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Student Instructions
How to use a topographical map to plan your railroad route 

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The topographical map you are working on shows the area from Donner Summit on the left to Truckee on the right. Notice the arrows on each side of the map. Your task is to engineer a route for the railway to cross this area. Further instructions and cautions are listed below

Using Topographic Maps

  1. You will notice a number of contour lines on the map. These lines show the elevation of that spot. The lines show an elevation change of 50 meters or 162 feet. If you follow one line, you are staying at the same elevation. When you move to another line, you have changed your elevation by 50 meters. For example, look at the area labeled Schallenberger Ridge in the center of the map. Notice a small area under the word ridge. It is labeled 2277. That means the point inside the small area is 2277 meters above sea level. The small rounded shape outside the dot shows the elevation is 2250 meters above sea level. Each line below that shows a change of 50 meters.
  2. Notice that in some areas the lines are close together. Close lines means the area is very steep. The further apart the lines are, the flatter the area.
  3. Notice that the map is divided into squares. Each square is one mile by one mile.

Creating a Route

The trains of the time were not able to go up steep slopes. They still need very gentle slopes to function well. Judah's challenge (and yours) was to get the train from the summit (approximately 2150 meters) to Truckee (approximately 1830 meters) without making the route too steep. You can gradually change levels, but you cannot change more than one contour line every 1 1/2 miles. Sometimes you can tunnel through areas to avoid having to go over a ridge. (Judah tunneled under the summit so he didn't have to climb another 147 feet over the top). Tunnels are expensive and take a long time to build. Try to avoid using them whenever possible. In the area you are working, Judah was forced to make 7 tunnels, some because the shape of the mountain was unable to support the tracks and others to avoid large elevation gains.

Hints:

  1. Take advantage of canyons that allow you to make a gradual elevation change over a longer distance.
  2. If you need to cross a ridge top (shown by a series of contour lines each coming to a point), think of making a short tunnel under it to avoid sudden changes in elevation.
  3. To cross short canyons, you might have to make a bridge. Again, they are expensive and time consuming.
  4. Try out a route with your finger rather than a pencil until you are fairly sure that route will work.
  5. When you have finished your route, ask your instructor how to compare it to the route Judah designed.


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