Moody 34 babystay - deformed deck

[pbirrell]

I've a 1984 Moody 34. Ive noticed that the foredeck where the babystay is attached seems to be deforming and cracks appearing. Is it as simple as the babystay too tight or might I have some other aspect of the rigging wrong ?

Many thanks

 

[pappaecho]

No this is a very common problem with babystays. My E 32 has a baby stay and when we removed the headlining in the forecabin we found a 10 inch crack in the grp.
Put simply, the GRP was not sufficiently reinforced to spread the load. The solution which I used was to massively reinforce the area, add a second forestay outside the genoa furler, and to keep the baby stay slack. (One of the uses of a baby stay is to distort the mast to flatten the main) - forget it, the main stays baggy!

 

[alldownwind]

I suggest you ask the same question on the Information Exchange at the Moody Owners' website, www.moodyowners.net

 

[john_morris_uk]

On our Westerly we had the same problem but fortunately without the cracks in the GRP.

I designed and had fabricated brackets and a 'tie-bar' to go between the babystay and the stringer that is moulded along the keel line of the hull on our boat. The tie bar has left and right hand threads at each end, and I have wound it up tightly to pull the deck back into the correct shape.

As originally designed, the babystay loads were transferred to an internal bulkhead (part of the f'wd heads) and the whole bulkhead was lifting with the strain of the babystay.

Reference comments by A.N.Other who says that prebend with the baby stay doesn't flatten the main. The answer is that it does - but it depends how knackered your main is as to whether it is effective!

 

[davidfox]

I had a 346 (different designer) but we had deformation in the foredeck, picked up by the surveyor when we were buying, Moodys got all handbaggy about it, contacted Bill Dixon, - never been heard of etc etc they then put in some sort of spreader bar by the forehatch and charged a bl...dy fortune for it.

 

[geoffatstanpit]

I had the same problem with the babystay on a Seal Sinbad. The main symptom was that when beating with 2 reefs in the main the babystay was distorting the deck and opening the seal in the forehatch. - lots of salt water in the forecabin! Looking up the back of the mast there was an alarming backward bend pulled back by the leech of the reefed main. I think that is universally acknowledged to be a very bad thing. A hefty girder across the cabin roof spread the load enough to cure the problem and it's surprising how much difference an even slightly flattened main makes when you need 2 reefs!

 

[30boat]

The best possible solution IMHO is an interior detachable stay with a block and tackle to a strong point on the bottom,not always an easy solution.I did that on my previous boat and it worked to perfection.My Fulmar has what seems to be a very strong layup in that area so I never had problems.Thankfuly.

 

[William_H]

The solution is either to add a stay internally down to the keel. I would suggest two U saddles one on top of the deck and one below bolted together with the inner forestay on top and the additional internal stay going down to the keel with a turnbuckle in it to adjust the tension.
However if you are not willing to have a wire down through the middle of the forward cabin then your only option is girder of some sort unnder the deck which will move the stresses towards the gunwhales. Obviously the deeper the girder the more stiffness /strength it will have but again you may not want a girder projecting down into the cabin. Even if it is under a lining.
If you elect to simply add more layers of f/glass under the deck then consider buying a little carbon fibre which is a lot stiffer than glass and is ok with epoxy resin (or polyester). But even then I suggest at least 1/2 inch of build up if you can fit it in.

The boat may be a victim of the "madness" of setting static tension of stays at 15% of the wire max strain. That figure may enhance the life of the wire but doesn't do much for the structure of the boat. IMHO wires need only be tension enough to do the job. ie keep the mast straight under all conditions.

Now the inner forestya has to counteract the loads of the intermediate side stays in their effort to pull the middle of the mast backwards. The distance aft of the mast of the int. sidestay chain
plates dictates the amount of aft pull. Likewise the distance the intermediate forestay is forward of the mast determines the amount of forward pull of the middle of the mast. So if you coulld cope with an intermediate forestay further forward on the deck you would get less upward force for the same or more forward pull (at the middle of the mast)
Unfortuanately to move the iner forestay forward means more interference to the jib as you tack.
One of my friend's boat has a piece of mainsheet track bolted to the deck and the inner forestay attaches to a traveller car. This means you can increase the inner forestay tensioon by pulling the car forward. (with a tackle) This has a better (greater) forward pull on the middle of the mast.
You can put more tension on the inner forestay in strong winds (to bend the mast) when beating and slacken it off or even pull the inner forestay back (out of the way) in light winds.
As a bonus the track spreads the load on the deck further forward and aft which is what you want. It can make a repair structue look like a "go fast" addition. good luck olewill

 

[wotayottie]

Got a later Moody and that has some deck deformation at the chain plates. Allegedly,there are webs bonded to the hull sides which carry the load and the chainplates pass freely through the deck - so why it lifts just a bit isnt obvious. The Moody comment is that grp moves under load even years after its "gone off". I can well believe that.

Absolutely everything moves / stretches under load - the only question is "how much?"