Knowledge Hub · Cluster 01 · Inspection & finding logic
Twelve damage classes that we capture regularly in ROV-based underwater diagnostics — as common vocabulary between operator, engineering office, expert witness and authority. Every class follows the same structure: definition, typical cause, and three documentation axes per finding (visual record, dimensional reference, classification logic).
A findings report is only useful downstream when class names mean the same thing to every party involved. “Spalling” and “material loss” are not interchangeable terms — and “undermining” is more than just “a hole under the structure”. The vocabulary documented here forms the basis of our findings dossiers, and is open to alignment in the briefing if the client uses their own damage catalogue system.
Every finding in our dossiers carries the relevant class code (such as SCH-AUSK-001) as a machine-readable reference. Follow-up surveys can trace the same finding across multiple inspection cycles.
Current-induced material erosion at the structure base or face. Emerges from local vortex formation at obstacles in the flow field.
Typical cause: High near-bed flow at bridge piers, mooring dolphins, sheet pile heads or sill structures — intensified by flood events.
What we document:
Surface or shell-shaped delamination of the concrete surface, often following freeze-thaw cycles or floating debris impact.
Typical cause: Freeze-thaw loading, reinforcement corrosion with bursting effect, impact from floating debris.
What we document:
Linear separation within the cross-section — from hairline cracks to structurally relevant through-cracks with water ingress.
Typical cause: Shrinkage, load change, settlement, thermal movement, construction deficiency.
What we document:
Surface or pitting-type material loss on steel sheet pile walls — typically most pronounced in the tidal/wave zone.
Typical cause: Alternating water level, microbially induced corrosion (MIC), electrochemical effects in harbour basins.
What we document:
Corrosion of reinforcement in reinforced concrete elements — often first visible through spalling or rust traces on the concrete surface.
Typical cause: Carbonation, chloride ingress, cracking with subsequent water and oxygen access.
What we document:
Growth from algae, mussels or other organisms — relevant for visual inspection, can hide findings and exert its own damage effects.
Typical cause: Standing or low-flow water, nutrient-rich sites, long downtime between inspection cycles.
What we document:
Deposition of suspended matter and bedload at structure bases, in basins or lock chambers — alters local flow and load conditions.
Typical cause: Flow change, flood events, missing flushing arrangements, basin asymmetry.
What we document:
Opening at construction joints or transitions — often following settlement, thermal movement or material fatigue.
Typical cause: Settlement differential, loss of joint filler, material fatigue, mechanical loading.
What we document:
Cavity formation beneath foundations, structure bases or pipeline routes through material transport — can lead to settlement or rupture.
Typical cause: Local flow concentration, leaking joints with sediment transport, flood event.
What we document:
Local deformation or material loss from impact — typical from floating debris, vessel collision or structure contact.
Typical cause: Vessel collision, floating debris at flood, structure contact from working equipment.
What we document:
Geometric position change of a structural element or section relative to baseline — visible through joint gaps, offsets or tilted reference edges.
Typical cause: Material transport in the subsoil, load change, uneven soil conditions.
What we document:
Collective category for volume loss that cannot be assigned to a more specific class — quantified by comparison with baseline geometry or prior survey.
Typical cause: Multiple overlapping mechanisms, long downtime without inspection, unclear damage history.
What we document:
Every documented finding from a mission carries in its dossier a class identifier, a dimensional reference, a position against the structural grid or GNSS reference, and a classification rationale. The client can trace each finding across multiple inspection cycles — the identifier stays stable, the measurements are re-captured at each follow-up survey.
An anonymised reference structure of this documentation is available in the Example Dossier on the Insurance & Expert Witness page.
You work with your own damage catalogue and want our capture mapped onto it?
Align class mapping