Grades

Discussion in 'Birmingham Subdivision' started by trainchaser007, Sep 30, 2015.

  1. trainchaser007

    trainchaser007 Passed away September 22, 2017

    Does anyone know the percentage for the grade at Greenwood Springs, MS coming up out of the Buttahatchee River plain?
    - Brandon
     
  2. Karl

    Karl 2008 Engineer of the Year Frisco.org Supporter

  3. trainchaser007

    trainchaser007 Passed away September 22, 2017

    Thanks Karl. I could not find that information in my search. Now I am curious about the incline angle. According to the chart I found at http://www.engineeringtoolbox.com/slope-degrees-gradient-grade-d_1562.html, the angle of a 1.04% grade is slightly less than 0.6 degrees. To me, that seems low for the hill at Greenwood Springs. Perhaps it's just not as steep as it appears looking downhill from the Splunge Rd. crossing. I screenshot some images from google maps (street view) for reference. - Brandon
     

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  4. William Jackson

    William Jackson Bill Jackson

    The eye's will really fool even the most experienced of people. 1% is pretty steep for trains, 1 foot to the hundred. The length of the grade is important also, some can be easy, if you get a run at it. The ruleing grade, is what determines the horsepower for a length of track. Ruleing Grade is determined by the percent and length. Curves and the degree of curve also play a part. For example, "The Eyebrow" on KCS has one strech with 9 curves on a 1% Grade. Tough Running!
     
  5. Karl

    Karl 2008 Engineer of the Year Frisco.org Supporter

    One of the first widely accepted formulas used to determine train resistance caused bearing friction, rail resistance, air resistance, and grade resistance was promulgated by W L Davis in 1926. It is still used, but it has been modified, and others are in use. In general terms, and assuming all other variables remain constant, and for grades < 4%, 20 lb of TE are required to lift 1 Ton up a 1% grade, 40 lbs of TE/Ton up a a 2% grade and so on. Curve resistance may be calculated at a rate of 0.8 lb of TE / Ton.
     

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