Gooseneck

[Theis]

When I was rehabing Solsken, I gave a great deal of thought to the concept of running the sheets to the boom, rather than the end of the boom.  I decided against it because the aluminum extrusion could take compression, but I had no confidence it could take pint bending stress, particularly when combined with compression -  and I wanted to be safe.

But then when I got a new mainsail, and realized that the new ones were loose footed, (the sail gives the boom NO support to counter act a bending force from the sheet) I was certain the guys that designed the Ariel knew what they were doing mounting the sheets to the end of the boom.

So you have those two points at either end of the boom - the gooseneck on one end, and the sheets on the other.  A vang or preventer is somewhere in between.  One of the four things (boom, gooseneck, vang/preventer fitting or mount, or the casting at the end of the boom holding the sheet lines and topping lift) has got to give.  Take your pick, but don't let mother nature do it for you.  You might not like the outcome.

[Bill]

Our most important project this winter was replacing the gooseneck toggle assembly on the mast.  Steve, one of the crew, volunteered to create the new fitting.  He is a top notch machinist at Lawrence Livermore Labs and  his work is always outstanding (though usually having something to do with nukes).  When it arrived,  I epoxied the inside of the fitting so that it would not weld itself to the mast.  Might want to remove it someday to paint.  Here is what Steve created.

[Bill]

Note that two of the blocks on the mast are being incorporated into the new fitting.

[Bill]

The old gooseneck toggle fitting for comparison:

[Bill]

Installing the new fitting required removing most of the old track on which the original gooseneck toggle rode.  The stuff was in pretty poor condition after 40+ years, and also, most of its fasteners were frozen.  Hammer and pry bar time.  

With the track finally removed, I lined up the fitting on the mast only to find that the strap holding a block for one of the reefing lines on the starboard side was in the way.  And, of course, its fasteners were frozen in place.  I attacked the fasteners with one of those impact screwdrivers that you hit with a hammer to get the fastener to twist out.  But as usual, it didn't work for me.  Ended up grinding down the interfering fastener, bending away the strap and then grinding down the remaining stub of the fastener so it was about level with the mast. (I'll get the rest of the offending strap off the mast before we sail.)

[Bill]

Finally, I could line up the new fitting on the mast, drill the holes and tap them for #8 machine screws.  Before installing the screws, I coated them with anti seize, again, just incase I wanted to remove the mast fitting someday..  Finally, the outhaul and reefing lines were run through their new blocks on the fitting and the gooseneck was slide into the toggle and fastened in place.  Here's how it now looks.

[Bill]

And, the starboard side . . .

[Tony G]

That is some very nice work!  Incorporating the blocks is a nice touch too.

Are both of those lines for reefing?  You know what I'm getting at, that elusive outhaul in a tube set-up.  Maybe you could give us a photo tour of your recent upgrades. :cool:

[Bill]

The block visible in the port side view is for the out haul.  The block with the red marked line in the starboard side view is for the leech reefing line.

[Bill]

Returning to Peter's comments on possible failure points in the boom assembly (see post # 31 above), Maika'i's boom attachment system is now all stainless steel, whereas the original Pearson system used aluminum castings for the both the gooseneck and the gooseneck toggle.  Adding the rigid vang should create a pretty strong assembly from its attachment point on the boom forward to the mast.  Could the system be too strong and lead to the boom failing in a major unintended jibe?  The aluminum toggle in the original system has been known to fail in such conditions and may have protected the boom.  Maybe the use of a preventer in very windy downwind conditions is doubly important with stronger attachment systems.

[Bill]

Continueing on the path to strength . . .  A future project is to tap and fill with 1/4-inch long machine screws all the many holes left in the mast from old hardware.  There are so many that I'm getting worried about them weakening the mast. Probably really not an issue, but  . . .

[Ed Ekers]

Bill if I recall  the vang installation correctly, would you not think the connecting point of the vang to the boom would be the weak link?......ed

[ebb]

Say Bill,
Why fill the holes with dissimilar metal screws?
Probably find some aluminum 'button head' screws that would work.
If the holes are small enough you might try some of that aluminum paste on the market.*  Just don't push too much into the holes.

I, too, am very interested by what Ed means as the weak link in the vang plate connect.
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* you can use it for filling in corroded areas too in spars or fittings.  While probably more cosmetic than structural it is easy to file and shape and finishes like the real stuff. Caswell 'Lab Metal' paste. {Dang, just looked it up it only comes in 24oz or something (group order?).  But I know I've seen squeeze tubes somewhere: Permatex, maybe?. Good for little holes.]

[Bill]

Bill if I recall  the vang installation correctly, would you not think the connecting point of the vang to the boom would be the weak link?......ed

It appears to be a pretty strong attachment (see post #13 at http://www.pearsonariel.org/discussion/showthread.php?t=201&highlight=rigid+vang)
but I guess the vang attachment at the boom could fail.  Or, maybe the boom would fail at the vang attachment point?

[eric (deceased)]

the photo of the old gooseneck fitting shows an existing tang---or that "eye" I used that plus one on the boom itself  with just one bolt thru these existing fittings----I juryrigged a gooseneck----a day later I was home