The dedicated mechanical, mounting, civil-interface and structural failure section of the AGL Failure Database. Covers base-can corrosion, frangible coupling failure, loose mounting, foundation settlement, water accumulation, hardware corrosion, structural damage and the full diagnostic hierarchy built around them — always separating the physical mechanical failure from its cause and from its operational consequence.
Key principle — Separate the physical mechanical failure from its cause and from its operational consequence. For example: vehicle impact → mounting damage → fixture misalignment → incorrect light aiming → operational/photometric impact. A tilted or misaligned fixture is usually a condition or symptom, not the root cause itself.
Core categories — Base-can corrosion, frangible coupling failure, loose mounting, foundation settlement, water accumulation, hardware corrosion and structural damage are the source framework's core mechanical/structural categories. The remaining thirteen topics expand these into a complete diagnostic hierarchy for field investigation, RCA and reliability trending.
Corrosion or deterioration of the base can affecting its structural integrity, mounting interface or serviceability.
Physical deformation of the base can that affects fixture mounting, alignment, cable routing or structural integrity.
Check the base-can geometry against the intended installation condition.
Failure or damage of the frangible coupling associated with an AGL fixture/support arrangement.
Record coupling condition, fixture condition, mounting condition, impact evidence and replacement history.
A frangible coupling failure should be investigated separately from the fixture itself.
Fixture or associated equipment is not securely mounted.
Unintended movement of an installed AGL fixture from its intended position or orientation.
Record the fixture's original/intended position and current condition.
Movement or sinking of the fixture foundation/base arrangement relative to its intended position.
Inspect both the fixture/base-can and the surrounding foundation/civil interface.
Cracking or deterioration of the supporting foundation/civil structure.
Photograph and record crack location, crack extent, associated settlement, water condition and fixture movement.
Persistent accumulation of water around or within the AGL installation area.
Corrosion affecting bolts, nuts, washers, mounting hardware or other metallic mechanical components.
Check the complete mounting hardware set rather than only the visibly damaged item.
Failure, breakage, deformation or loss of required integrity of a mounting bolt.
Failure of the nut, washer or associated fastening arrangement.
Verify the complete fastening arrangement, not just the nut/washer itself.
Damage affecting the structural integrity of an AGL support, base, mounting arrangement or associated structure.
Determine what was damaged → how it was damaged → why it was vulnerable → what operational effect resulted.
Fixture is no longer positioned at its intended physical orientation.
Fixture tilt is usually a condition/symptom. The underlying cause may be foundation settlement, loose mounting, impact or hardware failure.
Fixture is not aligned with its required installation reference/orientation.
Verify alignment against the applicable installation/aiming reference and record the measured deviation where applicable.
Physical damage to the mounting arrangement supporting the fixture.
Failure at the interface between the AGL installation and the surrounding civil infrastructure.
This category should connect the AGL engineering failure database with the civil-maintenance/inspection database.
Failure of the installation's intended drainage arrangement to prevent persistent water accumulation.
Damage resulting from a mechanical impact that does not necessarily involve a vehicle.
Mechanical damage resulting from vehicle contact with an AGL installation.
Perform a complete impact damage assessment, not just a fixture replacement. Check fixture, frangible component, base can, mounting, foundation, cable, connector, alignment and surrounding civil works.
A vehicle-impact event may create multiple simultaneous failure categories across Divisions 04, 05 and 06.
Progressive structural deterioration caused by repeated mechanical loading/cyclic stress.
Repeated fatigue failures may indicate a systemic design/material/component issue, rather than isolated maintenance failure.
Standard record structure, classification, failure-chain relationships, RCA linkage, evidence layer and severity scheme that apply across all 20 Division 06 failure topics.
