page_title: Jackshaft (locomotive)
section_title: Ganz and Kandó linkages
hierarchical_section_title: Jackshaft (locomotive) / Suspension movement / Ganz and Kandó linkages
caption_attribution_description: English: Design of the power transmission of italian electric triphase locomotives FS E.554 Italiano: Disegno di trasmissione del moto a biella articolata delle locomotive elettriche italiane FS E.554
context_page_description: A jackshaft is an intermediate shaft used to transfer power from a powered shaft such as the output shaft of an engine or motor to driven shafts such as the drive axles of a locomotive. As applied to railroad locomotives in the 19th and 20th centuries, jackshafts were typically in line with the drive axles of locomotives and connected to them by side rods. In general, each drive axle on a locomotive is free to move about one inch vertically relative to the frame, with the locomotive weight carried on springs. This means that if the engine, motor or transmission is rigidly attached to the locomotive frame, it cannot be rigidly connected to the axle. This problem can be solved by mounting the jackshaft on unsprung bearings and using side-rods or chain drives.
  Jackshafts were first used in early steam locomotives, although the designers did not yet call them by that name. In the early 20th century, large numbers of jackshaft-driven electric locomotives were built for heavy mainline service. Jackshaft drives were also used in many early gasoline and diesel locomotives that used mechanical transmissions.
context_section_description: Some of the more complicated linkages used for express locomotives were the Ganz, Kandó or Bianchi linkages. These were in the form of an inverted triangle, reaching down from the high-mounted motor jackshaft to the wheel axle line.
  The Ganz form was used on the Hungarian-built Les Belles Hongroisses 2BB2 400 locomotives for the French PO. This had four links forming the triangle, with the two upper vertices mounted to the locomotive frame (through a short swinging link) and to the jackshaft crankpin. The lower apex of the triangle contained a short triangular link, which linked the sides of the triangle to the wheel crankpin. By tilting this link, the suspension movement was absorbed. This linkage ran well at speed and as it was composed entirely of pivoting joints with no sliding, there was no lost motion. It was however complex, heavy and unbalanced.
  The Kandó linkage was similar in compensation, but the upper vertices were carried by a pair of motor jackshafts.
  The only one of these linkages with a widespread or long service life was the symmetrical, and better-balanced, Bianchi linkage, used in Italy.
caption: Bianchi linkage, used in Italy
exif: {}