Fully automatic twistlock ACV-1-2

Conduct brake rendering test using Brake Testing Kit or torque spanner method. Accept only if PRIMARY brake holds min. 60% of ship design MBL. Test after every brake lining renewal, before delivery, within 30 days takeover, and annually. Adjust lining if wear exceeds 40% residual thickness.

Measure link diameter at wear points - maximum 12% reduction allowed by class rules. Inspect for cracks, distortion, corrosion pitting, especially under gypsy where crevice corrosion occurs. Monitor for abrasion from rocks/sand. In saltwater, check galvanized steel for oxidation; in stainless, examine for crevice attack in oxygen-starved spots.

Check hydraulic lines and piping monthly for leaks, tightness, proper valve function. Inspect hydraulic fluid condition (contamination, moisture, oil breakdown). Oil, moisture, or heavy rust on brake lining/drum can reduce holding capacity up to 75%. Temperature monitoring on hydraulic pipelines indicates lubrication issues.

Inspect brake lining thickness regularly - renewal required when residual thickness drops below 50-60% of original (e.g., 8mm original -> replace at 4-5mm). Check for discoloration, scorching, unevenness, rough spots. Replace upper AND lower linings simultaneously. On non-tank vessels, renew at every drydock regardless of condition.

Test hydraulic-operated chain stopper self-locking release capability under FULL DESIGN LOAD. Verify proper engagement/disengagement cycles. For Pusnes EFCS: check eccentric mechanism for wear, hydraulic pressure (motor protection integration). For Hatlapa roller stopper: inspect roller wear, high-pressure hydraulic motor function. Examine for leaks, cracks, corrosion on stopper pins/bushings.

Examine foundation bolts, welds, support frame before and after heavy anchoring/mooring operations for stress cracks, corrosion pitting, galvanic corrosion at dissimilar metal joints (fairlead/deck interface). Verify no settlement or deformation. In rough weather operations, monitor for fatigue cracking under excessive loads. Apply protective coatings where needed (zinc-rich primer + topcoat).