it mostly a failure. The backward-driving rear cylinders were a poor choice; mounted next to the firebox, each constrained the other's size, and the area by the firebox was dusty and hot, which increased cylinder wear. These problems had previously been encountered on the B&O's N-1 duplex. The length of steam pipes required also meant a fair degree of power loss. Added to this, the passenger locomotive-sized drivers were not a good choice for freight service. From its experiences with this locomotive, the PRR came up with an improved design, the Q2. This had smaller drivers, cylinders mounted in front of the wheels they drove, was built largely unstreamlined and was designed for freight service only. References Bibliography Citations 4-6-4-4 locomotives Duplex locomotives Experimental locomotives Freight locomotives Individual locomotives of the United States Q1 Scrapped locomotives Standard gauge locomotives of the United States Steam locomotives of the United States Streamlined steam locomotives Unique locomotives