TOEIC Link Vocabulary Cluster — Ballast Tank Coating Condition Survey: The Report Lexicon for the Paint Film That Decides How Long a Steel Tank Survives

A ballast tank is a steel box that spends its life full of seawater, and the one thing standing between the seawater and the steel is a film of paint a fraction of a millimetre thick. That is what makes the coating condition survey conceptually unusual: it does not measure the steel at all. It grades the paint — the coating — because the coating's condition today predicts how fast the steel will corrode tomorrow. The question is never simply is the tank sound but is the protective coating still GOOD, or has it broken down to FAIR or POOR, and are the anodes carrying the load the failing paint has dropped. Every finding is written against a defined breakdown scale and a mapped location, edge by edge and weld by weld. Because the survey is so procedural and so grading-driven, it recurs as a source domain for TOEIC Link marine survey reading passages. The workflow is fixed: the coating is graded against the scale, the breakdown is located and mapped, the failure mode is identified, the anode condition is assessed, and a re-coating or continued-service recommendation is made. That sequence generates a stable cluster of roughly forty terms. A candidate who owns the cluster reads the passage at native speed; a candidate who does not stalls on the load-bearing nouns and loses the passage's argument.

This guide isolates the cluster, groups it by survey stage, and maps each term to its native collocation and register tier, because TOEIC Link scores writing as well as reading. Pair it with the writing vocabulary precision and collocation discipline guide for the skill of choosing the exact term, and with the hatch cover ultrasonic weathertightness testing cluster, whose watertight-boundary vocabulary overlaps directly with the tank-boundary language here.

Why this cluster rewards study

A coating-condition passage assumes its vocabulary the way a tailshaft or hatch-cover passage does. If a reader decodes breakdown, sacrificial anode, and edge failure one word at a time, the attention the module intends for the inferential questions is consumed by decoding. Learning the cluster converts those stalls to zero and frees the reader to answer what the passage actually asks — why a tank graded FAIR was flagged for early re-coating, what a grade was measured against, and where in the anode argument the disputed finding lies.

Stage 1 — The coating and the grading scale

The survey opens with the film itself and the fixed scale every finding is written against.

Protective coating — the paint system applied to the tank steel to isolate it from seawater; the subject of the entire survey. Collocation: the coating is applied; the coating protects the steel.
Coating breakdown — the percentage of the coated area where the film has failed and steel is exposed or rusting. Collocation: breakdown is assessed; breakdown exceeds the threshold.
GOOD, FAIR, POOR — the three-tier condition grade defined by breakdown percentage and hard-scale extent. Collocation: the coating is graded GOOD; the tank is found POOR.
Hard rust scale — flaking, laminated rust that has lifted off the steel; the marker that pushes a grade toward POOR. Collocation: hard scale is present; scale covers a percentage of the area.
Dry film thickness — the measured thickness of the cured paint, checked where original coverage is in question. Collocation: film thickness is gauged; thickness is below specification.

Stage 2 — Where and how the film fails

The heart of the survey is mapping the failure, because where paint fails is as diagnostic as how much.

Blistering — the lifting of the paint film into bubbles as water or corrosion works beneath it. Collocation: blistering is noted; the film blisters over the weld.
Flaking — the detachment of the film in sheets or flakes once adhesion is lost. Collocation: the coating is flaking; flakes are found at the bottom.
Edge failure — coating breakdown concentrated at sharp edges, where the film is thinnest and least durable. Collocation: edge failure is recorded; the edges are rusting.
Weld seam failure — breakdown along the weld beads, where the rough profile holds paint poorly. Collocation: failure follows the weld seam; the seam is corroding.
Undercutting — corrosion creeping sideways under an intact film from a break at its margin. Collocation: undercutting is observed; rust undercuts the coating.

Stage 3 — The anodes carrying the load

Where the coating fails, the sacrificial anodes are meant to take over, so the survey grades them too.

Sacrificial anode — a block of zinc or aluminium that corrodes preferentially to protect the exposed steel. Collocation: the anode is fitted; the anode wastes to protect the steel.
Anode wastage — the amount of the anode consumed, read as the fraction remaining. Collocation: anode wastage is assessed; the anode is 50 percent depleted.
Cathodic protection — the electrochemical protection the anodes provide to the bare steel. Collocation: cathodic protection is confirmed; protection is still effective.
Anode depletion — the point at which an anode is too consumed to protect and must be renewed. Collocation: the anode is depleted; renewal is recommended.
Bare steel — the exposed metal where coating has failed and anodes are the only remaining defence. Collocation: bare steel is exposed; the steel is actively rusting.

Stage 4 — Mapping and the recommendation

The survey closes by fixing each finding to a location and stating what the tank needs next.

Tank internals — the frames, brackets, and structure inside the tank whose coating is graded separately from the shell. Collocation: the internals are examined; the brackets are breaking down.
Location mapping — the record of exactly where each grade and failure was found, tied to the tank plan. Collocation: findings are mapped; breakdown is located at the aft bulkhead.
Re-coating — the recommendation to strip and repaint a tank whose coating has failed. Collocation: re-coating is recommended; the tank is scheduled for re-coating.
Spot repair — the recommendation to patch localised breakdown rather than recoat the whole tank. Collocation: spot repair is proposed; the failed areas are touched up.
Continued in service — the closing status: the coating is graded and the tank may remain in use, with or without conditions. Collocation: the tank is continued in service; the finding is noted for monitoring.

How to drill this cluster

Read the terms in the survey order above — the coating and its grade, where and how it fails, the anodes carrying the load, and the mapped recommendation — because that is the order a passage presents them and the order that makes each term predict the next. When a reading passage turns on a disputed finding — a tank graded FAIR yet flagged for early re-coating, an anode argued to be still effective — the dispute always lives in one of these four stages. A reader who has the cluster locates the stage instantly and answers from the argument rather than from the individual word. Pair this cluster with the hatch cover ultrasonic weathertightness testing cluster and the broader writing vocabulary precision and collocation discipline guide, and the tank-and-boundary vocabulary of a whole passage set becomes a domain you read at speed rather than decode word by word.