History Of The Railroad Article 16

Tunnels Part 2

Moffat Tunnel

     The Moffat tunnel, which passes under the continental divide were completed in February of 1928 and stretched for 6.2 miles.

Moffat Tunnel Western view circa 1928

HHT Co. (letters hidden in arrow), Public domain, via Wikimedia Commons

     The mountains of the Continental Divide were frustrating, dangerous and very expensive when they were built without tunneling through. This was due to the grade causing the excess wear and tear of the locomotive along with the excessive fuel consumption.

     David Holliday Moffat built the Denver, Northwestern and Pacific Railroad at an elevation of 9,239 feet above sea level. The railroad's purpose was to link the cities of Denver and Salt Lake City. To link these two cities, they had to go over the continental divide.

     Moffat spent his fortune trying to complete the railroad. At the time of his death, they had only completed from Denver to Craig for a distance of 200 miles.

     His route went over the Rocky Mountains and not through them. Bill made the railroad this way caused the grade to be over 4%, are the kiss of death for his infrastructure and cost efficiency.

By boring the tunnel through the mountain, it trimmed 23 miles of steep and dangerous mountainous trackage from the route. It also cut down operational time by hours.

     Others took up the project. On the West End there was poor and unstable rock deposits. It took three more bonds to get the cash needed to complete it at the cost of $23.9 million. In today's market that would be $370 million.

The nearly-completed tunnel in December 1927

International Newsreel Photos; Wiki Commons; Public Domain

     The tunnel was completed boring on July 7, 1927. It took until February 26, 1928, to be fully opened.

     The trouble with a tunnel 6.2 miles in length is that it requires ventilation to clear out the exhaust from the locomotives. In the early days it was exhaust from the wood and coal burning locomotives. Then the oil burning locomotive and the diesel locomotive. An excessive amount of exhaust.

     The Moffat tunnel used a system of canvas doors at both the east and west tunnel entrances. When a train cleared the entrance, the canvas doors closed, and ventilation fans circulates the air in the tunnel to clear the exhaust gases.

     The canvas doors are connected to a circuit that then is connected to the track to open close the canvas doors.

     Today it is computer controlled and takes 20-25 minutes to clear.

      During the peak coal traffic through the early 2010’s there would be 24 – 28 trains that pass through each day. This resulted in a bottleneck of where the process is sowed down enough to be a problem.

     Today, due to the capacity the train pulls, and the number of trains that go through the tunnel, the trains do not have to wait to enter the tunnel. The exhaust gases have already been dissipated. ⁶

      Post construction had its problems. A big one was the high cost of maintenance. The ventilation was a major one with its constant repairs. That was due to either the freezing or the thawing, the leaking water causing ice to build up in the winter. All of these led to a massive maintenance bill.

     Also, due to the amount of snowfall also hampered operational time as well as the removal cost. All of this was due to the high elevation.

     Another weather related catastrophe was cause for financial woes. Due to the amount of snowfall, avalanches would cover the rail tracks, adding to the removal cost to the high maintenance costs. Trains could also be buried in the avalanche and have to be dugout. Loss of life was ever present and had to be cleared as quick as possible.

     To combat the snowfall problem, avalanche sheds were built to deflect the snow and protect passengers as well.

     The tunnel being a transportation conduit, a pipe was built into the structure in which provided a water diversion system. It transferred water from the westward flowing Colorado River to the eastern cities.

     This diversion system provided a vital role in irrigation and urban water supplies.

     The role of the 6.2-mile Moffett Tunnel played, providing a faster, safer and economical passage through the Rockies. It helped transform Denver to a hub of western American railway service.

     A long-standing monument, to the ingenuity of the American engineering. the tunnel still provides a major component of American infrastructure.

Cascade Tunnel

 The Cascade Tunnel, which was also called the Stevens Tunnel of the Great Northern Railway. It was built and opened on January 1, 1929. It replaced the original tunnel that was opened in December 1900. The original was 2.6 miles in length.

     The second tunnel was 7.8 miles in length, with a ruling grade of 1.7%. It took four years to construct and cost $25.6 million. It is also one of the longest railroad tunnels ever built in the United States.

     The original tunnel had begun to construction late summer of 1897. It took three years to complete. It opened right before Christmas of 1900 and was set on a very high elevation of approximately 3383 feet above sea level. Its main purpose was to eliminate a grouping a switchback totaling a length of eight miles that were required to scale the Stevens Pass. Due to a steep grade ceiling it back between 1.7% and 2.2%.

     Due to the length of the tunnel, 2.6 miles, ventilation was required to clear the locomotive exhaust as it discussed under the Moffat tunnel.

     The extreme snowfall was never more evident than in 1910 when an avalanche toppled a passenger train that had been waiting to be dug out. One hundred passengers lost their lives.

     Due to this accident, the Great Northern railroad was forced to look for a better route through the mountains.

Cascade Tunnel construction west portal 1928

Lee Pickett, who was the official photographer for the Great Northern Railway,

builders of the tunnel., Public domain, via Wikimedia Commons

     The above photo is of the first work train of men arriving at the West Portal of the Cascade Tunnel from Mill Creek and Berne, Washington. The view also shows some of the construction camp at the West Portal.

     So, in 1925, the railroad began construction on the Cascade Tunnel. The tunnel was located 500 feet down the mountain side, below the highest elevation. Most of the tunnel was located away from the worst of the mountain’s winter.

     The tunnel was 7.8-mile length makes it the longest tunnel in the United States. The ruling grade was at 1.7% that would help ease the strain on the locomotives. Also helping with one safety transport of passenger and freight.

     But it came at a major cost of $25.6 million for its construction. Plus, over the years the ongoing maintenance cost over the decades has been in the millions. This has made it the costliest railway line in the world.

Cascade Tunnel E portal2 5 24 51 (22182103880).jpg

Mt. Baker-Snoqualmie National Forest Historic Photo

U.S. Forest Service- Pacific Northwest Region, Public domain,

via Wikimedia Commons

     The original exhaust ventilation fans were installed to take care of the fumes produced by the locomotives. They proved to be inadequate. Fumigation problems haunted the Great Northern Railroad and its predecessor. It was not only due to the tunnel’s length but also the 1.7% grade. The grade, even though it is within the acceptable guidelines, still made the locomotive work harder, causing the gases to be excessive. It took the train an hour to scale the tunnel.

     They installed a new ventilation system that cleared the tunnel within 20 minutes. The crew are still required to carry respirators with them at all times.

     Today the Burlington Northern - Santa Fe Railroad owns the line. They hold its freight trains and Amtrak passenger trains speed to 25 miles-per-hour while they transport the tunnel.

     Some have wondered why the Burlington Northern - Santa Fe Railroad, who owned the Snoqualmie Tunnel after the Milwaukee Railroad abandoned its main line in 1980, did not utilize it.

     The Snoqualmie Tunnel was known as the best engineered tunnel across the Cascade Mountain range. This would have saved the BNSF millions in maintenance and liability. ⁵