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By Dave McCracken

There can be a lot of gold deposited under and around the boulders located within a pay-streak!

Dave Mack

 

It takes an incredible force of water to move boulders in a river. Once they are moving in a flood storm, they can deposit in low-velocity areas, just like gold does. But, since boulders do not have a higher specific gravity, mass for mass, than most of the other streambed materials, they can be washed downstream just about anywhere in the river during a major storm. So you should not only use the presence of boulders to guide you in sampling. You would be much better advised to focus your attention on the boulders that have been deposited along the common path of gold’s travel.

In shallow streambed material, you can sometimes detect where important bedrock changes are located by noting where the boulders have deposited within the waterway. For a boulder, or a group of boulders, to be found in a specific location along the river’s path, there may be a sudden bedrock drop-off, a large crevice, or some other kind of lower-velocity condition in that area which caused the boulder(s) to be deposited there. Everything in the waterway happens for a reason, even if you cannot always see what it is!

If the boulder(s) is located somewhere along the common gold path, that would be a prime spot to do some sampling. In this situation, I suggest that you do not limit your sampling to the area just behind (downstream) of the boulder, though. Go around to the upstream side of it, as well. Look for any bedrock change which may have caused the boulder to stop there. If gold has moved through that area, that same bedrock change could also have caused gold to concentrate there. Finding the bedrock change that stopped the boulder, and following the bedrock change across the waterway, is a great way to locate the common gold path.

You do not always find boulders with every rich pay-streak deposit. But, it is not uncommon to find many boulders keeping company with a good pay-streak. When you do find them, most of them will probably have to be moved out of your way as you work forward through the deposit.

MOVING BOULDERS BY HAND

There can be a lot of gold deposited under and around the boulders located within a pay-streak. To get most of the gold out from under a boulder and into your suction nozzle, usually the boulder has to be moved at least a little bit.

One of the most useful tools that can help a dredger move boulders is a 5-foot (or longer) steel pry bar. If a boulder is too large to be moved to the rear of the dredge hole by hand, it can sometimes be rotated around to one side so that you can dredge out from under part of it. Then, it can be rotated around the other way to access the remaining gold and material beneath. A long pry bar can be a big help to you in moving boulders around in this way.

The key concern while working around boulders is safety! Loose boulders in and around a dredge hole are the gold dredger’s greatest danger, especially when working alone. Boulders resting up in the streambed material are usually more dangerous than those resting on the bedrock. But, those on the bedrock can cause trouble, too, if they are loose and able to roll – particularly, if the bedrock has any slant to it.

As they are uncovered in a dredge hole, loose boulders should be moved and safely secured as a top priority. They should be placed at the rear of the hole, if possible. But, wherever they are placed, they should be positioned so they no longer pose any threat of rolling into the hole and on top of someone working there. You can place smaller rocks and cobbles under the boulders as necessary, to make certain they will not roll or slide.

If you start to uncover a boulder that is resting up in the streambed material, do not forget about it. Until it has been moved and secured safely, a loose boulder should be foremost in your mind. If it is not yet ready to be moved, and you still need to dredge around it to free it up some more, it can be useful to place an arm or a shoulder against the boulder. This way, you can feel if it starts to loosen up in the material. Do not place your arm, head, or shoulder near the underside of the boulder, however. Because, sometimes a boulder will loosen up and crash down very quickly, without much warning. Physical contact with the boulder is helpful when you cannot keep your eyes on it at every moment. The face mask limits your visual perception underwater – especially when you need to watch what is going up the suction nozzle.

The main concern here is to take all necessary precautions to keep yourself from becoming pinned or crushed beneath a boulder in your dredge hole. If a boulder pins any part of your body to the bottom, it may be difficult or impossible for you to get the necessary leverage to move the boulder enough to get out from under it. And, if you are working by yourself …? I know of two dredgers who ended their careers in just this way.

Also beware of fractured bedrock walls that tower over you. They can fall apart and drop in your dredge hole as you remove the streambed material that holds them in place. I got pinned once by a slab of bedrock that broke free of a wall as I dredged away the material that was holding it there. Luckily for me, it landed on my steel-tipped boot, and that I was dredging with another guy on that day!

The second greatest danger to a dredger usually comes from a cobble falling off the side of the dredge hole and hitting the dredger in some way — like on top of the head. This can finish off a dredger just as surely as a boulder. Or, it may cause some serious pain/injury. Fingers and other body parts can get smashed if you are not careful!

Most trouble with cobbles and boulders can be prevented simply by taking your hole apart with safety in mind. The proper method of taking a dredge hole apart has already been fully covered in my Gold Dredger’s Handbook, so I will not repeat it again here. But, as a point of emphasis, the fastest way to take apart a streambed also happens to be the safest way.

Production dredging goes very smoothly and quickly when you have some area of exposed (dredged) bedrock between the non-dredged material in front of you and the cobbles, boulders and tailings behind you. When you start uncovering a boulder in the material, you should immediately begin planning where you are going to move it, once it is ready.

If you run across an occasional boulder that you cannot move by hand, sometimes you can dredge the material (and gold) out from around and under it without having to move it out of the dredge hole. You accomplish this by moving other, smaller rocks out of the hole to make room for the boulder. In this way, if there are not too many boulders, you can keep moving forward on the pay-streak without the few boulders slowing you down very much.

But, if there are a lot of large boulders down along the bedrock, you will likely discover that at least some of them will need to be completely removed from your excavation if you expect to uncover very much bedrock with your suction nozzle. Some boulders will need to be removed to make room for other boulders as you move forward on the pay-streak. If you cannot remove the boulders from your dredge hole by hand, then you will need some mechanical assistance.

DIFFERENT TYPES OF WINCHES

COME-ALONG: A “come-along” is a portable, hand-operated winching device that can be of considerable help to a small-sized digging program. It can be used to move those boulders that are not huge, but which are too large to be moved by hand. Come-alongs range in size. I recommend a larger version of the better quality, rather than the really cheap, imported models. Come-alongs have a great accessibility factor, because you can carry one just about anywhere. Their operation is somewhat slow. But, they will give you that extra edge when you need to move just a few boulders, and you do not own or want to set up a power winch.

GRIP-PULLER: Several companies make a hand-winching device that rides along on a steel cable. There is a handle that you crank back and forth, similar to a come-along. Each time the handle is cranked in each direction, the device moves an inch or two along the cable. These units also come in different sizes. In my opinion, grip-pullers are a substantial step up from a come-along, both in pulling-power and dependability. I have used these units underwater, but find that the water resistance adds substantial work to the cranking action. Still, when you are working alone, having this device in the hole with you allows you to see what the boulder is doing while you are winching it

Where you can buy winching supplies

USING YOUR TRUCK AS A WINCH: If your vehicle can be driven to a nearby position, you can stretch a cable from the vehicle to the boulder. The proper direction of pull can be rigged up by running the cable through snatch blocks (heavy-duty pulleys) which can be anchored to trees, boulders or whatever is available. Then you can use the pulling-power of your truck to help move the boulders out of the way. Four-wheel drive vehicles work better for this, especially when they are carrying a load to increase tire traction. Suggestion: It is better to connect the cable to something on the vehicle’s frame, rather than just the bumper!

When conditions are right for it, using a vehicle to pull smaller boulders can be much faster than using a come-along. One person operates the vehicle, while a diver is in the water, slinging the boulders. Safety becomes a greater concern when more than one person is involved in the pulling and the slinging of rocks. Communication and coordination between the “puller” and the “slinger” are very important to prevent serious accidents. Suggestion: If you turn the truck around and pull in reverse, you can better-see signals from your partner, and sometimes you get better traction, especially on a 4-wheel drive vehicle. Another suggestion: It is better to keep your vehicle a respectable distance from any drop-offs (like into the waterway), just in case the boulder gets momentum in the wrong direction. I know of guy who got pulled over the side of an embankment by a boulder gone wild!

