line attached to the clew and lead down to a snatch (or fixed) block way forward of the winch and almost below the clew and brought back to the winch. It pulls down the clew of the genoa, thus tensioning the genoa and adding more control of the draft of the sail. I'd recommend reading posts at the sail control forum on this subject. There is some good info there. Fairleads... Don
 
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Justin - O'day Owners' Web

Blocks

Mike - Don gives a good explanation of sheet lead placement, but it sounds like your tracks are further aft than that. I would guess they are for spinnaker lines. On a lot of boats you bring the sheets and guys for chutes all the way aft, then forward to the winches. Justin - O'day Owners' Web
 
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Mike

Thanks

Thanks to Don and Justin for the theories. I wish the boat had adjustable standup blocks on tracks further forward so that I could adjust the tension on the jib or genny sheets. I still tend to doubt that my current set up was made for a spinnaker; the mast is not configured to accept a spinnaker, and the boat was made to be a trailerable cruiser, not a racer. On the other hand, I have seen some old promo shots of the boat flying a chute. Maybe O'day just slapped on some tracks and cars in a readily available size even though they weren't a perfect fit.
 
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Josh

Have had this question...

...since I bought this boat. They are right on top of the toe rails along side the cockpit. Every picture of a 22, 23, or 25 I look at has them, but I have yet to see a picture that shows anyone using them. Is it possible they were placed there on the thought that they are easier to access? I don't have a spinnaker either, nor a set up for one. The genoa I have still needs to be set rather far forward to have them set properly. It would be a rather large sail to have to use them all the way aft on the tracks wouldn't it? I'm just as perplexed and would love to know why they were put where they are. They would be a lot more useful if they were set two feet forward. The way it's set up though, this would put them right over a life line stanchion. Perhaps the builders put it there for lack of a better place? Hope to hear what its for, Josh
 
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John Thomson

Difference in Sail Size

The reason is that that the fixed block location on the deck is for the jib (100%) and the toe rail is for the genoa (120 - 150%). Enough said on O'days intent ok, ok.
 
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