Wednesday, November 13, 2013

How I Bent My Boom
By Michael
VENTURA, CA


Does your boom look like this?
We left Tomales Bay, just north of San Francisco, for an overnight passage south. Thick, early morning fog hung low when we weighed anchor and the ocean forecast of strong winds and big seas seemed impossibly distant. Ninety minutes later, we reached the bar at the mouth of the inlet, pitching in the swells and threading our way through breakers on either side. We motored out at five knots, rolling in the beam seas until we reached Point Reyes and could turn left to head down the California Coast.

Del Viento is a pure sloop; her mast is far forward and her boom is relatively long. By late morning the engine was off and we were sailing downwind, fifteen knots blowing from astern, our big main all the way out forward, just resting on the aft shrouds. Whitecaps were multiplying and we began to yaw and roll as the seas grew. Steering a heading that kept us on course, the wind was just off our port quarter, but not to far from dead downwind.

And though this heading left us only a few degrees away from a jibe, our autopilot was set to steer according to the wind and we had our preventer rigged (a 3/8” line running from a bale near the end of the boom to a snatch block secured to our bow cleat to a block on our deck to a cockpit winch). We acknowledged the risk of an unintended jibe, but reasoned that with one of us always near the helm, the event would be manageable. In fifteen knots out of the northwest, the apparent wind from astern never rose above ten. If we jibed, the preventer would hold the boom to starboard while one of us would shut off the autopilot and quickly steer us back on course. We moved along comfortably at a good clip.

(You know where this is going, don’t you?)

By late afternoon, the wind and seas had increased as forecast. We sailed at just over seven knots and our indicated apparent wind had climbed to between twenty-two and twenty-seven knots. The seas had grown considerably and caused us to yaw by greater degrees. We made small changes in our heading so that we could maintain our course, walking the line to prevent a jibe. But we were still comfortable, the warm sun was shining, and from ten miles offshore, we could see the Golden Gate Bridge aft of our beam. As they say, life was good.

Del Viento lifted on a big swell. A big gust blew. The sail slacked for a brief moment and I could feel the stern falling exactly the wrong way. Before I could react the main filled with the speed of an automobile airbag and sent the boom flying across the cockpit in a blur. Then BANG! and the boat shuddered and rolled over hard on the opposite tack. I shut off the autopilot and grabbed the wheel as we accelerated into the wind. I countered to keep Del Viento running downwind, the wind now crossing our transom deep into the starboard quarter. I saw that the preventer line was still intact, stretched bar-tight across the starboard stays. I uncleated the line and eased it off the winch to spill the tension—all the while careful to make sure we didn’t jibe again.

My eyes met Windy’s and I could see she felt the same way I did.

“Can you quickly ease the traveler over to port?”

“Yeah.”

Then I saw the damage. An inch forward of the bale to which the preventer was attached, large pieces of thick, shiny, brittle white paint had fallen off the boom where it was creased in about a five- to ten-degree bend.

Damn. Damn. Damn.

What were we thinking? We’ve been sailing too long together not to have thought to reef before we were in a gale. We both felt sick that we’d let this happen, that we’d damaged our boat in circumstances that were so preventable, that we’d relied so heavily on a preventer—especially because a preventer isn’t intended to prevent in over-canvased conditions.

We just messed up.

·         We should have reefed.

·         We shouldn’t have tried to push it, sailing on the verge of a jibe to make a better heading for our destination. In smaller seas we could have pulled this off, but being pushed around as we were, we should have increased our margin of safety by sailing on the beam side of a broad reach.

We got lucky too, as the force of this jibe could have caused more damage. We were aware enough of the risk of jibing to not have let anybody be in the path of the boom, but we didn’t do our rig any favors.

Just a bad situation overall and another lesson learned in as many months. I offer this story so that anyone else who needs can benefit in the same way, without bending their boom.

We plan to continue down to Mexico as we are, but we’ve abandoned the preventer in favor of a brake we have that attaches just aft of the vang. Our plan is to have the boom cut and sleeved or otherwise reinforced in Mexico. (And I assume this is the best approach, any advice is welcome.)

--MR
The bend is where the paint is flaked off between the
two tangs. The preventer was attached to the aft tang.
   
Frances driving grandpa's tractor in Templeton.

Pre-departure from Morro Bay. Auntie Jana and her two
boys and my folks saw us off--though Ryan (orange shirt)
didn't have to say goodbye because he hopped a ride with
us down to Oxnard, where we arrived late yesterday.


12 comments:

  1. Hi Michael,

    Sorry to hear about your mishap. If it were my boat I wouldn't sleeve it in Mexico unless I had no other choice. Easier to do it in the US where it's probably easier to get proper materials and you can speak the language.

