RJRopes 8:19am, 23 May 2012
Hi all,

I purchased Archimedes earlier this year, and have been having a nice time sailing her, getting to know her, and competing in a few events.

I went out last weekend, and whilst out lost steering capability, and had to sail back to home rudderless.

Got back in and did some investigation, and the shaft between the rudder and the tiller has snapped.

I've been reading some of the posts which are highlighted in the index, but can't seem to find any relating to this problem.

Has anyone had this happen to them before? Do I have to take the rudder off and have a new shaft created and put back on?

If so, I've read that I have to weld the rudder back on, or split the rudder and put new bits on, which seems a little scary to me.

Anyone know how long this shaft is meant to be?

I'm going to dry the boat out (she's on a swinging mooring at the moment) and have a look at the rudder, as this isn't the entire shaft that's come out, there's still quite a bit of it left.

Other than this tear in the metal, the shaft looks to be in fairly good condition, only a little rust on the inside, and some very slight surface rust on the outside, so also don't really know why it's gone.

Any help would be appreciated.

Thanks

Richard

broken rudder shaft 1

broken rudder shaft 2
rothwell_neil Posted 6 years ago. Edited by rothwell_neil (member) 6 years ago
Richard

Hard to tell from the photographs but is that a hole at the front of the shaft that the crack has gone through?

It is almost certainly fatigue cracking from some defect in the shaft or from a stress concentrator such as a hole or just where it exits the rudder stock at the hull. Looking at the length of the shaft that is left I would suggest that this is at the hull just where the rudder joins as that is where the greatest stress will be as you will get torsional and longitudinal stresses. All in all you can either repair or replace. There is no reason why you can't get the rudder off and repair this shaft by putting a rod/tube up the middle and welding back round the crack. This would always be second best but would get you back on the water. There will be increased risk of corrosion on the inside after the welding as there will be a crevice around the join with the tube/rod. However if you do get the rudder off then would be best to replace with a new tube and then expect another 30 odd years from it. This type of damage is more likely on a drying mooring or on a bouncy mooring compared to life in a marina where the load on the rudder is far less.
RJRopes 6 years ago
Hi Neil,

Thanks for the reply.

Without the other part, I can't really tell whether it's a hole or not that it's gone around.

I presume that it's stainless, as it's not gone very rusty over it's long life in the sea.

If I take the rudder off, I may as well have the shaft replaced if it's one part, it will be stronger and would be less hassle than bridging it I would imagine.

How does it connect to the rudder? Is it welded to other pieces of metal that go through the rudder? I've seem some posts which say that there is in effect a metal 'F'. Do I just re-weld it back onto these existing parts by removing a little of the exterior of the rudder and welding the prongs to the tube, then glassing or filling over the top?

Looks like she'll be off the water for a little while anyway.

Thanks

Richard
rothwell_neil Posted 6 years ago. Edited by rothwell_neil (member) 6 years ago
Others have repaired rudders so will let them answer. With regard to replacement shaft it will be standard austenitic grade stainless and you should be looking for grade 316L or A4 stainless steel. A2 or 304 would be a poor second choice as for the few pennies saved not worth the risk of lower performance. 316L grade is low carbon and has better properties after welding and less likely to stress crack. If you can't get the L grade not the end of the world as cracking is only a problem over 50-60C and we rarely see that sort of sea temperature!
RJRopes 6 years ago
Hi,

I'll go for the 316 or L if I can. I take it it needs to be seamless as well.

Not finding much on the Internet at the moment. For others, the diameters are 1" outside diameter with around a 2mm wall thickness. I've yet to go to the boat and find an actual length measurement though.

Richard
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NormanKlipspringer 6 years ago
Richard,
Sorry about the problem you have, but I think you are getting good advice from Neil. Just a thought - if the break is at the join to the rudder then there may be very little if anything holding the top of the rudder to the boat. Either get it off fast or stick something down the shaft into the rudder to prevent the top going sideways.
I believe like you that the tube is welded to pieces at right angles that are embedded in the rudder, but I have no personal experience of any of this. If replacing then you might consider bar rather than tube.
Good luck
Norman
Skykomish E29 6 years ago
Yes didn't something like this happen to another member a little while ago, he thought somebody had stolen his rudder as it had vanished from the boat? he had a new one built, I believe there are pictures on here somewhere
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NormanKlipspringer 6 years ago
Malcolm,
I think this is the discussion you are refering to. I had forgotten about this until you mentioned it.
www.flickr.com/groups/achilles24/discuss/72157621940805353/
Norman
RJRopes 6 years ago
Hi again,

Yes I read through that (used the index, very good) which is how I knew about the F shape. Oh, and there was another one too, which explained about the F too

www.flickr.com/groups/achilles24/discuss/72157624573035333/

Just need to know how I can put the rudder back on again without lifting the boat out of the water. The rudder seems secure at the moment, there's still a bit of tube left holding it in, so will wait for the weekend (hoping that's not going to be famous last words)

Think that I might have been able to find a source for the metal now, just need to know whether I need seamless or whether welded will do (although I probably know the answer)

Richard
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NormanKlipspringer 6 years ago
Peter Richards 07754365800 of Swansea did the welding and sourced the steel for my stainless steel headstock. Could be a useful contaact. I would have thought seamless tube would be best.
blueachilles 6 years ago
How did you "sail back home rudderless"?
Skykomish E29 6 years ago
We used to find the Achilles steers well with weight changes
RJRopes 6 years ago
Hey all,

Sailing rudderless isn't too bad, you can sheet in sail to get the boat to turn, along with moving weight around the boat. If you sheet the main in, it moves the boat to windward. If you sheet the genoa in, it moves the boat off the wind.

Also, as above, move the weight so that the boat heels on top of you, it sails to windward, and visa versa.

It's quite pronounced on the Achilles, a lot harder in the dinghies that I also sail.

It's definately a good thing to try, just lock the tiller and have a go. You can also drag something off of one side like you would a canoe paddle (a bucket might be good if you've got a good speed) if you need to turn quicker, then you can alter the sails to suit sailing in that direction

Rich
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