Log in

View Full Version : Dredging in a Bouler Patch

03-23-2013, 10:30 AM
I'll be working a boulder choked canyon this year and would like to hear any advice :

The size of dredge you recommend as I'm planning to get a 5" proline from Steve ..

Would really like to hear about techniques to dredge an area like this efficiently ..

Advise on equipment to move a large amount of rocks manually ...

03-24-2013, 11:43 AM
I guess we need more info. Define "boulder", basketball or Volkswagen. How steep is the creek and how much water flowing?

The first thing is safety. A smashed finger really hurts your production, a smashed pelvis can be end of game. Many dredgers like to mine under large rocks, then tip them into the cleaned area. When doing this ALWAYS keep one hand on the rock and the other working your nozzle. This allows you to push off the rock and avoid getting caught.

When I was young working a large river, we built a raft out of barrels with come-along underneath. We would chain up boulders, then winch until the boulder just floated and work it downstream.

I have watched a very experienced dredger work an area that has a large amount of boulders in the 3'-6' diameter. All the voids between those boulders were filled with basketball size ones. He used an electric winch, lots of cable (both electric control cable and winch cable). In the early days he learned how to bolt loops of chain into a sling, and then hoist away. Then came the magic of nylon load straps. He would use straps with an eye sewn into each end. He would take a single wrap passing the winch end through the eye. Then as he loaded the strap with the winch he would smack the eye with a breaker bar to tighten it. Then he would get out of the way and winch. Out of the way means out of the way of a broken cable whipping back along with out of the way of a falling boulder. He made it look easy, but I was watching years of experience.

03-24-2013, 12:49 PM
Volkswagen , 4-wheeler , basketball , all intermixed .... Some of the larger boulders sitting just above the bedrock on a thin layer of gravel ... The canyon river width is between 10 and 20 yrds wide , waist deep to head high ... Mid summer the current slows to no white-water and manageable .. I will have to work a few feeder streams until then as I plan to be in no later than mid-May to take advantage of the smaller streams that flow early and dry up mid summer ...

Am I correct in thinking no motorized winches allowed when dredging ???

james a.
03-25-2013, 03:13 PM
Man I would just say good luck with that one.Would`nt like to here of you getting caught underwater like that from my advise.

Steve Herschbach
03-25-2013, 06:41 PM
No motorized winches unless Brian's safety provision got included. Even Washington state allows motorized winches so never could figure the big problem here.

03-25-2013, 07:17 PM
Anyone know the worst possible fine if one were to get caught power winching ??? The fine may be worth the production value not to mention the safety concerns ....

03-26-2013, 06:25 AM
If you get caught underwater - the penalty is obvious. It's a death sentence.

There's no place in the free world that I know of that regulates the use of a winch to move boulders. Moving bouldes represents the worst case scenario for dredging. From a practical, common sense point of view, there would have to be a very high probability that the effort will be rewarded. Why even attempt to dredge a boulder choked canyon? You have to restack the boulders. So, what does that operation look like? Well, you are stacking marbles from one stack to another. As you remove boulders, they get replaced by boulders at the margin. Water pushes boulders down stream into the hole you make. You can't operate a grapple because you need a solid base from which to work. How deep is the canyon? How wide? How much water? Just seems like a foolish question to me.

- Geowizard

Steve Herschbach
03-26-2013, 08:27 AM
The power of negative thinking again?

03-26-2013, 09:11 AM
Negative thinking that gives positive results! :)

- Geowizard

03-26-2013, 10:36 AM
The best book with the greatest meaning was read to me by my mother starting from the day I can remember ; I'm not sure if you could find a copy today ....

.................................... " THE LITTLE TRAIN THAT COULD " ................................

It was a great read with an very Important message , I would recommend it to anyone who has never read it ...

03-26-2013, 11:41 AM
Well, blowing bubbles at the bottom of a creek with a boulder on your back is a little more serious than is given credit.

