Compressed air dredge?

[Gilldiver]

That's great info - I really appreciate the help! I intended to use something like an Atrium Grate on the working end, maybe alter it to remove every other span or widen the gaps a bit if necessary. Also intend to use a gas engine contractor's compressor that will deliver 90 psi sustained, I think that should give me the work needed to dredge the light silt and shell fragment debris from the one wreck that I have in mind.

A screen head like that will pass sand but not much bigger. The good designs that I have used were all fully opened at the suction end to move small stones. After a while you will learn to control the head by its distance from the sand, just back it off when you want to slow down and look, move it forward when you want to speed up.

Form the list of items you are looking for, are you going to work on the Onondaga or the Grecian? The Onondaga hass a bigger sand and small stones then the Grecian so you need more power. If you are going to work the Metis, we need to have a talk about set up time, hose control, depth, gas plan, deco, a a deep working dive.

Well, we need to talk about line control on any of these wrecks, the Onondaga has a current window but is only 30-50 feet deep, the Grecian is at 90' usually has good vis, but time is key, the Metis is 140, dark, and has current. All have particular problems.

 

[H'Islander]

Gill,
I would be thrilled to talk some about the whole process - this is going to become a winter project. I'm as small-time as it gets. I have but 50 or so dives to my name and just got EANx ticketed. I am not planning deco dives, so deep water stuff is not in my stars at my level of experience. I'm thinking in a few years, if I stay at it, I'll look into tech diving. For now I'm still l'm fascinated by the idea of finding trinkets and other useless items. I noted your sig, would love to get more insight on resources for learning about those very wrecks that you mentioned. Yes, I'm thinking the 'daga...it's a great afternoon dive for fish, bugs, and bobbles.

 

[crlavoie]

I don't know a lot about the area you're working in but I do know some folks that have used the air lift design to clean out the pilot hose of a tug with excellent results. Done properly and using the current to your advantage, it's possible to clean out a substantial area over time. I have also heard of folks using scooters but I find this one far fetched, expensive and a huge pain.

Lastly, be aware of the local regulations and just as important, the local ethics. Again, I'm not familiar with these wrecks but established communities can be sensitive to folks altering the character of a site.

 

[M_Bipartitus]

Air Lift Device

I've tried this guy in a quarry, and it works pretty well. Definitely use a dedicated tank or you won't have much bottom time as it sucks air faster than you may think.

Also, these days you should be able to find more PVC fittings so you don't need as many brass parts.

 

[klauricella]

Has anyone tried one of these DF Series - Material Conveying Pumps it maybe more efficient. I have used these but not underwater.

 

[H'Islander]

I don't know a lot about the area you're working in but I do know some folks that have used the air lift design to clean out the pilot hose of a tug with excellent results. Done properly and using the current to your advantage, it's possible to clean out a substantial area over time. I have also heard of folks using scooters but I find this one far fetched, expensive and a huge pain.

Lastly, be aware of the local regulations and just as important, the local ethics. Again, I'm not familiar with these wrecks but established communities can be sensitive to folks altering the character of a site.

Thanks for the note about local considerations. As I understand it, the wreck that I have in mind has been scoured over for decades, but to your point, that doesn't mean it's been OK to do it either. I'll look into any wreck before engaging any methods to excavate.

 

[MSilvia]

With a 100 cubic foot tank dedicated to the lift, you should be able to do small scale work like you're talking about without surface supplied air.

 

[Gilldiver]

The wreck he is looking at is in NY waters and the NY position is that all "cultural artifacts" over 50 years old is State property.

That being said, there is Zero, Nada, None, No enforcement anywhere in the Long Island sound, Fishers Island Sound areas.

The wreck was heavily salvaged at the time of sinking, is in a high current area, is exposed to every storm coming from the East or South, and resembles a junk yard.

The alternative to an air dredge is a water dredge. It works on the same principles as an air dredge but you shoot water up the shaft creating the suction. Use a PVC clean out and put it so that the clean out points downward and put a garden hose coupling on it so that a pump on the surface can be used.