Scope of this guide

Loading loose bulk materials into ISO containers

This guide focuses on loose bulk flows such as scrap metal, grain, seeds, feed pellets, wood products, biomass and other suitable materials. It is not a loading plan for dangerous goods or a substitute for the container owner’s instructions, a site-specific risk assessment or applicable law.

The IMO/ILO/UNECE Code of Practice for Packing of Cargo Transport Units provides international guidance for packing and securing cargo transport units. Local authorities, carriers, terminals and customers may impose additional requirements. Confirm these before changing a loading method.

1. Characterise the material

Start with representative product data: loose and settled bulk density, particle size and shape, moisture range, flowability, abrasiveness, fragility, dust behaviour and any contamination or hygiene requirements. Do not base the system on a single best-case sample if the material changes by season, supplier or production batch.

These characteristics influence the feed system, loading rate, settling, wear, cleaning and the controls required around the process. They also determine whether container volume or permitted weight is likely to become the first constraint.

2. Select and inspect the container

Use the container type approved for the material, route and receiver. Before loading, check the identification and rating plate, structural condition, floor, doors, locking bars, cleanliness, odour, dryness and any liner or sealing arrangement. Reject or quarantine a unit that does not meet the agreed standard.

Container dimensions and permitted masses can vary by design and owner. Use the markings and documentation for the actual unit rather than a generic online capacity figure.

3. Calculate a realistic target payload

Estimate how much material fits by volume, then compare it with the maximum cargo mass permitted by the specific container and every limit in the route. Allow for density variation and the accuracy of the weighing method. The lowest applicable limit controls the target.

A lightweight material can leave weight capacity unused because volume runs out first. A dense material may reach the weight limit while visible space remains. Efficient loading means approaching the correct target consistently—not filling every void regardless of weight.

4. Choose a suitable loading orientation and method

Horizontal loading can suit bagged, palletised or certain mechanically conveyed products. Loose bulk may be loaded with conveyors, chutes, loaders, blowers or other dedicated equipment. In a vertical process, a container tilter positions the container upright so material can enter from above and settle with gravity.

No orientation is universally best. Compare product behaviour, container size, door or liner control, loading frequency, site space, existing hoppers and conveyors, mobility needs and unloading requirements.

5. Prepare the loading area and equipment

Define the operating zone, traffic route, operator position and communication method before the container arrives. Confirm ground conditions, clearances, weather limits, emergency arrangements and inspection status of the equipment. Keep people who are not involved outside the zone.

The UK Health and Safety Executive advises that loading areas should be clear, level and stable, with vehicle brakes applied and stabilisers used where provided. These are general principles; the manufacturer’s instructions and site risk assessment determine the actual procedure.

6. Stabilise and secure before material flows

Prevent unintended movement of the vehicle, trailer, container and loading equipment. Follow the defined sequence for supports, locks, restraints and doors or liners. Verify each state before lifting, tipping or filling. Never improvise access beneath or around suspended or moving equipment.

Remote control can give an operator a clear view, but it does not replace exclusion zones, interlocks, training or a safe operating procedure. Stop the process if visibility, ground conditions, equipment response or material behaviour differs from the approved conditions.

7. Control feed rate and distribution

Coordinate the supply equipment with the capacity of the loading system and container. Sudden surges can overload transfer points, create dust or make the final weight difficult to control. A stable feed rate usually produces a more repeatable cycle than alternating between starvation and overfeeding.

Monitor settling and distribution using the methods approved for the installation. Avoid manual intervention inside a hazardous zone. If bridging, segregation or uneven loading occurs, investigate product and process conditions rather than relying on repeated manual correction.

8. Monitor weight during the process

Link the filling target to a reliable weighing and stopping method. Account for tare and all cargo, liners, dunnage or securing materials included in the packed unit. Define tolerances that reflect material and measurement variation.

For containers carried by sea, SOLAS requires the shipper to provide a verified gross mass in time for vessel stowage planning. Use an approved method and follow the rules of the competent authority, carrier and terminal.

9. Close, return and inspect in a defined sequence

After loading, follow the designed method for closing or securing doors and liners before the container changes orientation. Return the unit smoothly and keep the exclusion zone active until all movement has stopped and the equipment is in a safe state.

Complete the final inspection: doors and locking bars, seals, external contamination or damage, markings, gross mass, documents and release status. The load must also be prepared for safe transport and unloading.

10. Review performance by material and load

Record net payload, complete cycle time, active filling time, waiting, product loss and exceptions. Compare like with like: the same material range, container type and operating conditions. Investigate variation rather than focusing only on the best load.

These records reveal whether the next improvement belongs in material supply, container preparation, the loading system, weighing or coordination with transport. They also provide the evidence needed for an investment calculation.