What advice are you looking for? i.e. Hey, dude!, Cool! Good Idea...!! Go for it!! :)

Everyone that agrees that dredging in a boulder choked canyon is a good idea, please chime in!

- Geowizard

03-26-2013, 12:04 PM
Well in my experience, if I was working a location like this, Id bring out a bunch of car jacks, chains, hand winches and pry bars.

1st,Id dredge out a hole in front of a big boulder and then use the car jacks and a chain attached to a hand winch to secure the boulder as I dredged in front and around it.

2nd, when I finished cleaning the area in front and around the boulder, I would take the car jacks out and slowly release the hand winch or winches attached to the chain, causing the boulder to slowly roll into the hole I already cleaned out and created for the boulder.

3rd,I'd dredge the spot where the boulder used to sit.

Id get what i could like this and leave the rest as its not worth an arm or a life to get it.

This is all assuming the boulder will "roll" at some point and has enough space to do so.

The size of the dredge depends on your hike in,the creeks water volume and the amount of room you have for a dredge in the creek. Unless you can drive right up to the spot and drop a dredge in,I'd always suggest you test the area with a 2 1/2 backpack dredge before you bring anything big in.

By car jacks I mean this style but in a 2 ton or so. We like these because they are small and powerful.You can get them out of junked cars for cheap.


Hope this helps :)

03-26-2013, 12:22 PM
Was thinking rolling to the side , but "up against the flow of the river " makes a lot of sense in dealing with the forces of the river not to "unexpectedly" roll it back on to you ....

Thanks for that "Tip"

03-26-2013, 12:26 PM
There are air powered jacks that auto shops use , I wonder if that would be an option underwater ....... They are powerful and fast to operate ....

03-26-2013, 12:27 PM
Was thinking rolling to the side , but "up" makes a lot of sense in dealing with the forces of the river ....

Thanks for that "Tip"

Not sure what you mean by rolling it "up." Its more just holding it in its original location, until you can clean downstream of it creating a hole.Then releasing it slowly into the hole you just made. I wouldn't be scared to work a location like this at all. Its quite safe with a few pieces of gear and ive never had a problem.Even with boulders near the size of a Volkswagen beetle.

03-26-2013, 01:09 PM
assuming you can see what your doing!! Do this in 5ft. of water that has no visibility.

03-26-2013, 01:23 PM
Great point Carter ,, I would really like to hear any suggestions on what to use to group multiple rocks together to remove from the hole and out of the way , like a tub from wheel barrow , car hood , snowmachine sled , etc....

Steve Herschbach
03-26-2013, 01:40 PM
I will offer one bit of practical advice. What kills profitability is how much time is spent handling material for the return. Handling boulders is not only dangerous, it takes a lot of time. Many mining operations have failed due to the time and expense of handling boulders, even if done safely.

There is actually decent gold in the Little Susitna River in Hatcher Pass. It has never been profitably mined due to the creek being choked with six foot boulders packed like ping pong balls.

03-26-2013, 01:49 PM
dynamite! quickest way to get rid of the big boys! Big rocks, dredge beside them them roll them onto that spot. Every scenerio is diff. I didnt think bottle jacks worked laying on their sides. Take advantage of physics, you can get alot of leverage on a 6ft. tall rock going over the top and pulling from half way down the back side to roll it over.

03-26-2013, 01:56 PM
That is definitely one of the reasons the old timers spent little time in there yet worked the river miles above and below ...Profitability will be figured out with in weeks of attempting ... I have prepared myself for being faced with that fact by having alternative places to dredge in the event it is found unprofitable ... In the same breath it is so inviting to think it hasn't been disturbed by past generations and there is a very high probability there are some extremely good catches in and around some of the features with in the canyon ...

03-26-2013, 02:50 PM
Dont know cost but look up boulderbuster. Very cool

03-26-2013, 03:16 PM

You're finally using words I like to hear. "planning" "preparation" I'm seeing a little discipline and expectation or apprehension of failure on the first attempt and having a "contingency plan". Cool!

