This post doesn't describe a beautiful vista or wildlife in Alaska. It might sound a bit geeky and technical. You may find it boring. The reason for us to include this topic is because we have come to realize how an engineering feat of transporting water over 90 miles of terrain transformed the Fairbanks mining district. Without the water, there would be no dredge for us to work at this summer and it is likely Fairbanks would be a tiny blip on the map. Digging a ditch changed the outcome of interior Alaska. Because of its significance, the ditch is something we hear about every day we work. It is as much part of our Alaskan experience as the train Allen drives and the cookies Terri bakes. Gold Dredge 8 owes its legacy to a ditch.
Gold Gamble
The life of a gold prospector is akin to that of a gambler. Gold prospecting and gambling share several similarities, making the comparison quite intriguing. Both activities involve a significant amount of uncertainty and risk. Each pan of dirt or new location in prospecting is a gamble, much like each card or spin in gambling. The thrill of the hunt is a common factor. In gambling, it’s the anticipation of beating the odds; in gold prospecting, it’s the excitement of finding that first glint of gold. This adrenaline rush keeps both gamblers and prospectors coming back for more. We understand what it means to get gold fever.
Prospecting requires an initial investment of time and equipment. The potential rewards can be substantial, but there’s always the risk of losing your investment without any return. It took Felix Pedro, the man who started the Fairbanks Gold Rush, ten years before he finally struck gold. Felix was an experienced prospector who increased his chances of success through knowledge and strategy, but ultimately, luck was the deciding factor.
After Felix Pedro made the first significant find in 1902, and after many struck it rich, the Alaskan Klondike gold rush peaked around 1910. At this juncture in time, smaller drift mines and prospectors had seemingly exhausted the area and mining was fizzling out. Luck ran out. It appeared as though Fairbanks was going to be just a sizzle in a pan and a historical footnote.
But, there was still lots of gold to be found in the Fairbanks mining district. It was near bedrock.
This model of a drift mine is found at the Pioneer Park historical center museum.
A drift mine replica that is part of the Gold Dredge 8 tour.
Paxson is hamming it up for the camera.
From Prospector Gambling to Corporate Calculated Investments
Gold dredges are very efficient for extracting gold. (Read a blog post about Gold Dredge 8 here.) The first modern gold dredge is generally considered to be the one designed by Choie Sew Hoy in 1889. During the 1920s, approximately seventy gold dredges were operating in California. Further north in Alaska, dredging quickly grew from four dredges in 1908 to forty-two in 1914. (After WWI the number of dredges in Alask reduced to about twenty-two until 1922).
United States Smelting, Refining, and Mining Company (USSR&M) operated mining operations in Nevada, California and Utah. They began busily extracting gold in Alaska in the early 1920s. USSR&M began their dredging operations in the Hogatza River region and Nome around 1922. They were using advanced ground preparation techniques that they knew could be used in the Fairbanks area. So, to focus their efforts, USSR&M created a wholly owned subsidiary in 1925 called the Fairbanks Exploration Company (F.E. Company).
Although Fairbanks was experiencing a decline in gold production through drift mining, which is a very labor-intensive effort, the F. E. Company recognized the potential for large-scale gold mining and began buying up smaller mining claims in the region by 1925. They acquired over 18,000 acres and set their minds on dredging the plentiful gold atop the bedrock in the Fairbanks region.
Dredges are a surefire way to extract gold, and they boast a 95% efficiency rate. (A joke we like to tell of Gold Dredge 8 is, "One day, a worker fell into the dredge. He came out unharmed, but all of his gold fillings were missing.") The F. E. Company knew that dredges are a viable and successful way to recover a sizable portion of Alaska’s gold that the prospectors and drift miners could not attain using shovels and a pickaxe. The dredge is getting gold using brute electrical-powered force and not hand-powered means.
The digging ladder and buckets of Gold Dredge 8 This picture is taken from the winch room.
The winch man (head honcho) operated the dredge using a series of levers.
In order for the F.E. Company to use the ground preparation techniques they employed in the Hogatza and Nome regions, they needed a robust water supply for the dredge operation. Without water, they could not run a dredge nor overcome the challenges of overburden and permafrost. To solve the problem of water, the F.E. Company dug a ditch.
Dig a Ditch
For their dredges to operate, the F.E. Company needed water, and lots of it. The water also needed to be under high-pressure. A dredge can consume 9,000 gallons of water per minute. The nearest source of water north of Fairbanks was the Chatanika River. However, the river had an inconsistent water supply, and the gradient was not ideal. The F.E. Company employed an engineer named James Davidson, the architect of what would become known as the Davidson Ditch. It's been said, "Ditch is such a mundane word and certainly doesn’t accurately describe the Davidson Ditch. ... The open canal section (83.5 miles total), with a width of 12-feet and depth of almost four-feet, was as large as some of the early tow-boat canals on the East Coast."
As a side note, if the open canal was still surviving today, it's not hard to imagine it being an attraction for people to go tubing. It could be called, "drift on the ditch." It would be a fun ride!
Davidson, a surveyor and engineer, meticulously mapped a route for a ditch that stretched 90 miles from multiple river drainages south of the Yukon River to the gold fields just north of Fairbanks. The water conduit was a combination of ditch and steel pipe sections, riveted together and ranging in diameter from 46 to 56 inches. The ditch was a testament to the engineering prowess of its time.
