Flexicoil truck

Flexicoil suspension is a wear-resistant and maintenance-free suspension system, used in railway vehicles. It is a secondary suspension, installed between the body and the bogie of the locomotive, passenger car or wagon so fitted.

This type of suspension is most commonly used in modern rail passenger cars when air suspension is not required, since it is cheaper to buy and to maintain than air suspension.

The word "Flexicoil" was coined by General Motors' Electro Motive Division, to describe a suspension system fitted to some of the diesel locomotives in its range. As early as the 1930s, flexicoil suspensions were being used in locomotives in Spain, the Soviet Union and Africa.

Flexicoil suspension technology in high speed electric locomotives was pioneered in Germany in the 1950s and 1960s, in various DB standard electric locomotives, and especially the DB Class 103. Between 1969 and 1971, British Rail conducted trials of a flexicoil suspension system in a British Rail Class 86 locomotive, no E 3173, which was affectionately nicknamed "Zebedee", after the jack-in-the-box character in the BBC television series The Magic Roundabout. These experiments were successful, and led initially to the rebuilding of 56 members of the class with flexicoil suspension, as class 86/2. Ultimately, all members of class 86 were fitted with flexicoil suspensions.

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