The Hardships of Dredging
By Reggie Gould
I had often seen pictures and film of a bunch of guys dredging and it looked like a lot of fun. It never dawned on me how they got all that equipment down to the river. The real thing that does not appear in all those pictures and films, is the terrain that they have to traverse in order to get to the river. I always imagined that you would just drive your car or truck right to the river's edge and unload your dredging equipment. For some strange reason I did not reason that if you can drive to the rivers edge, then half the country will be doing the same thing. One key thing to understand is that gold does not grow like potatoes in the ground. Once everyone has hammered the area, the large gold will be gone forever. The exception to this is the flood gold that will wash down after a good flood from where the gold originates from, it is then redeposited. down stream. The other exception is that the former dredgers did not go to the bedrock or try to open the cracks in the bedrock where the gold has been trapped. If the water is deep then you stand a better chance of finding some remaining gold. Not all dredgers use a hooka air breathing system. If they did use the hooka system, then they may not have wanted to invest the time in working the cracks in the rocks. It all comes down to how much time do you want to spend in the area that you are dredging. The first people to dredge the area most likely went for the easy to get gold and then moved on to a better spot once they had depleted the easy to get gold. Now we come down to the hard to get gold. I watched some guys dredging with canyon wall that were 400 feet or so high. I wondered how in the world did they manage to get all that heavy dredging equipment down those shear rock walls. Even if they lowered it down, they would eventually have to haul the equipment back out. One day when I was doing some gold panning on the South Fork of the American River in Northern California and I saw some dredges hauling their equipment on rafts. I went over to them and started up a conversation. As it turned out they had completed their dredging and were headed for home. They explained that to get to that spot that I had observed them dredging in, they had to float down from Chile Bar in rafts. There was a small area to set up camp in and that is where they dredged. Except for the occasional Recreational Rafters that would periodically come along, they were alone to apply their craft. I asked them how they restocked their provisions such as gas and food? They said that they had a predetermined schedule set up with some friends, and on that date they would float down to the Salmon Falls Bridge where they were taken to town for provisions. Then they were taken back to Chile Bar where they would float their raft and provisions down to their camp. Before they started their dredging trip they parked their car at the Salmon Falls parking lot and had their friends drive them to Chile Bar to float down to their camp. Now when they finished their dredging they could float down to their vehicles without someone waiting to pick them up.
My first experience with a conventual dredge was quite different; my friend had a claim on the South Fork of the Yuba River in Northern California. To get to the spot where we wanted to dredge, we had to drag the dredge down the side of a riverbank about 50 to 75 feet high. By the time we got all the equipment necessary to dredge, I was so tired I didnt feel like dredging. My buddy Steve, ended up doing most of the dredging. Then I remembered I forgot the food and water, so I had to scale the high bank and bring them back down. Now I was really tired, so I sat on a rock and rested. As I was sitting there, I kept thinking there has to be another way to do this without all this equipment. Most of the equipment was light but very bulky, especially the pontoons and the dredge hose. The heaviest part of the equipment was the pump and motor, of course the motor needs gas, so it has to be hauled down as well. So far I was not having much fun, where did this name recreational dredging come from? Once we got the pump and intake hose primed, we started dredging. I decided to man the sluice box and watch for any large nuggets that might clog up the system. Not to worry, I never got my chance, but we did find a lot of course gold with a ton of Black Sand. It is too bad that the Black Sand does not have any value, because we found a lot of it. The rapids were very swift with the high water, so we dredged mostly on the sides of the river. We quickly found that the best pickings were near bushes or rocks covered with moss. Steve told me to start moving rocks out of the way, while he dredged under them. I never realized how heavy those little boulders were until I moved a hundred or so, at least it seemed that many. I was beginning to wonder when the fun was to begin to start. When we did our first cleanup and panned out the gold, I began to understand why we were there. The lust for gold is in everyones sub-conscious. Finding the gold is really a blast, it is too bad we have to move all those damn rocks. Somehow I always thought that dredging was a lot easier and the gold was there to be sucked up into the dredge. I had found a lot of Black Sand while panning but I never dreamed that the dredge would recover this much. The one thing that I noticed was that the dredge was not getting the same amount of flour and fine gold that I was used to getting when panning. The wheels started turning in my head, there must be a better method to recover the fine and flour gold. We dredged for most of the day and I spent more time resting then dredging, old age I guess. I really felt old when we had to carry all that equipment back up the hill. The trail we had used was excellent for Bighorn Sheep but not so good for humans. The wet moss on the rocks were the worst obstacles to handle, without falling on the rocks below. I would have preferred a nice sandy beach to fall on but that was just not available. I used a long handle shovel for a walking stick to keep my balance while climbing over the rocks. Now I began to understand the criteria, if it is next to impossible to get to, then it will have some gold left to find. When I first went down to the river, I slipped on a rock and dropped my Nikon camera into the water, that was the end for that camera. I never dreamed dredging could be so expensive. By the time we hauled out all our equipment, I was really spent. Going through my mind was, "is this dredging really worth the effort"? By the time we split the gold in half, I doubt if there was enough money in it to cover our expenses. Oh well, that is the life of a dredger, you just have to wait for when you hit that big pocket of gold, then it will pay.
