Glossary of Terms


Navigate the Glossary either via the interactive search or filter by alphabet or number.

UIC
International Union of Railways


Disciplines:
Abbreviation for 'International Union of Railways'.
Alternative
Disciplines: ALL Disciplines
Unattended Interlocking
The term used to describe an interlocking which is not being controlled by a signaller. At some unattended interlockings the signals and points are worked by the train crew.

Regional
Disciplines: Train Control
Unattended Location
A signalling location or block location that is not a remote controlled location, and where a Signaller is not on duty. Or A location not attended by a Competent Worker for safeworking purposes.

Preferred
Disciplines: Train Control
Unauthorised
Not given approval, or exceeding the limit of authority

Preferred
Disciplines: ALL Disciplines
Undercutting
The process of removing from the track, all ballast above the formation.

Preferred
Disciplines: Infrastructure
Unidirectional
Allowing for normal travel in one direction only according to the infrastructure and system of Safeworking in use.

Preferred
Disciplines: ALL Disciplines
Unidirectional Signalling
Signalling provided to allow the movement of trains in one direction only over a line.

Regional
Disciplines: Train Control
Unit
A unit refers to a container, trailer, or a container mounted onto a trailer.

Regional
Disciplines: Operations
Unit Lever Operation
A method of signalling control with a separate lever for each set of points, each release switch and each signal. In setting up a signal route, the signaller is required to operate the levers for required points and/or releases individually before operating the lever for the particular signal. This contrasts with route control systems, entrance/exit or one control switch.

Regional
Disciplines: Train Control
Unsprung Mass
The mass of a wheel, or wheelset, and other associated components which are not dynamically isolated from the track by vehicle suspension arrangements. This includes components due to the rotational inertia of any traction drive and motor casing unless effectively isolated by means of resilient couplings and frame suspended traction motors.

Preferred
Disciplines: Rolling Stock
Up Line
In a double line area, the lines are generally referred to as the Up Line and Down Line. Usually, the up line is used by trains travelling towards the State Capital. However, local notices should be referenced to check this at any location.

Regional
Disciplines: Operations, Train Control
Upgradeability
the measure of the ability to be upgraded or modified

Preferred
Disciplines: ALL Disciplines
Upgrading
means any major modification work on a subsystem or part of a subsystem which improves the overall performance of the subsystem.

Preferred
Disciplines: ALL Disciplines
Utility
A powerline, pipeline, conveyor, telecommunications line or similar item, or a duct carrying any of these, together with associated equipment and systems.

Preferred
Disciplines: ALL Disciplines