Hatch Cover Weathertightness Testing
Testing hatch cover weathertightness before loading: the chalk test on compression bars, hose testing, ultrasonic tightness testing, and what a failed seal costs on a dry cargo.
Hatch cover weathertightness is verified before loading a moisture-sensitive cargo rather than assumed, and there are three established test methods with different strengths. The chalk test marks the compression bars to show whether the gasket is bearing evenly along its length, the hose test applies a water jet to the closed joint and looks for ingress, and ultrasonic testing measures sound transmission through the closed joint to locate leak paths without water.
The full article will cover each method, its limitations and when it can and cannot be used, including the practical point that a hose test is unusable once cargo is in the hold while an ultrasonic test is not. It will cover the components that actually fail: gasket compression and permanent set, corroded or worn compression bars, cross-joint wedges, drainage channels and non-return drains, and cleat condition.
It will also cover the commercial consequence, since a leak that is a nuisance under a coarse ore is a direct cargo damage and dust escape path under a fine powder, and the survey record of a passed test is the owner’s evidence in a wet damage claim.