Something wrong on rigging, need advise

[Guest]

My boat is built in 1985, a fractional rig with deck stepped mast, single spreader, single upper & lower stays. It was fine during the past years but currently got problem whenever sailing with the mainsail hoisted.

On riding each wave, the middle section of the mast (spreader) swing fore & aft and the mast foot sound "ad--" loudly . Standing on the deck around the mast foot feel it slightly moved on each "ad--" moment but there is no sign of cracks on deck. The "ad--" sound being worse day by day. Changing of upper, lower and backstay tension all got no improvement. However, when sailing with the geona alone, the problem does not appear.

I wonder whether it is due to aged stays / mast fatigue, or the deck under the mast foot being deliminated. Hope that you could help telling what the probem would be or adivse which professional party I ould acquire. Should I find a rigger, a surveyor or any other professional parties?

Thanks

Arthur Ho

 

[Twister_Ken]

Difficult to tell from your post - it might be something very nasty, but there are one or two less problematic things which might cause it.

First suspicion would be the goose neck fitting, where boom articulates on mast, and second would be the kicking strap fittings on boom and mast. Any noise generated by wear or looseness there would be transmitted through the spars and might sound like it was coming from elsewhere. If it's that, a rigger could probably fix it quick and easy.

Is it someting moving inside the mast? Halyards or cables slapping?

It could also be wear, looseness or something missing in the mast step, again a fairly simple remedy.

The more worrying thing is that it might be the deck collapsing under rigging strains, or chain plates moving. If that's the case then a surveyor would be my first stop.

Is there an owner's association that could advise?

 

[30boat]

The fiberglass under the mast step can distort under the pressure.The whole structure can be afected if the deck delaminates or the (possibly)plywood reinforcement becames crushed.This can happen if water penetrates the laminate through the bolt holes in the mast step.In any case the mast shuold be stepped down and the area carefully inspected.

 

[NickCharman]

A general solution ..

Whilst not immediately very helpful, you will think, I have to say that one solution would be to fit an unstayed mast, or make your next boat one with an unstayed mast. Seems this unreliable rigging problem in aircraft was solved in the 30s when aircraft designers stopped using wire rigging.

There are a limited number of boats types to look at ..........

Nick Charman

 

[davidwf]

I think it may just be the gooseneck. Put a drop of light oil on the moving parts. It worked treat on mine which is a Zspars fitting.

The noise it made was similar to the one you describe and very difficult to locate. Hope this helps.