A chain locker is the enclosed compartment, typically located forward and below the forecastle, where a ship’s anchor chain is stored when the anchor is not deployed.
Key Design Features
- Self-stowing shape — chain lockers are typically tapered or shaped so that as chain is heaved in, it naturally coils and stows itself in the space without needing to be manually arranged, and pays out cleanly when the anchor is lowered
- Drainage — chain brought up from the sea carries mud, sand, and water; the locker includes drainage arrangements (spurling pipes and drain holes) to let this drain away rather than accumulate
- Bitter end attachment — the chain’s inboard end is secured to the ship’s structure via a quick-release mechanism (the “bitter end”), allowing the chain to be released entirely in an emergency, such as if the anchor and chain need to be slipped and abandoned
Access and Ventilation
Chain lockers are typically accessed via a manhole for inspection and cleaning, and require ventilation — like any confined space aboard, entry requires following enclosed space entry procedures, not casual access.
Why Chain Locker Condition Matters
A poorly maintained chain locker — blocked drainage, chain fouling due to poor stowage — can cause real operational problems during anchoring, including chain jamming or fouling exactly when reliable anchor deployment matters most.
Routine Maintenance
Periodic cleaning and inspection of the chain locker, particularly checking drainage and the bitter end release mechanism, is standard deck maintenance — often carried out during dedicated periods when the anchor is out of the water for extended inspection.
Exam Relevance
Chain locker design, drainage, and bitter end arrangements are covered within Ship Knowledge and anchor equipment topics in deck officer competency exams.