296 thru 299 - The SD38-2 Units

Discussion in 'N Scale' started by jmoore16, Apr 28, 2016.

  1. jmoore16

    jmoore16 Member

    I found that some folks on another forum have had trouble with fitting a Kato SD40-2 underneath the CMR products SD38-2 shells. I guess I haven't had any issues yet as seen by the following video...



  2. pbender

    pbender Member Frisco.org Supporter


    I watched the video today, and thought I should point out one minor error.

    You say at one point that the yard in Memphis was a flat switching yard, but the one in Tulsa was a hump yard.

    In actuality both Cherokee yard and Tenessee yard are hump yards. The reason for the dynamic brakes on the Tulsa engines is that Cherokee yard is a "hold back" hump yard. Basically that means the approach to the hump is a downhill slope, so the hump engines control the speed of cars going over the crest of the hump through braking.

    Tenessee yard is a more traditional hump, where the hump is on a man made hill, and the hump engines push the cars over the crest.

    Those are the only two real hump yards on the system. ( Springfield yard is described as having "a rise on the west end" to facilitate switching. Cars are frequently gravity switched, but there are no retarders ).

    Last edited: May 3, 2016
  3. tmfrisco

    tmfrisco Member Frisco.org Supporter

    I worked the hump in Tulsa starting with the FMs then the SW1500s and finally the SD38s. These last engines were a dream to run, especially once we added the GP38s to go with them. The hump lead at Tulsa is both downhill and uphill. It is basically downhill until about 45 cars from the hump, and then it is uphill. We would use the dynamic brakes (supplemented with air brakes under the head five cars if needed) to hold the speed to the desired speed (2 for humping and 1 for weighing). We would then switch to shove mode when we reached the 45 car mark. When the hump controls worked correctly (which was most of the time), the hump job was basically baby sitting the speed unless something would need to be changed. I really loved working those engines.


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