Oh.. I was going to tell you about the last time I got up on a slippery boulder and tried to lever over another boulder. I slipped and busted my a**... You should see the scar! :)

- Geowizard

03-26-2013, 08:51 PM
I gotta agree with Steve.It takes a lot of time to set up chains and winches and often its not what worth what you get.Myself, I'm still fairly young and looking to open a can of whoop @ss on whatever I can get my hands on. Unlike Great Grandpa Steve, up top a few posts :P If you test and the gold looks good, i say go for it.Its not very dangerous if you know what your doing with jacks and winches. If you don't,I wouldn't mess with it due to the time costs and potential dangers.

03-26-2013, 09:16 PM
You gotta figure it out for yourself.

A rock 2' in diameter is roughly 1/4 ton. 3' in diameter about 3/4 ton. Moving one of each 6-8' can easily take half a day. How much gold do you need under them to pay off? I need at least 2 dwt every time. That is one long hard day for a measly $120/day before taxes.

I don't mind hard work. Lord knows I seem to go out of my way to find it, but this winching boulders every day for how much?

But each has to decide for themselves.

03-27-2013, 02:00 AM
Well then I guess dredging my Water falls is gonna be a cat's ass! but I have in mind to build a gin pole Tetter totter Fulcrum thingy. On one end 3 or 4 barrels welded to a boom in a framework, attached close to the short end of the fulcrum point, Plumb the barrels together with valves. Fill barrels as needed with water slowly and lift the cabled boulders out and swing them downstream building a semi bolder dam, open valves empty barrels set rock down. Fill in the boulder dam with dredge tailing, and all of this will be gravity feed water to the barrels, At the top of the set of 14 falls a small pup comes in, up the very steep pup 65 degrees or better, a hundred feet will be my venturi power catch cone, feeding a 4 inch lay flat that goes into 2 1/2 inch fire hose that will reduce down to a 1 1/2 inch to the jet. What ever four barrels of water will lift, I figure safely 5 to 7 hundred lbs, get moved back and the nice thing is the falls climb about 60 feet and almost all on bedrock, I have enquired and studied the gold is above and below the falls and no one has worked them except the pools, I want to clean it to bedrock and fish every crack in it. I have seen cracks that I figure go down 10-20 feet into the bedrock. Nice thing is some old falls sit to one side of the running ones, they have been picked over, and i plan to run hose over and down to the crash box, tails will fill the old falls and channel and give my tailings water a place to settle out a little before going back into the stream, I think silt water will return through the ground clean until the old channel fills with fines. I figure one summer of bust butt and see how she goes, no values no second year. I will be timber bracing some of the side boulders just to keep them in check, dead lodge pole everywhere up here, and in some areas i will probably put in sets of timber Poles across the stream side to side, and build a cordroy road out of lodge pole over my work area. It is so steep that I'm sure on a rainy day some nice rocks will come charging down the steep sides. If nothing else the pole cover over me will slow them down some Ha Ha. Lots and lots of work for me and my son but it may pay real well. I actually have a bonus situation here, the road is just above the falls and everything can be zip lined down or up. gotta build a Capstan winch out of a chainsaw and mount it to the truck, one of those slide into the trailer hitch and pin jobs. Think it out...nothing is impossible... but is it feasible? I will see. "V"

P.S. I will check the sides of my work area for potential Meteorites and knocking them down if they are loose probably on a two to three day basis.

