Wow... AC coaches are sparkling... credit goes to RSA with Ananya Express which gets great patronage for passengers from Kolkata who are interested in Rajasthan Tourism (Jaipur, Udaipur, etc.). Such passengers go for 3rd AC booking a lot so ER increases these coaches in Rajasthan bound trains... this may be a reason why Durgiana & Akal Takht Expresses have got 3rd AC coaches from 2 to 4 in the past few years :)
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PS: The Durgiana Express has RSA with Jaynagar Exp & Agra Cantt SF Weekly Exp so LHB doesn't seem...
more... to be an immediate possibility since 13135/36 and 12319/20 aren't Rajasthan bound trains :-p :'-(