Bow thruster incident

[peterg]

We have been trying to move our new to us Mainship 430 from Annapolis to our home port near Syracuse. We got out to Cape May and were stuck for a week with east winds and small craft warnings, with more of same forecast for the next week. Decided against the njicw. Made decision to backtrack to Chesapeak and haul there for winter. Stayed at Del City on way out, and at Summit North on way back

While leaving Summit North, the bow thruster became stuck on, pushing bow to port continually. Very exciting! Turning thruster controller off had no effect. I used engines to center boat in fairway while we spun. Engines could not counteract thruster. After about 3 revolutions, I remembered there is a thruster battery switch under fwd bed. Was able to explain to wife were switch is, she was able to turn it off. Crisis over.

It’s a Vetus thruster, any suggestions?

 

[Delta Riverat]

Suspect a high current relay got "welded closed" or the controller gave an wrong signal.

Did the thruster start by itself or where you using it and then it wouldn't shut off?

 

[Cold Duck]

The thruster motor usually has 2 solenoids like the old Ford starter solenoids mounted on the starter, one for port, one for Stbd. For emergency, just tap solenoid with hammer and it probably will disengage, or do as you did and turn the switch. You can find the p/n and order a new solenoid online or get from Vetus. After a lot of use, a tit will form on the contact of the solenoid and hold it in place even though you de energized it. Again, in emergency say out in the islands or something, you can open up the solenoid and file off the tit and it will be usable for a while. The solenoid is usually encapsulated for spark protection so you want to get a new one ASAP.

 

[Comodave]

You could even put a remote controlled battery switch so you can shut it down immediately from the helm. I believe Blue Seas makes them.

 

[peterg]

I was using the thruster and it wouldn’t shut off

 

[Comodave]

As suggested it is most likely a solenoid stuck. Just get a new one and replace it. Pretty easy to do. Probably the hardest part will be finding out what part to order…

 

[peterg]

Would be nice if it’s the controller. The solenoids I assume are near the motor. And the motor is under the fwd AC unit, which is under the fwd bed

 

[Comodave]

Yes, but is usually works out that the fix is hard to access. From your description I would be surprised if it is anything except the solenoid.

 

[Bmarler]

Agree with Dave, the solenoid contacts are probably welded together. My advice would be to change both. Especially if it’s tough to access.

 

[slowgoesit]

Peter, any final resolution on what caused your issue? Inquiring minds want to know!

 

[peterg]

No conclusion yet. Decided to live without the thruster for the remainder of the in-water season, and fix during winter haul-out. Chose Bohemia Bay Yacht Harbor for winter storage, boat has just recently been hauled.

 

[HeadedToTexas]

There is a really good reason to have a disconnect switch near the helm.

 

[Mountain man]

We have been trying to move our new to us Mainship 430 from Annapolis to our home port near Syracuse. We got out to Cape May and were stuck for a week with east winds and small craft warnings, with more of same forecast for the next week. Decided against the njicw. Made decision to backtrack to Chesapeak and haul there for winter. Stayed at Del City on way out, and at Summit North on way back

While leaving Summit North, the bow thruster became stuck on, pushing bow to port continually. Very exciting! Turning thruster controller off had no effect. I used engines to center boat in fairway while we spun. Engines could not counteract thruster. After about 3 revolutions, I remembered there is a thruster battery switch under fwd bed. Was able to explain to wife were switch is, she was able to turn it off. Crisis over.

It’s a Vetus thruster, any suggestions?

Your relay likely welded its contacts. This can happen from prolonged useage, rapid or frequently reversing the thruster or a low battery, alturnator output low or resistive cable conections.

Have a look at the repays contact surface ondition. If badly pitted I would suggest replacing the unit as it will likely weld again and test your hearts condition.