Larger-sized trucks, tractors, bulldozers, and other heavy equipment can sometimes be used to move bigger rocks with even better results.

AUXILIARY TRUCK WINCHES: Auxiliary automotive winches are also able to move small to mid-sized boulders for a dredging operation with excellent results. Some of those little winching units have a wondrous amount of power. A typical 8,000 or 10,000-pound electric winch will move a surprisingly-large boulder!

If you are going to be using an electric winch, you may want to consider installing dual batteries in your vehicle. It also helps to keep the engine running while you are winching, so the batteries can quickly regain their charge between pulls.

When using a truck-mounted auxiliary winch to pull boulders, it is a good idea to block all four wheels. This precaution helps to keep the vehicle from moving, rather than the rock you are trying to pull. The front tires should be blocked especially well. If there is an embankment to worry about, it is also a good idea to run a safety chain or cable from the vehicle to some additional anchor behind, like a tree or another truck. This will protect against losing your vehicle over the embankment if the boulder happens to roll the wrong way. Sometimes this added measure is necessary just to keep the vehicle from sliding during the pull.

Probably the best kind of auxiliary vehicle winch for dredging purposes is one that can be attached mechanically to the “power take-off unit” on your vehicle’s transfer case, if it has one. With this kind of winch, you can use the full power of your truck’s engine to pull rocks. Not only will this provide you with more pulling power, but you will not have to worry about your batteries running down.

There is also a lot of good to be said for the portable electric and hydraulic winches on today’s market. I know of many smaller-scale and commercial dredgers who use them. They are quite powerful! Portable electric winches can be framed up to (1) attach to a vehicle, (2) be taken out to the dredging site, or (3) even be floated on a platform, where there is deeper water. All that is needed is an automotive battery and a means of keeping it charged up. The portable hydraulic winches can be similarly effective. The winch controls can be extended out on a longer cable and even modified to work underwater, which can be very helpful!

LOG SKIDDERS: Most gold-dredging country is also logging country. So there are quite a few log skidders around that can be leased or hired to pull boulders for you. Log skidders are usually equipped with powerful winches. They can really do a job in pulling the larger boulders! Also, you can drive them into some pretty difficult areas. Hopefully, you can work out a deal that will be ideally suited to your operation; a deal perhaps, where you pay by the hour and have the skidder arrive at a certain time each day, or whenever you are in need of it’s services.

PORTABLE POWER WINCHES: Gasoline-powered, mechanical and hydraulic winches are available in all sizes. Generally, the larger they are, the more winching-power that they produce. But, the added size and weight also makes them more difficult to pack into some of the less accessible areas.

If you find a widespread, rich pay-streak with plenty of large boulders that need to be moved, you should set up on your dredging site the most powerful winch that you are able to haul in there. The more pulling-power you have available, the smoother and faster winching will go.

I never recommend that a dredger buy a portable power winch just because he or she will be dredging. It is probably better to wait until you know exactly what your needs are. I have worked many pay-streaks where no winching was needed at all. And, in many of the pay-streaks that did require winching, a number of the boulders were so large that the small, portable store-bought type of winch would not have been adequate for the job.

You can find some pretty heavy-duty used winches for sale at about the same cost as a lighter-weight, new portable unit. I advise waiting to see what you will need before putting your money into a winch.

Having said that, here is something to consider: Mechanical winches seldom have a control mechanism which can allow the operator to stand away from the machine where all the wrestling is going on (and in the line of fire if a cable breaks). While I have used some wonderful mechanical winches, there was never a time that we were pulling a big rock that I was not worried about something going wrong with all those tons of energy happening right next to me. There is a lot to be said about electric or hydraulic units that will allow you to step away from the danger with the controls in your hand.

WINCHING COBBLES IN DEEP MATERIAL OR SHALLOW WATER

As I have stressed in other articles about dredging, the main limiting factor to progress is in how quickly oversized material (rocks that are too large to be sucked up the nozzle) can be moved out of the ongoing excavation. In deeper streambed material, there can be so many cobbles that there is no longer any room directly behind the dredge hole to throw them. You can run into a similar problem in shallow water, where the cobbles must be lifted out of the water (where they become a lot heavier) to get them behind the dredge hole. In these types of situations, it is common to fill cargo nets with your cobbles and winch them out of your dredge hole in bulk. The following video sequence was taken in an operation where we were removing big lots of cobbles from a deep excavation in just this way:

SETTING UP A HOLE FOR WINCHING

Before you start winching boulders, it is a good idea to first make sure that you have located the lower (downstream) end of the pay-streak. You do not want to winch boulders onto any part of the pay-streak that you will be working at a later time. While the winter storms could possibly move some of the cobbles and dredge tailings which were placed on a pay-streak in error, it takes much more than a winter storm to move boulders from where you winch them. Believe me; it is much better to plan ahead, so you only need to move boulders one time!

BUILDING A RAMP

It takes a tremendous amount of winching-power to pull a boulder up and over another boulder from a dredge hole. The direction of pull is all wrong, and the second boulder will act like a barrier. The winching is much easier, smoother, and far less dangerous, if a ramp is built so the boulders will have an inclined runway to be pulled along. Cobbles can be used to make an effective boulder ramp. Therefore, an important part of setting up your dredge hole for winching is to construct a ramp/runway that can be used to easily remove the boulders, without them encountering difficult obstructions.

It can be really tough to pull a boulder out of a hole without a ramp.

Cobbles can be used to make an effective ramp for winching boulders out of a dredge hole.

One approach to setting up your hole is to dredge around a number of boulders as much as possible to free them up for winching. This way, more boulders can be pulled out of the hole once winching is begun. Then you can come back later to clean up the bedrock with your dredge.

To perform winching effectively, you will need plenty of air line attached to your hookah system. This is because it is necessary for the diver to sling each boulder and follow it to its final destination where he will disconnect it. Then, the sling and cable must be pulled back and attached to the next boulder. Since this process requires a lot of movement, depending upon the distance involved, you may need to attach an extension onto your air line to accomplish this smoothly.

FEASIBILITY OF MOVING BOULDERS

A dredging operation that requires a lot of boulders to be winched is going to move slower than if little or no winching is required. A winching operation almost always requires the involvement of at least one other person, sometimes even two or more. Those “extra hands” will usually expect to get something for their active participation in your dredging project. So you will find that when you need to use a winch, you will be moving slower through the pay-streak, and it will usually cost more to run the operation. Therefore, a pay-streak that has lots of boulders usually needs to pay pretty well to make the additional effort worthwhile.

The following video segment will give you a look at an organized winching program where multiple persons were involved:

Sometimes, you may discover an excellent pay-streak, but find that it lies beneath many boulders that have to be moved. Even though there may be plenty of gold under the boulders, after figuring the time and expense involved in winching, you may conclude that the gold recovery, though excellent, is still not sufficient to make the project economically feasible. Big boulders are not easy to move. Moving them takes time and money; more, sometimes, than the gold is worth. So, to avoid getting bogged down in an unworthy project, keep track of your daily expenses and your daily gold recovery. Then you will have some basis for calculating whether it is financially worthwhile to continue dredging in that specific location.

If your winching helpers are not full-timers on your dredging operation, and if the location is not too remote, you might arrange to have them arrive at a certain time each day to help pull boulders. That way, you can spend the morning setting up the hole to winch as many boulders as possible. Then, when your help arrives, the boulders can all be winched out of the hole at one time. After winching is completed for the day, you can let your winch helpers go, while you go back down and clean up the hole with your dredge. This way, you are not paying helpers to stand around with nothing to do while you are dredging. It can make a difference.

