The Offshore Voyaging Reference Site

Are Auxiliary Rudder Self-Steering Gears Strong Enough?

I was really saddened to hear that Golden Globe Race leader Simon Curwen is probably out of the race due to a catastrophic failure of his auxiliary rudder self-steering gear in a broach.

I have long wondered if these gears that actually steer the boat with a separate rudder, rather than control the main rudder as servo pendulum gears like the Windpilot and Cape Horn do, are a good idea.

After all, the rudder and its attachment are one of the most strongly engineered parts of a good offshore boat. So does it really make sense to try and steer the boat with a comparatively flimsy rudder bolted onto the transom?

The other worry is that, even if the gear is up to the job, huge loads are being transferred to the transom, which was probably not engineered by the original naval architect, or builder, to take them.

There is even a suggestion, albeit by a source with an axe to grind, that it was exactly this problem that caused a sudden break up and sinking of another boat in the same race.

And, finally, auxiliary steering gears can’t pivot out of the water and thereby unload in a knock down the way some servo pendulum gears can.

Nothing definitive in all of the above, but definitely something to think about when selecting a vane gear.

Thanks to AAC European Correspondent Colin Speedie for the head’s up and some of the above thoughts.

Much more on self-steering, both vane gear and autopilots.

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Mark Wilson

Dear John

Glad you have brought this up. I have been wanting to comment. Especially as the decision on my next wind vane is looming.

I followed the first GGR closely, this edition less so. I got the idea in the first edition that, as the carnage mounted and the race director looked to excuse it, all self steering gears apart from the Hydrovane were nominated as the guilty parties. Rather than a combination of bad luck, unusual weather patterns and a flawed race concept. Hydrovane was deemed to be the winner of the race rather than the superior skills, preparation and experience of VDH. This time round it’s the Hydrovanes that have failing.

I have sailed with quite a few self steering systems over the years. After a few days of blundering around and generally making a fool of myself I have always begun to get on with them. Except for the Hydrovane. I only had it and the boat it came with for 9 months or so. And I only sailed it from UK to the Grenadines. I never did feel I had mastered it’s use. Sometimes it worked well, sometimes it wouldn’t work at all. I could never work out what I was doing wrong – or what I was doing right. It was either me or the boat (probably me) that didn’t suit the gear.

Also for me it’s appearance is too heavy and forceful. More of a slugger than a dancer. More boxing than judo. And its not cheap.

PS. As the former owner of a Speedie yacht that came with a Monitor on it I am inclining towards getting what he got next.

PPS. A shame for Simon Curwen who had sailed such an exemplary race thus far. Perhaps with his massive lead he could with a bit of luck and a lot of shock cord and experiment struggle on. Things should get easier when he gets back into the Atlantic and the winds come abeam and forward.

Gerald Danko

“I am inclining towards getting what he got next.”

And what would that be Mark?

Mark Wilson

Windpilot Pacific.

Colin Speedie

Hi Mark

the most important thing is to select a vane gear that is robust and suits the boat’s hull form well. The Monitor that you had on FC was great, but maybe a little twitchy – it certainly needed far more ‘tuning’ and general ‘getting to know’ than the Windpilot Pacific we had on Pelerin.

Bearing in mind that as confirmed Luddites we used the vane always when we were sailing, from Scotland to southern Brazil and up to Newfoundland and never once let us down from 5 knots of wind over the stern to 3 days under bare poles, obviously we had picked the right gear for her.

I heard you have a very smart new boat and my bet would be that the Pacific will do you proud. And for what it’s worth, if we have a vane gear again it will be the Windpilot Pacific.

Best wishes

Colin

Mark Wilson

Thanks Colin

The Monitor certainly gives good lessons in how to balance one’s sails. I feel bad about abandoning FC. A fine boat but maybe a bit young and frisky for me.

Best

Mark

Drew Frye

I’ve always been facinated with wind vanves, ever since I saw one on the Dove as I read about Robin Graham’s adventures in National Geographic when I was in elementary school. I think he carries much of the blame for my sailing adiction, just as articles on the American Everest expedition and the first climb of Half Dome with clean gear inoculated my climbing obsession.

In “Autopilot vs. Windvane” you discuss relative merits of the two methods, in part concluding that the electronic pilots are power hungray and the windvanes are operator intensive (sail trim and adjustments). But I wonder if that is only a parcial answer. An elelctronic pilot is, in part, power hungry because you don’t have to adjust sail trim, and because the software isolates use from the elelctronic pilot. I admit to veryulally (a few hours) expereince with a wind vane … but it was cool! Windvanes barely work on multihulls for a number of reasons, but that is off topic and pointless.

