Hydraulic Motor Options

Yes. The design of the hydraulic motors will (most likely) have 2 seals - 1 for keeping hydraulic fluid in, and 1 for keeping water from getting into the motor.

Just my 2¢

Thanks Kilo.

and silt under the sealing surface

How much use will he get out of this dredging unit?

And out of curiosity,... how big a hydraulic motor is he looking at?

And may we ask, how large is this boat slip? 500' x 100'? How deep is the draft of his boat?

The slip is about 20ft X 30ft but the silt builds up another 40 ft out in the river. And, under current state regulations, the silt can't be discharged back into the river. We use a dewatering bag and also discharge in another area lined by silt fencing.

Not sure what the boat draft is.....I guess 16-18 inches. Unfortunately, the river level changes considerably. If we don't get rain for a couple of weeks, the river level may drop 2 or 3 feet.

I'm guessing he will be using the dredge at least twice a year and each use would be for about 16 -18 hours. And, if I can't get my local government to clean the canal behind my house, I may put at least that much time on it.

I'm not sure what size hydraulic motor he is considering. I believe the hydraulic power unit he uses puts out 10 gpm. But he currently uses it to power the hydraulic pump, about 6 gpm, used to discharge the silt and water. He is using a 300 gpm, gasoline powered, trash/water pump to kick up the silt which the hydraulic pump picks up and discharges. It works pretty well but it takes a lot longer if clay is encountered. And, it doesn't do much at all on sunken branches and logs.

Staffa make a hydraulic motor which is sealed against water ingress.

I’ll warn you now, they are not cheap.

This looks pretty cool......

http://www.diy-dredge.com/

So... use a weed whacker and convert the leaf blower to a silt thrower? That actually sort of makes sense.

What do you do about trees, carcasses, etc.?

"What do you do about trees, carcasses, etc.?"

Wait till they become silt...?

That looks like an agricultural manure slurry pump

Hey buddy, watch where you're aiming that thing!

Metaphorically speaking, it kinda reminds one of the political rants in the break room,... doesn't it?

Who slings the most in the widest swath is the winner?

Rust comes to mind as the biggest issue. Not all off the shelf hydraulic motors are designed to be submerged. Shaft composition to keep it from rusting. A rusted shaft will destroy and seal.

The current system uses a gasoline trash pump which suctions water from the river and discharges the water beneath the hydraulic suction pump. The trash pump discharge, 300gpm, breaks up compacted silt, leaves, etc. The hydraulic pump then picks up the "stuff" and discharges on land via a 4 inch hose. This system works effectively except when clay, branches, logs, etc. are encountered which happens often. The auger will work better than a water jet to break up the more compacted and harder stuff encountered. It is basically what is used on a larger scale on the Mississippi River and other larger rivers. The auger, which we will build, will probably be about 3 to 4 feet wide.

That sir, is a large auger. I hope you have good success with it!

James,

Sorry, I didn't explain the auger well. The auger will probably be about 6 inches in diameter and about 3-4 feet long. The 3-4 ft length of the auger will be laid down horizontally, not vertically. So, the auger will be clearing a 3-4 ft wide, and 6 inch deep swath.

As the auger spins it moves the spoils toward the center (the auger will be split into 2 sections, left and right) where the suction pump picks up the spoils and then pumps them out through the 4 inch discharge hose.

I hope this explanation is, at least, "clear as mud".

Don,

most of these designs put the drive unit at the front. as this is a somewhat limited use application, put the motor up in the dry and pull the belt upwards. the motor will stay "DRY" and you don't need to worry about the dual seal assembly. as for motors, WHITE, PARKER, CHAR-LYN are all good reliable units. also, any Farm Store should have hydraulic motors for silage and conveyor use.