NS Train 800 Ft To Long?

[NSSpike]

Tuesday evenings NS train 23N (ATLANTA, GA - MEMPHIS, TN) was advised by the North Atlanta dispatcher that their train was to long and CSXT Nashville advised NS they would not accept it over the Chattanooga Sub Wauhatchie to Stevenson. NS trains operating between Chattanooga and Memphis must travel about 33 miles on CSXT tracks in northern Alabama.  Not sure how long 23N was but 800ft of cars would need to be removed and the Rome switcher G36 would be called in to assist with the required removal. Anyone aware of a maximum train length requirement on this segment of CSXT line as this is the first I had heard of it? Perhaps just a temporary requirement due to the flooding experienced in the area after this weekends rain storms? 

[Beavis]

CSX generally won't take trains over 9000 feet long on this segment.  Now that I think about it, I've never heard the 'official' reason why.