What I have learned is that electronic pilots performa more quietly and with a lot less power draw if, like a windvane, you work with them. Trim the sails for balance; if the human pilot would labor, so will the elelctronic pilot. It might not be the best speed trim, but it may be very nearly as fast. Use the “wind” setting to windward, where adjusting to shifts and maintaining angle of attack is critical to pointing, but use the compass setting reaching deep, since sail trim is less critical and the apparent wind moves around too fast, particularly on a multihull prone to surfing. Again, trim for balance, with more head sail, less mainsail, and never too much heel. Electronic pilots also try too hard to maintain a perfect course. if they allowed as much wiggle as we accept from a windpilot the draw and noise would be far less.

I do these things just because a hard working elelctronic pilot seems … crude and not seamanlike unless racing short handed. But there is no easy way (that I know of) to de-tune the helm correction variables to allow a more relaxed course. They are auto-tuned at start up, and to my knowledge, do not change. It seems like they should either be user adjustable, or in high end models with a smarter program, perhaps “race, “cruise,” and “power save” modes. But I guess if you have a high end model they assume you have abundant power and like to hear mechanical things doing busy stuff.

Maybe you could write an article?

Star Tracker

I’ve debated on the servo pendulum vs auxiliary for a while, my boat came with the auxiliary style, with a trim tab. Very clever in use, it has no gears, I haven’t had any luck finding any info on it and the builder is out of business, but per the original owner who commissioned the boat, it worked without fuss all over the pacific. Every part was built in a local machine shop apparently, so replacements can be built likewise, but the original spares are still on board. It allows me to use a linear actuator(replacing the tiller pilot it came with) at a fraction of the power draw of a below deck system, I like to think it’s the best of both worlds? Other bonuses of the design include: few moving parts, the pivots are huge solid stainless pins. The lifting eye on the top of the unit, clips in to a block and line up to the radar/panel arch that doubles for hauling the outboard off the dinghy. The entire windvane can be hauled up safely and secured entirely out of the way without more than an arm over the back, no leaning up and over, any time it needs work, haul it out and work on it inboard in comfort. I suspect handy as well if you needed a drogue etc. The top has a socket and an emergency tiller is mounted in the cockpit, so losing the main rudder the boat is still steerable, even under sail manually or automatically. When it’s off, the heavy cast brackets are only 4″ out from the transom and have no edges to catch things.

Matt Marsh

As with many other things aboard ship, I would say that the quality of the installation is just as important as the device itself.
Our own Hydrovane is through-bolted to the reinforced section of the transom that supports the backstay chainplate. This is among the strongest parts of the boat.

I would be quite concerned if such a unit were mounted to a weak part of the structure, just as I would be if a servo-pendulum or servo-auxiliary vane were mounted the same way. Yes, servo-pendulum vanes are relatively lightly loaded in normal operation compared to direct-auxiliary and servo-auxiliary types, but if you actually build and mount them assuming light loads, they end up being vulnerable to damage. Bumping a log or dock with a Hydrovane is an “oops” moment; the same incident with a Windpilot Pacific is a “well, that’s wrecked” moment.

All of these vanes have moving parts that can wear out or break. The oldest Hydrovanes in service are now pushing 54 years; regular replacement of wear and fatigue items over that timeframe is just as important as initial quality. Any vane can break in a nasty broach, particularly if it’s an older one that’s a bit behind on preventive maintenance.

There are always trade-offs. If you install a Hydrovane or a Pacific Plus, you do need to make sure it’s very robustly mounted, which can be difficult and expensive. On the other hand, you won’t have control lines snaking all over the helm, you can generally use the vane in lighter air and lower speeds than with servo-pendulum types, and you can get ultra-low-power-consumption autopilot functionality just by hooking an ordinary cheap tillerpilot to the auxiliary tiller and locking the main helm in an approximately balanced position.

I think the comparison on Hydrovane’s own site:
https://hydrovane.com/hydrovane/compare/
is generally pretty fair as to the pros & cons of each type?

