Mast shakes violently!

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Capt Jeff

Member I
Hey guys and gals! Been a while since I have posted here cause I been cruising. I have recently come across a problem with my rig shaking very bad with even the slightest breeze while at anchor. I hired 2 riggers to re tune the rig and it STILL does it no matter what they did! It happened after I noticed that the starboard side spreader was up higher than port.... done an inspection and sure enough the upper and lower shrouds were very very loose. The rings were twisted like hell on the turnbuckles. Oh! All this occurred while sailing on a broad reach in VERY nasty seas and the wave height was only 10' but the following sea made me sail by the lee and sure enough BAM! Accidental jibe!... fun night! Everything went wrong....( whole nother story) gotta love it!

Anywho.. I live aboard and sure is hard to sleep with the rig and mast vibrating like hell shaking the whole boat ( E35). Anyone else had similar problem? Sure could use some advice! Good or bad... give it to me!

Jeff
 
S

sleather

Sustaining Member
Jeff, I've had minor harmonic vibrations that eminate from the main and jib halyards that I clip off to the lifeline stanchion bases in certain wind speeds. Something with enough mass to shake the mast "might" be a furled jib on the headstay that develops a harmonic vibration at certain wind speeds. That's all I've got. :egrin:
 
Rhynie

Rhynie

Member III
Jeff,
I have a 34, and I'm assuming the 35 is a keel stepped mast, check if there are any shim/chocks where the mast passes through the deck. In the old days wooden wedges were used, but a firm rubber would serve well. I would put my money on there being some sort of wedge in there that has backed out. Mine also has a turnbuckle from the front of the mast to the underside of the deck (to preload the deck), this would also help to stabilize the mast; it should be tightned enough for just a slight tension.
A temporary solution, until you find the source might be running your pole uphaul and/or staysail halyard if you have one, forward to the deck and putting a little tension on it.
 
G

Glyn Judson

Moderator
Moderator
Mast shaking while at anchor.

Jeff, I've had humming occur on both our E25+ and our E31 and in both cases got instant relief by wrapping the halyard around the mast from the spreaders down. I wonder if the same thing might be happening to your mast but causing the pumping instead of the humming. Apparently the harmonic can be from the wind passing the spar and by breaking up that air flow, it causes the humming (and pumping??) to go away. Glyn Judson, E31 hull #55, Marina del Rey, CA
 
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jgarmin098

Member II
I think you are getting what may be referred to as pumping. If you sight up the mast you will see it pumping fore and aft near the mid-section or just above the lower spreaders. My 32-3 does it when the wind is coming from either side of the bow, not when dead to wind. Solution: I put a bit of pre-bend in by tensioning the forward lowers more than the aft lowers and then taking down on the backstay to get the bend. It's important that both the forward and aft lowers are quite tight to prevent the pumping. Fortunately for us Ericson owners, we have pretty stiffly constructed boats. Some of the inferior quality boats I have been on get to shaking like frightened dogs when that mast is a pumpin'.
 
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C

Capt Jeff

Member I
Got it!

Thanks y'all for the help...took my extra jib halyard and bought some 3/4 pipe insulation (foam type) and slid it over the halyard about 30ft and wrapped the halyard around the mast several times. Works a LOT better! Still pumps...but not as severe or at lower wind speeds. Sucks to take the halyard off the mast to go sailing as I used my boat hook and stood on the boom to wrap the mast above the first spreader....but it works! I am now at a dock and will be for about 6 more months so the wind hit's from all directions....yay!


:egrin:
 
A

AleksT

Member III
You said the rings on your turnbuckles were twisted. I am assuming that you have cotter rings instead of cotter pins, if so swap out to cotter pins. Pins are much more secure than rings.
You have already gone through two riggers without solving the problem, and using another one seems like throwing good money after bad, but obviously something is very wrong.
That being said I suggest finding a rigger with exceptional references to look at your rig.
If you want to post more specific info about the what is going on with the hellish vibration I could give you some options to try. Without seeing the boat it would be a long shot.
 
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Guy Stevens

Guy Stevens

Moderator
Moderator
Mast pumping

Several thoughts spring to mind from your post.

1> Someone incorrectly tightened your standing rigging. The standing rigging wire on a sail boat should never be twisted, the turnbuckles should be turned and the wire held stationary. (There is an exception to this, but it still results in the wire not being twisted, and is a tightening technique that is off topic. The important thing to know is that you never leave an added twist in the wire. NEVER).

2> Your mast is pumping.

3> Check your mast partners, the spot where the mast comes through the deck. You should have wedges in there. If you don't think about installing some spar-tite or similar pour in place urethane.

4> Tightening up on the pole lift, or a forestay (The commonly referred to sta-sail stay. ) Should eliminate the pumping. Although there have been cases where even that did not eliminate it.

5> If tightening up on the forestay (sta sail stay), or the topping lift does not work. Counter intuitive as it may be, candy cane a halyard (Spinnaker) around the mast as far up and down as you can and tighten it quite tight. In general mast pumping is caused by turbulence on the flow of air around leward side of the mast, breaking the flow changes the turbulence by breaking the attached flow at the windward side.

Guy
:)
 
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B

Brian K

Member III
Spar-tite, though expensive, is something I would recommend to anyone. I added Spar-tite last spring and it worked really well. Before that my wedges would work free in heavy seas and I'd get some mast movement at the partners. Now there is absolutely no movement and the Spar-tite remains on the mast ready to fit back in place when the mast is stepped in the spring,,, if spring ever comes to upstate NY!
 
Matey

Matey

Member III
I used to hoist a small fender or coil of line a ways up the mast when I was berthed in Isleton and it blew 20 every night. It broke up the vortices mentioned. That's what your trouble sound like to me. When I re-wired my mast I removed my steaming light and replaced it with a combo deck-steaming light lower near the lower spreaders where I used to hoist the fender to. Guess what ? no more shakin'

Regards, Greg
 
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