The physical-interface division of the handbook. Division 20 covers the maintenance of the base can, frangible coupling, cable entry, internal pit, foundation, pavement interface and drainage that together support every AGL fixture — ensuring stability, correct elevation, correct alignment and protection from water ingress.
A base-can defect is never "just civil." A deteriorated base can or civil interface can cause fixture movement, incorrect elevation, misalignment, water ingress, cable damage, connector deterioration, frangible-component problems and FOD — so both sides of the interface are inspected and restored together, never in isolation.
Safety before work: isolate and lock out the affected series circuit before opening a base can or disconnecting any connector, transformer or cable — never open a live series circuit. Obtain the airside work permit and operational coordination before working on or near active pavements.
Every base-can or civil finding in this division follows the same underlying sequence, working outward from the fixture to the surrounding pavement.
Core principle: a stable base can + sound civil interface + proper drainage + correct fixture geometry = a reliable AGL installation.
How a base-can or civil finding is classified after inspection determines whether it is monitored, planned, or escalated as a priority response.
Stable, intact and properly positioned.
Minor deterioration without functional impact.
Base-can/civil interface affecting equipment condition.
Significant movement, structural damage, severe water ingress, or unsafe condition.
A quick-reference table mapping common findings to the typical maintenance action across the base can and civil interface.
| Finding | Typical Maintenance Action |
|---|---|
| Dirty base can | Clean |
| Damaged base can | Repair/replace as appropriate |
| Base-can misalignment | Correct |
| Base-can settlement | Investigate/correct |
| Loose mounting bolt | Tighten (to specified torque) |
| Damaged hardware | Replace |
| Damaged frangible coupling | Replace |
| Open cable entry | Seal |
| Water accumulation | Remove/investigate |
| Poor drainage | Correct |
| Corrosion | Treat/replace |
| Foundation crack | Assess/repair |
| Concrete deterioration | Repair |
| Pavement damage | Repair |
| Settlement | Correct civil interface |
| Damaged grout | Repair |
| Damaged pit cover | Replace |
| Damaged pit frame | Repair |
| Vegetation | Remove |
| FOD/debris | Remove |
| Disturbed area | Restore |
Grouped by interface category — click any topic to expand its checks and closing note.
Also check: the relationship between the base can and the surrounding pavement.
Standard: verify elevation relative to the surrounding pavement and approved installation requirements; record abnormal level conditions.
Standard: tighten to the manufacturer / installation-specified torque using the approved fasteners — over-tightening or substituting hardware can damage the base can, compromise sealing and affect frangibility.
Standard: the replacement must preserve the intended frangibility of the installation, using the specified fasteners and tightening torque.
Action: restore sealing using the approved method.
Purpose: cleaning also provides safe access for inspection.
Rule: removing water is not the correction — identify and correct the entry path, or the water will return.
Action: correct the drainage arrangement as appropriate to the installation.
Standard: repair should restore the intended civil interface without obstructing equipment access or drainage.
Goal: repair the interface to restore a stable and safe surface.
Standard: correct the cause as well as the level — settlement corrected without addressing its cause is likely to recur.
After repair: verify mechanical stability and equipment geometry.
Objective: prevent repeated water accumulation around the AGL installation.
Standard: the cover should be secure and suitable for the installed location.
Standard: vegetation control should follow airport environmental and airside requirements.
Standard: conduct a final FOD inspection after maintenance.
Standard: record the final condition after any civil/base-can work.
Standard: where a formal water-tightness test is specified, follow the applicable test procedure.
Standard: inspect the complete surrounding area before closing the maintenance activity.
Every topic in this division ultimately feeds this master sequence — the same eleven-step arc regardless of the triggering finding.
Base can and civil interface examined for defects.
Dirt, debris and contamination removed for a clear condition assessment.
Base can, foundation, pit cover and pit frame checked for structural condition.
Base-can and fixture elevation checked against the surrounding pavement.
Fixture orientation, alignment and position confirmed.
Seals, gaps and cable protection inspected.
Water accumulation, source and drainage path assessed.
Civil or mechanical defect corrected using the approved method.
Surface, drainage and surrounding area returned to a safe condition.
Level, alignment, cable entry and water-tightness confirmed.
Asset, civil condition, work performed and final verification documented.
Quick answers about base can & civil interface maintenance, based on the topics in this division.
It is the physical-interface division covering the base can, frangible coupling, cable entry, internal pit, foundation, pavement interface and drainage that support the AGL installation.
Division 20 (Base Can & Civil Interface Maintenance) contains 30 topics in three groups: Group A Base Can (12 topics), Group B Civil Interface (12 topics) and Group C Post-Maintenance (6 topics).
A deteriorated base can or civil interface can cause fixture movement, incorrect elevation, misalignment, water ingress, cable damage and connector deterioration.
Isolate and lock out the affected series circuit before opening a base can or disconnecting any connector, transformer or cable, and never open a live series circuit.
A stable base can, a sound civil interface, proper drainage and correct fixture geometry together.
Eleven steps working outward from the fixture: Inspect, Clean, Check Structure, Check Level, Check Alignment, Check Cable Entry, Check Water/Drainage, Repair, Restore, Verify and Record.
Good (stable, intact, routine PM), Acceptable (minor deterioration without functional impact, monitor), Deteriorating (developing civil or mechanical defect, planned maintenance), Defective (affecting equipment condition, corrective maintenance) and Critical (significant movement, structural damage, severe water ingress or an unsafe condition, priority or emergency response).
Base-can settlement is investigated and corrected, a loose mounting bolt is tightened to the specified torque, an open cable entry is sealed, water accumulation is removed and investigated, poor drainage is corrected, a damaged pit cover is replaced, and a disturbed area is restored.
Base can and civil interface maintenance is more than tightening a cover bolt.
Build the technical knowledge to understand foundation integrity, drainage behaviour, frangibility, and how pavement and civil conditions interact with the electrical asset beneath.
Maintain the interface. Protect the foundation. Understand the pavement.
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