CWS™: Container Weight System

The IMO’s SOLAS amendments provide two approved methods in determining the container weight:

• Method 1 – weighing the loaded container
• Method 2 – weighing the contents of the container and adding those weights to the containers tare weight

If the new regulation is clear, at least in principle, on what needs to be done to achieve compliance, it is also unambiguous on who is ultimately responsible: Container VGM determination can be subcontracted to a third party by the shipper, but the shipper remains responsible for regulatory compliance.

Under the SOLAS requirements, the shipper named on the ocean bill of lading is the party responsible for providing the maritime (ocean) carrier (master) and the terminal operator (terminal representative) with the verified gross mass of a packed container. The carrier and the terminal operator must not load a packed container aboard a ship unless they have the verified gross mass for that container.

Due to the complexity of the international supply chain, the entity identified as the shipper on the bill of lading may not have direct or physical control over key elements of the process by which verified gross mass is determined. A shipper in such circumstances should be aware of their responsibilities and ensure that arrangements are in place to obtain and provide a verified gross mass in compliance with these international and national regulations.

SOLAS does not instruct any particular form for communicating the verified gross mass of a container. The VGM information must be signed and dated by the shipper or a person duly authorised by the shipper. Signatures may consist of the last name of the responsible person in capital letters and can be exchanged electronically.

As an international issue, SOLAS regulations state that VGM weighing equipment, for both method one and two solutions, must meet national certification and calibration requirements. There is no provision in SOLAS for any margin of error.

Shippers using compliant weighing equipment and procedures will obtain VGM values that are well within any national tolerances adopted for enforcement purposes.

The new ruling will be officially enforced by the maritime authorities of individual nations, whose implementing regulations will vary depending on country and region. The real-world enforcement seems most likely to be carried out directly by the container lines and terminal operators, who are obligated not to load a container without the certified VGM document accompanying it. National enforcement agencies may implement measures to satisfy themselves that compliance is achieved, which could include documentation checks, auditing or random weight checks.

Compliance with this obligation by the carrier and terminal operator may result in commercial and operational penalties, such as delayed shipment and additional costs if the shipper has not provided the verified gross mass for the packed container. As a commercial issue, penalties may involve repacking costs, administration fees for amending documents, delayed or cancelled shipments.

Although the shipper is ultimately responsible for declaring the verified weight of a container, the new amendments will affect and therefore apply to everyone within the supply chain. Shippers, freight forwarders, vessel operators and terminal operators will all need to establish procedures to ensure the implementation of the SOLAS regulatory change.

The SOLAS rules require the shipper to communicate the verified gross mass as part of an official shipping document. It must be signed by a person duly authorised by the shipper, with a first and last name, not just a company name. The signature may be an electronic signature or may be replaced by the name in capitals of the person authorised to sign it.

The VGM and signature can be part of the shipping instructions communicated via electronic data interchange (EDI), or be contained within a separate communication including a hard copy document. In either case, the document should clearly highlight that the gross mass provided is the verified gross mass.

While the onus is upon the shipper to fulfil the container weight verification obligation, the most practical location at which weighing can take place is at the ports and terminals, where lifting is a part of the existing cargo handling process.

Our Container Weight System™ enables the weight of a container to be determined without the need to do anything different to what ports and terminals do today, the weight is obtained during the course of existing lifting operations. Spreader based weighing solutions are the only solution that have zero time and operational impact on existing terminal operations.

There is no need to implement separate lift and drop or more complex weighbridge based processes. This gives ports and terminals the opportunity to obtain a VGM for each container without any additional operational cost If a container turns up to a terminal without a verified weight it cannot be loaded onto the vessel. By installing a container weighing system on site, any potential issues of containers being stranded at the terminal need not be a worry.

The SOLAS regulations provide that verified gross mass shall be obtained under both method 1 and 2 by using weighing equipment that meets the applicable accuracy standards and requirements in the State in which the equipment is being used. Those national standards and requirements will determine the acceptable level of accuracy of the weighing equipment used.

There is no single international approval for weighing equipment to provide accurate VGM, however, all equipment used (whether for method 1or method 2) will need to meet the applicable accuracy standards and requirements of the state in which the equipment is being used.

NOTE: CWS™ has successfully achieved EU-type approval, ensuring full SOLAS compliance.

The requirement for Type Approval weighing systems generally only affects countries within the European Union (EU). However, each country is responsible for how weight verification systems for commercial use are regulated, therefore you should check with your own relevant governing bodies to determine if Type Approval is required.

Type Approved systems have been introduced as a requirement for container weighing systems used for commercial purposes operating inside of the EU.

The legislation was interceded to provide greater regulation of the performance of systems that are used for commercial weighing applications to ensure the accuracy of container weights, prior to being loaded on board container vessels.

There are several key differences between the way a non-Type Approved and Type Approved VGM system operates and is maintained.

