Drone to explore inside Sutro Tunnel

For the first time in nearly 20 years, the Sutro Tunnel will undergo formal exploration.

A Grass Valley, Calif., firm will be using a drone on Monday to squeeze through an 18-inch hole in the tunnel’s portal above Dayton to take a look inside.

EROCK Associates plans to send their Elios 2 Confined Space Drone, mounted with a RKI Instruments GX-3R gas detector.

The company is working with the Friends of Sutro Tunnel to determine how to move forward toward reopening the historic site to the public.

In addition to the confined space drone, they will also use a DJI M 300 Drone, Emesent Hovermap LiDAR System, DJI Inspire 2 and DJI X5S camera to collect information needed to help the Friends prepare the site for future renovation and restoration.

“Conventional mining exploratory missions are very dangerous and expensive” Eric Bennett, president of EROCK Associates, LLC said. “Using drone technology allows us to get into places that were previously out of reach or too costly to assess. My background is in underground mining and tunneling. I have a special interest in helping assess the Sutro Tunnel because it is a unique legacy site with a very rich history.”

The Sutro Tunnel is a 3.8-mile tunnel leading into the mines of Virginia City. It was the brainchild of Adolph Sutro, who envisioned building a 20,498-foot-long tunnel from the Dayton Valley connecting to the Savage Mine in Virginia City at a depth of 1,640-feet. Construction of the Tunnel began on Oct. 19, 1869. It was completed on Sept. 1, 1878. Anywhere between two-and-four million gallons of water were drained from the upper levels of the Comstock mines via the Sutro Tunnel daily in the late 1870s.

“Friends of Sutro Tunnel hired EROCK to investigate the site and collect data needed to better understand the condition of the Tunnel,” Friends of Sutro Tunnel Manager Chris Pattison said. “We are looking to gain insight regarding how far back we can go once inside the Tunnel, what the air quality is like, as well as learn more about the condition of the airshaft. Ultimately, data collected by EROCK will be used to determine the best next steps to take as we work to renovate and reinforce the Tunnel site. It is our ultimate goal to be able to safely reopen the site for tours and special events in the future.”

Friends of Sutro Tunnel have been working over the last several years to breathe new life into the 26-acre Sutro Tunnel site. Many artifacts, buildings and pieces of historic equipment located at the site are deteriorating. The Friends are seeking the public’s help with fundraising for restoration.

“Restoration work of the on-site carriage house, warehouse, loading dock, mule barn, machine shop and entrance to the Tunnel is underway, but it is quite expensive,” Pattison said.

Anyone interested in supporting the effort may purchase merchandise or donate by visiting the Friends of Sutro Tunnel website.

The Sutro Tunnel site is available for private events and tours and can be booked by calling 775-882-7777.

“The Friends feel very strongly that we can work together as a community to bring life back to the Sutro Tunnel site,” Pattison said. “We hope to offer daily tours, tours of the portal and more as we continue our work on this important piece of Nevada history.”