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Break Away Rudder

Started by Owly055, June 10, 2016, 10:01:48 PM

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Owly055

     One of the boats that rates pretty highly on my list is the Westerly Konsort (bilge keel).    The rudder on the Konsort is entirely transom hung, no skeg, nothing at all below the transom....... and it's quite long.  Looking at it, my reaction is that it would not take much of a rudder strike to literally tear it off the transom..... or break it.   While this rudder would lend itself to being nicely balanced, or installing a trim tab system for windvane steering, etc, the vulnerability of it is a bit alarming, though there are many boats with rudders that hang down like that.   A rudder strike could rip the bolts out of the transom, or shear pieces of the mounting, or break the rudder itself.   This looks to me like a very logical candidate for a break away system.  I've googled break away rudders and seen some ingenious ideas.    I've engineered many things, and building a weak link in a system is something I've often done.   The weak link in a break away rudder could be as simple as a zip tie properly located, or a nylon bolt that held it in the down position, that would shear on impact.   

     On a long cruise venturing into shallow water with reefs, etc, the likelyhood of clipping a coral head with a keel or rudder is significant.  Rudder damage or loss is not an uncommon scenario at all.   I've read accounts of various boats that lost rudders mid ocean, some of which used creative methods to provide control.  With a keel hung rudder, the probability of losing the rudder is pretty small.... assuming the rudder and post, etc are in good shape at the outset of the voyage.  Shockingly though an article in Sailmagazine.com claims that mid ocean rudder failure is close to 1%....... A figure I consider preposterous. 

     Any thoughts or experiences with this?


                                                                     H.W.

SeaHusky

Never thought about it so I am sorry if a digress but we on this forum we often, and lately, have discussed different systems and their merits and faults, self steering, diesels vs EP, rigs etc. When I watched this video
https://www.youtube.com/watch?v=tK8FYzPtj-M
I thought about how even the simplest things will fail at the most inappropriate time which is when you use them and put stress on them i.e. "need them". I have recently completely taken apart my diesel engine and the aluminium heat exchanger was eroded to the point where it is fixable but only just. If I hadn't taken it apart now it would have worked for several years but eventually it would fail and that would be when I was pushing the engine hard, probably to avoid a lee shore or similar.

I think the point I am trying to make, if I have one, is that whether the system is designed to fail or not we need to think about pre emptive maintenance and back up systems.
If you have a break away rudder, hit something and the system works, how will you steer?     
I look for subtle places, beaches, riversides and the ocean's lazy tides.
I don't want to be in races, I'm just along for the ride.

Owly055

Quote from: SeaHusky on June 11, 2016, 10:17:41 AM
Never thought about it so I am sorry if a digress but we on this forum we often, and lately, have discussed different systems and their merits and faults, self steering, diesels vs EP, rigs etc. When I watched this video
https://www.youtube.com/watch?v=tK8FYzPtj-M
I thought about how even the simplest things will fail at the most inappropriate time which is when you use them and put stress on them i.e. "need them". I have recently completely taken apart my diesel engine and the aluminium heat exchanger was eroded to the point where it is fixable but only just. If I hadn't taken it apart now it would have worked for several years but eventually it would fail and that would be when I was pushing the engine hard, probably to avoid a lee shore or similar.

I think the point I am trying to make, if I have one, is that whether the system is designed to fail or not we need to think about pre emptive maintenance and back up systems.
If you have a break away rudder, hit something and the system works, how will you steer?   

     The idea of the break away rudder is about like the fold back "west coaster" mirrors on pickups.   You hit them on something and they "break away" and fold back.  You stop and push the mirror back to where it belongs.  If your rudder "breaks away", it's true that you have no way to steer until you put it back into position.   If your rudder is destroyed, you had better have a way to steer without it.   There are lots of flip up rudders such as on trailer sailors like the McGreggor boats that allow you to fold the rudder up while trailering.    A heavy pivot bolt to pivot around, and a nylon sheer bolt is about all it takes to make a break away rudder for a transom mount.   A cable that holds the rudder in the full down position could be set up like an over center latch, and fed over a rubber block that would give enough when subjected to a blow, that the cable would go over center and allow the rudder to flip back and up.  It's the same technology that allows the latches on your tool box to hold it shut firmly until you flip them. 

     Roger Taylor carries a long oar tied down to the deck on Ming Ming II.     It's a very long oar, that could be used to steer, or for sculling, or even to rig a jury mast in a crisis.   If he broke his boom or yard, he could carve it to make one, and who knows how many other uses it could be put to.   