SETTING UP A WINCH FOR OPERATION

When you are using a portable power winch to move boulders in a dredging operation, the winch must be set up on a solid and stable foundation. It takes a tremendous amount of force to move a boulder. Sometimes, the boulder will move quickly. Or, sometimes, the sling will slip off the boulder, causing the cable to suddenly go slack. Maybe the boulder will loosen up and roll the wrong way, causing a sudden, heavy stress on the cable. When these things happen, and they do happen, you do not want your winch bouncing around or sliding off the platform. That could be extremely dangerous! The winch must be stable!

The winch also should be anchored to a solid object behind it which will hold its position much more securely than the boulders that are to be moved. A fair-sized tree, or a large boulder, directly behind the winch platform can work well for this purpose.

Also, the cable or chain being used to anchor the winch must be considerably stronger than the winch’s capability to pull. The last thing you need is your anchor chain or cable breaking while you are pulling a large boulder! This could cause the winch, and the winch operator, to be yanked off the platform, resulting in a serious accident. Undamaged, heavy-duty truck tow chains with the adjustable end-hooks are excellent for anchoring a winch. Make sure you get chains that are strong enough.

Your winch should also be anchored to a point which is lower than it is. If the winch is anchored from a low point, when boulders are being pulled, the winch will be held down more solidly onto the platform. If the winch is anchored to a higher point, during pulling the winch can be lifted off its platform. This can also be dangerous.

Sometimes, you will not be able to find a good location for your winch along the streambank. You prefer a location where the winch can be set up to directly face the boulders to be pulled, and which provides a level, solid foundation with a properly-located, fixed object from which to anchor the winch. But if that is not available, you can almost always find an acceptable foundation somewhere between two large objects along the bank. The platform may require a little concrete work to get it right. The winch can be anchored to one of the objects, while the other object can be used to attach a snatch block (heavy-duty pulley). The cable can then be run from the winch, through the snatch block, to the boulders that need to be moved. One advantage to this rigging setup is that if the cable does happen to break under a great strain, it will be less likely to fly directly at the winch and its operators.

Positioning the winch between two anchors on the bank,
because there is no easier way to get a straight pull with the winch.

When you set up a winch, it is usually best to position it so the boulders will be pulled as much as possible in the desired direction. The boulders will also need to be pulled far enough away from the dredge hole that they will not have to be moved again at a later time. Often, you will not be able to set up the winch in a position where you can directly pull the boulders in the desired direction. For example, you may want to pull them downriver, rather than toward the stream bank. This situation is most commonly corrected by using directional-change snatch blocks. A snatch block (pulley) can be anchored at a point from the exact direction that you want to pull boulders. The cable then runs from the winch, through the snatch block, to the boulder. In this way, you can usually move the boulders in any direction that you desire from a stable winching position along the bank.

Setting up the proper direction of pull by anchoring a snatch block directly downstream in the river.

Directional-change blocks for winching should be very heavy-duty. They need to be stronger than the cable being used, or the capability of the winch to pull. The best pulley is one that can be quick-released from the cable. This way, you do not have to feed all the cable through the block to get rigged for winching. Good winching pulleys are generally available at industrial equipment supply stores and at marine equipment shops. Directional-change blocks can be attached to trees or boulders with the use of additional cable, chokers or heavy-duty chain. You will find that a few extra tow chains (long ones) and chokers will come in very handy when setting up a winching operation. Chains which have the end-hooks on them are best, so you can adjust their length to meet your needs.

To minimize damage to the environment, you can place pieces of wood between the cable or chain and the trunk of any tree that you use as an anchor. When you anchor a directional-change block to a tree or boulder, you are almost always better off anchoring to a low point. This will reduce the chances of rolling the boulder over or pulling down a tree.

When you use a cable to anchor a winch or directional-change block to a boulder, set it up so that the pull will not cause the cable to become pinched (between two boulders or between a boulder and the bedrock) or be pulled into the material underneath the boulder. Otherwise, after the winching, you may have trouble retrieving your cable without having to move the anchoring boulder as well.

At times, you may need to set up a directional-change block, to pull boulders in a desired direction, but cannot find a downstream boulder that is large enough to use as an anchor. In this case, you can run an additional cable out from a fixed object further downstream on the opposite side of the waterway, and attach your directional-change block to the cable. Then, by increasing or decreasing the length of the cable, you can position the block right where you want it.

Setting up a directional-change block by extending it out on a cable from the other side of the waterway.

It is not a good idea to winch boulders with rope, even the smaller boulders being pulled by your truck or a come-along. When you use rope for winching, the rope stretches even if it is doubled-back multiple times for extra strength. And, it stretches. And, it stretches. Then, it breaks. Such breaks can be dangerous when working around boulders. Also, it can quickly exhaust your supply of rope. Rope is just not strong enough for the job. Steel cable is best. You might get a deal on good, used steel cable from the scrap metal yards. Call around to find out who has it when you need it. Scrap yards usually sell it at scrap prices, by the pound, even if it is in good condition.

The cable you use on your winch should always be considerably stronger than your winch’s pulling capacity. The last thing anyone wants to see is a bunch of out-of-control steel cable flying wildly back in his direction. Faulty or worn cable should be replaced immediately and never used thereafter for winching.

Winching boulders involves an incredible amount of force. So does hauling logs by cable. Similar cables are used in logging operations to pull trees to the loading area. I have heard stories of logging cables snapping, flying back, and cutting a man in two. You are dealing with a similar amount of force when winching the larger boulders in a dredging operation.

WINCHING SIGNALS

During a winching operation, it will be necessary to have a diver in the water to set the sling on the boulders. The diver will also need to remove the sling from each boulder after it has been moved, and then return the sling and cable back to the dredge hole for use in moving the next boulder. This process will continue until all the boulders for that stage of the dredging operation have been moved.

Unless the diver is slinging boulders and operating the winch (a very slow way to go, unless the controls to the winch are in the water with the diver), another person must operate the winch, truck or other device that will be doing the pulling. Once you have more than one person involved in the operation, communication becomes a critical part of the process.

If the winch is a smaller one, or if a truck is being used to pull boulders, and the pulling position is in sight of the target boulders, the job might be accomplished with only one winch operator. On the other hand, in a normal two-man operation, if the winch operator is unable to maintain constant eye contact on the area where the winching is taking place, perhaps a third person will be needed to help with the communication. Each situation will be different. Since this need for immediate and accurate communication is a safety matter which requires on-site judgment, you will have to decide how many people are needed to winch safely.

Sometimes a truck can be turned around to pull backwards, and the driver can directly see and simultaneously carry out the diver’s signals. The controls on an electric winch will often allow a second person to be positioned well enough to see what is happening where the rocks are being moved.

While a boulder is being moved, the diver can watch its progress and signal the winch operator to stop pulling and/or give slack on the line so the boulder sling can be adjusted, if necessary, to successfully complete the movement as planned. The main point is that the diver must be able to communicate to the winch operator quickly and without error. The greater the pulling-power and/or speed of the winch, the more important it is that these signals be accurately received and acted upon quickly. Imagine that you are using a powerful winch to pull a large rock with a heavy steel cable and solid anchoring objects. If your boulder gets jammed against something else in the dredge hole so that it will not move, and you continue pulling with great force, something is eventually going to give. And, it might not be the boulder! This uncertainty is what you want to avoid.

If you are using a winch that does not automatically feed the cable evenly onto the drum, the operator will sometimes need to manually guide the cable. Otherwise, on hard pulls, if the cable starts crossing itself and is allowed to pinch itself on the drum, it may become damaged and thereafter be dangerous for further winching. For this reason, the winch operator may need to focus some attention on the winch, rather than on the diver. In this type of situation, it is wise to include an additional person to help relay communication. Someone needs to be watching for the diver’s signals at all times.

