When preparing the pre-stow plan, the first thing to do is to check what load line zone/area the ship is in throughout the voyage, and then to calculate the deadweight according to the restricted draught and water density of the (un)loadport or channel, argues Captain Zhao Qingwei, the head of safety supervision department of Chinaland Shipping.
s per Article 12 of the load line Convention (Submersion), the appropriate load lines on the sides of the ship corresponding to the season of the year and the zone or area in which the ship may be, shall not be submerged at any time when the ship puts to sea, during the voyage or on arrival.
There is no ambiguity to these for summer and tropical zones, but when the ship transits different load line zones/areas, especially when the ports of loading/unloading standing on the boundary lines of different zones or Areas, disputes about the amount of cargo to be loaded often arise, and improper declaration of cargo not only exposes the ship to port state inspections, but also may lead to claims by the charterers/shippers.
The following is a brief description of the relevant provisions of the loadline Convention, using the port of Ho Chi Minh as an example:
#1 The port of Ho Chi Minh (Saigon until 1975) is described in the Convention as follows.
Saigon is to be considered as being on the boundary line of the Tropical Zone and the Seasonal Tropical Area. （Refer to convention ANNEX II Regulation 48 – Tropical Zone）
#2 The provisions relating to ports on the boundary line are set out in Article 11 of the loadline Convention.：
A port standing on the boundary line between two zones or areas shall be regarded as within the zone or area from or into which the ship arrives or departs.
Ho Chi Minh port is located in two load line area/zone, just standing on the boundary line between the tropical zones and China sea seasonal tropical area.
- When the ship loading cargo from the tropics zone (for example, Indonesian ports) to the port of Ho Chi Minh to unload (Arriving), tropical load line will apply when preparing the pre-stowplan.
- When the ship loading cargo at the port of Ho Chi Minh on August 1, and then proceeding to the port of China to unload (Departing), ship will pass through the South China Sea seasonal tropical region, then summer loadline will apply.
In order to avoid any disputes while prepare the pre-stow plan, please pay attention to the following matters:
- There are many loadline maps in the market (Eg, NETPAS can display loadline zones which are commonly used by industry), but some of the markings may not be accurate. For example, most of them do not mark the ports standing on the boundary line, which may easily lead to misinterpretation in the process of using them, and it is recommended to purchase D6083 Loadline Chart published by UKHO.
- When determining the loadline limit, one should not only refer to the load line charts, but also to the relevant provisions of the load line convention for careful checking in order to avoid mistakes.
- The latitude mentioned in the load line ZONE/AREA is for the sea, and the river ports on the specific boundary line involved should be based on the sea entrance of the port, where the deeper loading is allowed (the amount of overloading does not exceed the fuel consumption for navigating in the river channel), as long as it is ensured that the loadline not be submerged when the ship puts to sea.