Andrew Wade

Hi Matt
I’ve been investigating which way to go for vane steering on my boat for some time so have looked at all the options.
I don’t think I’m particularly biased either way. I think it depends to some extent on the design of the boat and what kind of sailing it’s going to do.
I did consider a Hydrovane a while ago, partly because I was offered one at a very fair price, but I decided against it when I lifted it up. It was very heavy. Not a problem on larger boats, but on my 29 footer that seemed like a lot of weight to be hanging off my transom. I like to keep my bow and stern as light as possible. So that’s not a criticism of its substantial build, which is obviously necessary and I actually rather like, just not right for my boat.
I’ve sailed on a Swan 38 across the Bay of Biscay with a Hydrovane steering downwind in a F6-7. It was absolutely fine as far as I recall.
However I do question a couple of your comments.

« Bumping a log or dock with a Hydrovane is an “oops” moment; the same incident with a Windpilot Pacific is a “well, that’s wrecked” moment. »

I don’t see this at all.
If you hit something substantial in the water when you’re underway with a Hydrovane doesn’t it have a shear pin that saves greater damage higher up?
So yes ‘oops’, but not that easy to replace in a seaway I’d imagine.
The Windpilot Pacific has a pivot at the top of its rudder that allows it to pivot up and out of the way. More a case of resetting it and carrying on. Not wrecked.
A windvane’s durability as a fender hasn’t been that high on my list of pro’s and cons. Ideally I want something I can easily remove for venturing into a marina. After all a windvane steering doesn’t really excel at coastal sailing. I picture myself picking up a mooring or dropping the hook once clear of vulnerable topsides and snaggly pontoons before fitting it onto the transom.

You also talk of the advantages of not having lines ‘snaking all over the helm’, but surely if you have a tiller steered boat you’ll need lines to lock off and position the helm with a Hydrovane?
The only difference I can see is that with a servo-pendulum these then run along the cockpit coamings and out over the stern. And they’ll be in constant motion of course.
And finally I’m pretty certain that all the Windpilots come with a fitting to accept a tiller pilot so you can sail a compass heading. Possibly Hydrovanes are better under power with a tiller pilot though.
I am basing this on what I’ve discovered in my research, it’s not based on a lot of experience of using different types of windvane. I’m no expert. It’s more that you’re comments made me scratch my head. And I’m a pedantic arse!

All the best

Andy

Olli Pietikäinen

There is even a suggestion, albeit by a source with an axe to grind, that it was exactly this problem that caused a sudden break up and sinking of another boat in the same race.”

GGR had a webinar debrief of this incident on Monday – recording can be found here https://www.youtube.com/watch?v=M1T2FbFUsuA

TL;DW; Based on modelling and Tapio’s observations it seems that the reason for sinking is something hard (container?) hitting the bottom of the boat. This then caused leak that was comparable to 12 cm round hole.

No indication that the windvane was the culprit.

Olli Pietikäinen

Yeah, I got what you were trying to say and share some of concerns you have. Just wanted to share this video as there has been quite a lot speculation about the reason why Asteria sunk. Of course they still don’t know for sure, but this sheds _some_ light to the accident.

Video is quite slow pace, so it might be a good idea to jump straight to 26 minute mark where discussion about the watertight compartments begins.

Then they have some technical difficulties with SolidWorks simulations and answer some questions in the meanwhile. Discussion about load simulations continues at 55 minute mark.

Andy Schell

Why nobody has chosen the Cape Horn for this race is a mystery to me. Yves designed this for exactly the same purpose as the GGR, has proven it many times over, and yet not a single boat fitted one. I think that’s a shame.

Mark Wilson

Hi John

It looks like Abilash Tomy has slipped a Windpilot past the race organiser while he wasn’t looking. From the photos on the GGR website it appears to be a slightly awkward installation due to the stern hung rudder. Abilash is now in second place so it seems to be working alright so far.

William Elliott

Simon is not out. sheet to tiller the last I watched and read the updates two days ago. The other hydrovane problem was do to a rudder shaft pin modification that wreaked the shaft. To my knowledge no hydovanes have failed save Simons possibly, that weren’t modified by the user/ installer.
I’m on my second boat and Hydrovane. Chosen for the proven reliably and having it as emergency rudder. It’s also a more simple system that doesn’t have control lines to the quadrant or the tiller. I do agree that not being able to swing the rudder out of the water can cause some problems for some boats due to fact that the rudder on the hydrovane can be more effective than the ships rudder. This is for two reason. One, if the ships rudder is not trailing on actual end of the boat the hydrovane is more effective because it is past the stern and is very hydrodynamic. Two, like on my Pearson vanguard! I felt the rudder was under sized for the boat alone before having to overcome the stern hung hydrovane. Both of these are easily overcome by fitting a tiller to the hydrovane (which it is designed for and has a handle ).