The significant change is the creation of essentially a single track line. In the 1950s, it was operated as a two track line from Prospect Park up to Dean Street station,now gone and single track North of there, although prior to the 50s, there was a second track . I always remembered the Northbound platform being extended over the Northbound track so that trains on the Southbound track could receive and discharge passengers to both platforms.
Here is a Zephyrette at Franklin back in the day
On Fulton Street, there was a piece of the old Fulton Street El left in place used for walkways to reach the North side of Fulton Street. It was there for almost 50 years after the El was removed.
Here are standards at Franklin
Here are two shots coming into Franklin
Low V's
More modern equipment
At Dean Street just South of Franklin, the Northbound track switched over to the Southbound track to continue the short distance into Franklin. Here is a couple of shots of the Dean Street area.
At Dean Street
South of Dean street, the line was operated as a two track line. Southbound Shuttles would crossover just before the Malbone st Curve into Prospect Park and discharged passengers on the island platform. The Northbound local track just South of Prospect Park was used as a layup for a shuttle train. I remember seeing the Zephyrette there.
There was a Franklin service that did go South of Prospect park . It Operated on the Southbound Express track and entered Prospect park using the infamous Malbone st tunnel.
The El service that connected with the Fulton El at Franklin ended when the BRT extension was placed in Service serving 7th ave and Atlantic avenue into Dekalb. That was in late 1920. A BMT map from 1922 or so still showed the el connection, showing a single dot for the stop. A subsequent map from 1928 till showed the connection but now showed the station as two seperate stops. The map stayed that way for a while after that. Before the turn of the century, the Brighton Franklin route connected with the LIRR at atlantic Ave. when that arrangement stopped after LIRR had control of the Manhattan Beach line, the connection was made to the Fulton El . Appears that it was used for about 20 years.