The Offshore Voyaging Reference Site

Servo-pendulum is Not Bullet Proof Either

A few weeks ago I pondered the very high loads that auxiliary-rudder self-steering gears put on themselves and the parts of the boat they are bolted to, based on the failure of Simon Curwen’s Hydrovane gear while leading the GGR.

Now we are getting reports that Abhilash Tomy is having a hell of a time keeping his Windpilot servo-pendulum gear operational.

As I understand it, both Abhilash and Simon started having big time trouble with their gears when they got in really nasty weather west of Cape Horn and got broached repeatedly.

Obviously, this is a small sample, but I think the takeaway might be that no vane gear is going to consistently stand up to broaches in big seas, no matter how well made. Seems logical.

And, further, that the idea that a servo-pendulum gear will kick out of the water and unload before damage is done might not be true, at least in really big seas.

And this in turn makes it even more important to have storm survival gear aboard, a strategy in place to prevent broaches, and the ability to get through really nasty storms without steering and with the vane gear safely out of the water.

Of course, as I understand it, that last requirement is easy to execute with the Windpilot and Cape Horn, and very difficult with gears like the Hydrovane.

On the other hand, the Hydrovanes seem to have done better than the Windpilot in this and the last GGR, aside from Curwen’s unfortunate experience.

Again, nothing definitive here, but worth thinking about when we are selecting a vane gear.

I think, on balance, I would select one that I could easily pivot out of the water.