Technical Information
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CAM – Cam, Door Latch
CAM – Cam, Door Latch
In global logistics, the cam is one of the most important, yet often overlooked, elements of safety and functionality of shipping containers. This article is a detailed guide to the world of cams and container locking systems – from their construction, through use to maintenance, safety aspects, and technical standards.
What is a cam in a shipping container?
Cam is a robust steel component that forms the basis of the shipping container door locking system. The cam is welded to the upper and lower ends of each vertical locking bar on the outside of the doors. Its main task is to securely lock the container doors against unauthorized opening and to ensure tightness.
Principle of operation
- When the door handle is turned, the locking bar (lock rod), at the end of which the cam is located, also turns.
- The cam slides into a fixed counterpart – the cam keeper, welded to the container frame.
- This mechanism (cam locking) pulls the doors to the frame, compresses the rubber seal, and ensures the container’s watertightness and dust-tightness.
- It also prevents the doors from twisting or deforming (anti-racking).
Catalog number: HZ000245 and HZ000246 and HZ000249 with eye
Key features of the cam:
| Parameter | Value/Description |
|---|---|
| Material | High-strength steel (Q235, or stainless steel) |
| Manufacturing technology | Forging (preferred for higher strength), or casting |
| Surface treatment | Hot-dip galvanizing / galvanization (against corrosion) |
| Weight | approx. 0.65–1 kg |
| Dimensions | approx. 127 × 76 × 26 mm (depending on container type and manufacturer) |
| Tensile strength | ≥ 500 MPa (according to ASTM A653 standards, etc.) |
| Durability | High – designed for extreme climatic and mechanical stress |
Anatomy of a container locking system
Main components
| Component | Function and description |
|---|---|
| Locking bar/rod | Transfers force from the handle to the cams, allows door rotation and locking |
| Cam | Mechanical element that slides into the keeper and ensures locking |
| Cam keeper | Fixed forging/casting welded to the frame, into which the cam fits |
| Door handle | Lever for rotating locking bars and operating cams |
| Handle retainer | Secures the handle against unintentional movement |
| Security cam | Has a hole for a seal, increases security against unauthorized manipulation |
| Lock box | Steel box protecting the padlock from theft and vandals |
Detailed description of the cam and cam keeper
Cam
- Made of forged or cast steel, often surface-treated with hot-dip galvanizing.
- High resistance to wear, corrosion, and mechanical damage.
- The design allows for smooth engagement into the keeper without snagging, even with temperature differences.
Cam keeper
- Material: Q235 steel or stainless steel (for refrigerated containers).
- Surface treatment: hot-dip zinc, galvanization.
- Technical specification: must withstand repeated stress even under maximum load during transport.
- Certification: often meets ASTM, ISO standards, and other strength requirements.
Shipping container doors – construction and components
Materials and construction
- Doors are made of corrugated steel sheet (often CORTEN), for maximum durability.
- Each leaf has 2–4 locking bars with cams.
- Rubber seals around the perimeter of the doors ensure watertightness and dust-tightness.
- Hinges and pins must withstand not only the weight of the doors but also vibrations and shocks during transport.
Safety features
- Security cam – a cam with a hole for a seal (diameter usually approx. 15 mm).
- Lock box – protects the padlock from direct attack.
Types of shipping containers and locking systems
Overview of main types
| Container type | Description and locking specifics |
|---|---|
| Standard “dry” | Doors with 4 cams, universal locking system |
| High Cube | Increased height, identical locking mechanism |
| Refrigerated (reefer) | Stainless steel due to condensation, special seals and cams |
| Open Top | Same doors, tarpaulin roof, increased emphasis on tightness |
| Flat Rack | Often collapsible ends, may have different cam types due to construction |
| Tank container | Reinforced frames and locking due to liquid transport |
| Storage | Possible individual locking modifications, lock boxes, additional security |
Technical standards and certifications
ISO and ASTM standards for cams and keepers
- ISO 1161 : International standard for corner fittings and structural components of containers.
- ASTM A653 : Standard for steel sheets with a protective zinc coating.
- Tensile strength : min. 500 MPa, for extreme safety.
- Corrosion resistance : requirement for corrosion resistance for the lifespan of the container (min. 15 years in a marine environment).
CSC certification (Convention for Safe Containers)
- Every container must have a CSC plate, which declares compliance with all safety requirements – including the locking system.
Practical aspects: maintenance, replacement, malfunctions
Common problems and their solutions
| Problem | Cause and solution |
|---|---|
| Bent/cracked cam | Mechanical damage – replacement recommended, repair only temporary |
| Corrosion of cams/keepers | Insufficient maintenance – regular lubrication, coating inspection necessary |
| Sticking during rotation | Dirt, ice, deformation – clean, lubricate, or use OPNBar |
| Missing cam | Immediate replacement necessary, endangers cargo safety |
Recommended maintenance
- Regular inspection of cams, keepers, and locking bars (min. twice a year).
- Lubrication of moving parts with a suitable anti-corrosion lubricant.
- Inspection of door seals, tightness, and condition of rubber lips.
- In case of any deformation or crack in the cam – always replace with a new part (original or with corresponding certification).
- For storage containers, we recommend adding a lock box and a quality padlock.
Container safety and security
Levels of security
- Primary : Cam locking system – resistance against prying, breaking out.
- Secondary : Quality padlock in a lock box.
- Administrative : Customs seal on security cam (proof of integrity).
- Additional : GPS tracking, electronic locks for valuable cargo.
Modern trends in security
- Emphasis on resistance against mechanical attack (cutting, drilling, hydraulic shears).
- Development of electronic seals and sensors (for monitoring door opening).
- Systems with multiple locking points (Tri-Cam Locking).
Related terminology
- ISO container – certified container complying with international standards.
- Intermodal transport – possibility of transporting the same container by different modes of transport.
- CSC plate – marking of the container’s safety suitability.
- Corner casting – corner casting of the container, part of the frame.
- Twistlock – locking mechanism for securing the container to a transport vehicle.
Examples of use and real-world experience
- In industry, containers with quality cams are used not only for transport but also as secure warehouses, garages, technical facilities on construction sites, or even as modules for building schools or hospitals.
- A faulty or low-quality cam is one of the most common causes of problems when handling a container in practice – from the inability to open the doors to the risk of intrusion.
Conclusion
The cam and its holder are a small but absolutely crucial part of a shipping container. Their correct selection, maintenance and possible replacement are decisive for the safety, tightness and service life of the entire container – and therefore the protection of cargo worth millions. Anyone who works with shipping or storage containers should understand the details of this system, follow the latest safety news and choose only high-quality, certified parts.
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