New Cascade Tunnel

If we are headed eastbound, we will soon enter the New Cascade Tunnel. If you just exited the tunnel traveling westbound, here is some history of the tunnel. During our nearly 15-minute passage, the track climbs over 600 vertical feet to a maximum elevation of just under 2,900 feet above sea level. This tunnel is the longest in the United States at 7.8 miles. It is 16 feet wide, over 21 feet high, and completely lined with concrete. The New Cascade Tunnel opened in 1929 after 3 years of construction. 1,800 men worked from both ends toward the middle and from the middle toward both ends. A vertical shaft was blasted from the surface down to grade level in the middle of the tunnel route. The cost to build the tunnel was $25 million in 1920 dollars.

The construction of the new Cascade Tunnel stemmed from the tragic Wellington Disaster of 1910. The previous Cascade Tunnel suffered from poor ventilation, exposing passengers and crew to thick smoke from coal-fueled steam engines. To address this issue, electric locomotives were proposed, and the construction of a hydroelectric plant commenced in 1907. Completed in 1909, the Tumwater Dam on the Wenatchee River near Leavenworth supplied power to trolley lines within the tunnel, facilitating both freight and passenger transit. However, advancements in diesel locomotives and ventilation systems rendered the electric train system obsolete. This prompted the decommissioning of the power plant in 1956.

Petruzzello, M. (1998, July 20). Cascade Tunnel | Description, History, Avalanche, & facts. Encyclopedia Britannica. https://www.britannica.com/topic/Cascade-Tunnel