• What container types and sizes can BISON C-Jacks weigh?

    BISON C-Jacks can be used to weigh any length container up to 35,000 kg (77,000 lb). The scales are compatible with all ISO containers, including tank containers and reefers.

  • Are C-Jacks safe?

    Yes, the C-Jacks and C-Jacks with Stands are safe. Each of the C-Jacks, Stands and bottle jacks are rated to lift and support 10 tonnes per corner, and have a conservatively high safety margin. The container is also elevated just a few centimetres. The hazard to be most concerned with in practice is the potential pinch / crush point between the container and trailer, although there is absolutely no reason why any body parts should go near this danger zone.

    BISON can supply a detailed hazard control register for C-Jacks, to help users integrate the system into their health & safety procedures. Contact us  for more information.

  • Can I weigh containers on a slope?

    The weighing surface should be level. Weighing containers on a slope poses a safety hazard, as the elevated container may have a tendency to slide downhill unless due care is taken. It is also important for accurate weighing to keep the C-Jacks vertical, this is indicated by the “ANGLE” warning on the display.

  • What surfaces can I weigh containers on?

    The ground surface should be firm, compacted and level for weighing. With due care and attention, it is possible to weigh containers accurately on rough (i.e. gravel) and uneven (i.e. pot-holed) surfaces. Steel ground plates are supplied with C-Jacks to spread the load at each corner and minimise marks on the ground. The height and tilt adjustment features on C-Jacks assist with accurate weighing on uneven surfaces and help avoid overloading single corners when weighing heavy containers.

  • Can I weigh containers from the ends, instead of the sides?

    Yes, you can weigh containers from the ends. As the door-end of the container is recessed, BISON can supply a pair of customised plastic blocks - called "spacers" - to fill the gap between the door and the weighing module. The spacers are customised to fit the majority of containers and use magnets to attach to the container. We recommend that care is taken with heavier containers (>20 tonne) to ensure the loading doesn't damage the container door seals and hinges. The rear of the container is the same as the sides, so spacers are not needed at this end.

  • How many people are needed to weigh a container with C-Jacks?

    Only one person is needed to weigh containers using C-Jacks, but two or more people can work in parallel for a faster operation.

  • How high do the C-Jacks lift the container to get an accurate weight?

    The container only needs to be lifted just clear of the ground or chassis. Typically the lift height is 2-3 cm.

  • How long does it take to weigh a container with C-Jacks?

    For grounded 20' containers, it takes one person 4 - 5 minutes to attach, weigh and pack the C-Jacks away. The operation can take a little longer for 40' containers and less time if more than one person is involved. Here is a time compressed video of the full operation.

    For containers on chassis, an experienced user in good site conditions, it takes one person 8 - 10 minutes to attach, weigh and pack the C-Jacks with Stands away. The operation can take a little longer when weighing on spring suspension chassis, as the chassis may travel up to a point with the container during lifting. It also takes less time if more than one person is involved.

  • How accurate are BISON C-Jacks?

    The Maximum Permissible Error acceptable for BISON C-Jacks to be 'legal for trade' is ± 75 kg at 35,000 kg, which equates to an accuracy tolerance of around 0.2%. The actual error is typically half this when the equipment is calibrated with accurate test weights. For general container weighing applications where 'legal for trade' approval is not required, the C-Jacks can be easily calibrated on BISON's Calibration Kit, and this results in an accuracy tolerance of better than 1%.

  • How are BISON C-Jacks calibrated?

    All BISON C-Jacks are factory calibrated prior to shipping. Over time and heavy use, the scales may need to be re-calibrated with BISON's Calibration Kit. The accuracy tolerance from this method of calibration is better than 1%. A higher accuracy tolerance of better than 0.2% can be achieved by fine-tuning the scales with certified test weights. You can buy your own Calibration Kit, or contact BISON or your dealer to talk about re-calibration service options.

  • How frequently should I re-calibrate my BISON C-Jacks?

    We recommend you have your C-Jacks' calibration checked annually, but timing really depends on how you use them and how critical accuracy is to your operations. Calibration can be affected by overloading and shock-loading. If your C-Jacks are often used to weigh heavy containers, then their calibration should be checked more frequently than if they are seldom used or used to weigh light containers. With your own Calibration Kit you can check as often as you wish.

  • What maintenance is required?

    BISON C-Jacks require very little maintenance. The batteries need to be changed periodically. We supply high quality Japanese-made bottle jacks which have proven to be very robust but can be easily replaced if issues arise. You may also need to re-calibrate and/or re-certify the scales periodically, depending on your application.

  • What units of measurement do BISON C-Jacks have?

    Kilogram (kg) and pound (lb). The Master Display can be pre-set in either unit. The BISON VGM App can be switched between kg and lb.

  • What is the weighing resolution?

    BISON C-Jacks resolve the weight in 1 kg increments, but for OIML certification the total weight is displayed in 50 kg (or 100 lb) increments. This is a tolerance that BISON C-Jacks can easily perform to regarding absolute accuracy and repeatability. It is possible to view the weight results in 1 kg (or 2 lb) increments, where applications require higher resolution and formal certification is not required.

  • How do C-Jacks round up and down?

    BISON C-Jacks resolve the weight in 1kg increments, and the Master Display and BISON VGM App round up or down to the nearest 50 kg or 100 lb.

  • What approvals do BISON C-Jacks have?

    BISON C-Jacks have OIML R-76 MAA and OIML R-60 approvals, issued by NMi, Netherlands. C-Jacks and C-Legs are type approved and can be certified 'legal for trade' in Europe, New Zealand, Australia, South Africa, Malaysia and a number of other countries. Contact BISON for copies of relevant certificates.

