I attached a document from railways that provides details of each platform at Bhagalpur. Platform 2 and 3 is primarily used for passenger trains and a few express trains, not because it cannot accommodate long trains, but because there are other wider and longer platforms (1, 4, 5) that can be used. Also, platform 2 and 3 does not have a shed, is not wide so cannot handle many passengers; and is not connected to all 3 over bridges. I have been to the station and the platform is fairly long. It starts at the same point on the west side as platform 1, and ends about hundred meters before on east side.