Where does derailment collide?

In railway engineering, derailment is the event in which a wheelset leaves the rails, whether by the flange climbing over the railhead, by the track gauge spreading, or by the vehicle rolling or lifting under lateral and vertical forces. The Handbook of railway vehicle dynamics edited by Iwnicki treats the contact mechanics and the ratio of lateral to vertical wheel force (Nadal's criterion) that decide when a wheel will climb and run off, and this physical meaning is the literal origin from which the psychiatric and managerial uses borrow. The referent is a loss of guidance of a running vehicle, assessed by force ratios and safety margins against climb, and the later metaphorical meanings keep only the image of running off the intended line.[1]

Unit

The lateral-to-vertical wheel-force ratio at which a wheel climbs off the rail

Recovery means

Not applicable

Measured by

Evaluated by the Nadal limit and derailment coefficient (L/V ratio), flange-climb distance, and wheel-unloading criteria in testing and simulation

In psychiatry, derailment is a disorder of thought and speech in which a person slides from one idea to a loosely related or unrelated one without awareness of the gap, a cardinal sign in psychotic and schizophrenic disorders long described as loosening of associations. Andreasen's 1979 Thought, language, and communication disorders gave the sign an operational definition and reliability criteria so clinicians could rate it from a patient's spontaneous speech. The referent is an observable breakdown in the connectedness of discourse, scored from speech samples, and it borrows the railway image of leaving the track while sharing nothing physical with a train or a stalled career.[2]

Unit

The presence and severity of off-track slippage in spontaneous speech

Recovery means

Derailment may lessen as the underlying disorder is treated; it is a state sign rather than a permanent trait

Measured by

Rated from spontaneous-speech samples using defined thought-disorder scales such as Andreasen's assessment of thought, language, and communication

In the study of leadership, derailment is the pattern in which a manager once judged to have high potential is fired, demoted, or plateaued well short of expectations, despite earlier success. Van Velsor and Leslie's 1995 Why executives derail: Perspectives across time and cultures synthesized the recurring causes (problems with interpersonal relationships, failure to deliver, inability to build and lead a team, and inability to adapt) found across their research programs. The referent is a career outcome in an organization, identified by the gap between a leader's early promise and later fall, and it takes only the metaphor of running off the track from the railway meaning.[3]

Unit

The failure of a high-potential career to continue its expected rise

Recovery means

Not applicable

Measured by

Identified by comparing early high-potential ratings with later outcomes (termination, demotion, plateauing) and the behavioural factors preceding them