 The P-7 Pacifics were particularly targeted for improvements, culminating in the "Cincinnatian", for which four of the engines were upgraded and streamlined to a design by Olive Dennis, who also supervised the refurbishment of the rolling stock.The B&O did not emphasize standardization, and when road diesels were bought, they were purchased from nearly every manufacturer.By the time of the railroad's purchase in 1963, though, they were well on their way to becoming the all-EMD line which they remained to the end.