Photo courtesy of Credit Baker County Library, Baker City, Oregon. Crowd at launch of dredge base April 16, 1935. 3 build was well documented in these amazing photos. Photo courtesy of Credit Baker County Library, Baker City, Oregon.ĭespite these impressive statistics the dredge was not always profitable, and when it finally ended operations in 1954 the company was in sizable debt.Ĭonstruction details of historical mining structures were rarely documented but we are fortunate that the Sumpter No. Detailed photo of the dredge buckets at work. At today’s price of around $1,350 per ounce, Sumpter No.3 would have produced over $150 million dollars in gold. 3, closed in 1954 after producing over $4 million in gold over its lifetime. The last dredge, known simply as Sumpter No. Between them the dredges traveled more than 8 miles, extracting $10 to $12 million worth of gold. Three gold dredges worked the Powder River in Sumpter Valley between 19. Photo Courtesy of Baker County Library, Baker City, Oregon. In 1912 construction commenced on the first Sumpter gold dredge. Sumpter was a remote and isolated town which grew very slowly, and it wasn’t until the 1890s, with improvements in transportation routes and the arrival of a railroad, that Sumpter turned into a mining boom town.Įventually attention was turned to the deep placers of the Powder River where it flowed through Sumpter Valley. Rope should be tightened properly leaving sufficient sagging.Sumpter, Oregon was settled by prospectors in 1862, making it one of the earliest mining settlements in the Northwest. A nylon rope can be used for this purpose as it is very strong. To facilitate this, you should drill holes through plywood and fasten rubber inner tubes using rope. Add rubber inner tubes enabling the dredge to float.Ī dredge should float on water while operating it. The pump will intake water along with soil and deposit on the sluice. One end of the hose should be attached to the pump and the other end should be over the sluice. This whole setup should be assembled firmly. It means you will require a 1-inch intake pipe to serve 1 feet of load. The ratio of diameter of pipe to the overload is 1:1. Build the intake system using pipes and hoses.Īn intake system must be built using pipes.īased upon the volume of deposit you aim to process, choose the diameter of the pipe.
Using galvanized steel U-straps, attach them to the frame firmly.Ī better practice is to avoid welding pump and motor on the frame as it may hinder operations of the machine in the future. The plywood which you have attached on top of the frame as a part of step one will act as a base for motor and pump.
The motor should be connected to a water pump.
To power the dredge, you should install a lawnmower motor at the rear end. Install the mechanical components like motor and pump. If you find constructing this difficult, you can get this spare part in stores or online markets. Similarly, corrugated aluminium sheet should be soldered on top of the ladder assembly.Ī gold dredge should be operated using water, so by adding additional aluminium strips, you can create an inclination and make a provision to pour water onto sluice. Generally, use corrugated aluminium sheets for roofing. You should be familiar with soldering to build a sluice box.Īluminium strips should be soldered in the shape of a ladder with a width of 24 or 36 inches. Construct a sluice box which has to be mounted on the frame. A sluice box will be placed on the frame and a large plywood should be attached on top of it. The crossbeams of the frame should be V-shaped for it to be laterally strong. The mount should be strong enough to hold the motorized components.Īccording to the dimensions, tubing should be welded in the shape of a rectangle. The first step is to build a frame and galvanized tubular steel, 0.5 inch should be used for this purpose. To sift rapidly through large amounts of gravel, you have to build a powered dredge.
Here are the steps for how to build a gold dredge: 1.