Express Trawler 36 - Bow Thruster

[krc]

Hello,
I have a Vetus 25 bow thruster installed on a single engine (cat 3126B) TE.
Went out for fleet week today and had a problem getting out... as in the
bow thrust went anemic. Was able to back and fill to get out, but very heart pounding. It does seem to work a little (maybe 10% power of before).

Anyway, the bow thruster had been working fine. At this point, I can hear the motor going, but I can't see what is going on so (1) how do you tell that a shear pin has broken (2) could this be a motor brush issue. Any advice on how to get access to the bow thruster and what people has seen for setups (battery location, separate charger?) would be great to hear.

Thanks.
Karl

[Mariner]

My guess, and that's all it is, is that you may have broken a blade, or it may have become fouled. If it's still producing thrust at all, I would gues the shear pin is not snapped. A failure of the electric motor is a posibility, but seems less likely.

[krc]

Thanks Mariner,

If it was the shear pin or prop, can this replacement be done in the water? I understand that some shear pins can be accessed from the motor (so dry replacement) but this unit I think the shear pin is behind the prop. So would assume this is a wet replacement. Can this be done by a diver or will this need to be hauled?

[joe.baar]

Karl,
First, if you can hear the motor running and it sounds pretty much the same as it used to then I doubt there's a broken shear pin. If the pin was sheared then it seems likely you would hear a motor sound as if it was unloaded, i.e., running at rpm way higher than you expect. Also if you can hear the motor running then the brushes are probably OK.

My 28TE had thruster issues all last year. I replaced the fuse next to the motor, cleaned up and greased all the wiring terminals I could find, hauled the boat, scraped all that rough antifouling paint off the (slippery plastic) prop, added a zinc, and carefully painted the badly eroded gear-train housing that's in the water with non-metallic antifouling.

Late this summer after I cleaned ALL battery terminals the thruster began to work again. I'm not sure if I trust it completely yet but the lesson appears to be "AMPS". Those big starter motors really need amperes to work right. Replacing the cables feeding that motor with a size larger than what's there now is on my list. Good luck with this, Karl.

[RicM]

The shear pin on the 28TE is dry, it's in the connection between the electric motor and the geartrain that goes through the hull. To access you remove the 3 through bolts that hold the motor in place and lift it out AFTER MARKING the exact position of the motor with a scratch across the motor body to the mount. Shear pin is easy to replace, getting the motor back on lined up perfectly is the b@#$%h. If it's not the pin the prop could be crusted up with growth or fouled in some other way.

[Mariner]

This is a 36' Express Trawler, not a 28' Tournament Express. I am not familiar with the configuration of the thruster motor, so I don't know if the shear pin is inboard or outboard. I have the documentation for this unit somewhwere. I will look for it when I get a chance and see what I can find.

Could be a while. I'm pretty sure all the paperwork is on the boat, which I won't be getting down to any time soon.

[RicM]

Try:

http://www.vetusweb.com/manuals/files/B ... 008-06.pdf

Be patient it took a minute or two to load due to size. I also see the link in the post is truncated, copy and paste into browser.