One of my YouTube subscribers Chris has been very observant and may be onto something. He noticed my near permanent crease from throat to clew. Regular readers of my blog will know about my love-hate relationship with my mainsail and my complete inability to trim it correctly. Whenever I sail, this crease is a sign to all those out on the water that I am an idiot, devoid of sail setting skill.
Chris noted the following points:
- Arwen has the yard on the starboard side of the mast and the sprit boom on the port side. This arrangement seems to be creating a twist in the foot of the sail on the port side and then another twist in the top part of the sail on the starboard side near the yard. These two twists manifest as a crease.
- He also asks whether it is a crease or a 'fold'....which makes sense because if you watch the videos of my main sail....that fold runs down the inner edge of the half battens in the upper sail down to the clew and the top part of the sail, especially in light winds, looks as if it is 'flopping' over.
Now, if I was truthful here, I'd say I have no idea what he is talking about. But I understand the instruction 'try switching the yard over to the other side'. I also understand his instruction ' try to adjust the lines so that the boom lies more horizontally'.
And, I definitely liked his analogy 'this might reduce the indigestion of your sail'!
So, last week, the boss decided the weather was sufficiently nice enough to embark on her annual boat trip over to Cawsand. The fact that there was barely any wind, the temperature was 30C+ and it was an outgoing tide were mere trivialities.
We motored across to Cawsand and beached Arwen. While I held her bow to the small wavelets, the boss went in search of coffee and freshly baked croissants. A yachtie type ambled down to admire Arwen and ask all about her; a local strolled down to warn me about the submerged rocks immediately ahead of me (which I already knew about).
After threading our way through swimmers (who seem oblivious to the need to get out of the way of a small boat powered by an outboard) , we went three hundred metres out and along Penlee point, where we anchored twenty metres offshore.
The sea was crystal clear and the sandy bottom could just be discerned through the aquamarine waters. Compass jelly fish floated by on a regular basis. we were visited by some kayakers and paddleboarders.
I donned wetsuit and went for a swim. I checked the centreboard casing from below. A jellyfish hitched a ride on my back for a few minutes.
Eventually after an hour, there was sufficient breeze to go for a short sail along the southern outer edge of the breakwater, where we put to the test Chris's theories.
And then the winds died completely so we motored down Jennycliffe Bay and into the Plym river.
The boss declared it 'a perfect day'.
I'll take that!
As for the crease? Well, on the first test of the new rigging strategy, it was definitely far less than it has ever been before. So thats a good start!
Steve, I too have been fighting exactly the same thing on my navigator. I'll need to check the set of the top yard, per this post. The other thing I found is that making the yard as vertical as possible reduces the crease significantly. As you know, this is the one adjustment that is the most difficult!
ReplyDeletehello Mike - how are you - well and safe I hope in these strange times.
ReplyDeletemany navigator owners with the sprit boom standing lug sail arrangement al seem to have a crease. A few seem to have cracked it. Tim Ingersoll seems to be one - so I assume that I am doing something wrong. he has some useful youtube videos that he posted for me. I have done what he says but to no avail. somewhere I'm not understanding something, I have missed something, I have not set things up right or worst case the sail wasn't cut correctly, or i should have stuck with the full sail battens and not the shorter upper ones. It is very frustrating not to be able to do what John designed the boat to do.
Steve,
ReplyDeleteI sail a Drascombe Scaffie with a lug sail, so definitely not an expert on Navigator rigging. But, I noticed that you have the tack of your sail wrapped behind your "sprit-boom" and attached to the mast with parrel beads. If you are using a sprit arrangement, wouldn't you want the tack of the sail to be stretched to the forward end of the sprit-boom, and then have the sprit-boom attached to the mast with some sort of snotter arrangement, or at least use the parrel beads to attach the sprit-boom to the mast? Please feel free to tell me to mind my own business if I'm way off base here.
Bill
Steve,
ReplyDeleteAfter looking at some of your previous videos, I can see that I misunderstood the set-up of your sprit-boom. Please allow me to retract my post. The one thing that I did notice, though, and I think might still be helpful is if the tack were routed outside and underneath the boom and then secured to the mast. In its present position it looks as if it would chafe between the boom and mast. Hopefully, I haven't misunderstood this, also.
Bill
Hey Bill - how are you and thanks for dropping the comments. It is only through generous people like yourself that I can learn how not to be a sailing idiot :)
ReplyDeleteI went back and looked at John's plans last night and actually I have set it up exactly as per the plans. The tack under the boom bit I am trying to get my head around what you mean. John has the tack on small block tackle arrangement the bottom of which is attached to a stainless steel eye on the deck, immediately behind the mast and forward of the coaming. I altered it slightly so it is same position but the downhaul sheet from the block runs down through the deck around a truning block at mast base and then back along to the aft cockpit.
Other than that the snotter, sprit boom etc are set up as per John's plans. I double checked because someone else is building a navigator here in Plymouth and has just ordered his sails from the same sail maker as me.
John says when you set it up like a standing lug sail - the boom goes to the port side; the top yard to the starboard side. the bottom forward part of the yard extends past the mast.
I am increasingly of the opinion that I think I have five things wrong
1. the attachment of the clew to the aft end of the sprit boom
2. the positioning of the sprit boom and use of snotter to set sail in different conditions
3. the amount of tension on the downhaul - the parrel beads are there to keep the sail as close to the base of the mast as possible per John's instructions
4. the absence of full battens at the top part of the sail - which the sial maker at the time insisted would be a complete pain when dropping and furling the sail
5. the tie on point of the main halyard on the top yard - I suspect that has to go forward slightly more to make the yard more aft heavy.
If you are a member of the Dinghy Cruising Association - I wrote an article in one of the journals last year about my poor sail trimming skills and the standing lug sail yawl rig I was using. I had hoped it might generate some ideas and discussion but it didnt - ah well it was a good try I guess.
Other standing lug yawl navigator sailors - some have the crease and many don't - so I definitely think it is me, my set up and not being able to see the wood for the trees.
When Matt launches his navigator with the same sail configuration - then we may be able to do direct comparisions and work out what I have or am doing wrong
In the meantime - I can get places - just slowly; and very slowly in light winds :)
Steve,
ReplyDeleteIf you're trying to avoid being a sailing idiot it's probably best not to listen to me. My seaman's license lists "sailing idiot, less than 10,000 tons" as my specialty. However...
In your photograph, #8 of 8, the sail appears to trapped and crumpled between the boom and the mast. I'm not sure if this is due to the tension being released from the fore end of the boom, allowing some luff at this point, or if this is the fully rigged arrangement of the sail. Would this be corrected by routing the tack outside (to port) of the boom and then coming underneath it?
At any rate, I hope you are successful in getting this sorted as it looks like an arrangement that might improve the performance of my lug-rigged Scaffie.
Bill
hey Bill - thanks for the help - appreciated. photo 8 is interesting. the actual arrangement is right as per the plan but what seems to be happening recently is that the lower part of the sail and the tack should be going lower on the starboard side of the boom. The boom should go to the outside of the sail on the port side as per plans. I think I had allowed the sprit boom to drop somewhat if i remember and hence it looks like this - but that in itself is an issue as well.
ReplyDeleteI dont know what would happen if I routed the sail so it when to the outside of the boom - i might try that next trip out just to see what difference it makes. I am also going to loosen the lashings on sail where it attaches to the yard as that may be causing the crease as well.