03-27-2013, 03:22 AM
I got my hands on some Large thick plastic pipe, 10 inch, 50 feet of it. And sitting in the dark the other night having a smoke it dawned on me that I could make a "cobble Shooter"...it would consist of a section up steam with a big flare Cone (big aluminum road sign) in the fastest flow out of an upper pool, the big pipe would have a "U" Made of metal, then pipe coming off the "U" leaving down stream to you desired location for exiting the water/cobbles. The "U" or "P" trap would have a hole cut in it with a conveyor belt bolted inside like reverse nozzle flap, The "P" trap would be anchored close to the dredging area and when you need to move the cobbles say up to 8 inches they could be pushed through the flap and the fast water inside the pipe carries off your cobbles down below you in the stream, i have also thought that if a small cage like tube were welded over the hole and flap the dredger could place the cobbles in the cage/tube (which stands "lets say" at a 45 deg angle) one side would have Legs to hold it at that angle, and the weight of accumulated stones would push open the flap like a loaded clip, they would drop into the pipe when the weight over powers the water holding the flap closed. Instead of baskets of rocks muscled out of the way, feed the cage and send them on... just like gravel and stones up your dredge nozzle, just on a larger scale for cobbles. And of course there will be lots of them you will have to move by hand because of size, but we're looking for speed Right? I don't know why a "P" trap came to mind I guess as a way to get the cage over to the dredger. I suppose a straight piece of metal would not impede the flow or have a long one jam up in the corners on the way out. will have to experiment with this Idea. "V"

03-27-2013, 09:40 AM
Your gonna get Wes all excited to read what you got going on, you most certainly have had alot of time to think about stuff!! I want to see some pictures of all you contraptions, What gold fever does to people. GOOOOOOD Luck buddy & have lots of fun


03-27-2013, 11:48 AM
I am definitely intrigued and fascinated with the thought of gravity water power and supply ; I would even be "Cool" and fit in with this new generation of born "Greenies" and some really hot young woman would ask to marry me because I'm doing my part in saving the world from noise pollution, emissions, buying foreign equipment, buying foreign fuel ....
My new young wife will want to mine with me because of no diesel smell and the tranquility of no motors running, just the sound of the birds singing and the animals playing in the meadow .....

Anyone with me on this one ????

03-27-2013, 12:00 PM
Wes, ur gonna smell terrible though!!! You have lived in Hawaii too long and will be afraid of the ice cold water to bath in!!!

03-27-2013, 12:16 PM
That's why I'm so happy to have a friend with a bath-tub and HOT water so close by !!!! He probably even has a Jacuzzi and a bottle of Mr. Bubble !!!!!

Its winter here and there's no way I'll get in the water except to maybe go out and stretch a net to have fresh fish once in a while ... Tourists meanwhile, think it's summer here !!! I'm scared of the cold, maybe that's the reason I have been here 20+years ... S C A R Y - I may only last 2 days back in Ak. , If you see a fire sale of dredging equipment on the side of the Parks near Healy the 3rd week of May that would be me tossing in the towel and heading for warmer waters .....

03-27-2013, 01:17 PM
The falls stretch out about 150 feet in length as they climb the valley to another flat, and are in a slot 8 to 14 ft wide. There are runs of kinda flat area's that only extend to 10 or 20 feet before they plunge. So everything is at a steep angle. I am WORRIED that by removing bigger rocks at the bottom as I go may possibly set off a semi underwater land slip. I will Cautiously work the bottom, if I get any liquefaction type movement it may have to be choked, and I do have a plan for choking the upper material. That would be dredging a trench/slot across the stream and placing spaced large timbers in them and wedging them tight to the rock walls, probably 2 or 3 timbers and some vertical slab cut lagging spaced for water to pass. If the choke thing doesn't work and the values are there I will try to find a safe start point and work the material off the top and make the bottom end work safer, I am sure there will always be a high risk in this endeavor. I think there are pockets in those cracks that contain up to 3 oz (a story told to me by my great uncle about the area) now this is all I can think about, prepping materials and waiting for spring runoff to mellow out the falls. I also want to work this claim over the winter just to take advantage of the low water and easy snow machine access. So If all goes well I will video my efforts and change my Name to GRAVITY PUNK!.... I plan to let winter ice freeze in the cracks I excavate by feeding them water. come spring they will be wedged open by ice expansion or at least kept from closing as they thaw, Maybe giving me access deeper or getting them to split/slab off, giving me better access to reach deeper with a spoon and nozzle. Well that's all for now, see you in church! I'll be in the back row...

03-27-2013, 06:45 PM
This may be of service to you.You could always use a hand winch.