Spare part for the shipping container door No. 2 – Keeper – cam keeper

Spare part KEEPER, in technical terminology often also called door cam keeper, cam retainer or cam holder, is one of the key components of the locking system of a shipping container door. It is a robust, permanent metal part (usually a cast from steel) that is firmly welded to the door frame of the container – specifically to the upper and lower parts of the door frame, i.e., the header and the sill.

Its main function is to provide a safe and solid attachment for the cam, which is part of the rotating locking bar. When the door is closed and locked, the cam is inserted and locked into the keeper. This connection prevents any movement of the door, thereby preventing accidental or forced opening of the container. The keeper is therefore an element that fundamentally influences cargo security, container tightness, and overall structural integrity.

Catalogue numbers: right HZ000243 and left HZ000244

Why is the keeper so important?

Although the keeper is small and inconspicuous at first glance, its failure means failure of the entire locking system. A weakened or damaged keeper will allow the door to open, which can lead to damage or loss of goods or endanger safety during transport. For this reason, the keeper is one of the most frequently inspected components during container inspections.

Detailed anatomy and function of the keeper

Role of the keeper in the container door locking system

Modern shipping containers are equipped with a very robust locking mechanism that must withstand not only normal handling but also extreme forces during sea and land transport. The whole door locking system can be divided into these main components:

Operating principle:

When the door is closed and the handle rotates the locking bar, the cam at the end of the bar moves toward the door frame. The shape of the cam and the keeper is designed to interlock precisely, creating a strong, resistant connection. At the same time, the door is pressed against the rubber door gasket, ensuring water‑tightness and dust‑tightness of the whole container.

Physical properties and materials used

To fulfil its function under extreme conditions, the keeper must meet strict strength and durability requirements:

Why cast steel and galvanisation?

Cast steel provides high resistance to tension, impact and fracture even at low temperatures. Hot‑dip galvanisation protects against corrosion, which is a major threat in the marine environment.

Significance and applications of the keeper

Why is the keeper a critical component?

The keeper is far from being “just a door holder”. Its role touches several key areas:

• Cargo security:
  The keeper is the first line of defence against theft and unauthorised entry. When the cam is firmly locked in the keeper, the door cannot be easily pried open.
• Accident prevention:
  During transport by ship, truck or rail, large dynamic forces act on the container. Keeper failure can cause the door to open spontaneously, endangering people and cargo.
• Weather tightness:
  A properly functioning keeper presses the door against the rubber gasket, preventing water, dust and pests from entering.
• Structural integrity:
  The door locking system contributes significantly to the overall stiffness of the door frame, which is the weakest link in the container’s structure.

Real‑world application examples

Keepers are essential not only in ordinary logistics but also in special container conversions:

• Museums and workshops built from containers:
  Securing exhibits and tools during closing periods.
• Cash points at sports venues and festivals:
  Quick and safe locking of cash and equipment.
• Chemical storage:
  Hermetic sealing to prevent leaks of hazardous substances.
• Housing units for homelessness relief:
  Ensuring safety and dignity for occupants.
• Container conversions for generators and power plants:
  Protecting specialised equipment from weather and theft.

Maintenance, repair and replacement of the keeper

Typical problems and signs of damage

Inspection and maintenance procedure

• Visual check: Look for signs of rust, deformation, cracks and weld integrity.
• Play check: Verify that the cam holds firmly in the keeper without excessive movement.
• Seal test: After locking the door, confirm proper contact with the rubber gasket.

Keeper replacement – recommended steps

1. Grind off the old keeper from the door frame (careful not to damage the frame).
2. Thoroughly clean the area for the new part (remove rust, paint, weld spatter).
3. Precisely position and weld the new keeper (correct alignment is crucial!).
4. Apply a protective anti‑corrosion coating to the weld and surrounding area.

Recommendation:
Always replace the keeper together with the cam as a “Cam & Keeper Set”, because both parts wear out simultaneously and only this ensures flawless operation.

Keeper in the context of standards and certifications

ISO standards and their relevance

ISO 668 and related standards (e.g., ISO 1496) define not only the dimensions and load capacities of containers but also the requirements for locking mechanisms and their compatibility across manufacturers. This makes it possible to interchange keepers and other parts among containers of different brands, provided they meet the ISO specifications.

CSC (Container Safety Convention) certification

Every container must be regularly inspected under the CSC convention. Deficiencies in the locking system, such as a damaged or missing keeper, are grounds for immediate withdrawal of the container from service for repair. Keeper checks are therefore part of all major inspection protocols (e.g., IICL).

Related terminology and components

Dimensions and properties of a standard keeper

Practical tips and recommendations

• Preventive inspection:
  Each time the container door is opened/closed, check the condition of the keepers.
• Use only certified parts:
  Low‑quality or incompatible keepers can jeopardise the safety of the entire container.
• Leave installation to professionals:
  Correct alignment and a high‑quality weld are essential for function and longevity.

Conclusion

Spare part KEEPER is a clear example of how even a small component can be a key guardian of safety, quality and the lifespan of a shipping container. Regular inspection, maintenance and timely replacement are fundamental conditions for safe transport and long‑term use of containers, not only in logistics but also in modern conversions and architectural solutions.

Price and delivery

The price is quoted per unit, excluding delivery. Shipping can be arranged via a carrier or collected in person at our facility in Třebíč, Czech Republic. Delivery cost depends on the ordered quantity and destination country. We ship only within Europe.

If interested, please send a request including the desired quantity through the form below.
Always provide a phone number, country, city + ZIP code for delivery so we can calculate shipping costs.
We will send you a complete quotation including transport.

We offer all spare parts for shipping containers. Parts are in stock and can be dispatched immediately. Larger quantities are available on request.

All information, services and prices may vary. The price list is indicative; we always charge based on actual conditions.