How to electrically release a buoy ?

[KeithG]

Thanks, gentlemen.
Akimbo : For a weekly release and years of operation, 1Km offshore.

Yes, Aviyes. Something like that. The mechanism is what am after, resettable as in a snap shackle, instead of fuse-melting.

The snap shackle that uses a pull pin, the pull pin could be longer made of magnetic stainless, (series 4xx?) becoming the core of a solenoid. And the solenoid being fully waterproof-corrosion proof is another hurdle.

What quantity? you want to consider custom design and machining?

 

[gopbroek]

The acoustic frequency used on a flight / voice recorder under water locator beacon is 37.5 KHz which can be detected at a fairly long distance. PPS pressure transmitters use the same basic frequency range. I would be discreet with the final design, a remote deployed bouy and a remote deployed tethered mine are very similar in basic design.

 

[ScubaSteve85]

I recently met a guy working on a similar project for his senior design project in college. I actually bought the tank off of him when he was done with the project. I think the goal was to be able to trigger a lift bag that could return an anchor to the surface. Anyway, he sent me this video of what they came up with.

 

[KeithG]

The acoustic frequency used on a flight / voice recorder under water locator beacon is 37.5 KHz which can be detected at a fairly long distance. PPS pressure transmitters use the same basic frequency range. I would be discreet with the final design, a remote deployed bouy and a remote deployed tethered mine are very similar in basic design.

Interesting. I am a fan of the May Day tv series https://en.wikipedia.org/wiki/Mayday_%28Canadian_TV_series%29 (It's Canadian)

Often (well always) they get a little bit over dramatic about the recovery of the orange colored black boxes since they claim the signal only lasts 30 days.

Anyone know what the battery capacity of these devices are?

 

[Akimbo]

... Akimbo : For a weekly release and years of operation, 1Km offshore...

Hmmm.

1. Are you retrieving a device and replacing it or collecting data via a cable on the buoy?
2. Can you also change batteries weekly?
3. How flat is the bottom? Example: Can you float a buoy 1-2M off the bottom and find it with a fathometer or plant a big piece of scrap iron to locate with a magnetometer?
4. Are you paying commercial labor rates or is this volunteer? IE: Would sending a Scuba diver over the side to retrieve it be cost effective?
5. One Km isn't that far. Have you looked into laying a cable for power and data compared to labor and boat costs?

 

[Aviyes]

DELETED

 

[herman]

The bigger issue is how are you going to reset it? Unless you intend to retrieve the entire thing- anchor and all then reassemble it on the surface, it's going to be very difficult to devise a way to retract it and reset the latch. the anchor line must be captured some way (spooled for example) and not allowed to float around since it will tangle on something or tie itself in knots. If you can't retrieve the entire assembly for resetting, your best bet is just use a diver to deploy and retrieve it...no need to release the buoy or have to deal with storing the anchor line.

 

[USNMARS]

This is actually what I do for a living, so I may know a thing or 2 that can help you out. We use acoustic releases and using a surface transponder you can send a signal to release the buoy. The preferred release has a "jacking screw" that is turned by a motor and will spin a piece that the buoy is connected to until it spins free. Like a nut coming off of a bolt. I like these because they are almost free of any marine fouling issues. One single barnacle will jam a pelican hook style. the Pelican hook style has been around for years and woks ok. They have a spring actuator that snaps the hook free upon recieving commands. The key with these is to make a mixture of Desitin paste, yup the stuff for a baby's bottom, and mix it with Cayenne pepper. This combination is a great anti fouling mixture and will keep growth from happening. Our bottom moorings stay down for months and sometimes years and the releases have almost a 100% success rate.

 

[USNMARS]

Marine Electronics Ltd. - Acoustic Release

 

[Externet]

Thanks, guys. The commercial - proven equipment in the market may be too much for a wimpy system as sought.

Still learning and hunting for re-purposable items and mechanisms.

----> Crane machine mid size replacement claw hand kit, height is 7 inch with coil and cap

Which would need modifications and rethinking. But it is a start to evaluate. Similar clever contraptions on the market is what am looking for.

giffenk: 10 pieces, will keep your expertise in mind when the moment comes to decide.

ScubaSteve85 : unable to see all video; it halted. Will retry another time.

Akimbo : Retrieving devices also tied to the buoy. Battery is no problem. Bottom is mostly sandy. Additional expensive equipment to be avoided. Part of the task is to not need divers. No hard lines from shore, as unit to be relocated periodically.

herman : Resetting is manually on surface.