Gasoline-powered winches make noise. So does a gasoline-powered hookah-air system supplying air to the diver. The diver also usually has a regulator in his mouth. With all of this noise present, and the diver having his mouth full, verbal signals are usually not very dependable – especially, if there is a substantial distance between the diver and the winch operator. For these reasons, I have often found visual signals to be more trustworthy, particularly when there is a person positioned at the winch to relay the diver’s signals to the winch operator.

In shallow water, hand signals can usually work pretty well. You really only need three of them: “PULL” , “STOP” and “GIVE SLACK ON THE CABLE”. I highly suggest you take a look at the standard set of signals that my partners and I use in our own dredging operation. These can be found in a special video segment included with an article I wrote about teamwork. Otherwise, create your own signals so that they can be quickly and clearly understood, and one signal cannot be confused with another. There is also a section on winching and signals in my video, Advanced Gold Dredging & Sampling Techniques.” You might want to check it out to get some ideas.

At times, you may be faced with the need to winch boulders out of a dredge hole located in deeper water. In this case, the diver will be heavily weighted down to stay on the river-bottom. He may also be some distance from the streambank. In this setting, it may be nearly impossible for the diver to surface to give timely signals to the winch operator. The process of getting up to the surface can simply take too long! When this is your situation, and if the water is not moving too fast, you may consider using a buoy, tied to a rope that is anchored near the dredge hole, to relay your signals. I personally have found the best and safest signals to be: (1) buoy underwater means, “PULL” (2) buoy floating at the surface means, “STOP PULLING” and (3) buoy bobbing up and down in the water means, “GIVE SLACK”.

This method of buoy-signals is relatively safe. If the buoy is anchored a short distance from the boulder, in order to pull the buoy underwater and hold it there, the diver would have to be away from the boulder on the “PULL” signal. If the buoy is floating, the diver can be anywhere, which is why it is the best choice for the “STOP” signal. You need to make certain, however, that nothing is allowed to snag the buoy’s rope (like the pull cable or an air line) which could pull the buoy underwater and cause a false “PULL” signal!

One other safety note:All divers must always watch their own hookah air lines during winching, to make sure an air line (or the signal rope to the buoy) is not snagged up in the cable or rolled over by the boulder as it is moved.

BOULDER SLINGS

When slinging boulders, try to make sure the pull cable will not rub too heavily or get crushed against other boulders. It is always best to protect the pull cable and let the boulder sling take the pounding. The boulder sling is going to be pounded anyway. Because of this rough duty, boulder slings should be replaced or repaired periodically.

One type of boulder sling often used out in the field is a long, heavy-duty tow chain with end-hooks which allow the chain to be quickly and easily adjusted to any length. This system gives you a fast set up. Just wrap the chain around the boulder in the proper place, connect the end-hook to give you the right fit, and she’s ready to go.

Tow chain boulder sling with end hook.

However, some boulders are smoother and rounder, which makes it more difficult to get a good “bite” with a sling made out of chain. Every time you start to pull, the boulder might move just a little and then the chain slips off. You can waste a lot of time working on a single boulder in this way; it can get quite frustrating.

Logging cable-chokers are also useful for making a cable sling that will tighten up on the boulder as you pull. This may improve the situation, but still not work problem-free on smooth, round rocks.

For round and smooth boulders, I have found the best remedy to be an auxiliary “boulder harness.” This homemade boulder harness consists of heavy cable, chain, steel pipe and cable clamps. It is very easy to construct. The sections of steel pipe slide onto the cable to protect it and to keep the cross-chains properly positioned. The harness is set up like a lasso. It pulls tighter around the boulder as stress increases on the line. And, it generally works well in pulling even the most difficult boulders.

How to put together an excellent boulder harness for winching.

PULLING BOULDERS

Some boulders come easy and some do not. A lot of the problem is in breaking the boulder’s initial suction/compaction in the streambed. If your winch does not have the power to pull a boulder the way you have slung it, sometimes you can break the boulder free by using a rolling hitch A “rolling hitch” is rigged by slinging the boulder backwards, then running the chain or cable over top of the boulder. This places the winch’s pulling-power along the most-leveraged position on the boulder. This will sometimes free a stubborn boulder by rolling it.

How to sling a rolling hitch.

When pulling boulders up and out of a dredge hole, you should pull them some distance away from the hole. Otherwise, if there are more boulders to be moved, they may begin backing up along your ramp and block the passage of any more boulders. This could require you to move them all again, which is a time-waster that you can avoid with proper planning in the first place. For example, take a look at the image at the beginning of this article. That is a top view of a winching operation we did on one of our Group Mining Projects a short while ago. See how we were pulling the boulders back well out of our ongoing excavation?

If you are dealing with relatively deep streambed material and a lot of boulders, you may want to set up an adjustable, directional-change block behind the hole. This way, the boulders can be winched out of the hole in several different directions. This will prevent them from backing up so quickly.

Setting up an adjustable directional-change block to pull boulders in several different directions.

Once the dredge hole has been opened enough, some of the boulders can be winched or rolled to the backside of the hole, rather than taking them up the ramp. Winching will start to go faster when you get to this stage. Depending upon the situation, it may be necessary to winch some of the boulders up the ramp and out of the hole to prevent too much jamming. Be sure to keep access to the ramp free and clear. Otherwise, you may get closed in with too many boulders in the rear of your hole. The more boulders that are jammed up, the more difficult it can be to clear them out of the hole.

Sometimes, when you have winched your boulder to its destination, it will end up on top and pin your sling underneath. If you are using a tow chain as your sling, you can usually just unhook it and have the winch pull it out from underneath the boulder. But, if you are using a sling made of cable, you may not be able to pull it out from under the rock without damaging the harness. For this reason, it is a good idea to have a second sling on hand to help move the boulder off the other harness when this happens.

DIVER’S SAFETY

A diver will be safest by staying well away from the area where a boulder is being winched, and the path it will be taking as it is being pulled. The forces involved in winching are more than enough to cause a very serious accident. Since the diver is underwater, the winch operator sometimes cannot see what is happening where the bolder is located.

What can happen down there, though, is when the diver sees the boulder getting hung up on things as it is being pulled along, he wants to move in and help it along with his pry bar. The less power that your winch provides, the more the diver will naturally feel the need to help the boulder along in this way. Never forget that your safety margin is considerably reduced when you get near a boulder while it is being pulled! A safer course of action would be to stop the pulling and reset the harness, or reset the direction of pull, or improve the boulder ramp, or find a stronger winch for the job. Or, you can increase the pulling power of your existing winch by double blocking…

DOUBLE BLOCKING

“Double blocking” is accomplished by attaching a snatch block to the boulder sling, running the pull cable through that block, and then back to the last directional-change anchor. This type of rigging will nearly double the amount of pulling force that can be exerted against the boulder by the winch and pull cable.

Double blocking back to the last directional-change anchor
will nearly double the winch’s pulling power against the boulder.

If even more power is needed, another block can be set up on the line to run the pull cable back to the boulder sling. The pulling force of any winching device can be increased by continuing to double block in this way. There is a disadvantage to all this rigging, however. It takes much more cable to pull boulders any significant distance. Also, it is equally more difficult for the diver to pull the boulder sling and cable back to the dredge hole after each boulder has been moved. With all that cable going back and forth, it can get pretty complicated – especially if you are dealing with a limited amount of visibility. Quick-release snatch blocks are a must when double blocking. This way, you can detach the pulleys from the cable without having to feed it all the way through.

Actually, one double block is not that hard to manage as long as you have enough cable. It is when you double block a second time that it starts getting difficult to keep track of which cable is going to where? But, this alternative is available to you if you need the extra pulling power to move a particularly large boulder.

Directional-change blocks, by themselves, do not give you an increase in pulling power. For a power increase, the cable must be doubled back so that the boulder is moved only half the distance that the winch is pulling on the cable.

