THE BLUE COLOUR DENOTES THE GANGA.
1) These are the Main+ Chord combined lines coming from Howrah (via Liluah, Belur till Bally). All ER trains use these lines.
2) It is the Main Line going towards Bandel Junction. Trains like Black Diamond use this line.
3) It is the C.C. (Calcutta Connector Lines) coming from Sealdah/ Kolkata Chitpur Terminal (via Dum Dum Junction, Dakshineshwar)....
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Trains like Darjeeling Mail, Sealdah Rajdhani use this line.
4) It is the A.C.C. (Additional Chord Connector) Link Line's first wing, connecting Rajchandrapur with SER. Sealdah- Puri Duronto use this line.
5) It is the A.C.C. Lines connecting ER with SER (via Bhatanagar). Both Sealdah- Puri and Shalimar- Patna Duronto use this line.
6) It is the line coming from Amta. Only freights and Howrah-Amta EMU use this line.
7) It is A.C.C.'s second wing, coming from SER's Santragachhi Junction. Shalimar- Patna Duronto use this line.
8) It is A.C.C.'s third wing, coming from SER's Andul. Puri- Sealdah Duronto use this line.
9) It is A.C.C.'s fourth wing, coming from Dankuni side. Patna- Shalimar Duronto use this line.
10) It is once again the C.C. Lines, same as the mentioned in point (3).
11) It is a bye-pass line, which is extensively used only by freights. The lines curve out from DKAE outer, go up the gradient, and then takes the bridge to connect to C.C.. The importance of this line is that if the line didnt exist, then a freight going towards C.C. would have blocked the lines coming from Howrah, thus congesting the already busy Chord lines.
12) This is another Howrah- Sealdah Connecting line (via ER). Earlier the Howrah- Sealdah EMU (now decomissioned) used to take this line. Now the line is meant exclusively for freights.
13) This is the popular, busy and high speed Chord lines coming from Howrah. Howrah Rajdhani, Poorva and Kalka use this line.
14) This is the Dankuni- Shaktigarh triple line section from Dankuni onwards. All ER trains (via Chord) use this line.
++ I HOPE THAT THE COMPLEX DANKUNI JUNCTION WILL BE CLEAR TO EVERYONE. :-)