What is the minimum GM required for cargo ships carrying timber deck cargoes?

The minimum metacentric height (GM) required for cargo ships carrying timber deck cargoes is stipulated to ensure adequate stability during operations. Timber deck cargoes can significantly raise the center of gravity of a vessel because of their weight and the way they are typically stacked. This can impact the vessel's stability, making it more prone to listing or capsizing if the GM is not sufficiently high.

A minimum GM of 0.10 meters is considered a baseline to provide an acceptable level of stability for these ships under normal operating conditions, including loading, unloading, and handling of the timber. This ensures that the vessel can return to an upright position after being heeled to an angle by waves or wind, thereby enhancing safety for the crew and the cargo.

In contrast, lower GM values might not provide enough righting moment to overcome forces that could lead to instability, especially when dealing with potentially top-heavy loads like timber. Therefore, a GM of 0.10 meters is established as a reliable threshold to maintain sufficient stability while managing the risks associated with carrying timber cargoes.