 

 
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This story first appeared in Gold & Treasure Hunter Magazine May/Jun, 1993 on Page 45. This issue is still available! Click here.

By Dave McCracken

Classification is necessary to increase the amount of smaller particles of gold that you will trap in your recovery system.

Dave Mack

 

It takes more water velocity to move larger-sized material than it does to move the smaller-sized material through a sluice box. Yet, to the degree that the water velocity over a sluice box is increased, there may be a loss of fine gold recovery. Or, to the degree the water velocity over a sluice box is slowed down, there is likely to be an increase in fine gold recovery–as long as there is still enough flow over the box to keep the riffles concentrating.

When larger rocks are pushed through a sluice box by water force, they also create greater turbulence behind the riffles as they pass over, which may cause an additional loss of fine gold.

To improve gold recovery, it is common practice to run material through a screen to classify out the larger rocks before running the material through the recovery-portion of a sluice box. In this way, less water velocity is needed through the box, which allows for a more orderly flow, and an increase in fine gold recovery. The action of screening materials is called “classification.” Materials which have been passed through a classification screen are called “classified materials.” The following video segment demonstrates this very important point:

The size and depth of riffles within a sluice box play an important part of this. A slower water flow might not keep a deeper riffle concentrating. A greater water flow can sometimes “boil-out” a lower-profile riffle. So as water flow is slowed down to catch finer-sized gold, it is generally necessary to use shorter riffles.

Half-inch mesh screen is commonly used for primary classification in small and medium-sized sluicing operations, because the screen is large enough to allow classification to take place quickly, yet no materials greater than half-inch in size will get into the sluice. Therefore a slower-velocity of water can be directed through the box, and fine gold recovery will be improved.

Classification for a sluicing operation can be done in any number of ways. One is to place a piece of strong half-inch mesh screen over a bucket, and shovel or pour through the screen into the bucket while sweeping the larger material off to the side. Once the bucket is filled with classified material, it can be poured into the sluice box at a uniform rate. It is better to not dump the whole bucket into the sluice all at once! This is because too much material is likely to overload the riffles and cause a loss of gold recovery.

In a situation where it is necessary to haul material a short distance to the sluice box, sometimes it is easiest to classify the material directly into a wheelbarrow and transfer only the classified material to the sluice.

Perhaps one of the best screening methods is to build a classification device that you can shovel into, and which will stand directly over the top of, and drop the classified materials into, the head of your sluice box.

The device should be built with the screen set at an angle. This way, larger material is helped to roll off of the screen as the pay-dirt is shoveled onto it. Smaller materials should fall through the screen and be directed into the head of your sluice box. This is actually a miniature model of the big classifiers used by large-scale heavy equipment bench-mining operations. A classification device such as this is rather easy and economical to build and will speed up a production-sluicing operation while screening is being done to improve gold recovery.

Any recovery system will only recover gold effectively down to a certain size-range. Most gold particles smaller in size than that will be lost with the tailings. Classification is one effective way of increasing the amount of gold that will be recovered out of the material that will be processed. As demonstrated in this following video segment, this is especially true of suction dredges; because dredges are able to increase the volume of production over other types of hand-mining activity.

Here is a substantial explanation of the system which we have developed to effectively recover more fine gold on our conventional suction dredges. It combines two classification screens to more-effectively separate material-feed into three size-fractions, each which is directed into a different recovery system. The smallest gold particles (which are most difficult to recover) are directed into low-profile riffles along the bottom of the sluice box which have long been proven to be very effective at trapping fine gold.

 

 
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By Dave McCracken

“The Gold Pan as a Production Tool”

Dave Mack

The main thing to remember about the use of a gold pan is that while it is very effective as a gold-catching device, it can only process a limited volume of streambed material. For this reason, the gold pan is normally not used as a production tool in commercial use, other than in the most remote locations where it would be very difficult to haul large pieces of equipment, and where there is only a small amount of streambed material present — which is paying well enough to make the panning worthwhile.

The gold pan is most commonly used to locate a richer paying area by sampling, so that larger production equipment can be brought into that location to work the ground to recover more gold.

There are stories in the old mining records about the ground being so rich during the 1849 gold rush that as much as 96 ounces of gold were recovered from a single pan. That is $100,000+ at today’s rate of exchange, and must have been some very rich ground indeed!

Stories like that are rare and pay-dirt like that is not run across very often. However, it is not too uncommon to hear of prospectors today who are able to consistently produce better than an ounce of gold per week with a gold pan in the high country, and have the gold to show for it. Some do better, but these prospectors have usually been at it for awhile and have located hot spots. I personally know of two guys who support themselves with a gold pan, and one of them lives pretty well. As mentioned earlier, the gold pan gives you unlimited accessibility, and these prospectors look around to find the pockets in the exposed bedrock along the edges of the creek-beds in their areas, picking up a few pieces here, a few there, and a little pocket of gold once in awhile. It adds up, and to them it is better than punching a time clock.

There is still plenty of rich ground to be found in gold country if you are willing to do the work involved in finding it.

Gold Panning Procedure

Panning gold is basically simple, once you realize that you are doing the same thing that the river does when it causes gold to concentrate and deposit during flood storms.

The process basically consists of placing the material that you want to process into your pan and shaking it in a left to right motion underwater to cause the gold, which is heavy, to work its way down toward the bottom of your pan. At the same time, the lighter materials, which are worthless, are worked up to the surface of the gold pan where they can be swept away. The process of shaking and sweeping is repeated until only the heaviest of materials are left-namely the gold and heaviest black sand.

Once you are out in the field, you will notice that no two people pan gold exactly alike. After you have been at it awhile, you will develop your own little twists and shakes to accomplish the proper result.

Here follows a basic gold panning procedure to start off with which works well and is easy to learn:

STEP 1: Once you have located some gravel that you want to sample, place it in your gold pan-filling it about 3/4 of the way to the top. After you have been at it awhile, you can fill your pan to the top without losing any gold. While placing material in your pan, pick out the larger-sized rocks, so that you can get more of the smaller material and gold into the pan.

STEP 2: Choose a spot to do your panning. It is best to pick a location where the water is at least six inches deep and preferably flowing just enough to sweep away any silty water that may be washed from your pan. This way, you can see what you are doing better. You do not want the water moving so swiftly that it will upset your panning actions. A mild current will do, if available.

It is always best to find a spot where there’s a rock or log or stream-bank or something that you can sit down upon while panning. You can pan effectively while squatting, kneeling or bending over, but it does get tiresome. If you are planning to process more than just one or two pans, sitting down will make the activity much more pleasant.

STEP 3: Carry the pan over to your determined spot and submerge it underwater.

STEP 4: Use your fingers to knead the contents of the pan to break it up fully and cause all of the material to become saturated with water. This is the time to work apart all the clay, dirt, roots, moss and such with your fingers to ensure that all the materials are fully broken up and in a liquid state of suspension whithin the pan.

The pan should be underwater while doing this. Mud and silt will float up and out. Do not concern yourself about losing any gold when this happens. Remember: gold is heavy and will sink deeper in your pan while these lighter materials are floating out and away.

STEP 5: After the entire contents of the pan have been thoroughly broken up, take the pan in your hands (with cheater riffles on the far side of the pan) and shake it, using a vigorous left and right motion just under the surface of the water. This action will help to break up the contents of the pan even more and will also start to work the heavier materials downwards in the pan while the lighter materials will start to surface.

Be careful not to get so vigorous in your left and right shaking that you slosh material out of the pan during this step. Depending upon the consistency of the material that you are working, it may be necessary to alternate doing steps four and five over again a few times to get all of the pan’s contents into a liquid state of suspension. It is this same liquid state of suspension that allows the heavier materials to sink in the pan while the lighter materials emerge to the surface.

