"Charles River Bridge" . "Commuter Rail Bridge" . . . . "the North Station drawbridges" . . . "28.0416" . . . . . . . . "Boston and Maine Railroad, Charles River Bridges" . . . . . . . "Charles River Bridge (Commuter Rail)" . . "pair of two-track drawbridges" . "Charles River Bridge (Commuter Rail)" . . . "1931" . . . "1" . "0" . . . "rail traffic over 4 tracks, split between the two bridges" . .