CWS™ has been certified to the most stringent standards and offers full OIML certification (R51) issued by the NMO, as well as EU Type Approval offering compliance for use in EU countries.

Our CWS™ system for RTGs , Straddle Carriers, RMGs and ASCs using our advanced proprietary software algorithms to capture the VGM in real-time as the containers are lifted. There is no requirement to stop the lift.

Our CWS™ for Reachstackers differs in that it requires the operator to pause once the containers are lifted to capture the VGM in order for the forces from the hydraulics to subside. The process is still very efficient however, and takes less than five seconds in most cases to capture the VGM once the container lift has stabilised.

CWS™ is designed to require minimal modifications. A display needs to be mounted within the driver’s cabin, and an interface unit fitted to the spreader. The load cells are designed to replace existing pins or collars, so require a simple swap from a non-instrumented pin/collar to a load monitoring pin/collar.

Developed in partnership with the world’s leading original equipment manufacturers (OEMs), CWS™ is fully adaptable to suit all the major crane and spreader manufacturers’ equipment types.

CWS™ provides a range of streaming outputs (Ethernet, RS232, RS422 and RS485) allowing CWS^TM to have the ability to be integrated into all major TOS systems.

Within +/-1% of full scale, in line with type approval regulations. CWS™ is more accurate than traditional load cell-based systems currently available.

CWS™ is designed to retrofit onto existing container handling equipment with minimal modification required. CWS™ offers a quick and easy installation process, allowing two systems to be calibrated and commissioned in one day.

CWS™ sensors (load cells) can be easily retrofitted into the spreader headblock or at the twistlock (replacing existing pins/collars) making installation simple with like-for-like replacement as each load cell are designed bespoke for your machine. The interface unit is mounted on the spreader either using bolts or welding the mounting brackets. The cabling is then routed from the load cells to the spreader mounted interface unit. The interface unit then transmits the weight data via a wireless connection to an in-cab display.

Whilst the preference is for our fully qualified and experienced engineers to supervise installation and commission the system, we do also allow terminals to install and commission the systems themselves once they have received training from our commissioning team.

CWS™ does not come with an in-cab printer as standard. However, this can be purchased as an optional extra.

We recommend outputting the data directly to the TOS, which fully automates the process.

No. A key advantage of the CWS™ system for RTGs, Straddle Carriers and RMGs is that CWS™ is able to weigh in motion.

Using our advance in-house developed proprietary software, CWS™ is able to define the VGM (to +/-1% accuracy) in real-time as containers are lifted in-motion without any need to interrupt existing lifting and stacking operations by stopping the lift to take a stable weight.

Our CWS™ system for Reachstackers differs in that it requires the operator to stabilise lift and forces from the hydraulics in order to obtain an accurate VGM reading. The process is still very efficient, the system will identify once a stable holding weight can be taken and in most cases captures with VGM in less than five seconds.

CWS™ is fully adaptable to suit all the major crane and spreader manufacturers’ equipment types.  Contact us for confirmation regarding compatibility with your existing equipment.

We will review your machine configuration and will design a bespoke load cell that offers the best performance for your machine and spreader. In most cases, a load bearing pin that replaces the existing pin in the hoisting sheaves is appropriate however, we can also supply a diaphragm (annular) compression load cell that replaces the existing collar around the twist lock.

CWS^TM can be supplied for both new machines and retrofit for most crane makes/models available.

CWS™ requires minimal maintenance for typical use. Once installed the load cells need to be regularly greased – we recommended that the systems are calibrated at least once yearly to ensure accuracy is maintained.

For EU-type approved systems, the system requires calibration once per year by technicians with the required certification. Our engineers are able to offer certified calibration in order to maintain type approval.

For non-type approved systems, terminals are able to calibrate their own systems once trained.

If you are considering using VGM certification as a commercial opportunity, please Contact Us for more information [link to CWS enquiry page]

Yes, CWS^TM is fully automatic in operation when integrated with the terminals TOS. Weights are captured with no operator intervention required, or change in operation as the stable weight is captured in real-time during normal stacking operations and automatically output into the TOS.

CWS^TM has been specifically designed to comply with SOLAS regulations and also offers further compliance with EU-type approval for terminals operating inside the EU.

Yes. The system is able to identify eccentrically loaded containers – in addition to the stable holding weight, all four load cells weights are displayed (and can be output to the TOS) making the identification simple and automated if required.

CWS^TM is a wireless system as standard. Whilst the load cells themselves are cabled in either option to the spreader-mounted unit, we can provide either a wired or wireless communication between the spreader mounted interface box and the in-cab display. If a cable option is preferred, you will need to find suitable cable routing between the spreader and cab display.

Yes, the system offers two types of data logging. We offer a short data-logging application within the CWS™ configurator software to aid in troubleshooting as well as live data streaming output to log the data via an external system – i.e. TOS.