VRIOGS 012.2.1 - Public Transport Victoria

22 VRIOGS 012.2.1 REVISION A
approved by the Infrastructure Manager ( should this be the case then the trough
and lid shall be capable of carrying a load of 4.5 tonnes as a minimum over a
contact area of 100 mm x 300 mm applied to any part of the lid.)
l) Alignment for the GLT route should be outside the clearance limits of the minimum
structure gauge detailed in VRIOGS 0001 Structural Gauge Envelopes-Minimum
clearances for Infrastructure adjacent to the Railway. However small ground level
troughing as used for local equipment access may encroach into the clearance
diagram dimensions, provided it is installed so that is does not become an
impediment to rail sleeper maintenance. Infringements to these limits require
approval by the Infrastructure Manager.
m) Where the communication cable is in conduit or separated by a permanent rigid
barrier, the separation to HV cables shall be 150 mm minimum horizontal separation
with the minimum distance from sheath to sheath around the barrier being 175mm.
and in accordance to AS/ACIF S009.
n) Air mains installed in GLT shall be laid above the signalling cable.
o) Signalling fibre optical cables do not require separation from power cables, however
it is recommended that the optical fibre cables be installed in separate conduits
where possible, or in subduct within the power conduit, GLT or trunking in order to
provide mechanical protection.
p) For directional changes of 45 degrees or greater in GLT, the change shall be made
using turning chambers.
q) Where there is a need to provide an enlarged enclosure for cable joining, air
reservoir, etc, such enclosures are to be constructed of reinforced concrete,
maintaining a fixed concrete partition for separation of services. The GLT is to butt
the enclosure squarely sealing all joints. Expanded chambers (which may be
fabricated from 6 mm galvanised chequered plates) shall have their lids cut to
required size.
r) All cut edges of galvanised plate shall be de-burred and painted to protect from
corrosion. Galvanised steel lids shall be secured.
s) GLT shall have the means to enable bottom entries or exits.
t) For side entry/exit, an access hole may be cut into the side wall. The cutting angle
shall not exceed 45 degrees, so that a minimum cable bending radius is maintained.
Sharp edges shall be removed and the access sealed and cables protected after
cables are in place using an enclosure or approved sealant.
u) GLT of any type construction shall not be installed under rail lines
v) Concrete troughing shall be accurately manufactured to enable each segment to
interlock securely with each other and lids to fit securely on the top of the troughing
without rocking.
w) Where GLT is being installed near a running line it shall be positioned such that it
will not obstruct or be likely to be damaged by, the removal and replacement of
railway sleepers.
x) GLT to be installed within 3 metres of the face of the nearest running rail shall be
installed such that the top of the GLT lid is not higher than 200 mm below the
underside of adjacent sleepers.
7.2 Troughing Route Capacity
a) One or more troughs shall be installed to provide the necessary capacity to
accommodate the cables and shall provide 25% spare capacity, in each
compartment of the trough, to provide for future requirements.
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