UIC Classification of Locomotive Axle Arrangements - Structure

Structure

Whereas the Whyte notation counts wheels, the UIC notation counts axles.

Upper-case letters
the number of consecutive driving axles, starting at A for a single axle. C thus indicates three consecutive pairs of driving wheels.
Numbers
consecutive non-driving axles, starting with 1 for a single axle.
Lower-case "o", suffixing the driving wheel letter
axles are individually driven by electric traction motors.
Prime sign " ′ "
the axles are mounted on a bogie.
Plus sign "+"
the locomotive or multiple unit consists of permanently coupled and mechanically separated individual vehicles.
Brackets
groups letters and numbers describing the same bogie. For example, (A1A) indicates a three-axle bogie with the outer two axles driven. When brackets are used a prime is not needed to indicate a bogie. Mallet locomotives can be indicated by bracketing the front power unit — for example, the Union Pacific Big Boy, 4-8-8-4 in Whyte notation, is (2′D)D2′ in UIC notation.

Garratt-type locomotives are indicated by bracketing or placing plus signs between all individual units.

Other suffixes
  • h: Superheated Steam (German: Heißdampf)
  • n: Saturated Steam (German: Nassdampf)
  • v: Compound (German: Verbund)
  • Turb: Turbine
  • number: number of cylinders
  • t: Tank locomotive
  • G: Freight (German: Güterzug – freight train). Also used to indicate shunting locomotives
  • P: Passenger (German: Personenzug – passenger train)
  • S: Fast passenger (German: Schnellzug – express train)

The most common wheel arrangements in modern locomotives are Bo′Bo′ and Co′Co′.

Read more about this topic:  UIC Classification Of Locomotive Axle Arrangements

Famous quotes containing the word structure:

    I really do inhabit a system in which words are capable of shaking the entire structure of government, where words can prove mightier than ten military divisions.
    Václav Havel (b. 1936)

    The philosopher believes that the value of his philosophy lies in its totality, in its structure: posterity discovers it in the stones with which he built and with which other structures are subsequently built that are frequently better—and so, in the fact that that structure can be demolished and yet still possess value as material.
    Friedrich Nietzsche (1844–1900)

    ... the structure of a page of good prose is, analyzed logically, not something frozen but the vibrating of a bridge, which changes with every step one takes on it.
    Robert Musil (1880–1942)