Climax locomotive

A Climax locomotive is a type of geared steam locomotive in which the two steam cylinders are attached to a transmission located under the center of the boiler. This transmits power to driveshafts running to the front and rear trucks.

Rush S. Battles patented the basic design in 1891. Battles' design had horizontal cylinders connected to the drive shaft through a 2-speed transmission. The drive shaft passed just above the axle centers, requiring the use of hypoid bevel gears to transfer power to each axle. Unlike the later and somewhat similar Heisler design, there were no side rods on the trucks and all gearing was open, exposed to the elements. Battles' patent describes the core design that became the Class B Climax, and his patent illustrations show the name Climax emblazoned on the locomotive cab.

Charles D. Scott, an inventor who had previously proposed a less successful geared steam locomotive, patented improved versions of Battles' trucks in 1892 and 1893. Scott's 1892 patent was the basis of the Class A Climax. His 1892 patent included gear-case enclosures.

All Climax locomotives were built by the Climax Manufacturing Company (later renamed to the Climax Locomotive Works), of Corry, Pennsylvania. In addition, an agency and service facility was established in Seattle, Washington to sell and maintain locomotives for west coast buyers. Production began in 1888 and the last Climax locomotive was produced in 1928. Between 1000 and 1100 were built.

Many loggers considered the Climax superior to the Shay in hauling capability and stability, particularly in a smaller locomotive, although the ride was characteristically rough for the crew.

Climaxes were built in three distinct classes:

These featured a steam engine unit with two vertical cylinders mounted in the center of the locomotive. Class A Climaxes had a frame similar to a flatcar with wooden boxcar-like bodywork built up above it to protect the crew and fuel from the elements—this could be more or less covering between locomotive to locomotive. The front half of the locomotive, in front of the engine unit, contained the boiler. In smaller examples this may have been a vertical boiler, while in larger ones a tee boiler was employed. Class A Climaxes were small locomotives, generally under seventeen tons. Class A Climaxes, unlike Heisler and Shay locomotives, had two-speed gearboxes.

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