Hello cDiver community,


We would like to know if any of you out there can help us resolve our problem. We have a 8' pipe who is 3/4 full of water. There is like a foot maybe more of mussel all around inside of it. Our guys can clean a good part of it but there should be a mechanical way out there that can help us do that quicker and safer.


Your expertise would be greatly appreciated.


Thanks all

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Ohh I forget to mention that, we dont want our guys to go in. Something like high pressure jetting head, or a pig.....but of this size I dont know if its doable.
You could replace the pipe! Job Security you know! Dales answer is more cost effective.
Replacing wont be an option in this case, and we know about job security, we are very carefull with what we do. Thanks for the reply.

Your second idea Dale might worth investigating, I will do search on that. Time is factor for this one, but we might think about it for the next shutdown of the plant.
Just kidding guys, Dales idea is best. But like he said, be careful, those shells are like razors when they fly out of the pipe, got scars to remember that one. Good luck with your project. God Speed

This fixed our problem. We use this pump aswell to cut steel or concrete at 3000bars. 700 bars with a long jetgun will turn those mussels into soup.
A med psi water blaster (commercial pressure washer), high cfm.

3500psi @ 8-12 gpm, fed by electric submersible pump of 125% higher potential flow rate at same hose size, ambient water utilization, zero pollution accountability.

Add a venturi style dredge (gold dredge) powered by 2.5" fire pump ambient water utilization, zero pollution accountability, to vacuum up the displaced muscles and dispose of them in an ecologically friendly manner, especially if we are talking about an invasive species.

Ensure on paper that retention, mitigation or disposal of displaced biologic materials, invasive species or hazmat is to the client's account, and also make sure that they hold you, the contractor harmless and fully released from any arising indemnity.
Yup, you can use a venturi dredge to push sand and other irregular, heavy debris to a collection/dump site probably 150' away. given the flow of your pump and the ratio of inlet line size vs discharge line size. I prefer 1/2 ratio with a smaller pump, a 4" discharge with a 2" or 2.5" inlet. Blast and suck.

I have used three configurations.

Diver in h*** with blaster and venturi intake, each separately , diver blasts clean 6' square, then vacuums up with gold dredge. I found this is actually fastest. When diver is blasting he holds the dredge on bottom below the area being cleared with his foot, a good amount of the debris settles down and is sucked in, requiring minimal time spent "sweeping up"

We tried other methods that had a hp jet discharge proximal to the inlet, didn't work as well, except for clearing silt from a settling basin for example, sand and shell pissed it and the diver off in that mode.

Also used the configuration as an experimantal pile jetting/suction setting technique, kind of like a leave in place jet-string, with the jet component and suction/venturi dredge removed from inside the leave in place pile/airlift, the pile then gets the grout. Worked good.

Designing stuff is fun.
Review the following patent and drawings, patent is expired.

Pipe pig with running gear
Patent number: 4677865
Filing date: Apr 24, 1985
Issue date: Jul 7, 1987

See URL:



Here is how I did it on a 12 foot diameter X 900 feet long RCP outfall.
I ran a cable through the pipe to the end then through a snatch block and back.
then attache to both ends of a pig I fabricated. with swivel connections.
hooked the cable up to a double drum winch and ran the pig back and forth to clean the pipe.
100% clean in 24 hour shift.Pig rotated as it traveled.
Did the same with 2000 lin. ft 24 inch pipe. Divers set the rigging and winch did all the work.
This is what I am looking for, you made the pig in what material?
made out of steel, wiper blades used extension bars to extend wipers against pipe sidewall.
wiper bars could be set for depth of cut.
measure depth of mussels on side wall and estimate volume of material for removal; example three inch's of growth = 235 cu. yards debres.
Okay I see, how far would you go with the depth of the wiper. Did the middle of the pig was open, like could you see trough, so water can flow and sweep the mussel as we go
Would you have a picture of it by any chance.



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