Tag / Twistlock

by Mike Poverello

Finding the best solution for 100% container weight verification

Bromma load verification sensing technology (www.bromma.com)

Bromma load verification sensing technology (www.bromma.com)

The International Association of Ports and Harbours (IAPH) has helped the container handling industry to put focused attention on the issue of container weight verification. The IAPH and the International Shipping Organization have called for near 100 per cent container weight verification as a standard industry ‘best practice’. IAPH has recognised the value of container weight verification for both safety and operational reasons. Accurate container weights can help guide critical plans regarding stowage, and verifiable load data also serves to ensure worker safety. Lifting containers within an acceptable weight range also prevents accelerated stress on the spreader, thus extending equipment life.

The issue that organisations such as IAPH and the World Shipping Council have raised is not merely an academic one, studies of container weight indicate that there is often significant variation between listed and actual container weight. The problem is a familiar one: not everyone tells the truth about their weight, as the consequences of inaccurate weight can include equipment damage in ports, injury to workers and collapsed container stacks, among others.

The question is ‘how’, not ‘should’?

The general consensus has grown that universal container weight verification is a worthy standard, the key question has quickly begun to shift from whether we should we have a universal requirement to how we can best implement this commitment. Along these lines three general approaches might be possible.

The container crane option

The first possible approach is to utilise container cranes to meet the weighing requirement. The advantage of weight verification by cranes is that weighing occurs during the normal course of handling operations. The disadvantage of a crane-based approach is that weighing accuracy is only approximately 90-95 per cent, and cranes cannot distinguish between the weights of two containers when lifting in twin-mode. Since many terminals load and unload container ships using twin-lift/twin-20 foot spreaders, the actual weight of each of these individual containers will remain in doubt if there is a reliance on container cranes to yield this data. Also, with the emergence of the mega-ship era, more and more terminals will be looking for productivity solutions that enable more containers to be handled in each lift cycle, and so twin-handling of 40 and 20 foot containers is likely to expand in the future, thus adding to the number of containers with an uncertain weight.

The weigh bridge option

A second option for terminals would be to meet the container weight requirement through the use of weigh bridges. Unfortunately, there are multiple weaknesses in this approach.Containers can be weighed from the weigh bridge, but driving every container onto a weigh bridge will obviously add another operational step, and slow productivity. It also requires, especially at larger and busier transhipment terminals, that considerable land and transit lanes be set aside for weighing activities. In addition, there are two weight variables on the weigh bridge – the variable weight of up to 300 litres of truck fuel and the weight of the driver. Further, as with a container crane, a weigh bridge cannot distinguish between the weights of two containers, and so the weight of each individual container will always be inexact. The only way to gain a precise weight is to weigh one container at a time, and to adjust for fuel weight and driver weight variables.

The spreader twist lock option

The third option is to ascertain container weight from the spreader twist locks. For container terminals, a spreader-based weighing approach has several key advantages. Firstly, weighing from the spreader twist locks yields much more accurate information, as container weight precision is greater than 99 per cent. Secondly, unlike weigh bridges or crane-based container weighing, spreaders weigh each container separately when operating in twin-lift mode. When a Bromma spreader lifts two 20 foot containers or two 40 foot containers at a time, the spreader can provide highly accurate data on the weight of each separate container, and without any of the variables (fuel, driver) associated with the weigh bridge approach.

In addition, with a spreader-based approach you weigh containers from the spreader twist locks without adding any extra operational steps or requiring any extra space or transit lanes. Terminals simply log container weights in the normal course of lifting operations – with a warning system alerting the terminal to overloaded and eccentric containers. Container weight verification during the normal course of terminal operations is a way to accomplish the weighing mission without impairing terminal productivity, and especially at busy transhipment terminals. To read the full report, Click Here!

Source: www.porttechnology.org

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by Mike Poverello

Box Innovation – More Volume and Higher Payloads

A revolutionary new container design is set to change the economics of shipping palletised cargo, allowing cargo owners and consolidators to increase significantly the volume of cargo shipped at any one time.

A revolutionary new container design is set to change the economics of shipping palletised cargo, allowing cargo owners and consolidators to increase significantly the volume of cargo shipped at any one time.

Maritime-Executive.com recently featured the following article. UK-based container design company Container Group Technology (CGT) Ltd has announce the availability of the 20-20 SeaCell Container. From the outside the patented ‘20-20’ looks little different from a conventional ISO 20ft shipping container. However, subtle innovations on the outside and inside of the container enable the unit to provide for 36% greater pallet space.

In practical terms, this means that for each tier, 15 Euro-pallets (1200mm x 800mm) can be loaded into the container instead just 11 Euro-pallets in a standard ISO 20ft dry container. With standard ISO pallets (1200mm x 1000mm), the 20-20 can load 12 units, two more than in a conventional 20ft container (see graphic).

And by using 100% of the floor area, pallets fit snugly together inside the container making the 20-20 ideal for using lightweight slip-sheets or paper pallets, thereby reducing costs and increasing useable volume and payload at the same time.

The 20-20 SeaCell Container achieves this feat by being exactly 20ft (6096mm) in length and 2426mm wide internally. Standard 20ft containers are, in fact, 19ft 10½ ins (6058mm) long x 7ft 7¾ ins (2330mm) wide internally. Thus the internal length of the 20-20 allows it to accommodate the additional four Euro-pallets or two ISO pallets per tier. The door opening width is 2408mm which allows fork-lift trucks to load pallets two or three at a time.

However, the innovation does not stop there. Two 20-20 containers can be easily locked together from the outside with no special tools to make a 40ft container, but again with significantly greater internal volume than standard. Two 20-20 containers will carry six more pallets than one standard 40ft container. It is also possible to mix Euro & Standard pallets in the same 20-20 and still have 100% pallet utilisation.

The 20-20 is fitted with larger corner castings of the type typically used in flat rack containers, enabling them to be lifted by standard 20ft or 40ft spreaders, loaded singly or as a pair into a container ship’s 40ft cells or onto any current road chassis and rail wagon.

An integral locking mechanism in the corner casting is activated from the outside of the container. In just a few minutes, the two 20-20 containers can be securely locked together and lifted as a single ‘40ft’ unit. In the standard configuration, two 20-20s are joined at the front ends, i.e., with the doors accessible at each end of the combined containers. However, if requested CGT can also position the locking mechanism at the door-end corner castings so that the two 20-20 units are effectively sealed until reaching their final destination. This is an important feature for high value or sensitive cargoes.

Lifting two 20ft containers together has been made possible in the past decade by innovations in container lifting technology, and it has become increasingly popular with shipping lines and container port terminals as a way of loading and discharging ships faster and more efficiently.

However, it is only now, with the introduction of the 20-20 SeaCell Container, that the ability to lock and lift two 20ft containers and handle them as a single 34 ton maximum gross weight (MGW) unit has been made possible. The benefits of this innovation are numerous, including:

  • It can significantly reduce ship loading times and the time needed to lash containers on deck.
  • Estimates suggest it could reduce handling and transportation costs by 25% to 35%.
  • The fact that 20-20 containers can be linked or unlinked at any stage of the logistics’ chain should also reduce the need for empty repositioning, thereby optimising each container’s usage.

Prototypes of the 20-20 container have been built and fully tested in China, and the new design is being made available for sale or lease.

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