Bow Roller Cracks - How worried should I be?

[Iliade]

I took mine off, had it welded (my welds were cracking, not the base material) and refitted it in about two hours. IIRC I used mole grips to hold the nuts inside while I unbolted from outside. The hardest part was not falling headlong into the mud as I did the stem one The most unpleasant part was chiseling off the grp over the nuts.

I also replaced the nuts and bolts with new lest there were any crevice corrosion after ~35 years afloat.

My forestay is also now on one of the holes further back so that the load is more appropriately distributed; Attaching it to the foremost hole is asking for trouble.

 

[Iliade]

Looking at your crack propagation, moving the forestay back a hole or so should alleviate the issue entirely. Get it drilled and welded nonetheless...

 

[macd]

Of course it's going to fail. It's clearly on the way there already and the stresses on what remains can only become greater as the cracks propagate. The design of the fitting is basically unsound, loads being concentrated on what is already a stress-raiser and a weld. If the OP chooses to have it 'fixed' it will need more than simply making good with weld. Some reinforcing is needed. Any competent fabricator should be able to see what's needed.

 

[NormanS]

U

The forestay fits directly onto the roller.

I think that statement, which is obviously rubbish, has caused some confusion.

 

[Tam Lin]

I think that statement, which is obviously rubbish, has caused some confusion.

It just shows the difficulty of explaining something which is obvious to to one person, in exact language so that it is clear to others - sorry!

Thanks for all the replies so far, they have confirmed what I thought in my heart of hearts, it looks like I will be replacing it in the near future!

 

[John the kiwi]

Of course it's going to fail. It's clearly on the way there already and the stresses on what remains can only become greater as the cracks propagate. The design of the fitting is basically unsound, loads being concentrated on what is already a stress-raiser and a weld. If the OP chooses to have it 'fixed' it will need more than simply making good with weld. Some reinforcing is needed. Any competent fabricator should be able to see what's needed.

+1
It is apparent from the first photo that the crack propogates from the crater left at the end of the Tig weld by a poorly skilled welder.
I used to collect failure samples. Here is a clkassic example of poor design and poor execution leading to stress corrosion cracking.
This is not a self healing situation. It wont magically get better if you ignore it. I would not put to sea with this fitting in this state. The failure will probably be sudden and catastrophic in the sense that it will fail totally. End of!
On the Good news side, it is a simple fitting to re build in fabrication terms. Just get a competent stainless fabricator to do it this time!

 

[wooslehunter]

My centaur went a similar way. Also, the holes for the forestay had started to wear. I replaced it with one made of thicker steel, had a tang and also had a thickening piece welded over the forestay hole.

The original westerly one was thin steel with the welds ground out to be the and no tang down the bow so was only bolted to the deck.

Asa precautionary note, I went onto a yacht that had suffered a forestay failure that had brought down the mast. There was a short 5mm thick extending the forestay that had failed. It was around 50mm wide. I took a look and at had a nice clean break over 35mm and a dirty one over the remaining 15mm. It had obviously been failing for a while & had then suddenly let go. It was not a windy day so stresses that day were likely to have been minimal.

Reweld, strengthen or replace. But do not leave it.

 

[philip_stevens]

Your bow roller/forestay fitting is not as supplied with the boat when new: someone has modified the setup substantially. If remade or properly rewelded the setup might even be stronger than the original fitting, but as it is it looks like it's heading for catastrophic failure. The failure could be in 24 hours or 24 years time, but going that way it is.

That is the original bow roller fitting as supplied when the boat was new - look at VicS photo. Some boats on swinging moorings have had a second roller fitted to the original fitting to save having to remove the anchor when mooring.

Tam Lin is one of the older Centaurs, having a "600" number out of over 2400 built. So the fitting has lasted well.

 

[macd]

That is the original bow roller fitting as supplied when the boat was new...

In that case I suspect it's been cracked and 'repaired' before, at least on the port side. That or Westerly were prepared to let some pretty horrible welds go to customers.

 

[vyv_cox]

If I understand the photos correctly the forestay loads are carried directly on the bolts through the deck. The crack appears to be between the relatively solid part to which the forestay is attached and the extension that carries the bow roller. This is more clearly shown in VicS' photo of the new replacement. The forestay is not attached to a lever arm. Since the loads at the bow roller act downwards they will be putting the crack in compression, not tension. It appears to me that the crack has nothing to do with fatigue due to excessive loading but is something else entirely. If the OP can confirm that this is the case I would do as Charles suggests - drill a small hole in the end of the crack to arrest it and monitor for a while.

