Rudder Stock Failure

[DeepFrz]

Do you think maybe the OP just posted that as a rhetorical question?

[HappyMdRSailor]

Originally Posted by SkiprJohn

I'd appreciate knowing what boat this happened to. Just curious.
kind regards.

RERAX!... Doesn't look like a cascade rudder to me...

Originally Posted by DeepFrz

Do you think maybe the OP just posted that as a rhetorical question?

Deepster...

Leaning toward your hypothesis with the 100/1000 open/coastal parameters... and no replies...

[Fog Bank]

Originally Posted by DeepFrz

Do you think maybe the OP just posted that as a rhetorical question?

Considering the OP states so the rudder stock just sheared off as per pics below... Any advise much appreciated on what to do now... it would seem this wasn't rhetorical. New poster...low post count...who knows...

[SkiprJohn]

In my point of view, depending on the boat and whether or not you have to sail downwind to the 100NM destination, for an emergency repair to just get you where you can go to get a new shaft installed or a new rudder rebuilt I'd go with the rod inside the tube welded up fix. This is an emergency fix, right? If your destination is downwind there will be a lot of work on your rudder if it's a fin keeler which it looks like from the rudder shape and attachment. There will be strain but not as much working back and forth if your destination is a beam reach or close reach.

Have an emergency backup steering system in mind, drawn up and ready to cobble together with a whisker/spinnaker pole and a table/locker top just in case.

If you have a hole drilled in the aft top corner of your rudder and a couple lines led up to your cockpit you might be able to steer if the weld doesn't hold and the pipe spins free on the rod.

Hang in there and good luck.

[rognvald]

There is one obvious problem with welding: if the cage inside the rudder is as rusted as it was at the juncture of the shaft/rudder, a catastrophic failure is highly likely leaving the hapless problem solver with a spinning rudder blade and no steering. This is not a problem that can be fixed properly, if even only temporarily, since the rudder is obviously waterlogged. This is far beyond a reasonable calculated risk. Good luck and good sailing.

[Cheechako]

Originally Posted by rognvald

There is one obvious problem with welding: if the cage inside the rudder is as rusted as it was at the juncture of the shaft/rudder, a catastrophic failure is highly likely leaving the hapless problem solver with a spinning rudder blade and no steering. This is not a problem that can be fixed properly, if even only temporarily, since the rudder is obviously waterlogged. This is far beyond a reasonable calculated risk. Good luck and good sailing.

I don't know.. we are talking about a 100 mile trip... an over nighter. Every person on this forum who has an old boat and who has not rebuilt their rudder is pretty much in the same shape.. they just don't know it yet!
Seems like every old rudder I see out there is waterlogged. Even one I had that was 6 years old was.
Maybe rudders should be made from SS heavy sheet welded onto the stock instead of glass. Leave a few holes in it for water circulation!

[crazyoldboatguy]

Hell, if you are worried about the internal cage, make an external one. Take some straps long enough to span the rudder leading to trailing edge. Drill a hole in the center which you will bolt using the holes previously drilled thru the rudder post and the internal sleeve. Make sure to use some fender washers to take up some of the strain in the event the internal cage fails.

Some folks here seem to think this is supposed to be a repair. It is not. It is a jury rig to get back to a boatyard where the rudder assembly will be replaced. Doesn't matter if bolt heads are sticking out unless they restrict movement of the rudder. Doesn't matter how pretty it is.

I would, again, urge the OP to motor on the calmest day possible. Do not sail the boat. Why take the chance on breaking the jury rig especially since the damage you can see is very likely NOT the only damage there is? I dinghy with a motor which could be used, in a pinch, to steer the sailboat may work but I would be leery of such a strategy if you are in any restricted waters.

[rognvald]

"Maybe rudders should be made from SS heavy sheet welded onto the stock instead of glass. Leave a few holes in it for water circulation! " Cheechako


Cheech,
I have always mistrusted accepted rudder construction methods. There is no doubt that weight and cost is always a factor . . . ergo, the status quo. If a rudder were made with thin plate stainless with a cage and shaft, filled with high density foam and welded at all seems, would that not be a much more reliable and perhaps bullet proof construction. Then, any flaws in the rudder would be readily visible. However, there would be a serious drawback and that would be that those of us who are neurotically obsessed by subjects of this nature would have less to talk about. Good luck and good sailing.

