| Horseshoe Curve-1966. Here is an original photo that?I took at the Pennsylvania Railroad's Horseshoe Curve near Altoona, Pennsylvania, during early May of 1966. Shown here (L to R) are PRR engines #6507, #6036, and #6307. All three were built in 1965. #6507 is a GF-25A built by General Electric and rated at 2,500 horsepower. Ý"6036 is an EF-25A built by EMD and rated at 2,500 horsepower. #6307 is an AF-27 built by the American Locomotive Company and rated at 2,700 horsepower. They are pushing a westbound merchandise freight. |