Recovery robot

I have a nifty submarine for recovering ships. It has two cameras used for spotting and rangefinding to the wreck, a passive sonar system for detecting pumps and motors still running, has a cruising speed of 30knots (big gun speed chart, can go faster for short bursts), is capable of diving 8' to the bottom of my pond (haven't tested it deeper), and has two articulated mechanical graspers to interface with the wreck for retrieval. Codename: Me.

On a more serious note, I participated in a national ROV competition in 2006, and I learned some interesting tricks. Things such as thruster placement, ballasting tips, and how to use the water as a tool. I'm not an expert, but I've got a few ideas that might help.

Thruster placement: position four thrusters around the frame at 45* angles to the direction you want to go. It should look lik this:
\./
/.\
This arrangement allows you to run all four thrusters at once and get more thrust than the traditional arrangement which only allows two thrusters and looks like this:
_|_
.|

ballasting tips: use solid pieces for buoyancy, not foam. For buoyancy chambers use air-filled PVC pipe, which will collapse less than foam when you submerge: this compression will change your buoyancy the deeper you go. You can reduce this even further by filling the pipe with oil rather than air. Since we are talking about shallow operations, air-filled is probably OK. Have more buoyancy than you need, and add weight to get the balance.

Water can be used to suck up or shoot out objects. Part of the competition I participated in was to pick up two "plugs" (1"x1' pvc pipes) and plug them into sockets on a seafloor sensor package. Most teams made robotic arms to grasp the plugs, but one of the teams that did very well sucked up the plug using water pressure then reversed the flow to shoot it back out at the socket. While this might be a useful tool, this also makes me worry about thrusters kicking up silt or weeds on the bottom of the pond.

My team attempted to use wireless video and control for one of our two ROVs, and it simply didn't work. Keep things simple by using a tether for power, control, and video. You really aren't going far or through any tight spaces, so you don't need anything special like fiber-optic control line. I also wouldn't waste money on a sonar system when I doubt it will provide much benefit (if any, they're not usually meant to find small objects that barely stand out from the pond bottom).

I would worry about how much buoyancy you need after you figure out how to interface with the wreck and pull it off the bottom. I think it would be best if it could work with any ship, and didn't need special mating equipment installed in the ship, like extra strong float strings (floats occasionally fail) or custom attachments that the ROV docks with. Can you make a giant claw that reaches around the whole ship (big enough that it won't damage masts or superstructure)? Can you put a loop around the bow and stern?

 

I like the idea of a bouy of some type, with enough boyancy to lift a yamato. The thing is, the floats would have to be standardized to simplify the process. Also, with that said, maybe a deployable camera to located to wreckage, a deployable "fork" to get the float, and thrusters on the bouy to manuever it slighty. I also like a sub idea, but it would have to be quiet large to have the amount on boyancy. Interesting problem with an interesting solution. Remember, Keep it Simple Stupid. KISS will allow for more clubs to have one, making it better for everyone.

 

Slightly off topic, I like my whole superstructure float. Rope is attached to it so you lower the ship to the bottom, not raise the float to the surface. It is 20 foot long, quick clips and I can pull the boat up with it due to strong anchor points on the ship. Definitely not as cool as your design but I am in it for battling. See what the sub guys do as they must have some good ideas for getting their subs back when they get lost.

 

A sunken ship weighs exactly the same as it did when floating. It just displaces a heck of a lot less, hence loss of buoyancy.

JM

 

the thing with that is, is that then, you cant just get it with some sort of robotic device. Good thing youve got a boat rob.

 

So, this is approximately what we are talking about seeing @ our battles.

 

maybe a corresponding drydock can list the recovery vessel and ship out of the water for those of use with bad backs.

 

In my opinion, the biggest issue that needs to be solved before this idea can really move forward is determining how to grab hold of the wreck and bring it in to shore. Once this is solved, everything else will fall into place naturally. I think it would be ideal if the method was able to retrieve any boat currently in operation, without adding any special equipment like hard points or high-tension float lines, but that isn't necessary.

 

Thats the reason for a standardized float to go along with Justin's fork idea.

 

I agree with Boomer, if we develop this thing & you want to be compliant... then you need to update your float, otherwise you go swimming.

It's harsh, but it's the right way around. We will already have a difficult enough engineering job without trying to cater to every conceivable ship.

 

Thanks Justin, i just think its the only way to get every ship, the standardization, but otherwise, you would need something that has to adapt to different ships, which would be a problem.

 

And its a nice discrete cutoff... If you don't want to get wet, you accept the standard.

 

Floats don't always work. I'd prefer to see something that doesn't require a float, but it won't kill me if you want something different.

 

No one is building this thing, this is just a brain storming session... How would you make it?

 

very true Tuggy, very true