When I got home I started thinking of how I could make the dredge lighter and be able to recover more fine and flour gold. I started my research by building a better sluice box which I called the Gould-Gravity-Trap. The riffles were only ½" high and it only needed 30 GPM to operate it. Instead of the gold being trapped into a rug or miners moss, it dropped into a trap for further processing. I constructed 5 traps but found that the first 2 slots were enough to catch the gold. I used this device to High Bank but you could not move much material by shoveling alone. The dredgers were moving yards of material to each of my shovels full. If I was going to find much gold, I was going to have to find a better more efficient method. I finally came up with a round sluice box that had all the features of the Gravity Trap that I had developed. The one problem I had with the Gravity Trap was, that when using it for a dredge sluice box, the gold would overshoot the traps with a high water flow. The round sluice tube, eliminated this problem, you could not over drive this system with water. The diameter of the tube self regulated the flow of water and the Traps got the flour and fine gold due to the dynamics going on inside the round sluice tube. I built one out of plastic so I could further understand the dynamics going on inside this little critter. The walls of the tube caused the water to twirl, which made the Gravity Traps even more efficient then I had ever realized. There was even a scrubbing action going on which helped clean out the Black Sand. Talk about dumb luck, I wished I was that smart to invent all that was going on inside that device. The next step was to improve the efficiency of the Venturi Jet that created the vacuum necessary to suck up the sand and rock. I experimented with every thing that was on the market in my back yard. I finally settled on the Suction Nozzle, which had been around since Mosses was a boy. The Suction Nozzle had a 67% improvement over the Straight Jet Venturi that most Dredger's were using. I did not want to float the unit; I wanted to get rid of the pontoons, so I decided to make it a Sub-Dredge or underwater dredge. I later found that I could dredge in 12" of water or 30 feet of water with basically the same efficiency. The one beauty with the Suction Nozzle, is that if you lift it out of the water, it will re-purge itself of the air-bubble. In most dredges, that air-bubble has to be forced out until you can dredge again. I put the Suction Nozzle and dredge hose in front of the Sub-Dredge, so if there are any air leaks it wont matter, it is pushing water, not sucking it. The traps inside have a limitation of capturing ¼" size nuggets, so I constructed a Nugget Trap to catch the larger ones. The cleanup is accomplished by removing a 3.0" plug and washing the gold and remaining Black Sand into a bucket. The whole cleanup process takes less then 10 minutes, but of course you still have to pan the material in the bucket. I ended up calling this device the Gould-Bazooka. At the time I did not realize that there was another product on the market that was called a bazooka. Oh well, that name has been used for everything from Bubble Gum, Speakers, to a Tank Killer. I probably should have picked a better name but the construction of this device looked like the Tank Killer. I built a 2.5", a 4.0" a 5.0" and a 6.0" Sub-Dredge. I finally decided that the 4.0" and the 5.0" were the best sizes to manufacture. Now when we dredge, all we need to carry is the motor & pump, the Sub-Dredge, and 30 feet of 1-1/2" high pressure hose, to feed the Suction Nozzle. Between the Sub-Dredge and the Suction Nozzle, I used 5.0 feet of suction hose. For digging deep holes I use 20 feet of suction hose. For an old guy like me the reduction of weight on the equipment is a big deal, for the younger guys it probably does not matter.