7 Consequences Of Container Weight Miscalculations

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Posted on Sep 03, 2015

Container weight false declaration has been the scourge of shipping lines, truckers and ports for many years.
With Solution Export being the current flavor of the year, we thought it would be a good time to remind everyone of the consequences of false container weight declaration, through a synopsis of a few incidents reportedly caused due to false container weight declaration.
Hopefully below synopsis will open everyone’s eyes to its dangers.

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The ship in the picture above suffered a significant stability incident. A review after the incident found that out of the 168 containers on the load list, 16 – or roughly 1 out 10 –containers had actual weights far in excess of the declared weights. The actual weights exceeded the declared weight in a range from between 1.9 times as much as the declared weight to as much as 6.7 times the declared weight. The total, actual weight of these 16 containers was more than 278 tons above their total, declared weight of about 93 tons or 4 times higher than their declared weight.

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About 660 containers were stowed on deck in the ship above. The weights of 137 (20%) of these containers were more than 3 tonnes different from their declared weights. The largest difference was 20 tonnes, and the total weight of the 137 containers was 312 tonnes heavier than on the cargo manifest.

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The container above fell 12 meters and narrowly missed two workers, was severely overloaded. Two workers at the Port had to run to avoid a shipping container crashing onto East Arm Wharf. The container was listed as four tones, but the Maritime Union says it weighed 28 tonnes and exceeded the crane’s load limit.

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An overloaded forklift lies on a container yard in an undisclosed port after its load tipped it forward.

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Container stack above collapsed due to stack overweight. The master’s incident report to the authorities notes that: “Excessively heavy units loaded in the upper tiers and that the maximum stack weight had been exceeded considerably in some rows. The effect of the overweight units was to impose excessive forces on the lashings. Further, exceeding permissible weight distribution and/or exceeding the maximum stack weight in any stack, results in overstressed stowage/securing elements and overstressed containers”. The actual container weights were established by the devices on the gantry crane when lifting and shifting the collapsed containers. The actual container weights exceeded the declared weights by 362% (Row 08), 393% (Row 06), 407% (Row 04) and 209% (Row 02) in Bay 52 where the collapse occurred.

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The declared weight of a container above 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. Although there are no financial gains to be made by the shipper who declares less than actual weight, the industry acknowledges that over-weight containers are a problem. However, as yet this has not justified a requirement for compulsory weighing of containers prior to loading.

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The large container vessel above was loading at the final load port before  commencing a trans-ocean voyage. The exit channel from the terminal had a draught restriction and sailing was subject to a narrow tidal window. Pre-arrival loading information listed some 350 containers, most of them going on the deck stacks. Being a regular vessel at the port, the terminal’s computer system provided a departure stability condition with the sailing draughts allowing for adequate underkeel clearance (UKC) as per company’s SMS. However, during the latter half of the 12-hour loading period, the chief officer realized that there was substantial under-declaration in the manifested container weights (later estimated to be an average of 12 per cent). This meant that after loading the manifested boxes, the ship was in serious danger of grounding in the channel. Thanks to quick thinking by the master, a total of about 850 tonnes of ballast was discharged before sailing from the twin autoheeling tanks, which due to their high location and narrow width resulted in a safe even-keel trim and an acceptable stability condition. The ballast was restored in the heeling tanks after reaching deep waters but unfortunately, it was realized after sailing that stack-weight limits had been exceeded in many deck stacks.

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