3-009-043 - The Print Collector/Heritage Images

The International Exhibition: Austrian locomotives - the Duplex engine, 1862. This locomotive is the first application of a doubled system of cylinders, pistons, and cranks...The State Railway Company required twelve express-engines to work safely over lines having gradients of 1 in 150, and curves 930ft. radius...The duplex...differs in no other respect from its compeers except having four cranks and four cylinders...The double cranks on the driving-axle look small in proportion to the usual dimension of such work; but the diminution in size is owing to the employment of Krupp's steel in the forgings of several working parts of this engine. In working railways there are three several motions acting in unity, and forming compound motion, influencing at high speed the steadiness of the locomotive when in a state of forward progression...This description of motion is termed swing-jerking, rocking, and side-swinging. To lessen the effect produced by these injurious actions the duplex was designed, and one of the great objects sought to be obtained was that of diminishing, or nearly superseding, the use of the balance-weight usually placed on the driving-wheels of locomotives'. From "Illustrated London News", 1862.