ULUp local. Refers to the train that is on, or to the track itself, that carries the local traffic (around the station) in the up direction. See also down local. |
UMUp main. Refers to the train that is on, or to the track itself, that carries the main through traffic in the up direction. See also down main. |
Uninterruptible Power SupplyAn electrical device that provides instantaneous power to a circuit when the main power source fails. |
Unit of competencyA training package has many units of competency. A unit of competency has multiple elements of competency. Each element of competency describes what a person should be able to do to achieve the unit of competency. These are broken further into performance criteria. |
Up directionIn most countries — but not all — a train travelling in an "up" direction is travelling towards the capital city. Where a train travels between two regional cities, one may be designated the up direction. The train is often referred to as an up train (i.e. the 13:20 up train). The signals that face this train are often called up signals. Also see down direction. |