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gp40-2 vs sd40-2

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  • Member since
    July 2006
  • 9 posts
gp40-2 vs sd40-2
Posted by Hottshot65 on Monday, November 15, 2010 3:03 PM

Beyond the obvious chassis and truck differences, how do the carbodies compare between the two?  Looks like the dynamic brake blister for the SD is longer with a second fan, which I presume is extended range dynamics.  Since the blister is longer, I suppose that means the SD carbody is longer as well.  Any help you could provide woudl be appreciated.

I got a large scale GP40-2 carbody that I'm contemplating upgrading to an SD40-2 as long as it doesn't require too much surgery.

Thanks!

  • Member since
    January 2002
  • 4,612 posts
Posted by M636C on Tuesday, November 16, 2010 4:28 AM

Apart from the dynamic brakes, the carbodies above the frame should be exactly the same on a standard GP40-2 and SD40-2.

The dynamic brakes are larger on the SD40-2 because they are braking six motors rather than four. This is nothing to do with extended range dynamic braking which would apply to both four and six motor units.

For a model, just replacing the single dynamic brake fan with two of the same type would probably do.

It would be best to use a set of plans to size the new frame....

M636C

  • Member since
    July 2006
  • 9 posts
Posted by Hottshot65 on Tuesday, November 16, 2010 3:17 PM

Thanks!

  • Member since
    January 2001
  • From: SE Minnesota
  • 6,845 posts
Posted by jrbernier on Tuesday, November 16, 2010 3:39 PM

M636C

Apart from the dynamic brakes, the carbodies above the frame should be exactly the same on a standard GP40-2 and SD40-2.

The dynamic brakes are larger on the SD40-2 because they are braking six motors rather than four. This is nothing to do with extended range dynamic braking which would apply to both four and six motor units.

For a model, just replacing the single dynamic brake fan with two of the same type would probably do.

It would be best to use a set of plans to size the new frame....

M636C

  The carbody above the frame is longer on the SD - note the extra length between the cab and the engine compartment.  As mentioned, the double fans are to cool off 6 traction motors of BEMF.

Jim

Modeling BNSF  and Milwaukee Road in SW Wisconsin

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