 

[VicS]

If I understand the photos correctly the forestay loads are carried directly on the bolts through the deck. The crack appears to be between the relatively solid part to which the forestay is attached and the extension that carries the bow roller. This is more clearly shown in VicS' photo of the new replacement. The forestay is not attached to a lever arm. Since the loads at the bow roller act downwards they will be putting the crack in compression, not tension. It appears to me that the crack has nothing to do with fatigue due to excessive loading but is something else entirely. If the OP can confirm that this is the case I would do as Charles suggests - drill a small hole in the end of the crack to arrest it and monitor for a while.

I'm pleased you chipped in Vyv. You said what I was thinking.

I was going to suggest moving the forestay to the aftermost of the three holes to eliminate any leverage . It may not be possible though if thats the sail tack attachment point for hank on sails.

Interesting that there is a crack in the stbd side cheek, which carries no load from the forestay.

I'm wondering if its been modified? Has that bow protection piece been added and is some bad welding the cause of the cracks ? Or has it been bashed at some time?

 

[LadyInBed]

Drilling a hole might be a stop gap (literally) measure, but a crack is a crack and should be sorted out.
As it is now winter, what better time is there to get it done?
Would you be happy sailing next year, knowing it's there?
Would the insurance pay if it failed, knowing that it's there?
Another point is when was the last survey, and would it pass another with the crack?

 

[Tam Lin]

Alright, alright, I'll replace it! If I was worried about it before I am now petrified!
The boat was surveyed four years ago when I bought her and as I have hardly used her I wouldn't be surprised if the cracks were there then and the surveyor missed them, after all he got other things wrong!
Interesting about the crack on the starboard side as has been correctly pointed out there is no tension from the forestay on it.
Thanks Phillip, I did look on the WOA site but didn't find anything, as the boat is forty years old the fitting hasn't done too badly! I am sure the next one will see me out!
On a totally different matter, I used to get emails to tell me that someone had contributed to a post that I had contributed to but not any more. Is this a YBW setting that I can correct?

 

[Birdseye]

U

The forestay fits directly onto the roller. You can just see the bottom of it looking black at the top of the first photo and an alternative hole where it fits. I believe it is stainless. The force of the forestay is trying to open the crack.

In which case you must do something about it, and drilling holes just to stop the cracks propagating wont work / be enough.

If it is stainless it can be welded. Propbably can if alloy but less reliable.


Take the mast down, remove the fitting, replace . Relatively simple - I did it myself two years ago.

 

[macd]

If it is stainless it can be welded. Propbably can if alloy but less reliable.

It's pretty obviously stainless. And the OP has said he believes it is.

 

[charles_reed]

Your bow roller/forestay fitting is not as supplied with the boat when new: someone has modified the setup substantially. If remade or properly rewelded the setup might even be stronger than the original fitting, but as it is it looks like it's heading for catastrophic failure. The failure could be in 24 hours or 24 years time, but going that way it is.

I'd agree - the forestay directly onto the bow-roller bracket is a real botch. Why not attach it direct to the tang?

 

[lw395]

I'm pleased you chipped in Vyv. You said what I was thinking.

I was going to suggest moving the forestay to the aftermost of the three holes to eliminate any leverage . It may not be possible though if thats the sail tack attachment point for hank on sails.

Interesting that there is a crack in the stbd side cheek, which carries no load from the forestay.

I'm wondering if its been modified? Has that bow protection piece been added and is some bad welding the cause of the cracks ? Or has it been bashed at some time?

Not sure I'd move the forestay bay, I might be concerned about flexing the deck.
I'd prefer the forestay loads to be going into a strap running down the stem with the bolts in shear, but as it was made must be Ok if it's lasted this long.

I wouldn't forget that the problem may have started with somebody ramming the boat into a wall etc, or some other damage rather than design or manufacture flaws. These things happen, the damage may take years to show.

 

[JumbleDuck]

I'd agree - the forestay directly onto the bow-roller bracket is a real botch.

Having the forestay attached to to the bow roller bracket is very common indeed, and I can't see any reason to call it a botch. My Hunter 490 has it attached - in traditional Oliver Lee style - to a tange which passes through the foredeck and bolts to a web glassed into the stem. That's far more troublesome.

 

[vyv_cox]

Having the forestay attached to to the bow roller bracket is very common indeed, and I can't see any reason to call it a botch.

Exactly. That's how it is on my Sadler. The forestay is to the left of the shot with the nylon spacers. Perhaps more heavily built than the OP's, reflecting the size of boat.