1st- CNW needs about 200 trailers, and there are only 98 7400's so they won't go to the CNW.
2nd - They are replacing about 30 origanal CB&Q trailers on the B.N. Right now the B.N. has #7400 - 7423. It wouldn't surprise me if they send 7424 - 7453 to the B.N. off of the MILW, and then give the MILW 30 6000's.
3rd - The reason the trailers were numbered in the 6000's is because they're getting over 200. If they put them in the 7500's it would look like this:
7501 - 7710.
They can't use the 7600 series because that series was owned by the CNW St. Louis, and early Pullman cars. And the 7700 series is still occupied. Even though they 7600's have been gone for 8 years now, they can't use that series until they've been gone for about 10 years. it has to do with the way thier computers are set up. Even though they're gone, the computer thinks they're still there until they've been gone for 10 years.
Which explains why the MP36's are in the 400 series, and not the 300 series. Remember F7's #305, and #308. They've only been gone for about 4 years now. Otherwise the MP36's would be numbered #301-327.
Uphill slow, downhill fast,
tonnage first, safety last!