     I watched the Utube video you linked to............  and my conclusion is that most people simply do not look at the things they use every day.   How long had there been slop in this fitting?   When was the entire rudder assembly last dropped out of the boat?   If you are doing a haul out for a bottom job, this is the time to do things like drop the rudder out of it's stock.  Is the rudder dribbling water after the boat has dried off?   Better think about the consequences of water logged foam.  It's the time to examine your through hull fittings, and look at replacing them, make sure they have proper sea cocks on them, and ask yourself if you could eliminate some of them.   Do you know where they all are, and have a way to hammer a plug into one if it fails?    How about an axe to destroy the liner in an emergency to get at the hull for repair?  It's time to think about the keel attachment, check to see if it shows signs of being less than optimal.  Is it solidly bedded, does it show any indications of trouble, are the bolts tight, does the hull show any damage on the interior from grounding?    With modern fin keel boats, keel loss is a significant concern.  There have been quite a few keel losses, some of them resulting in fatalities such as the notorious Cheekie Rafiki incident where 4 people lost their lives when a Beneteau 40.7 lost it's keel in rough weather in the Atlantic. 
The engine as you mentioned is considered a critical system in modern yachts, though there are still those who sail without an engine, it is critical to getting into some anchorages, and could save your life when you find yourself off a lee shore.   The photo I've included here is of sailboat without an engine that got caught off a lee shore in a storm, and was forced to use his full sail unreefed to fight his way off.  A rather dramatic photo of the yacht Kehaar.  He made it but there wasn't much left of his rig.   The sail was pretty used up before hand.  It is perhaps worth thinking about alternatives to using sea water directly or indirectly for cooling.   It's cheap and plentiful, but it also is extremely destructive.   
     The worst aspect of a Bermuda rig is all the standing rigging.   Failure any of dozens of components can bring the mast down.    Running rigging can be repaired pretty easily, but standing rigging can be a matter of life and death.   A jammed halyard block creates a mini crisis, but a failed backstay, chainplate, shroud, etc, can put you right out of business.  How often do you examine blocks, and what do you carry for spares?   How about winch parts.  Do you have a decent set of tools, or pliers and a crescent wrench?  There are dozens of systems to fail on a boat.  On an airplane, you are required to get an annual inspection by a trained AI.   Not a cheap prospect.   Marine surveys are not cheap either, but perhaps are a good investment.  These guys are trained to see all the little things you and I might miss.   How much would you have to set aside to pay for an annual survey?   Perhaps $50........ It might be a good investment if you are planning long ocean crossings, etc.

                                  H.W.


ralay

Aleutka 26 - bilge keeler with kick up rudder held in place by a soft dowel.  Ours worked as advertised.

Frank

Can't help thinking simple small boat technology wouldn't work with this concept.

I've had several trailer sailors with centerboards and kick-up rudders.
Would always joke they doubled as depth sounders  ;D

Even the 23 pilot house had a kick up rudder.

A sacrificial pin to hold it in the down position would be too simple.
Pin would have to be light enough to severe easily but not so light as to sheer too easily.

Then....the only issue becomes having several spare's and remembering where they were. It's the remembering part that scares me more and more  :)
God made small boats for younger boys and older men

CapnK

Frank - you make a list, of everything on the boat and where it is stowed, so you can reference it to find the small parts like that.

Of course, then you lose the list... ;)
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Please Buy My Boats. ;)

Owly055

     Perhaps a checklist???   It works in aviation.    I would hate to think boaters as a group were less capable than farmers, though there is plenty of evidence to that effect.  Probably because of the occasional nature of the sport.  How many people get out on the water more than a few times a year.   Farmers have been using shear pins since the baler was invented, and most have a handful of them in the toolbox attached to their baler.  Many modern ones have a little rubber fixture on the baler to insert spare shear bolts.  I would hope that sailboat owners were as capable and resourceful.    Perhaps Tow Boat US and a destroyed rudder is a better option??  It's often a better policy to make something to break easily with no serious damage than to try to make it indestructible.   I remember years ago a customer was complaining that the chain on one of his pieces of machinery was breaking when the machine got jammed up.  I told him that was a good thing, and that if I were him I would install a bunch of master links so there was always one on the pressure side of the chain, and I would file all the master links so they were weaker than an ordinary link so that when a link broke, it would be a job of about 5 minutes to simply pop out the link and replace it, instead of having to take it to the shop and use a grinder.    He ignored my advice, and instead bought heavier chain and sprockets, and within a few days wrecked the gearbox.... costing over $1k to replace.   After that he listened to me ;-)   An expensive lesson.   
     As I mentioned before, a cable holding the rudder in position could be designed to go over center and allow the rudder to flip up without having to shear anything.  There is more than one way to skin a cat, but there is only one cure for stupid.
                                                                                                                       H.W.