STEP 6: As the shaking action causes rocks to rise up to the surface, sweep them out of the pan using your fingers or the side of your hand. Just sweep off the top layer of rocks which have worked their way up to the pan’s surface.

Don’t worry about losing gold while doing this, because the same action which has brought the lighter rocks to the surface will have worked the gold deeper down toward the bottom of the pan.

When picking the larger rocks out of the pan, make sure that they are clean of clay and other particles before you toss them out. Clay sometimes contains pieces of gold and also has a tendency to grab onto the gold in your pan.

Note: Working the raw material through a classification screen into the gold pan during Step 1 or Step 3 will eliminate the need to sweep out larger rocks in Step 6. This will also allow you to pan a larger sample of the finer-sized material(which contains all the gold you will find in a pan sample).

STEP 7: Continue to do steps five and six, shaking the pan and sweeping out the rocks and pebbles(if present), until most of the medium-sized material is out of your pan.

STEP 8: Tilt the forward edge of your pan downward slightly to bring the forward-bottom edge of the pan to a lower position. With the pan tilted forward, shake it back and forth using the same left and right motion. Be careful not to tilt the pan forward so much that any material is spilled over the forward-edge while shaking.

This tilted shaking action causes the gold to start working its way down to the pan’s forward-bottom edge, and continues to work the lighter materials to the surface where they will be more easily swept off.

STEP 9: Carefully, by using a forward and backward movement, or a slight circular motion just below the surface of the water, allow the water to sweep the top layer of worthless, lighter materials out of the pan. Only allow the water to sweep out a little at a time, while watching closely for the heavier materials to be uncovered as the lighter materials are swept out. It takes some judgment in this step to determine just how much material to sweep off before having to shake again so that no gold is lost. It will just take a little practice in panning gold before you will begin to see the difference between the lighter materials and the heavier materials in your pan. You will develop a feel for knowing how much material can be safely swept out before re-shaking is necessary. When you are first starting, it is best to re-shake as often as you feel that it is needed to prevent losing any gold. When in doubt, shake! There are a few factors which can be pointed out to help you with this. Heavier materials are usually

darker in color than the lighter materials. You will notice while shaking the pan that it is the lighter-colored materials that are vibrating on the surface. You will also notice that as the lighter materials are swept out of the pan, the darker-colored materials are uncovered.

Materials tend to get darker (and heavier) as you work your way down toward the bottom of the pan, where the darkest and heaviest materials will be found, they being the purple and black sands, which are usually minerals of the iron family. The exception to this is gold, which is heaviest of all. Gold usually is of a bright and shiny metallic color and shows out well in contrast to the other heavier materials at the bottom of the gold pan.

One other factor to keep in mind is that the lighter materials sweep out of your pan more easily than do the heavier materials. As the heavier materials are uncovered, they are increasingly more resistant to being swept out of the pan, and will give you an indication of when it is time to re-shake.

As you work your way down through your pan, sometimes gold particles will show themselves as you get down to the heavier materials. When you see gold, you know it is time to re-shake your pan.

There is another popular method of sweeping the lighter materials out of the top of your pan which you might prefer to use. It is done by dipping your pan under the water and lifting it up, while allowing the water to run off the forward edge of the pan, taking the top layer of material along with it.

STEP 10: Once the top layer of lighter material is washed out of your pan, re-shake to bring more lighter materials to the top. By “lighter materials,” I mean in comparison to the other materials. If you continue to shake the lighter materials to the top and sweep them off, eventually you will be left with the heaviest material of all, which is the gold. It does not take much shaking to bring a new layer of lighter material to the surface. Maybe 5 or 6 seconds of shaking will do it, maybe less. It all depends upon the consistency of the material and how much gold is present.

Continue to pluck out the larger-sized rocks and pebbles as they show themselves during the process.

STEP 11: Every few cycles of sweeping and re-shaking, tilt your pan back to the level position and re-shake. This keeps any gold from being allowed to work its way up the forward-edge of your pan.

STEP 12:Continue the above steps of sweeping and re-shaking until you are down to the heaviest materials in your pan. These usually consist of old pieces of lead and other metal, coins, BB’s, old bullets, buckshot, nails, garnets, small purple and black iron rocks, and the heavy black sand concentrates. Black sands consist mainly or in part of the following: magnetite (magnetic black sands), hematite (non-magnetic black sands), titanium, zircon, rhodolite, monazite, tungsten materials, and sometimes pyrites (fool’s gold), plus any other items which might be present in that location which have a high specific gravity-like gold and platinum.

Once down to the heaviest black sands in your pan, you can get a quick look at the concentrates to see how much gold is present by allowing about a half-cup of water into the pan, tilting the pan forward as before, and shaking from left to right to place the concentrates in the forward-bottom section of your pan. Then, level the pan off and swirl the water around in slow circles. This action will gradually uncover the concentrates, and you can get a look at any gold that is present. The amount of gold in your pan will give you an idea how rich the raw material is that you are sampling.

A magnet can be used to help remove the magnetic black sands from the gold pan. Take care when doing this. While gold is not magnetic, sometimes particles of gold will become trapped in the magnetic net of iron particles which clump together and attach to the magnet. I prefer to drop the magnetic sands into a second plastic gold pan, swish them around, and then pick them up once again with the magnet. Depending upon how much gold this leaves behind, I might do this several times before finally discarding the magnetic sands.

Many beginners like to stop panning at this point and pick out all the pieces of gold (colors) with tweezers. This is one way of recovering the gold from your pan, but it is a pretty slow method.

Most prospectors who have been at it for awhile will pan down through the black sands as far as they feel that they can go without losing any gold. Then they check the pan for any colors by swirling it, and pick out any of the larger-sized flakes and nuggets to place them in a gold sample bottle. Then the remaining concentrates are poured into a small coffee can or bucket and allowed to accumulate there until the end of the day, or week, or whenever enough concentrates have been collected to make it worthwhile further process them. This is really the better method if you are interested in recovering more gold, because it allows you to get on with the job of panning and sampling without getting deeply involved with a pair of tweezers. Otherwise, you can end up spending 25% of your time panning and up to 75% of your time picking out small colors from the pan!

Panning Down All The Way To Gold

It is possible to pan all the way down to the gold-with no black sands, lead or other foreign materials remaining in the pan. This is often done among prospectors when cleaning up a set of concentrates which have been taken from the recovery system of a larger piece of equipment-like a sluice box or suction dredge.

Panning all the way down to gold is really not very difficult once you get the hang of it. It is just a matter of a little practice and being a bit more careful. When doing so, most prospectors prefer to use the smooth surface of the gold pan, rather than using the cheater riffles. The key is to run the concentrates through several sizes of classification screens and pan each size-fraction separately. Use of a smaller-sized pan (“finishing pan”) makes this process go easier.

When panning a set of concentrates all the way down to the gold-or nearly so, it is good to have a medium-sized funnel and a large-mouthed gold sample bottle on hand. This way, once you have finished panning, it is just a matter of pouring the gold from your pan into the sample bottle through the funnel. Pill bottles and baby food jars can make good gold sample bottles for field use, because they are usually made of thick glass and have wide mouth. Plastic bottles are even safer.

Another method is with the use of a gold snifter bottle. This is a small hand-sized flexible bottle with a small sucking tube attached to it. Squeezing the snifter bottle creates a vacuum inside. Submerged gold from the pan can consequently be sucked up through the tube.

If you do not have a snifter bottle or funnel, try wetting your finger with saliva and fingering the gold into a container, which should be filled with water. The saliva will cause the gold and concentrates to stick to your finger until it touches the water in the container. This works, but the funnel method is faster.