  • Are C-Jacks and C-Jacks with stands SOLAS approved?

    In general, yes, all BISON C-Jacks are OIML approved and suitable for producing SOLAS VGMs, however there may be specific Maritime Rules and Weights & Measures Regulations of your country. The scales are trade approved in many countries, including all EU countries, New Zealand, Australia, South Africa, and Malaysian, which further satisfies requirements for SOLAS VGM Method 1 weighing.

  • What is OIML Certification?

    OIML is the International Organisation of Legal Metrology (French: Organisation Internationale de Métrologie Légale), is an intergovernmental organisation that promotes standardisation of the legal metrology (weighing) procedures. BISON's weighing equipment is independently certified by NMi Certin, in the Netherlands, to the OIML standards and this is recognised by around 120 countries. OIML certification is usually a pre-requisite for 'Trade Approval'.

  • What does 'Trade Approval' mean?

    Where a product is sold by weight, it is a legal requirement that weighing equipment is verified as ‘legal for trade’ or 'trade approved'. This means the equipment must undergo a stringent set of tests to ensure it's sufficiently accurate and fit-for-purpose. This process is managed by a country's governmental "Weights and Measures" authority, and OIML certification is usually one of their pre-requisites.

  • Are C-Jacks water proof and dust proof?

    Yes. BISON C-Jacks have an IP 64 ingress protection rating. This means the system has complete protection against ingress of dust and there will be no harmful effects from dripping, spraying and splashing water. We recommend inverting the hydraulic bottle jacks after use in wet conditions to extend their working life, thereby avoiding internal corrosion. A water displacement spray applied to the piston-rod will also help the longevity of the bottle jacks.

  • What range of temperatures can I use BISON C-Jacks in?

    BISON C-Jacks have been tested and certified accurate over a temperature range of -10˚C to 40˚C (or 14˚F to 104˚F). The C-Jacks still work beyond these temperature limits, but the weighing accuracy may be slightly compromised.

  • What is the expected life cycle?

    BISON C-Jacks have a design life of 10 years. Their actual life will depend on how they are cared for and serviced. The internal components are very modular, meaning it's easy to replace the load cell, electronics etc and keep your scales operational.

  • What batteries do the C-Jacks use?

    Each scale and the Master Display run on 4 x regular AA batteries. Good quality alkaline or lithium ion batteries are recommended and will provide the longest life span. Rechargeable AA batteries may also be used.

  • What is the expected battery life?

    The batteries provide 45 hours of continuous operation. This reduces to 20 hours if the scales are used in low light environments and the LCD backlight turns on. Nevertheless this is sufficient for hundreds of container weighing operations.

  • How do I know if the batteries need changing?

    There is a battery life indicator on the display of the scales and the Master Display. It will flash when the batteries need to be replaced.

  • What do the bar symbols mean?

    The bar symbols on the scales' display show how much weight is on the scale. The OIML standard does not permit the weight to be shown on the individual scale, so the symbol display was used instead. For non-certified applications, C-Jacks can be configured to show numbers.

  • How do I zero my C-Jacks?

    Give the yellow button a short press. The display will show ------- for about three seconds, and then the zero will be manually reset. A tilda symbol (~) next to the battery symbol will indicate that the zero is set. Note that the zero can only be manually set by this method if the reading is less than 200 kg. Use the Config App to permanently set the zero. Contact BISON for further details.

  • What weighing capacity do BISON C-Jacks have?

    BISON C-Jacks have a weighing capacity of 35,000 kg (77,000 lb). Each scale has a weighing capacity of 10,000 kg (22,000 lb).

  • Do I need specific training or a qualification to use BISON C-Jacks?

    No. BISON provides user manuals and instructional videos advising how to weigh containers safely and accurately, it is recommended operators read and watch these prior to use. No special qualifications are required. The C-Jacks and optional Stands are designed to be intuitive and easy-to-use. Once you have weighed around six containers, you'll be an expert.

  • Can I use C-Jacks with Stands on air and spring suspension chassis?

    Yes, C-Jacks with Stands attached are compatible with both chassis types. Spring suspension chassis tend to "travel" with the container as it is lifted until the suspension reaches its maximum height. Air suspension chassis provide a firmer lifting platform, particularly when the trailer is parked and the air-bags are empty. It is also possible to lower chassis with air suspension beneath the container once C-Jacks with Stands are attached.

  • What is the minimum and maximum height of the C-Jacks with Stands?

    The C-Jacks with Stands handle chassis heights from 1010mm to 1500mm.  The stroke of the hydraulic bottle jack is 150mm.

C-Jacks Specifications

Standard Components
4 x certified wireless container scales
4 x custom bottle jacks
4 x steel ground plates
1 x master indicator
1 x trolley
Optional Extras
C-Jack stands
Calibration kit & configuration app
Service kit & spare parts
Unit of Measure
kg or lb
Weighing Capacity
35,000 kg or 77,000 lb
Display Increments
50 kg or 100 lb
OIML Approvals
OIML R-76 MAA and OIML R-60
Load Cells
10,000 kg or 22,000 lb weighing capacity per scale. 150% service overload capacity. 300% ultimate overload limit.
High strength steel frame with thermoplastic powder coat. Tough glass-filled nylon casing
4 x standard AA batteries per scale. 40+ hour battery life cycle.

Operating Manuals & Training Videos

Fill in the form to access the C-Jacks Operating Manuals and Training Videos.

They include:

  • Detailed safety information
  • Task hazard control assessment
  • Technical specifications
  • Operating instructions
  • User checklists
  • Maintenance guidelines

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