I'm reposting a comment of mine for further elucidation.
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Both 12272 and 12234 are tri weekly. Suppose 12233 starts from LKO on Sunday, reaches NDLS on Monday, leaves same day in the night and reaches LKO Tuesday morning. Again it leaves on Tuesday and similarly on Thursday from LKO. Same with 12271 on OTHER three days. Now WHERE in this is the rake getting 'shared'?
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more... Following is another one By Mr. Vinay (Ref:
/blog/post/734962/2):.
No RSA is required even & only it existed if bth train's total schedule would have been 7 days, not 6!!
Its simply, DRNTO runs to & fro NDLS & rest @ LKO on Wednesday while AC Express runs same way & rests @ LKO on Thu!!
When DRNTO run from LKO on Mon & reach NDLS on Tue, ideally, if in RSA, it should start as AC Exp on Tue, but on Tue, DRNTO starts frm NDLS!!
Same way, no such linkage any other day!!
PS: DRNTO exist in DRNTO Livery (with 1-2 Red Coaches), while AC Exp is all red, with 1-2 DRNTO Livery Coach!!
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Further its been only who's been claiming this for long:
/blog/post/650104/blog/post/708528/blog/post/651820/blog/post/682822.
Please try to understand that YES they share TT, and also a few coaches but NOT entire rakes.