English: Inside the Rotation, Processing and Surge Facility, or RPSF, at the Kennedy Space Center in Florida, an overhead crane lifts NASA locomotive No. 2 off of its trucks to be moved aside, clearing the way for locomotive No. 3 to be raised off its trucks and moved into position atop the trucks previously used by locomotive No. 2. The RPSF was built to support work on the solid rocket used motors during the space shuttle era. The facility had never previously been used for another purpose, but is now free to serve other customers. With rails running into the building's high bay and a pair of heavy-lift cranes positioned overhead, the facility's capabilities were a perfect fit for the NASA Railroad's needs. Railroad managers wanted to trade the wheel and axle assemblies, or trucks, of locomotives No. 2 and No. 3. Locomotive No. 3 was painstakingly restored in recent years by the NASA Railroad team, and handles much of the rail work required at the center in the post-shuttle era. But the trucks on locomotive No. 2 are in better shape and are more environmentally friendly.