An automated weighing system for Straddle Carriers enabling ports to automate VGM weighing, increase efficiency and maximise terminal revenue.

CWS™ has been specifically designed for both straddle and shuttle carriers to provide a highly accurate container weighing system that is able to measure the weight of a container within 1 percent full-scale accuracy in real-time as it is lifted during stacking operations.

CWS is available retrofit or as a factory-fit option for new machines and can be installed into all major manufacturers of spreaders and straddle carriers.

Strainstall's straddle carrier VGM system CWS™ utilises Strainstall’s proven load monitoring pins to to provide a more efficient, integrated and automated method for producing a verified gross mass (VGM). By utilising straddle carriers and stacking cranes to capture VGMs during stacking operations, ports can reduce their dependency on weighbridges, process more containers in the same time, and, reduce the point of failure from a single weighbridge across an entire fleet of straddle carriers.

Weighing in motion

CWS’s advanced in-house developed algorithms allow the system to capture the VGM during lifting, without the need to stop the lift to take a stable weight as with other systems on the market.


Weight icon

Automatic operation

Unlike other systems available, CWS by design captures the VGM automatically using our in-house developed algorithms without operator input and can integrate into existing TOS systems.


Automatic operations

Increased revenue for terminal

By removing this process with a substantially more efficient method, terminals can now implement a new, chargeable, weight validation service as a new revenue source for the terminal.




Significantly faster method of VGM capture

As VGMs are captured as they are lifted in real-time during stacking operations, removing the need to be weighed on a weighbridge and re-weighed to determine the tare weight.


Proven track record

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How does the CWS system for Straddle Carriers work?

CWS uses JF Strainstall’s proven load monitoring pins that replace existing load bearing pins located in either the spreader or hoisting sheaves of the straddle carrier to capture the VGM (verified gross mass) of a container.

The four load cells are connected via a wired CanBus connection to a spreader-mounted interface unit to aggregate data. The interface unit connects to an in-cab display using either a wired or a wireless connection to the in-cab display that provides the operator with a view of the current load, the holding weight and identifies eccentrically loaded containers.

CWS as standard is also able to integrate with Terminal Operating Systems (TOS) via Ethernet (standard), serial output (RS232/422/485) or CanBus output from the display. Data output includes the container’s VGM, load eccentricity and the time/date stamp.


Read more about our CWS™ systems


RTG system diagram




Case studies

DP World Southampton

Container Weight System (CWS) installed on to all DP World straddle carriers in Southampton

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Quote from DP world who have over 50+ systems on their straddle carriers.

Nick Loader, chief executive officer, DP World Southampton:

We assessed a number of different options to be able to offer a container weighing service to our customers and selected JF Strainstall's system because it doesn't require any changes to our port operating procedures and is quick to install. The trials demonstrated an accuracy above our expectations and the system will be fully integrated into our TOS to ensure we are able to offer a full VGM service by the first of July. 




Container weight verification

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