A Climax locomotive is a type of geared steam locomotive built by the Climax Manufacturing Company (later renamed to the Climax Locomotive Works), of Corry, Pennsylvania. These had two steam cylinders attached to a transmission located under the center of the boiler, which sent power to driveshafts running to the front and rear trucks. Some 1000-1100 were built in three classes - A, B, and C - between 1888 and 1928. Invention and production The invention of the Climax locomotive is attributed to Charles D. Scott, who ran a forest railway near Spartansburg, Pennsylvania between 1875 and 1878. A lumberjack of considerable mechanical ingenuity, Scott sought to bring an improved logging locomotive of his own design to market and brought the drawings to the nearby Climax Manufacturing Company in Corry, Pennsylvania. The first four Climax locomotives were built and delivered in 1888. The design patent was filed in February in the same year and granted in December. The invention was not patented in the name of Scott, as he had only a limited education, so he left the drawings to his brother-in-law George D. Gilbert, who was a civil engineer by profession and worked for Climax. Gilbert had the invention patented in his name without mentioning Scott. Gilbert patent Gilbert's patent specified an upright maritime-type two-cylinder steam engine, a 2-speed transmission and a drivetrain in the underframe passing just above the axle centers. The patented differential for transferring the power from the drive shaft to the wheels was only used in the first Climax locomotives. In a similar way to that used in an automobile, the force was transferred to the two wheels of an axle separately, with one wheel being firmly connected to the wheelset shaft and the other wheel being able to rotate loosely on a sleeve around the shaft. The idea of the differential transmissions was to reduce resistance on tight bends by allowing one wheel to turn with fewer revolutions than the one at the other end of the axle. The design did not prove workable, because when driving at the adhesion limit, less tractive effort could be exerted compared to locomotives with rigid wheelsets. Battles patent Rush S. Battles patented the basic design of the drivetrain without the differential, using simple hypoid bevel gears to drive the wheelsets with normal fixed wheels. Unlike the later, somewhat similar Heisler design, there were no side rods on