GNRW through the cascades.
1) When the first line was built: it had 4 switch backs on both sides of Steven's pass. The line also had a horseshoe tunnel at Martin creek. Engines on both ends of the train and very few cars: 10-15.
2) 1900-1929: a 2.6 mile tunnel was bored and used until 1929. Had a 2.2 percent grade so had to electrify it. Car capacity increased to 35-40 cars with electrics.
3) 1929-around 1956 (diesels took over): a 7.8 mile tunnel bored and, also, electrified a total of 73 miles.
4) around 1956 the tunnel was fan ventilated so electrics no longer needed and diesels could traverse the entire line from St. Paul to Seattle.
