Complex sentence: It then crossed Metropolitan Avenue, Grand Street and a portion of Newtown Creek, the South Side RR's Bushwick branch and then crossed over Varick Avenue, continued across Johnson Avenue, and alongside the main tracks was Varick Avenue Yard.
Split into simpler sentences: It then crossed Metropolitan Avenue, Grand Street, and a portion of Newtown Creek, the South Side Railroad's Bushwick branch. After that, it crossed over Varick Avenue, continued across Johnson Avenue, and alongside the main tracks was Varick Avenue Yard.