Maritime New Zealand, MNZ, has issued a safety alert recommending loop lashing as the safest practice for securing timber deck cargoes to prevent damage or hazard to the ship and persons on board, and to prevent cargo loss.
A number of incidents have occurred around the world when best practice methods have not been used to secure cargoes resulting in injuries and loss of cargo overboard.
Says MNZ: “Any lashing practice must be able to overcome the transverse forces generated by the ship’s rolling movement. If the cargo is poorly lashed and the cargo moves during the voyage, it can cause a ship to lose stability. At present, the most common practice for securing timber deck cargoes to a ship is top-over lashing.”
Top-over lashing is a frictional lashing practice that applies vertical pressure that increases the friction force between the outer stows of deck cargo and the ship’s deck or hatch-cover. Top-over lashing as the sole securing practice for timber deck cargoes is sufficient only when the friction is very large or the expected transverse acceleration is very small. This practice is not recommended other than for vessels trading in restricted sea areas, inland or sheltered waterways.