Practice Gold Panning

If you are not in a known gold-producing location, but want to do some practice panning to acquire some skills before going out into the field, you can practice in your own backyard. Use a washtub to pan into and some diggings from your garden (or wherever) to simulate streambed materials. I recommend that you throw in some rocks and gravel along with the dirt so that it takes on an actual streambed consistency. Take some pieces of lead, buckshot or small lead fishing weights, cut them up into various sizes ranging from pellet-size down to pinhead-size, and pound some of them flat with a hammer. This puts the pieces of lead in the same form as the majority of gold found in a streambed-flake form. They will act in much the same way as will flakes and grains of gold. Leave a few of the pieces of lead shot so that gold nuggets can also be simulated.

When panning into the tub, place some of these pieces of lead into your pan, starting off with the larger-sized pieces first. Keep track of how many pieces of lead you use each time so that you can see how well you are doing when you get down to the bottom of the pan. Practice panning in this manner can be very revealing to a beginner, especially when he or she continues to put smaller pieces of lead into the pan as progress is made.

If you can pan small pieces of lead successfully, then you will not have much difficulty panning gold (higher specific gravity) out of a riverbed. And, who knows? You may end up with gold in your pan-right out of your own backyard! It wouldn’t be the first time.

Bags of real panning material are also available from different sources within the industry. These bags usually contain some real gold along with the type of materials you would commonly encounter when panning out in the field. Practice panning with the “real thing” is the best way to get started!

 

 

 
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This story first appeared in Gold & Treasure Hunter Magazine May/Jun, 1992 on Page 36.
This issue is still available! Click here.

By Dave McCracken

Experienced gold miner lays out fundamentals of running a successful surface prospecting program.

 

A “sluice box” is a trough-like gold recovering device which has a series of obstructions or baffles, called “riffles”, along its bottom edge. While a steady stream of water is directed to pass through, streambed material is shoveled into the upper-end of the box. The flow of water washes the streambed materials through the sluice and over the riffles, which trap the gold out of the material.

The reason a sluice box works is that gold is extremely heavy and will work its way quickly down to the bottom of the materials being washed through the box. The gold then drops behind the riffles and remains there, because there is not enough water force behind the riffles to sweep the gold out into the main force of water again.

A sluicing operation, when set up properly, can process the gold out of streambed material about as fast as it can be shoveled into the box. This can be many times more material than a panning operation can handle, yet with similar efficiency in gold recovery. How much material can be shoveled into a sluice box greatly depends upon the consistency and hardness of the material within the streambed itself, and how easily it can be broken away.

A sluice requires a steady flow of water through the box to operate at its best efficiency. Most often, the box is placed in a stream or creek where water is moving rather swiftly, with the sluice being placed in such a way that a stream of water is directed through the box.

In locations where water is available, but is not moving fast enough to be channeled through the box for sluicing purposes, the water can be pumped or siphoned to the box with excellent results (covered later). How much water is available, and whether or not it will need to be transported to your sluice box, is something that needs to be considered during the planning stages of a sluicing operation.

Because so much more material can be processed with a sluice, than with a gold pan, streambed materials which contain far less gold values can be mined while recovering just as much or more gold. Therefore, if the streambed material had to pay a certain amount in gold values in to be worked with a gold pan to your satisfaction, gravel containing only a fraction of as many values can be worked with the same result using a sluice box. This is an important factor to grasp; because it means the modern sluice box opens up a tremendous amount of ground that can be profitably mined by an individual.

Motorized sluicing (also often called “high-banking”) is an activity similar to sluicing, except that sluicing is almost always accomplished with the water-flow from the creek or river keeping gravel moving through and over the riffles. As demonstrated in the following video sequence, a motorized sluice (also called a “hydraulic concentrator”) is usually set up with a water pump that supplies water for the sluice box:

Motorized sluices are usually equipped with a recovery system that is set up with adjustable-length legs. This allows the box to be adjusted from side to side and front to back on uneven ground. This allows the water flow to be created for optimum gold recovery. Most motorized sluices available on today’s market also include a screening device over the top of the feed-section of the sluice box. Screening the larger-sized rocks out of material to be sluiced is one of the primary methods for improving fine (small) gold recovery. Any time you can screen larger rocks out, you can slow the water down through the sluice, which will allow even smaller particles of gold to become trapped inside the riffles.

In normal sluicing, the operators must find a location alongside of a creek or river where the water is flowing just right, at the proper depth, to set up the sluice so the proper amount of water can be directed through. Once the sluice is set up, gold-bearing material must be carried to the sluice, screened separately, and carefully fed through the sluice box.

With a motorized sluice, all you need is a supply of water within several hundred feet of where you want to dig. The screen and sluice assembly can be set up directly at the work site so that pay-dirt can be shoveled directly onto the screening section. The pump/engine assembly will pump water from the water source, through a pressure hose, to the sluice.

Another advantage to the motorized sluice is that in some areas today, it is not legal to wash silt directly from the bank into an active waterway. With a motorized sluice set up some distance from the stream or river, you have an opportunity to utilize natural contours up on the land to slow the water down enough to allow the sediments to settle before (if ever) the water re-enters the creek or river.

SAMPLING

Just like in any other type of gold mining activity, the key to doing well is in digging sample holes to first find a high-grade gold deposit.

Placer Geology

In many places, there is more gold up on the banks than you will find in the river. This can sometimes be true on the Klamath River in northern California. Actually, it is not only that there is more gold on the banks than in the river. The gold on the banks can sometimes just be easier to get at for a small operation.

What happened along the Klamath River, and in many other areas, is not difficult to understand. The old-timers started mining down in the creek or river, and moved uphill, allowing gravity to carry the water and tailings back down towards the creek or river. As the old-timers worked further up into the banks, often the gravel became deeper and more difficult to remove by conventional hand methods. In time, the old-timers developed hydraulic mining. This is where they directed large volumes of water from nearby (or sometimes distant) creeks under great pressure through monitors (huge pressure nozzles). The high-pressure water was used to wash large volumes of gravel through large sluice boxes placed on the banks of the creeks and rivers. As the sluicing operations cut further up into the banks, the sluice boxes were moved forward, which left tailings deposited on the banks.

It is estimated that as much as 50-percent of the gold washed right through the sluice boxes in hydraulic operations because of the large volume and velocity of water which such operations used. Hydraulic operations did not lose gold in the same amounts all of the time. Much of the gravel that these operations processed contained little or no gold. The concentrations of gold were found along bedrock or at the bottom of lower strata flood layers. So, valueless top-gravels were processed at volume speed, and they would try to slow down when getting into pay-dirt materials. Sometimes, however, they would cut into pay-dirt materials at volume speed–before having a chance to slow down. This is where large volumes of gold would wash directly into the tailing piles.

Since the time of large-scale hydraulic mining, there have been several occasions of extreme high water. The 1964 flood in the western United States is one example. Floods of such magnitude, all throughout gold country, re-deposited old hydraulic tailings piles into newly-formed streambeds up on the banks and within the active waterways. Places where gold was lost from hydraulic operations formed into new pay-streaks–often only inches or a few feet from the surface. This is true all up and down the banks of the Klamath River–and probably many other rivers as well–which has created a wonderful and exciting opportunity for modern small-scale gold miners.

Contrary to popular belief, many pay-streaks today are not found down along the bedrock. In fact, many of the pay-streaks surface miners are finding along the Klamath River are situated in a flood layer (1964 flood) within two feet of the surface. This flood layer is often resting directly on top of undisturbed hydraulic tailings.

We are also finding similar pay-streak deposits inside the active river with the use of suction dredges.

Finding pay-streaks with a surface digging project is usually done by setting up the sluice in several different locations, and giving each sample a large enough test hole to obtain an idea of how much gold the gravel is carrying. Sample holes should be taken to bedrock if possible. However, if the gravel goes deep, you have to avoid getting in too far “over your head.” At the point where you start digging deeper than 3 or 4 feet with a pick and shovel, any pay-streak is going to have to be exceptionally rich to make the effort worthwhile. Richer deposits are more scarce; and therefore more difficult to find. So it is important to stay within effective digging/sampling range, and not get yourself into a full-scale production operation before you have found a high-grade gold deposit.

