Published on Australian Maritime Safety Authority (

When a verified gross mass is required

Commonwealth legislation requires a verified gross mass (VGM) be supplied before a container can be loaded onto a ship.

The shipper must provide the gross mass as part of the cargo information. The shipper must also ensure that the gross mass of a cargo unit recorded on the shipping documents is accurate. The shipper must provide a VGM for both packed and empty containers.

Empty containers

Empty containers require VGMs in accordance with Marine Order 42. However the tare mass marked on an empty container can be used as the VGM on the shipping documents. An empty container is one where the contents have been completely removed. For liquids and gases in particular, residues after discharge are considered as container contents for the purposes of obtaining a VGM.

Offshore containers

Shippers must provide a VGM for offshore containers in the same way as any other container.

Marine Order 42 applies the description 'container' as prescribed in the revised regulation 2.4 of Chapter VI of SOLAS.

Containers on chassis and vehicles

Marine Order 42 applies to domestic roll-on roll-off (ro-ro) operations. The SOLAS waiver for short international voyages does not apply. The need for an accurate gross mass of cargo for the safety of the ship applies on every voyage.

If containers arriving at ro-ro terminals are consolidated with trailers/wheeled chassis, the cargo loaded onto the vessel is a ro-ro unit of cargo. A container that is part of such a ro-ro unit of cargo does not need to have a VGM.

The person/entity consolidating cargo into a ro-ro unit of cargo must ensure that all declared gross mass are accurate, for containers or cargo other than containers. If a container is provided with a VGM, this may be used as part of the accurate gross mass of the ro-ro cargo unit.

If a container is loaded onto any vessel and stowed, secured and carried other than as part of a consolidated ro-ro unit of cargo, a VGM must be obtained and provided as required by Marine Order 42 for a container.

Portable tanks, containers holding bladders of liquid

A VGM can be obtained by using either method 1 or 2 of the SOLAS regulations. Method 2 is not always suitable for determining the weight of all container contents (such as unbagged grain or scrap metal)3. If this is the case, method 1 must be used instead. Any weight obtained using other measurements such as specific gravity or volume, and/or using equipment not meeting the order requirements, could not be used as, or as part of, a VGM.

3. See section of MSC.1/Circular 1475 Guidelines.

Last updated: 20 October 2023