May 1, 2013 • 661 views
Tale of the Tailings
An Environmental Feat …. The Mother Lode area of California’s Gold Country is the home to a number of engineering feats which were initiated by the Gold Rush. Kennedy Tailings Wheel Park in Jackson, California is the home to one of the more amazing environmental construction projects in the early 1900’s. In 1848, the mining site named Botellas was founded and the next year the mining camp Jackson Creek was established. The camp housed many of the miners of lucrative Kennedy Mine. The Kennedy Gold Mine, the deepest in the world when it was closed in 1942, the Kennedy Tailings Wheel System and the historic mining camp of Jackson Gate make up the entire tailing wheel system. So what is a ‘tailing wheel’? Well first let’s start with the Kennedy Mine, which was a combination of three Quartz claims filed in 1851. By 1860, the three claims merged into one mine under the ownership of Andrew Kennedy and the Kennedy Mining and Milling Corporation was established in 1886. Over $34 million dollars in gold was reaped from the Kennedy Mine, making it and the Central Eureka mine the richest gold mines in the entire Mother Lode. The mine was over a mile deep when it closed in 1942 and over 4,500 feet below sea level. To put it proper perspective, the mine had a vertical depth of over 19 football fields. Gold ore was extracted from the mine and then crushed under large and heavy mining stamps. The stamps crushed the ore and separated the gold from the quartz rock. The gold was captured and the remaining rock or tailings were remained as leftover rubble. The Kennedy Mine operated 100 stamps, all operating 24 hours a day. Each operated with a load booming sound and mine operators often lost their hearing from the excessive noise. All was going well for the Kennedy Mine until 1911 and a 20 inch rain season brought unplanned consequences. The leftover rubble from the large stamps washed down to the valley below the Kennedy Mine causing problems for downstream agriculture interests. A lawsuit was filed against the mine, and the courts ruled in favor of the farmer owners and the environment. In order to comply with the court order, Kennedy engineers designed a wheel based solution to move the tailings up and down hills and finally to a waste basin to further begin the eradication process. Four wheels were used to move the tailings through the system. Each was built of cedar and redwood, stood 58 feet high and weighed over 800 pounds. The wheels allowed the tailings to be lifted 42 feet up and then move through a series of flumes filled with water. The last wheel dumped over 850 tons of waste each day into the waste basin. Today, three of the four wheels are still intact and efforts are being undertaken to preserve them from the elements. The environmental damage caused by the Kennedy mining process caused one of the first successful environmental protection projects to be completed. The Kennedy Tailing Wheel project initiated to preserve the remains of that significant project is truly a project with an engineering and environmental impact.