[Jim Cate]

Seems to me that the welder can determine (with some digging into the glass and foam) whether the internal structure is sound enough to weld/repair.

Also, as suggested above, installing a pair of lines from the trailing edge through some temporary blocks and up to the cockpit will provide enough rudder control to allow motoring in calm conditions, and with zero torque on the shaft. A weak repair would suffice for that usage.

Jim

[Panope]

Originally Posted by Jim Cate

Seems to me that the welder can determine (with some digging into the glass and foam) whether the internal structure is sound enough to weld/repair.

Also, as suggested above, installing a pair of lines from the trailing edge through some temporary blocks and up to the cockpit will provide enough rudder control to allow motoring in calm conditions, and with zero torque on the shaft. A weak repair would suffice for that usage.

Jim

Jim,

While I agree that setting up trailing edge steering lines will decrease the total load on the rudder shaft, I believe that the bending loads on any cantilevered lifting surface far exceed the tortional loads resulting from the control of the surface. Especially a surface like this rudder that does have a degree of hydrodynamic "balance" (rudder area ahead of the shaft).

Steve

[Jim Cate]

Originally Posted by Panope

Jim,

While I agree that setting up trailing edge steering lines will decrease the total load on the rudder shaft, I believe that the bending loads on any cantilevered lifting surface far exceed the tortional loads resulting from the control of the surface. Especially a surface like this rudder that does have a degree of hydrodynamic "balance" (rudder area ahead of the shaft).

Steve

True, but the proposed repair of sistering the shaft with an internal reinforcement should be man enough to resist the bending loads. It seemed to me that getting torsional strength might be the hard part.

It would be helpful to know more about the proposed 100 mile passage. IE, is the weather settled enough to ensure a mild window of sufficient length to get there? Is it coastal with bailout options. Can he get someone to accompany him with a potential tow boat? And so on...

JIm

[SkiprJohn]

Originally Posted by DeepFrz

Do you think maybe the OP just posted that as a rhetorical question?

Possibly. We haven't heard from them again.

[rognvald]

Digging into a rudder for inspection is no easy task as revealed by my recent rudder rebuild on a perfectly dry, but delaminated rudder. To reveal the cage would have been a feat of drastic engineering as I used a hammer and chisel to remove the 20 pound high density foam.

[OceanSeaSpray]

It is a bending moment problem and this rudder blade is a balanced spade rudder as already pointed out above, torsional stress is not such a big deal.

Shove a solid piece of steel or stainless steel in there, weld or pin it by drilling through and for 100NM you can pick your weather and go if you have to. Sail cautiously if you want/can, but don't load that rudder or you will bend that repaired stock like a spaghetti - long before breaking it off - and jam the steering.
You could possibly attach a couple of spectra lines from the tip at the bottom to a cleat on each side, so there is something to support it if it starts to bend... or at least think about it, if it still allows enough rotation.
Make sure you are in a position to deal with the situation if it goes pear-shape. This could mean letting it go and jury-rigging something else.

Years ago, I remember a US yacht that had arrived in the Marquesas after breaking the rudder blade in mid-ocean exactly like this. They had attached a piece of floorboard to the end of their spinnaker pole, hinged it on the backstay chainplate with shackles and controlled it with a line to a winch on each side. They had gone some 1500NM this way, even making better time than some other boats on the same passage, no drama.
If you have a problem, you deal with it. You don't "think EPIRB and water".

Now, in my experience, this is the fate of all hollow stainless steel rudder stocks eventually. It is not an acceptable way of building a rudder stock, it would take too big a tube to make it work. They lack the strength, they yield a little under load at the maximum stress point where they come out of the hull, it causes micro-cracks, corrosion starts and one day the rudder snaps off. It is textbook.
The boat in the Marquesas was a US production boat of 36' or so from memory. Nice boat. The entire production run is likely to exhibit this problem, if not the entire range of what they were building at the time.

If you suspect a rudder stock might be hollow, ultrasonic testing can clarify this in 30 seconds. If you find a hollow stock, you are up for replacement. I would be even more concerned with coastal cruising than offshore sailing, because out there at least you have plenty of room and time to make a plan.

Eric

[stara]

thank you for the advice. So instead of trying to sail with a jury rigged rudder I had the rudder transported off this island (no road access, no lift-out facilities). Rudder is being professionally rebuilt by a boat yard. This is what they have done, attached a solid piece inside a similar hollow metal tube and apparently re-used the top and bottom part. Is this going to last?