the ex-B&O line you are refering to (that runs along the Schukill River Park) interlocks with the ex-RDG line inside the subway. Originally this was an interchange and terminus of the B&O. The RDG line started at the Reading terminal, breaking off the main and headed West just North of Callowhill St-desended below grade not to emerge until 27th&Penna. Ave.
see the inset on the lower left
