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The Royal Institute of Naval Architects

Jotun 09/11/2016

Bentley Systems 10/11/16

IMO to make container weighting mandatory

IMO are on the brink of amending SOLAS to make it a mandatory requirement to verify the gross mass of containers before they are loaded on board a ship. The mis-declaration of container weights has been an issue that has concerned many in the shipping industry for some time. The SOLAS amendment will require all containers to be either be directly weighted to confirm the shippers declared weigh or to use a method of “calculated” verification whereby the shippers can weigh all packages and cargo items including pallets, dunnage and the tare (unladen weight) of the container to confirm the weight. This compromise solution will disappoint many that wanted all containers to be actually weighed but some argued that it would not be possible in some countries to weight each container

The draft guidelines agreed by the IMO Dangerous Goods, Solid Cargo and Containers sub-committee in September 2013 will now be put forward to IMO’s Maritime Safety Committee for approval in May 2014 and hopefully to be adopted in November 2014, so that they can come into force before May 2016. The amendments would add new paragraphs to SOLAS regulation VI/2 Carriage of Cargos, Regulation 2 - Cargo information. An exemption would apply to containers carried on a chassis or trailer driven on or off a ro-ro ship engaged in short international voyages.  

Deneb Container Audit

In June 2011 the 508 TEU container ship Deneb heeled over to an angle of 45 degrees, impacting and ending up resting on the pier while loading containers in the port of Algeciras, Portugal.  At the time of the accident 150 containers had been loaded on board the vessel and 13 were still to be loaded. All the containers in the cargo holds and some of those on deck were submerged and subject to water ingress. Only 13% of the loaded containers remained “dry”.

The various parties involved (insurers, shipper and terminal) agreed a procedure for taking into account the effect of the sea water on in the weight of the cargo inside each of the containers, so that they could effectively the compare the “dry” weight of each container against the data declared in the container documentation. The estimated “dry” weights were then compared with both the weight declared by the shippers in the Bill of Ladings (B/L) and the weights included in the BAPLIE electronic documentation, which are used to carry out the stowage calculations for the containers on board the vessel.

Weight of containers (tons)
  163 scheduled containers 150 loaded containers 
Weight in the B/L 4087 3775
Weights in the BAPLIEs 3996 3684
Calculated "dry" weights 4327 4016


For the 150 containers that there loaded there was a weight difference of 91 tons between the weights listed in the B/Ls and the BAPLIEs. The weights listed in the BAPLIEs should be identical to the weights listed in the B/L. No explanation was provided as to why there were differences in most of the weights of the loaded containers.

Of the total of 150 containers that were on board the vessel at the time of the accident 92 weighted more than the weight declared in the B/L and 58 weighted less. The total calculated "dry" weight of the loaded containers was 241 tons higher than the B/L. The actual stability calculations would have been carried out based on the BAPLIEs weights, whilch were 332 tons lower than the calculated weights. This is without considering the effect of the 13 containers that were not loaded on board.

P&O Nedlloyd Genoa ­ loss of containersPO Nedlloyd Genoa

In January 2006 the container ship P&O Nedlloyd encountered heavy weather while sailing across the Atlantic from Le Havre, France to Newark, USA. A succession of large swell waves produced a series of large vessels rolls motions, which eventually resulted in a container stack collapse in a cargo bay directly in front of the bridge. This resulted in 27 containers being lost overboard, 28 containers collapsing on to the deck with 9 remaining secured in position.

Abstract from Marine Accident Investigation Branch Report No 20/2006

"Although a container may pass over a weigh-bridge for the purpose of satisfying road transport requirements, there is presently no requirement for it to be weighed prior to shipping. At a container terminal, the gantry crane confirms a total lifted weight for the purposes of safe working load requirements, but neither this information nor the weighbridge information is available to the carrier. This appears a missed opportunity for computer integration of weight data into the stow planning process.

The declared weight of a container provided by the shipper and used for all stow planning and onboard stability purposes can, if inaccurate, cause major discrepancies between actual and declared weights. Furthermore, incorrect weight can result in stack overload and the application of excessive compression and racking forces on containers and their lashings".

As part of the accident investigation Blue Star Ship management arranged for the remaining damaged containers on the deck to be weighted. Some of the results are shown below:  

Container No. Actual Wt Declared Wt Wt Error
GATU 8184916 11.36 11.5 -1.2%
TEXU 5434816 11.00 11.3 -2.7%
OOLU 8165576 16.50 16.3 +1.2%
HLXU 6350380 10.50 10.5 0.0%
FSCU 6390008 11.00 11.7 -6.0%
OOLU 5590817 18.90 24.0 -21.3%
PONU 7153901 16.13 17.5 -7.8%
PONU 7405109 16.31 18.1 -9.9%
GCNU 4613425 27.78 24.0 +15.8%
OOLU 8052184 16.00 13.7 +16.8%


MSC Napoli Container Audit

Following the beaching of the damages 4419 TEU container ship MSC Napoli in January 2007 the containers that were removed from the vessel were weighed. While the containers stowed in below decks had been submerged and subject to some water ingress about 660 containers that had been stored on deck remained dry. Of these containers 137 (20%) were found have a weight difference of more than 3 tonnes from the weight declared by te shippers. The largest single difference being 20 tonnes. The extra weight from these 137 container added extra 312 tonnes to the cargo manifest.

The actual position of these deck containers was also compared with the positions reported by the terminal operators and used in the ships loading computer to calculate stability. A total of 53 containers (7%) were in either the wrong position or declared as the wrong container. It would seem that the industry generally agreed that up to 10% of containers loaded onto a vessel may not be stowed in their planned positions.

Alfa Laval 260x120

Stone Marine 260x120

Rolls Royce Marine 2016

JETS VAC July 2015


Drew Safety