Outside Plant Pathway, Burial and Closure - Inspection

What it is

The outside plant pathway, burial and closure inspection is the construction and close-up record of customer-owned outside plant up to the building entrance. It covers the elements entered for the route: trench, burial and conduit segments with their plant class, the power sharing the trench, required and measured cover, length and bends between pull points, bend radius, concrete encasement, warning tape, separation from power and pipelines and the as-built deviation; building entrance conduits; handholes; route markers and warning tape; splice closures with their bonding, air valve and air pressure; and a checklist for maintenance holes, duct seals, sheath bonding, splices and record symbols. Cable performance (optical loss, splice loss and copper tests) stays on the cables form, and bonding inside the building, where the cable shield isolation gap and the primary protector conductors are bonded, belongs on the telecommunications bonding and grounding form. The record speaks for the segments, entrances, handholes and closures entered; it does not certify elements that were not inspected.

Why it is performed

Buried plant is the part of a telecommunications route that cannot be seen once the trench is closed. Cover that is too shallow for its plant class or for the power in the same trench, a conduit run too long or too bent to pull through, an entrance that lets water into the building, a handhole built where a maintenance hole belongs, a closure that breathes under water, or armor left unbonded all turn into faults that appear only after the cable is in service, when the repair means opening the ground again. ANSI/TIA-758-B sets the cover, conduit, entrance, handhole, marking and closure requirements for this plant; recording the measurements against them while the trench is open and at close-up, with the as-built deviations noted, is what lets the owner accept the route with evidence rather than assumption.

When it is performed

The form carries an inspection stage: during construction with the trench open, when cover, conduit geometry, warning tape, separations and the entrance conduits can be measured before backfill; at closure close-up, when each splice closure, its bonding, its air valve and its pressure test are recorded; and final acceptance, when the handholes, markers, checklist items and the as-built record are confirmed. A route can be recorded over several visits, each on its own stage. A started record needs at least one segment, entrance, handhole or closure to be inspected; otherwise it reads not determined. Shallow cover is resolved during construction, before backfill, because added protection and an evaluated deviation are the only way a short cover conforms.

How it is typically performed

The inspector walks the route with the design documents and, where the local code sets more cover than the standard, enters that value so the required cover follows it. For each segment the construction (conduit or direct-buried), plant class and any power in the trench set the required cover, which the form computes; the measured minimum cover, added protection and the deviation reference go beside it. Conduit segments take the length between pull points, the total bends, any reverse bend and whether a pull box was placed, two 90-degree bends within 3 m, the trade size and internal diameter against which the required bend radius is computed, the smallest radius measured, whether encasement is required and provided with the concrete strength, the drain slope, warning tape height and offset, the medium and distance to a power conduit, the pipeline separation, the design cover, the horizontal deviation from the design route and whether it was recorded on the as-built. Each entrance records the count of trade size 4 conduits, extension into undisturbed earth, reaming and bushing, fastening, slope, drainage box, plugs and pull box. Each handhole records length, width and depth, use, drainage, conduit count and cover. Markers and tape take spacing, content, color and width. Each closure records location, type, submersion exposure, air valve, armor and its bonding, bond hardware capacity, air-core cable with its water head and pressure, and the pressure test (psi, minutes, leak). The checklist marks maintenance hole equipment, base and lid, no power in a hole, sealed ducts, bonded sheaths and metallic members, closure splices and the Annex A symbols with a legend as satisfactory, unsatisfactory or not applicable. The form computes a conforms flag per element and the record's completeness.

What gets recorded

Identification: project, site, route or duct bank, inspection stage and the local code minimum cover where greater. Per segment: identifier or stations, construction, plant class, power in the trench, required and measured cover, added protection and deviation reference, length and bends between pull points, reverse bend, back-to-back bends, trade size, internal diameter, required and measured bend radius, encasement trigger, encasement and concrete strength, drain slope, warning tape height and offset, power separation medium and distance, pipeline type and separation, design cover, route deviation and whether it was recorded. Per entrance: trade size 4 conduit count, extension, reaming, fastening, slope, drainage box, plugs and pull box. Per handhole: dimensions, use, drainage, conduits and cover. Markers: spacing, content, tape color and width. Per closure: location, type, submersion, air valve, armor and bonding, bond capacity, air-core cable, water head and air pressure, pressure test values and leak. Checklist answers, the as-built record reference, the record of inspection and the comments and deficiencies.

How results are evaluated

The verdict rests on the computed conforms flags. A segment conforms when its cover is at or above the required value: 750 mm for toll or trunk cable and for a main conduit run, 600 mm for feeder or distribution, 450 mm for a service or drop, raised to the greater of that and the depth the power voltage in the trench requires, or to the local code value where that is more; exactly the required cover conforms, and shallower cover conforms only with added protection and an evaluated deviation, which still raises an issue. A conduit segment also keeps at most 183 m and 180 degrees of bends between pull points, a pull box at any reverse bend, a sweep radius of at least 6 times the internal diameter up to trade size 2 and 10 times above, and concrete encasement where nonmetallic conduit lies under traffic or sharp bends. An entrance conforms with at least three trade size 4 conduits plus a spare, extended 600 mm or more into undisturbed earth, reamed and bushed, fastened, sloped to the exterior and plugged, with a drainage box where water may enter and an inside pull box where the run calls for it. A handhole conforms at no more than 1.2 m in length, width and depth, drained, and never in a main conduit system or in place of a maintenance hole. A closure below ground is air and water tight, a hermetically sealed closure carries an air valve, armor and metallic members are bonded, and air-core copper cable at a closure that is not aerial is held at the pressure its water head requires. Any unsatisfactory checklist item fails. Everything else raises an issue only: warning tape placement, drain slope, separations from power and pipelines, an unrecorded as-built deviation, handhole conduit count and cover, marker spacing and tape width, closure exposure advice, bond hardware capacity, air-core cable at a buried closure, and the sealed-closure pressure test, which the form takes at 5 psi for 5 minutes as a field convention disclosed on the form. Conforms means no element entered was found nonconforming; a record with no element inspected reads not determined.