Structural Gauge Envelopes - Public Transport Victoria

VRIOGS 001 Revision B 11
l) 300m: Add 390mm to the horizontal clearance on the inside of the curve and add 135mm
to the horizontal clearance on the outside of the curve
m) 200m: Add 480mm to the horizontal clearance on the inside of the curve and add 200mm
to the horizontal clearance on the outside of the curve
Note these figures are based on a 100mm and 0mm Cant to provide for clearances on the inside and
outside rail on curved track respectively. Where a curve radius value falls between the curve radius
as given in points c) to m), the tighter curve radius shall be used.
Alterations to the structure gauge envelope on curved track that provide allowance for Cant elevation
and rolling stock Centre and End throw may also be derived by the use of the principles outlined in the
Section 11.
If these principles are used it shall be demonstrated to the Public Transport Victoria, Technical
Services Division and to the ARO on how the allowances for curved tracks have been derived.
SECTION 5.0 Deviations and Critical Clearances to Infrastructure
5.1 Deviations from the Minimum Clearances to Infrastructure
Clearances less than the minimum stipulated in this Standard are only permissible on works where
there are alterations to existing track geometry, the installation of additional tracks within an existing
rail environment or where significant physical constraints exist that prohibit complying with the
dimensions outlined in this Standard. No deviations to the minimum clearances outlined in this
document shall be employed in a particular situation if more clearance can be provided. In
cases where existing Infrastructure does not conform to these conditions, refer to section 5.2 for the
absolute limits.
Any deviations to this Standard shall be received prior to the construction/modification of the
Infrastructure. Where deviations are proposed, an ARO shall apply its Engineering Change/Waiver
process to determine if the deviations are acceptable. In the event that an Engineering Change/Waiver
process is approved the absolute minimum conditions as outlined in Section 9 shall be met.
5.2 Critical Clearances to Infrastructure
Critical clearances are defined as those where Infrastructure is situated closer than, or at the
minimum clearance specified in Section 9.0 and cannot be improved without substantial changes to
the Infrastructure. It is only applicable to a specific location and requires the application and approval
of the AROs Engineering Change/Waiver process to demonstrate that the risk of collision is
manageable. It may incorporate site specific track and rolling stock tolerances and may require
conditions to be placed on the location or rolling stock such as a reduction in train speeds or an
increase in inspection or maintenance. Infrastructure that has been identified with a critical clearance
shall be defined as an Identified Structure which is held and updated by the ARO responsible for that
particular railway.
Due to the reduced clearances and the increased risk associated with these it is essential that:
a) The ARO is to conduct a post construction clearance survey to verify that the dimensions
are not less than those specified in the Engineering Change/Waiver process.
b) The actual track design position shall be tied into a monitoring mark/s to enable manual
checking by a track inspector at regular intervals and allow checking after any maintenance
work has been carried out.
NOTE: This document is controlled only when viewed on the VRIOG Engineering Standards website. Any other
copy of this document is uncontrolled, and the content may be inaccurate.