Saturday, March 5, 2016

Emergency Steering

rev. 7-24-2024

So what, it snowed yesterday. Testing does not wait.

This grew into a number of articles for Practical Sailor and Good Old Boat. Later articles focused on emergency steering drogues you assemble in minutes from gear on hand: An anchor, some chain, and a fender. Hang the anchor from the fender, with some chain in front of it, and then use as a steering drogue as below.  It works and people have sailed 1500 miles with that rig and no rudder. 

 That said, I repeated the test with a commercial drogue (Delta Drogue) the same day, and the Delta Drogue was much easier to handle and very compact to store. If I were crossing an ocean I would pack a commercial drogue. More importantly, I would take a test day, as below, and try it out in a breeze. There are lots of ways to rig it wrong and screw up. Best to learn near home.

This past fall I jammed a rudder on a submerged tree. Two loud thumps, the helm did not answer at all, and the boat was turning left. To reach my destination I adjusted sails (genoa in, traveler down) and even lowered one engine (just for drag--not running) and played the traveler as though it was the helm. Maneuvering into the harbor under power was made reasonable by having 2 engines. Once anchored, I disconnected the jammed rudder and enjoyed the rest of the cruise on one rudder with slightly mushy steering. The autopilot even worked , so long as I kept the sail balance fair.


Towing SeaBrake 24GP under power at 4.5 knots. Should be 7.4 knots at this throttle.

What if I had only one rudder, like most half-boats? A rather expensive tow would have ensued, perhaps anchoring for a time when I reached shallow water. The cruise would have been ruined for certain. I always thought emergency steering and drogues where for ocean crossing and storms, but now I realized that even on the Chesapeake, a bent rudder can lead to trouble in short order. And so my closet interesting in drogues (I actual have 2, leftovers from my Stiletto off-shore days) has exploded into full-on testing for Practical Sailor. So far I have 4 brands lined up and one factory team that wants to help me play. What fun. The intention will be to try them all on all courses and hopefully in several wind speeds, seeing what works and creating drogue speed polars. There will also be some high-load testing related to storm use, but that is separate article.

Though I have had these for years, I never tried them for steering. A few tips:
  • For storm use, of course, they go farther back, 150 feet-250 feet.
  • But for steering, bring it in close, as little as 20 feet off the stern. Much more responsive.
  • Spinnaker sheets work well for a bridle. You can actually steer by sitting next to a winch and playing just one leg.
  • Attach the sheets at the widest point, particularly on monos. Near the stern is fine for cats, but a little forward is better (more responsive).
Observations:
  • 100-110 true with the rudders jammed 65% to leeward. I was surprised. The wake was reasonably straight and leeway less than I feared.
  • 70 true with rudders straight.
  • Very slow in light winds. You are going to loose about 1-3 knots. The Seabrake is too large for this boat. We'll have to see how the Small Shark works. I also need o try the Seabrake in close, partly out of the water, to reduce drag. I forgot.
  • Pretty stable. I can imagine using it for days, with crew. Not as good as autopilot, but not bad.
  • There is a tendency to round up if sailing to weather in variable winds; when the genoa looses pressure, the drogue is still pulling, and the boat comes up. But if you catch it before it stalls, by releasing the windward bridle line a few feet, it recovers well.
 Rudder 65% port requires the drogue full to windward to maintain anything close to a beam reach. Without the drogue we would be going in tight circles at best, stuck.


  • With the rudders straight we could make some ground to windward... but slow. Only about 70 degrees true course over ground, and slow. Notice that the drogue is nearly centered. The drogue is clipped to the sheets with only 8' of 3/8" BBB chain as an extension.
     
    Slower than sailing, but much faster than sailing in circles, faster than waiting for help, and more comfortable than drifting beam-to-waves. Good for parking the boat transom-to-waves while making any sort of repairs (they will be easier if the boat is not rolling).

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