Quote from: Frank on June 12, 2016, 09:48:24 AM
Can't help thinking simple small boat technology wouldn't work with this concept.

I've had several trailer sailors with centerboards and kick-up rudders.
Would always joke they doubled as depth sounders  ;D

Even the 23 pilot house had a kick up rudder.

A sacrificial pin to hold it in the down position would be too simple.
Pin would have to be light enough to severe easily but not so light as to sheer too easily.

Then....the only issue becomes having several spare's and remembering where they were. It's the remembering part that scares me more and more  :)

Owly055

Quote from: ralay on June 12, 2016, 09:19:42 AM
Aleutka 26 - bilge keeler with kick up rudder held in place by a soft dowel.  Ours worked as advertised.

Nice looking boat....... I'd never seen one before.  Can't find anything on their kick up rudder though.   I assume from looking at the photos that only the very lower end breaks away??

                                  H.W.

Owly055

Here's a quote from a PDF on rudder failure.... bottom of page.     The PDF is here:     

http://bermudarace.com/wp-content/uploads/2013/11/3-Emergency-Steering-Solutions-v2-.pdf

BASED ON STATISTICS THAT MY
partner, Beth A. Leonard, and I?ve been
gathering in the decade we?ve been out
cruising, approximately fve to 10 boats
out of 1,000 sufer a rudder failure while
crossing oceans each year. Experienced
ofshore voyagers consider the successful
steering of a boat without a rudder to
be one of the most demanding feats of
seamanship. Faced with the challenge,
some crews simply give up and abandon
their boats. However, with the proper
preparation and attitude, almost any boat
can be steered to within sight of a safe
harbor. We?ve met several crews who?ve
sailed hundreds of miles?and, in one
case, more than 1,000 miles?without a
rudder.

Frank

#9
Owly....since my post was connected to your reply of only one cure for stupid...I thought I would show you a pic of the 23PH kick up rudder. It has a rod for assisted lifting but also  'clips' in the down position, but will 'pop' out when needed. Couldn't find picture quick...but about half way through this video you'll seethe concept. Simple n easy

https://m.youtube.com/watch?v=XaJI-NyhwBU&time_continue=16

   Reply from H W
  ""As I mentioned before, a cable holding the rudder in position could be designed to go over center and allow the rudder to flip up without having to shear anything.  There is more than one way to skin a cat, but there is only one cure for stupid.
                                                                                                                       H.W.

Quote from: Frank on Today at 08:48:24 AM
Can't help thinking simple small boat technology wouldn't work with this concept.

I've had several trailer sailors with centerboards and kick-up rudders.
Would always joke they doubled as depth sounders  ;D

Even the 23 pilot house had a kick up rudder.

A sacrificial pin to hold it in the down position would be too simple.
Pin would have to be light enough to severe easily but not so light as to sheer too easily.

Then....the only issue becomes having several spare's and remembering where they were. It's the remembering part that scares me more and more  :) ""

:) ;D >:(
God made small boats for younger boys and older men

Owly055

     Nice simple system.  One of the things I really like about transom hung rudders is that this sort of thing is possible, as well as mounting a trim tab for a  wind vane..... and of course installing a counter balanced rudder, not to mention the fact that it is one less hole piercing the hull below the water line.   I read about people replacing the tubular stainless steel rudder stock with a solid stainless shaft, and I can't help but imagine what happens with a solid hit.....Instead of shearing off clean, it is liable to fracture the fiberglass tube where it passes through the hull............ the weak link school of thought........... and experience, tells me that this is a bad idea.  Instead of the rudder stock being a weak link, many times more force is transmitted to the hull.  Sinking is not my idea of fun.

Cute little gaffer cat boat!   

                                                    H.W.

ralay

We made a bunch of softwood pins for our Aleutka's rudder and kept them in a big bag inside the companionway.  They sheared every time we ran aground but never any other time, at least in the year we sailed the boat.  I'd say the system worked more or less as advertised.  It did a good job of protecting the rudder from fore and aft stresses like running straight aground.  I think the rudder would still be more vulnerable to blows from the side than a boat with a keel hung rudder, but it worked for our (and John Letcher's) purposes.