Every mechanical/structural failure should capture the following fields:
Several Division 06 categories are conditions or consequences rather than root causes. The database keeps these separated:
Failure event: Fixture outage/photometric issue
Failure mode: Fixture misalignment
Failure mechanism: Fixture movement
Root cause: Loose mounting
Failure event: Base deterioration
Failure mode: Base-can corrosion
Failure mechanism: Persistent moisture
Root cause: Drainage failure
Failure event: Fixture damaged
Failure mode: Structural damage
Failure mechanism: Mechanical impact
Root cause: Vehicle impact
Failure event: Fixture movement
Failure mode: Loose mounting
Failure mechanism: Reduced clamping force
Root cause: Hardware corrosion / improper installation
Chain 1 — Drainage
Chain 2 — Foundation
Chain 3 — Impact
Chain 4 — Hardware
Division 06 links every failure to the Root Cause Analysis Database. The most relevant RCA categories for mechanical/structural failures are:
Every failure receives a severity classification, plus operational-impact tagging:
Critical / Safety-Critical — immediate operational or safety risk
Major / Operationally Critical — significant availability impact
Moderate — reduced performance, not yet critical
Minor / Non-Critical — limited or no operational effect
Degradation / Intermittent / Latent — developing or hidden fault
Visual evidence
Technical evidence
Division 06 records should determine what was damaged, how it was damaged, why it was vulnerable and what operational effect resulted — always keeping the physical mechanical failure, its cause and its operational consequence in separate, linked fields rather than one collapsed entry.
Quick answers about mechanical, mounting, civil-interface and structural failures, as covered in Division 06 of the AGL Failure Database.
Division 06 covers mechanical, mounting, civil-interface and structural failures affecting AGL installations. It contains 20 published topics (MSF-01 to MSF-20), including base-can corrosion, frangible coupling failure, loose mounting, foundation settlement, water accumulation, hardware corrosion and structural damage.
Base-can corrosion, base-can deformation, frangible-coupling failure, loose mounting, fixture movement, foundation settlement, foundation cracking, water accumulation, hardware corrosion, bolt failure, nut/washer failure, structural damage, fixture tilt, fixture misalignment, mounting damage, civil-interface failure, drainage failure, mechanical impact, vehicle-impact damage and structural fatigue.
They fall into four groups: Base-Can & Mounting Failures (5 topics), Foundation & Civil Failures (6), Structural & Alignment Failures (6) and Impact & Fatigue Failures (3).
Several categories are conditions or consequences rather than root causes, so the database separates failure event, failure mode, failure mechanism and root cause. For example, a fixture outage or photometric issue (event) may be fixture misalignment (mode) caused by fixture movement (mechanism), with loose mounting as the root cause. Similarly, base-can corrosion caused by persistent moisture may have drainage failure as its root cause.
In the drainage chain, drainage failure leads to water accumulation, base-can and hardware corrosion, mounting deterioration, loose mounting, fixture movement and fixture misalignment. In the foundation chain, settlement leads to base-can movement, fixture tilt, misalignment and photometric deviation. In the impact chain, vehicle impact leads to structural damage, base-can deformation, mounting damage and fixture movement.
Each record should capture identification (failure ID, location, fixture ID, base-can ID, foundation ID, associated civil element, installation and failure dates), failure category, mode and symptoms, and the physical condition of the base can, mounting, frangible component, hardware, foundation, drainage and alignment. Impact evidence, photographs and repair history are also recorded.
Visual evidence includes photographs of the base can, mounting, foundation and frangible coupling, and of corrosion, cracking, deformation, water accumulation, impact damage and hardware and civil-interface condition. Technical evidence includes alignment and tilt measurements, foundation levels, drainage assessment, previous repair history and photometric verification where applicable.
Records should determine what was damaged, how it was damaged, why it was vulnerable and what operational effect resulted. The physical mechanical failure, its cause and its operational consequence are kept in separate, linked fields rather than one collapsed entry.
Every failure receives a severity classification, plus operational-impact tagging. The classes are Critical / Safety-Critical (immediate operational or safety risk), Major / Operationally Critical (significant availability impact), Moderate (reduced performance, not yet critical), Minor / Non-Critical (limited or no operational effect), and Degradation / Intermittent / Latent (a developing or hidden fault).
Frangible coupling breaks, mounting failures and structural fatigue rarely happen without a reason — real troubleshooting means understanding the mechanical loads, frangibility requirements and installation tolerances behind every fixture.
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