Sometimes you can learn valuable information before you start sampling. If other miners in the immediate area are finding gold deposits along a specific flood layer, you should be sampling for gold along the same flood layer while digging around in the nearby vicinity. Gathering information such as this is one of the many benefits of belonging to an active mining club or association. Active mining organizations will include others who are actively pursuing the same type of mining activity that you are engaged in.

While sampling with a pick and shovel, it is very seldom that you will actually see gold in the gravel as it is being uncovered. Usually, you do

not see the gold until it is time to clean-upthe sluice box after the sample is complete.

If you finish a sample hole and end up with a good showing of gold, the next step is to find out exactly where the gold came from. In other words, did it come off the bedrock, or did it come from a particular layer in the streambed? You must know where the gold is coming from to evaluate the value of the pay-streak. For example, digging two feet into a paying flood layer requires much less time and effort than digging four feet and having to clean rough bedrock. If you do not know for certain where the gold is coming from, and you assume it is coming from the bedrock underneath four feet of hard-packed streambed, you might decide it is not rich enough to work and walk away from a very rich deposit located at the two-foot flood layer

At the same time, if you are able to reach bedrock, you always want to get a good sample there by thoroughly cleaning the surface and any irregularities there. Sometimes that is where the richest deposits are found.

Pinpointing the source of gold is reasonably easy once the sample hole has been opened up. It is likely that the gold will be concentrated either along the bedrock, along the bottom of a flood layer, or at both locations. Sometimes, there is more than one flood layer that carries gold. You can run small production samples of each stratum separately to see which is paying. Or, sometimes you can simply take pan-samples in the different contact zones between the layers

Some pick & shovel miners are using metal detectors in their prospecting activities. Some of the new gold metal detectors will sound out on pieces of gold as small as the head of a pin! But in gravel deposits, metal detectors can also be used quite well to locate the concentrations of magnetic black sand. Black sand tends to concentrate in pay-streaks, just like gold. Therefore, locations sounding out heavy concentrations of magnetic sand on metal detectors are excellent places to follow up with pick & shovel sampling.

One question commonly asked about sluicing procedure is the proper slope-setting for a sluice box. A sluice box generally requires about an inch drop per each linear foot of sluice. This is just a guideline. Basically, you need enough water velocity to keep the material active in the sluice behind the riffles, but not so much that you are washing most of the material out from behind the riffles. I like to get enough water flow to keep the larger material moving through and out of the box. If I see lots of rocks building up in the sluice, I know I do not have enough water velocity. An occasional rock needing to be helped along is alright in a sluice (although maybe not a dredge sluice!). In surface sluicing (non-dredging), I would rather toss out an occasional rock and have the peace of mind that I am also achieving maximum possible fine gold recovery.

A common practice in sluicing is to also to set up a second sluice behind the primary sluice. The plastic Le’Trap sluice works exceptionally well for this because it recovers fine gold so well, and for its ease in cleanup. The idea is to have a safety check on your primary recovery system to make sure it is working properly.

And if all else fails, you can always do some pan-testing in your tailings to see if your sluice might be losing any gold.

One mistake that beginners often make is in thinking that the recovery system is at fault because they are not recovering very much gold. Most often, however, it is not the recovery system. It is the lack of a good-paying pay-streak! The answer to this is to hustle around with more sampling. Ask around to see what and where it is working well for others in the area. Use their operations as a model.

Flood layer pay-streaks are often easier than bedrock pay-streaks to clean up with pick & shovel surface mining operations. There are several reasons for this. One is that a flood layer pay-streak is closer to the surface. This means less gravel to shovel to reach the gold. Another reason is that it takes more effort to clean the gold off of a bedrock surface when you are not using a dredge. You can only do so much with a shovel. After that, you must resort to a whisk broom and/or a motorized vacuum cleaner. This is why portable dry land dredges are also becoming so popular. They give you the ability to clean bedrock surfaces and cracks with minimum effort. If the gold is coming off bedrock, you must invest the extra effort to clean it off well. Otherwise, you stand the chance of leaving an important portion of the gold behind as you mine forward on the pay-streak.

Many pick & shovel miners today also are equipped with an optional suction attachment. To use it, the pressure hose from the water pump is attached to a suction nozzle that directs the water and material through a suction hose into the sluice. So after an initial hole is dug up out of the water, the hole can be filled with water and material can be sucked into the sluice box. The recovery system can be positioned so that the water discharge can run back into the hole– keeping the hole from running out of water.

So you can dig a hole up on the land, and then begin a suction mining operation outside of the active waterway. This is great!

In California, dredging permits are only required when dredges are operated inside of the active waterway. Therefore, my personal understanding is that suction miners up on the land are not required to have a dredging permit as long as they are not dredging inside the active waterway.

Some surface miners also sample for the gold-path up on the bank by pan sampling the moss. Sometimes, how well the moss is producing gold at the surface can also be an indication of how well the gravel is paying underneath.

When moss, roots, clay and other types of materials are producing good quantities of gold, it is always a good idea to break up the material as much as you can before running it through a sluice box. This is usually done by pulling it apart over the top of a classification screen, or breaking it up inside a bucket of water before running it through the sluice. This slows down production, so the additional work must be rewarded by the recovery of more gold.

Once you find a pay-streak in pick & shovel mining, you want to give some thought to how you are going to develop the deposit with a minimum of wasted effort. For example, you will have to pile the cobbles (rocks too large to pass through your recovery system) and tailings somewhere. Preferably, cobbles and tailings would not be placed upon some other section of the pay-streak. Otherwise they might need to be moved twice, or you might be forced to leave behind high-grade areas that have been further buried. So it is worth some extra sampling to get an idea of the pay-streak’s boundaries. Then you can deposit the tailings material in a location where you will not need to move them again.

Placing tailings is, and always has been, one of the most important aspects of a mining operation–of any size. Yet, it is one of the most neglected aspects of mining by a substantial portion of small-scale miners. In fact, we have a standing principle, true as it may be, along the Klamath River: “Dowsing works: just look where a successful pick & shovel miner or dredger has been throwing his or her cobbles. It is almost guaranteed there will be excellent gold underneath!”

This usually comes back to a simple case of gold fever. The miner starts getting a good showing of gold, gets excited, and never slows down to define the boundaries of the deposit. This almost guarantees an important portion of the deposit will end up underneath cobbles.

Pay-streaks up out of the water are often different from those found in the river or creek. What I mean by this is that they do not always follow the same gold path. When you find a pay-streak in the river, you can usually line it up with the next river bend and make a pretty fair guess where the next several pay-streaks are likely to be. This is because river pay-streaks usually form from gold that has washed down the river along its own gold path during major flood storms.

Pay-streaks outside of the river often were formed from gold out of tailings from old hydraulic mining operations. So you can find a small pay-streak up on the bank, follow it until it plays out, and then not find any sign of it further upstream. This is because the source of the gold deposit was not from a point further up river. Then you can find another pay-streak on another path altogether. In other words, pay-streaks up on the bank might not follow a specific single gold path, as they usually do in the river.

Pick & shovel mining is a lot of fun – when you are finding gold. A healthy portion of our miners along the Klamath River mine out of the water. The reason for this is that it gives them an opportunity to find pay-streaks without having to commit to an underwater dredging operation.

We manage Group Mining Projects just about every other weekend during the spring, summer and fall months in Happy Camp You can find this year’s schedule HERE. You have my personal invitation to come out and get some firsthand experience. We always send participants home with a sample of gold that they help recover–that is, those who go back home. Many join up with us. Watch out–the biggest challenge in gold mining is not in finding the gold; it is getting over the “fever” after you have found it!

 

 

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