The town of Wilmerding Pennsylvania was a significant place in the history of railroads, not only for its trackside affiliation with the PRR, but because of a local manufacturer, The Westinghouse Air Brake Company. In 1890 George Westinghouse opened a plant in Wilmerding, 13 miles east of the City of Pittsburgh to build one of the primary devices that lead to the rapid growth and speed of the modern railroad, the air brake. Peaking at aprx. 3000 employees, Westinghouse was a forward thinking employer, the first to offer 9 hour work days, 55 hour work weeks, affordable housing for employees that diverged from the typical dismal "company towns" typical through out PA, and cultural activities for employees and their families. Further East the PRR had a sprawling yard complex know as Pitcairn Yard. The facility, originally built in the late 1880's, served as a classification facility for Westbound Pittsburgh Division traffic and Eastbound Panhandle Division Freight. Once the largest facility on the Pittsburgh Division, having multiple roundhouses, car shops and two hump yards, Pitcairn lost its status as in the 1950's with the construction of the Samuel Rea Car Shops in Hollidaysburg and the modernization of Conway Yard, west of Pittsburgh.
One last and final significant note on the Turtle Creek valley was the divergence of the Port Perry Branch from the Mainline. The Port Perry Branch was part of a traffic bypass for the PRR, joining the Monongahela Branch in Duquesne to route traffic around the congested Mainline and Station Terminal Complex of the Steel City. Traffic from the Mainline could take the Port Perry to the Mon, connect with the Panhandle Main, or back to the Fort Wayne Mainline West via the Ohio River Connecting Bridge. In addition, the Perry also provided connection with the Mon Valley Line south to the various coal mines, coke facilities, and mills along the Monongahela River, and ultimately connected to the Pittsburgh and Lake Erie and infamous coal carrier Monongahela Railroad in West Brownsville Pennsylvania.