Tuesday, October 14, 2008

Beautiful Day, Frustrating Sail

Excited to implement at least one of Kristian's rigging suggestion (the jib pendant) I headed out to the boat for some tinkering and a sail. I tried a couple of different ideas of how to raise the jib to the 5 inch reference I got from Kristian but settled on this using items I had on hand.




Please forgive my blurry photo, I was underway by myself in a nice breeze when I took it from the cabin. This seemed to improve the jib trim a little bit. I am optimistic that when I mount the ti-lites directly on the clew I may get the trim that I am looking for.

With the jib fix implemented for now, I plan to get a length of low stretch line this winter, I readied Bolero for some sailing. The forecast was for 10 to 20 knots out of the northwest and that is what we got.



I have to admit right up front that I am still not used to this boat when the wind starts to pipe up. Especially when I am single handing her. She has a lot more power than I am used to and she is a bit intimidating. I will also be the first to admit that I rushed Bolero into the water without everything being perfect or even intact (read reefing system). That said, this was the second time I had taken Bolero out alone with winds in the mid to upper teens and it was a bit windier last time.

Right away I became frustrated. Although there was a bit of wind and a pretty good chop it was the mainsheet system that cause me frustration and concern. It seems that in higher winds, and loads, the Harken Ratchamatic blocks (I have two 75mm) wouldn't release. I also noticed this the last time I was sailing in higher winds and it was quite disconcerting. Having to constantly worry about the mainsheet releasing during the puffs really threw off my concentration. Although the conditions weren't terribly severe, Bolero was healing plenty (with only my weight aboard) and it was a pretty wet ride.

I have a couple of videos showing how the forward line goes slack while the two 75mm Harken Ratchamatics dutifully continue to keep the main sheeted in.



In addition to my frustration I was pissed. I had worked hard trying to setup an easy to use mainsheet system and I was tired of it not working. So I sail back and forth on reach for a bit then sailed back to the mooring with the idea that I was going to figure this out.

The first thing that I did was to recreate the issue I was having while sailing. What I found was that by pushing hard on the boom and cranking down on the mainsheet (with the topping lift on) I could engage the ratchets in the Harken blocks. Then I would lift up (uncleating the Spinlock PXR) and release the mainsheet. The mainsheet would give just a bit and then stop hard.



I then pulled a fair bit of line aft of the swivel base block and repeated the test hand holding the mainsheet. This time the main ran free. So somehow there was just enough friction in the swivel base to keep the Ratchamatic from releasing.

Next I tried removing the spring between the Ronstan swivel base and the 57mm Harken block. It is hard to see in the picture, but the swivel base only allows this block to swivel in one plane so sometimes is seems that the mainsheet binds depending on the location of the boom and where the swivel is. This seemed to help a bit but still the Ratchamatics held firm. I retried my free line test just aft of the spinlock and everything work great.

Here is a closeup of the type of Spinlock PXR that have.



This cleat is size to handle line diameters from 8-10 mm or 5/16 to 3/8 inch. That blur of a line releasing in this photo is obviously not 3/8 inch. I found 3/8 very difficult to even thread through during installation. So perhaps this bit of friction is hanging up just enough to cause the Ratchamatics to stay locked on heavy loads.

In any case I am going to replace the Spinlock PXR with the Ronstan cam cleat that originally came with the Ronstan swivel base and repeat my test.

I also wonder if these Ratchamatics are a bit like the vacuum cleaner cord. That is you have to pull a bit and then release. If this is the case it seems they would work better with a cam cleat than the Spinlock.

4 comments:

Anonymous said...

Bill,

Checking in on your blog has become part of my daily routine again!

Forgot to mention something about the jib tack strop; you may find it gives better trim if the tack is held forward (to the headstay) as well. Lots of boats use a piece of one-wrap velcro, wrapped through the tack grommet, around the forestay and then around itself. You can also lash it forward like the north sails od page shows.

The concept of ratchamatics in series is great, but I've had similar problems to yours in practice. I tried this on our V15 mainsheet, and only got it to work when I turned the engagement on the second block (futher from you in the purchase) all the way down. We ended up ditching the second ratchamatic because of the same problem you describe.

Have you tried replacing the second ratchamatic with regular block? I'd use a 57mm carbo single. This would definitely solve the easing problem, with only a small decrease in the ratcheted holding power.

-Kristian

Anonymous said...

also: the px cleat may be causing problems, because even "open" they put quite a bit of drag on the line, which can cause the ratchet to engage.

Anonymous said...

One of our folks at Harken read your blog and we would like to help. Looking at how the Ratchamatic works can help understand the situation. In light conditions, a Ratchamatic spins freely to let the mainsheet out easily, great for light air gybes. In heavier air, the ratchet stays engaged so the line drags across the fixed sheave, providing a nice controlled release. You can adjust the load at which the ratchet turns on with an Allen wrench (see product manual [PDF]).

Using two Ratchamatics in series puts too much drag on the line so the sheet cannot release. The 180 degree wrap of the line on the block adds even more drag and effectively locks the system. Getting the ratchet to turn off is out of the question because there is too much load—so you have to resort to shaking the line. The solution is to use one Ratchamatic. If a second is required, a switchable ratchet at the swivel arm where it has a 90 degree wrap will reduce drag on the sheet. More info on our ratchets and Ratchamatics is here. We can help you out by exchanging one of the Ratchamatics for a switchable ratchet. You can then move that plain block up on the boom. Please contact me, dan [at] harken [dot] com and we'll work this out for you. -Dan Rondeau for Harken.

Bill Evans said...

Dan,

Thanks for the generous offer. I have sent you an email. Please let me know if you haven't received it.

Thanks, Bill
wre1962@yahoo.com