Strange Noise

[bobk]

I'm running south with Walt P and Ralph (also a Hatt owner). Made it from Baltimore to north Florida so far.

Last night when anchoring at Lanier Island, GA we heard a noise like a whine intermittently while maneuvering to anchor. The guys described it as like the sound of an electric servo motor. The same thing occurred tonight when we anchored at Pine Island. We did not hear the sound when pulling the anchor this morning. The sound is so intermittent we could not even determine which side it came from. The transmissions are Allison M15's. Any ideas?

Bob
Chateau de Mer
1981 48MY
6V92 TI 425's

 

[Pascal]

hard to say, but could it be the AP electric pump? they can sound like a servo motor.

if it happens only after a long run, it could be heat related... tranny? maybe but until you can actually hear it long enough to go in the ER and find the source, it's not going to be easy.

next time it happens, try to shift from N into gear for instance.

 

[RyanN]

An autopilot system can sound like that. That's the obvious thing. Maybe a bilge pump float switch kicking the pump on and off. That's all I can think about.

 

[TopHattandTails]

Possibly the stabilizer pump winding down?

 

[SKYCHENEY]

Possibly the stabilizer pump winding down?

I've never heard the "winding down" from the stabilizers until the engine is shut off. Then I can hear the gyro humming as it winds down, but only if I'm standing right next to it.

I'd be more inclined to think it was the AP pump as Pascal mentioned.

 

[REBrueckner]

Is the autopilot shut off when this occurs??

 

[Top Shelf]

Try Checking the oil level in the gears. It seems to me that when one of my gears is low I can barely hear what you're describing. But it's always docking or manuevering and shifting after a long run.

I've got a shaft seal leak that I'm just living with. Just a thought. Thx.

 

[Hattenuff]

Could this possibly be a cutlass bearing?

 

[kwerges]

X2 on the AP pump. When maneuvering to anchor, could reversing (backing down) on the anchor be changing the angle of the boat enough to shift water in the bilge and kick the bilge pump on momentarily?

 

[trogers]

Occasionally I can hear the servos on my KVH disk. Not sure if you have one, but if so, it is a possible explanation.

 

[Daybreak]

I went through something similar with Daybreak, whine-stop, whine stop, not long enough to really locate. Turns out it was the satellite dish re-acquiring the signal.

Ben

 

[bobk]

Thanks guys. We have eliminated all of the suggestions. AP is not on when anchoring, Stabilizers were off all day, The KVH was also off and makes a very different sound. Bilge pumps are not audible on the bridge. Cutlass bearings were checked during the September haul out.

Has anyone heard of a crab trap line causing this kind of noise? We got in close to some just before it started.

Bob

 

[captddis]

I have heard crab traps with a lead sinker attached to the line make noise. Do you have Spurs? They can make a noise when shifting if the isolators are missing or worn.

 

[saltshaker]

It could be a shaft zinc that has slid down to the strut.

 

[bobk]

I don't have spurs, but do have the circular knives type cutters. Hadn't thought about zincs. We are 100 miles from our destination. I'll have a diver have a look when I get there.

Bob

 

[bobk]

Thanks guys. We had no noise on the last anchoring or the docking maneuver the day before. Also a very slight vibration went away. I'm thinking I may have had a crab trap line which them line cutter eventually discharged.

Bob