and it was the reporter who said it was stuck in gear.“I found I had extremely limited control, almost limited to only the bow thruster, but with now only 50 metres between us and the bridge I had to make a decision fast.
Not at all a surprise. Many of us have fly by wire controls and there have been a couple reports of incidents of malfunctions (as listed on this forum) and crashes as a result. I have them on my boat and there is always a bit of a background worry, but I find them very nice to use.
As the boat slowed to almost zero and the autopilot tried to correct against the current, it eventually reached the rudder limit. When I went back to the helm, the rudder was locked in position against the stop. Even turning the autopilot completely off (power down) did not release it. After a couple minutes with the pilot off, and trying to move the wheel but not forcing it, it released.
Sounds like the AP forced the rudder to the mechanical limits of the rudder or ram. The AP has preset electrical limits to prevent this IF properly set. Generally these limits are set at about one half of the way from center to the mechanical limit. Get out your AP Installation Guide and double check the Rudder Limit setting. Something is still wrong.
He was departing and had been off the dock for quite some time. Clearance through the bridge was so tight fenders could not be used. He choose to hit the dock because that was the best option out of only bad options.To be fair, he did have 1 fender out, so he was well prepared to dock.
Some autopilots have limits. Set the limit a few degrees off hard over, that last little bit of rudder doesn't do much anyway.I had something happen on my tiny (by comparison) boat last year that was unsettling, but did learn something from it. All feedback is welcome, as well as criticism, I can take it.
I was bringing my boat to a different harbor for winter haul and storage. It's a fairly narrow channel into the harbor with docks and mooring on both sides. I was alone on the boat and when I got out of the rough weather and into the harbor channel where it was nice and calm, I prepared to dock. I was barely making headway and had to put out fenders and lines. I put the gear in neutral and hit the autopilot so I could make quick runs to the bow etc. No worries as there were no other boats operating nearby and I was watchful while working. As the boat slowed to almost zero and the autopilot tried to correct against the current, it eventually reached the rudder limit. When I went back to the helm, the rudder was locked in position against the stop. Even turning the autopilot completely off (power down) did not release it. After a couple minutes with the pilot off, and trying to move the wheel but not forcing it, it released.
In hindsight, I should have slowed the boat to a near stop and not engaged the autopilot, at least that's what I would do next time.
I saw reverse thrust from the port prop, so its not like it was solidly stuck in fwd. Must be more to the story. And he hit twice, so there was a decision after the first incident to give it another go.
Puzzling there, and the videos make no comment on either.
Also, with the port in reverse and the starboard in forward there is very little movement of the bow to port as you would expect. Perhaps the props are closely spaced or due to the size there is little effect from opposite thrust.
Watch the video in post #13 - it explains quite well what happened.
The video around 4:10 discusses the 1st failure, around 4:50 discusses the 2nd
failure.
I could argue that electronic controls leave a few things to be desired... one is accidents. Electric vehicles has a higher rate of crashes. (Kelly Richmond, Future insights)
I'm not a big fan of computer control that could cause catastrophic accidents when they fail. Look at Sully's issue, the Boeing Max, this incident, etc.
In "my" world my electronics have failed significantly more that their old mechanical counterparts and are MUCH more expensive to fix. (mostly aircraft, fortunately)
My boat is pretty much mechanical, except for the Glendinning throttle/shift control, which is really a great unit. I "can" operate it manually if it quits, but would require two people to do that.
Good old mechanical is hard to beat. And a good electronic device for information gathering (MFD) works great with that, as it can't cause the engine or thrusters to quit or malfunction.