Kolkata Metro: The only Metro of IR. কলকাতা মেট্রো : তিলোত্তমার জীবন রেখা ।। - PPG

In other words, SCREW SER n SR, both for not maintaining 12839/40/41/42 properly.
The train has to b taken into yard for a regular wash up. but SR doesn't do it.
The idiotic RSA has ruined it completely.
Instead, IR/SER/SR has to plan in another way.
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soon as 12839 arrives gets in pf, it should b shunted back to yard, n another rake has to b kept at pf after 7.30 am, just 1 hr 15 mins before 12842 departs. meanwhile, the rake of 12839 can get cleaned up n return back as 12840 in the night.
But for 12842 doesn't need this process as it has enough time to get cleaned n get back in 12839 process.
and 12840 can b turned into 12841 later in the noon!! at SER, it has ample space for cleaning.