The SOLAS, Safety of Life at Sea, is a global treaty that requires shipping containers to have their weight verified prior to being loaded on a ship for export. SOLAS imposed the Container Weight Verification requirement, making it mandatory for shippers to verify the weight of the containers being exported to reduce shipping accidents related to the misdeclaration of weights. The weigh verification is performed by the shipper, either by weighing the shipping container once it is packed or summing each individual item’s verified weight, including the packaging and the weight of the container providing a total verified amount.
Weighing has thus become integral to the shipping process increasing the importance of weighing systems for containers in ports and terminals. There are several weighing solutions that can be incorporated into your port or terminal, including:
Weighbridges which are placed at the entrance and exits of the shipping yard allow the total weight of trucks to be registered as they drive into the yard. The tare weight of the truck is measured as it exits and deducted from the total weight to calculate the container weight. Weighbridges are highly accurate however they require the truck to come to a standstill on the bridge increasing turnover time and potentially causing traffic if multiple trucks arrive at once. Weighbridges also require regular recalibration by accredited technicians. Both decrease the productivity of the shipping yard as they affect the efficiency and speed of operations.
Load cells can be installed on Ship-to-Shore (STS) cranes, Rubber-Tyred Gantry cranes (RTGs), and Straddle carriers. On STS cranes load cells are typically installed as an overload protection system and have a limited weighing accuracy. RTGs load cells are installed in the shafts of the rope sheaves on the trolley or in the rope anchor making it difficult to install if there are no drawings of the sheaves and shafts, and if it is equipped with twin-lift spreaders measuring individual containers becomes a challenge. Straddle carriers present challenges in the form of highly inaccurate weighing, an inability to determine container loading eccentricities when equipped with a twin-lift spreader, and a high rate of accidents when simultaneously lifting a loaded and empty/ light weight container.
Weighing systems on Mobile Harbor Cranes are often integrated during the production process and used to measure hydraulic pressure in the boom lift cylinders. The load weight limit on a MHC’s boom outreach is strictly limited thus a weighing system is required to maintain the crane’s stability.
Container reach stackers usually have built-in weighing systems that use hydraulic oil pressure in the boom lift cylinders to measure the container weight. However, most reach stacker weighing systems are inaccurate as their performance is hindered by friction in the hydraulic cylinders.
The weighing system on container handling forklift trucks generally also use hydraulic oil pressure in the lift cylinders to measure the container weight, and experience inaccuracies due to friction in the hydraulic cylinders. Container handling forklifts may also have loadcells installed under the chain anchors.
CFAO Equipment SA’s Heavy Lift division, a Konecranes South Africa supplier, offers innovative solutions for convenient, accurate and reliable container weighing. All Konecranes container lift trucks and reach stackers are equipped with Konecrane’s smart load-sensing hydraulics system. The weighing system is designed to sense the container load and adapt the lifting power accordingly, optimising fuel consumption and reducing emissions and noise, while automatically registering the container data to the Terminal Operating System (TOS) for easy and accurate recording.
The Konecranes weight verification system uses a static weighing system to measure the hydraulics in less than 5 seconds and provides a 1% full-scale accuracy. This allows operators to obtain accurate results quickly and conveniently, significantly improving productivity and safety, while adhering to the SOLAS requirements. As the weighing system is connected to the EMC in-cab connectivity service, the weight information is synced to YourKONECRANES cloud services instantaneously ensuring real-time verification by linking the Verified Gross Mass (VGM) to the container reference ID.
To find out more about how the high-precision Konecrane weighing system provides your terminal port with a solution capable of meeting the SOLAS-requirements in a cost-efficient and reliable manner contact a CFAO Equipment SA consultant here.