Section 5: Other Maintenance Considerations
Duct Cable
Duct cable is a conduit system and must be treated as such.
If the system is damaged the duct may be spliced, however, the electrical
conductors in the duct cannot be spliced inside the duct. Depending
on the length of the duct run, maintenance personnel may want to
remove the existing wire and pull new conductors or consider placing
a ground box and splicing the conductors.
If the conductors are spliced, splicing procedures in the
Electrical Details standards should be used to make the splice.
Heat shrink tubing or gel caps are the only recommended splice insulators. Where
two or more conductors enter one heat shrink tube, wrap the conductors
with heat shrink tape. Heat shrink tubing must then be applied to
insulate the splice. It is important to note that when duct cable
is severed to make a splice, the ends of the duct must be cut straight
and neat. Ends must also be reamed to remove sharp edges.
Grout
Prior to about 1975, grout was required to be placed between
the illumination pole base plates and concrete foundations. Since
then, it has been determined that such grout placement under pole
or sign bridge base plates causes moisture to become trapped. This,
in turn, contributes to excessive corrosion of the pole, support,
base plate, anchor bolts, nuts, and other appurtenances.
It is imperative, therefore, that this grout be removed from
under existing poles and not placed under newly installed poles.
Anchor bolts should then be cleaned and painted with zinc rich paint. If
severe deterioration is discovered, a more detailed investigation
should be made into the remaining strength of the bolts.
Rehabilitation of Old Circuits
For older roadway illumination systems where maintenance is
excessive due to faulty circuits, rehabilitation of the circuits
by TxDOT should be considered to reduce maintenance costs.
When practicable, existing two-wire circuits should be replaced
with a three-wire system that includes a continuous grounding conductor.
Maintenance Level of Service
The
Maintenance Management Manual
establishes guidelines for planning and performing various maintenance activities in accordance with available funds. Three possible funding levels are defined: desirable (the highest), acceptable, and tolerable (the lowest). Maintenance priorities are assigned based on the level of funding, and maintenance forces are directed to “substantially maintain” the various highway components accordingly.
of the Maintenance Management Manual
explains the concept in detail, and
includes the maintenance level of service guidelines for highway illumination.For general guidelines on maintenance practices related to highway illumination, see the
Maintenance Operations Manual
, Chapter 4,
.Maintenance Responsibilities of Cities
Maintenance of freeway illumination systems provided by some
cities under agreement with TxDOT sometimes falls below acceptable
levels. Unless an adequate level of lighting maintenance is being
provided by a city, no further agreements for city maintained illumination
should be executed with that city until corrective action is taken.
Problems
Maintenance problems involving electrical and illumination
design and materials should be brought to the attention of TRF so
that possible alterations can be made to the appropriate specifications
and standards.