Think about this: the route for the Davidson Ditch extends over 10% of the total length of the trans-Alaska oil pipeline! It was mostly constructed by hand and with more difficult conditions.
This is an old F.E. Company employee camp built to house and feed employees working to build the Davidson Ditch. It later housed dredge workers of the Goldstream Valley.
Another view of the old F.E. Company camp.
The camp mess hall could feed up to 130 people in two sittings.
The site was renovated and used as a restaurant and hotel, but it is now for sale.
The construction involved significant earth-moving efforts, primarily using tractors, graders, and steam and diesel shovels. Gangs of workers armed with shovels dug in places where it was inaccessible to machinery. Notably, the steam shovels had previously been employed in the construction of the Panama Canal, highlighting the scale and importance of the project. The inverted siphons, visible even today, were masterpieces of engineering, with fifteen in total crossing ridges and creeks.
This steam shovel was used to build the Panama Canal and the Davidson Ditch. It is on display at Pioneer Park in Fairbanks.
A picture of the open ditch. This picture is at the Pioneer Park.
Davidson was age 70 when he finished surveying and turned the details of the project over to the F.E. Company. Sadly, he died four years later in California, never seeing the engineering feat bearing his name.
The first crews began clearing the right-of-way for the ditch in April 1926. Paralleling the Steese Highway, the workers also served as road crews, maintaining the roadway before the Territory of Alaska took over on June 1 each year. Several work camps were established along the route to house the labor force. The construction concluded on May 18, 1928, when the first water flowed into the pipeline, marking the completion of a project that was ahead of schedule but over budget. The total cost was $1,773,841, slightly above the anticipated $1,662,894 (over $30,500,000 today).
It's hard to imagine spending years yielding a shovel in the hot continual summer sun and the cold dark winter days of Alaska. Keeping a work force happy in those conditions must not have been easy. It's certainly not something we can imagine doing. What about you? Would you wield a shovel for three years?
The Davidson Ditch runs parallel alongside the Steese Highway
Signs from the Davidson Ditch historical site.
An inverted siphon spanning the valley still exists almost 100 years after being built.
Ditch Water Prepares Land for Dredging
The F.E. Company knew where most of the gold lay buried. They knew because they mapped the area with thousands of core samples from extensive drilling. The core samples told them how much gold existed and how deep the gold lay. It was not near the surface, but in a gravel layer near the bedrock. On top of the gravel layer was what they called overburden. In mining, overburden refers to the layer of soil, rock, and other materials that lies above a mineral deposit or ore body. This material must be removed to give the dredge access to the valuable gravel beneath.
To remove the overburden, the F.E. Company diverted water from the Davidson Ditch. The water from the ditch was fed into increasingly smaller pipes until the pipe was only 3 inches in diameter and over 150 psi. The high-pressure water was used in water cannons, called hydraulic giants, and aimed at the overburden. Imagine having high-pressure water available only using a gravity fed supply!
The workers aimed the high-pressure cannon (super-duper-super-soaker) at a pile of dirt. The F.E. Company used the hydraulic giants to wash away all the overburden to expose the gold-bearing gravel. In essence, much of the soil where the dredges operated ended up being eroded by the water cannons and ultimately washed away as sediment in the Chena River and its tributaries.
An old hydraulic canyon shoots water into a pond at Pioneer Park.
The F.E. Company had another obstacle to overcome and that was permafrost. The ground was rock solid because of the ice. The F.E. Company used thaw points, long metal shafts pounded into the ground like needles, to inject water and thaw the ice. Workers pounded the thaw points into the ground all day for $0.33.3 an hour. Once the permafrost was melted, the dredge could be brought in to process the gravel and remove the gold. In many places, it took several years to remove the overburden and thaw the gravel before a dredge could be brought into place.
Hollow rods were pounded into the permafrost ground and water from the Davidson Ditch was fed into the pipes and used to thaw the ground. These are called thaw points.
This "thaw field" is part of the Gold Dredge 8 tour.
The figure below from a 1949 USSR&M brochure illustrates the basic features of mining gold with an Alaskan floating, bucket line stacker gold dredged, which included four activities:
Hydraulic stripping of muck over burden with water giants
Point field cold water thawing of gold bearing gravels
Dredging of pay zones, often dug to bedrock, and processing of the gold-bearing gravel aboard the dredge’s washing plant, using standard sluicing technologies
Disposal of waste gravel tailings via stacking at the opposite end of the dredge.
The Legacy of a Ditch
Without the water from the Davidson ditch, it’s likely Fairbanks would be another of many towns in Alaska known only for its early 1900 gold strike days. And, without the ditch it is unlikely Allen would be an engineer on a train and Terri making cookies in Alaska in the summer of 2024.
The Davidson Ditch stands as a remarkable example of early 20th-century engineering and its pivotal role in the gold mining industry. Its legacy continues to be felt in Fairbanks, where the ingenuity and hard work of its creators are still celebrated. Some of the engineering problem-solving techniques used in its construction were later applied to the building of the Alaska Pipeline.
We hope you enjoyed reading about Alaska's gold mining years. Feel free to ask any questions and we will try and answer them.
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