    It's hard to do it well because the sleeve must match the inside of the extrusion shape fairly closely. If you do sleeve it, the sleeve sides should have a V shaped notch in it to taper the stress concentration out. A rolled section of alum. plate each side of the boom will do it. Cut out the bend and leave the edges very square so they butt into each other perfectly.

    Here is a very good thread about how to do a mast sleeve (same as a boom)
    http://briontoss.com/spartalk/showthread.php?p=2596

    Another option is to phone some local boatyards and riggers and see if they have a suitable used boom or boom extrusion in stock. As you have a loose footed mainsail it's pretty easy to just swap hardware over. Tricky bit is usually attaching the gooseneck.

    http://www.minneysyachtsurplus.com/ probably has lots of used extrusions.

    Now thinking about the failure mechanism - how did the boom fly across the cockpit if you had the preventer on? The preventer should be tight and if so, when the sail backwinds, the preventer just stops the boom from moving to any significant degree. It seems the preventer didn't prevent the accidental gybe?

    ReplyDelete
    Replies
    1. Thanks Evan (I presume). I'm just writing a more detailed post about this, what I've learned and where we are now. I'm disturbed about the preventer not preventing too, addressing that. Looks like we will try and go the Minney's route, waiting to hear back from them. Thanks again. Michael

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    2. First and foremost - thank you for sharing this mishap with us Michael. It has lead me to re-evaluate my own gybe prevention system. Take a look here to see somebody else who had the same mishap: http://www.yachtingworld.com/blogs/elaine-bunting/510850/boom-goes-the-boom. It seems to me that the cause of a failed preventer is not running the line to from the boom to bow and back to cockpit but boom to midships to cockpit. The latter still allows the boom to swing across deck somewhat while a line to the bow really minimizes that movement.

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    3. Here is the setup I am now considering: http://www.ybw.com/forums/showthread.php?175899-boom-preventer-trial&s=d53b3b3c1c6e16379efa8970119897f1&p=1839001#post1839001

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  2. Ugh. No fun at all. try not to beat yourselves up too much. I think anyone who has sailed for any length of time has had situations where it could go wrong. Fortunately, no one was hurt. Booms can be replaced or repaired. People? Not so much.

    This is a good reminder to me as we get ready to start designing the deck hardware layout. Accidental jibes are no fun for anyone. I'm going to have a serious think about coming up with a back up. Preventer and brake? Now to figure out how to make it work...

    ReplyDelete
  3. Michael,

    Sorry to hear about the boom! I also want to thank you for sharing about your mishap. I am normally one who learns through personal experience; your post may have saved me one of those lessons.

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  4. Sorry to hear about your boom mishap and thank you for sharing your experience. I also hope to learn from your experience here instead of my own which is what usually what happens.
    As for the boom repair, I recently had a new spar and boom made and surprisingly affordable.
    It was made by Lefiell Manufacturing and they may be able to make you a new one for around $1000.00 or so and would also be able to repair possibly cheaper. you can contact Rodney Higuera at (rhiguera@lefiell.com) or his number is (800)451-5971 x277. They are located in South Gate, CA not too far from the Los Angeles harbor area.

    ReplyDelete
    Replies
    1. Thank you for the excellent info. I'm waiting to hear if a used spar is available at Minney's, and then there are San Diego resources too. I hope that avenue pans out, we'll see. If it doesn't, I will likely call Rodney to bend his ear, at least. Michael

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  5. Hi Del Viento Family,

    Just wanted to let you know that your email (delviento@hotmail.com) is not working. I tried to email you twice and got mail delivery errors both times. Is there a better way to reach you?

    Thanks!

    Sam

    ReplyDelete
    Replies
    1. Thank you Samantha. I don't know what to say, we keep getting emails and I just emailed the delviento address from another account and it was fine. You're welcome to try dcwritereditor at hotmail dot com. Best wishes, Michael

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  6. Hey Robertson, Windy, Eleanor & Frances. It was so great to see all of you on your floating home and thank you so much for dinner on the Del Viento, it was excellent! Send me the Kale recipe when you get a chance, I know Jordan will love it too. The picture with Mug & Skipper is great, they are looking really good. It is amazing how much Jana looks like your Mom. Have a safe trip and hope to see you guys again soon, maybe I will make it down to Mexico. Thanks again. Lots of Love, JO

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  7. Thanks for sharing your experience. It has encouraged me to put the installation of our boom brake higher on the "to do" list. As you head south hopefully our paths will cross. We will be around Bandaras Bay most of the winter. Cheers, Max, Elizabeth, Victoria, Johnathan and Benjamin.

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Thank you for taking the time to comment; we look forward to reading your feedback. Don't forget that you may also contact us directly at delviento@hotmail.com (please type DEL VIENTO in the subject line)

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