Southern GP30 question

The Southern did have run through power with the MoPac and UP.

The Missouri Pacific and Southern interchanged a run through train, UMS, SMU (Southern-Missouri Pacific-Union Pacific) at Memphis with the UP receiving the train at Kansas City. High nose Southern SD40's, SD45's were common as well as Mopac SD40's U30C's and the any type UP six axle power.

Dan

2594 is at the Tennessee Valley Railroad Museum in Chattanooga.  2601 is at the North Carolina Transportation Museum in Spencer, NC.  The "A" is a check code that Southern used to help distinguish engines that had the same road number.  I remember in the 1970s and 1980s seeing Southern and Missouri Pacific power running together in NW Alabama.  The trains ran through to Little Rock, AR via Memphis.  I don't remember if the MP power was pulled off at the classification yard in Sheffield, AL or if it ran to Chattanooga.  I do remember seeing a MP small bay window caboose in the middle of the train.  I assume when they got to Memphis the cars behind the MP caboose were left at Memphis and the rest of the train continued to Little Rock.  With Lionel now doing the Southern GP30s, you can run them with the Lionel MP GP35s recreating the run through trains that MP and Southern operated.  Of course you could use the Atlas O Southern GP35s that were made in 2003 with the Lionel MP GP35s as well. 

Check code information:  http://southern.railfan.net/check.htm

Neal Jeter

Thanks guys for the help.

What years did Southern use the check code or was this from the start?

Actually it is as the name imply a "check" "code."  If an engine number was written down incorrect, misread, and/or inputted incorrectly the check code would reveal that.  Each individual number of an engine number was used in a computation that would result in a single numerical digit of 0 through 9.  The digits 0 through 9 had a alphabetical equivalent.  Thus if the computation was not the check code they knew it was not written,read,and/or inputted correct.

I believe (but not sure)this was started in the 70's and ended with the merger.

Ron

I always wondered what the letters were for. I would not think there were two units with the same number.

Here is a shot I took of SOU 2540J at E. St. Louis, IL in 1978. It is against a Radio Control car, but I don't think it is MUed to it. I only saw SD40's or 45's running with Radio Control cars.  

 Dan

It doesn't have anything to do with "two units having the same number". That little letter is a cross-check to make sure that someone, anyone, reports that unit number CORRECTLY. In other words, if someone makes a mistake and reports, say unit #2504, instead of unit # 2540, that little cross-check letter will "catch the mistake".

I've wondered if any other road used the check code system; I'm not aware of any, but

were there some? 

I can not recall ever seeing any other railroad, besides the Southern Railway, use such a system.