Snow Sheds: How the CPRR Crossed the Summit
Across the snowy mountains of the world, railroads are protected from avalanches by snow sheds, sturdy roofed structures of a uniquely American origin. Today these protective structures are built from concrete and steel, but they originated from massive galleries of timber that were erected during the construction of the transcontinental railroad.
In 1860, when Theodore Judah was completing his survey of a route for the transcontinental railroad, he recommended a route across the Sierra Nevada Mountains through Donner Pass and Dutch Flats for the best passage. Judah was aware of the severity of winters at the mountain summit having personally experienced some of its weather extremes. He was also familiar with the history of the infamous Donner Party who had spent the winter of 1846-47 stranded on the eastern side of the summit. Judah had faith in his dream and he had faith in technology, asserting that state-of-the-art snowplows piloted by powerful locomotives would manage the snow. Unfortunately, in his enthusiasm, he underestimated the formidable winter weather.
By 1865, the Central Pacific Railroad was concentrating its workforce on building a series of tunnels to cross the summit of the Sierra Nevada Mountains. Between the tunnels, mountain slopes provided ample surface for tracks, but the extreme weather at the highest elevations impeded progress. Snow-heavy areas were worked in the summer months and, as winter approached, the construction leap-frogged east to lower elevations with milder temperatures. This pattern provided a short-term solution. Workers were digging out snow impacted tracks as late as July, which left only a few months for construction and made winter rail travel on completed tracks impossible.
By the autumn of 1866, the Central Pacific was preparing for the onslaught of snow. The Sacramento, the Central Pacific's original locomotive was by then retired, returned to service to deliver a gigantic snowplow with enough size and power, railroad administrators believed, to conquer the deepest blizzard. The plow was a heavy load for the locomotive. Scouts rode ahead to warn teamsters of their advance because the noise so terrified horses and oxen, that they would run wild. The journey took six weeks, from early November to mid December and the winter snows were beginning in earnest by time the Sacramento reached its destination and the plow put to work. The plow was mounted on a standard railcar, but the car was hidden by the body of the structure since it was intended to operate close to the track. It measured 10 feet wide, 11 feet tall, and 30 feet long. The front was a huge wooden wedge, reinforced along the edge by iron plates that sloped down to the rails. The lower portion of the wedge would scoop up snowdrifts and on the upper portion, a jutting prow would part the drifts, throwing the snow as far as 60 feet. But on December 28, 1866, a town on the west side of the mountains, Cisco, California, experienced its largest snowfall in 10 years and even the giant snowplow was no match for it.
The winter of 1866-67 was the worst on record. There were 44 snowstorms, ranging in severity. The smallest was a squall with only ¼ inch of snow accumulation, but the largest lasted two-weeks and dropped at least six feet of snow. The total snowfall that winter accumulated to 40 feet. Tunnels were cut through the snow so that the men could continue the arduous job of boring the granite