[Nomen Nescio]

Это один из т.н. дополнительных сигнальных огней (auxiliary light), применяемый, согласно их ПТЭ (NORAC rules) при подходе к переездам.

Матан на языке оригинала

Скрытый текст:

22. Engine lights

...b. Auxiliary Lights
The leading end of leading engines that operate over
public highway crossings at grade at speeds greater than
20 MPH must be equipped with auxiliary lights. Auxiliary
lights consist of two ditch lights (auxiliary lights on
steady), two crossing lights (auxiliary lights alternately
flashing), or one oscillating light (auxiliary light that
moves in a circular or figure eight pattern). Auxiliary
lights are considered operative when they illuminate after
the engine horn and/or bell is sounded or the auxiliary
light switch is activated.
Auxiliary lights must be operational before the engine
leaves its initial terminal, and must be displayed when the
engine is approaching and operating over public highway
crossings at grade.If one of a pair of auxiliary lights fails en route, the
train may continue at Normal Speed, but the defective
auxiliary light must be repaired no later than the next
calendar day inspection.
If all auxiliary lights fail en route, the train must not exceed
20 MPH while the leading end of the train is operating over
public highway crossings at grade, and the auxiliary light(s)
must be repaired at the next forward repair point.