Moving Empty Containers Where They Are Needed—Across Shipping Line Boundaries

Global container transport does not move cargo alone. Large numbers of empty containers must also be transported between ports, inland depots and regions to correct imbalances between import and export demand.

Every unnecessary empty-container movement consumes fuel, occupies truck and vessel capacity, adds handling work and generates CO₂ emissions.

NPO ESCOT promotes Container Round Use (CRU): matching an empty container generated after an import movement with a nearby export shipment so that the container can be reused without first returning it over a long distance to a container yard.

Conventional CRU, however, faces a major practical barrier: the shipping line that owns the import container may not be the shipping line selected for the export shipment.

To address this barrier, ESCOT proposes a model combining:

  • Container Round Use (CRU);
  • authorized free use of the container;
  • shipment as a Shipper’s Own Container (SOC) on another carrier; and
  • repositioning of the container to a location where its owner needs it.

This page explains the concept, its potential benefits and the conditions that must be verified for each shipment.

1. Why a Nearby Empty Container Cannot Always Be Reused

Suppose an import container arrives at a factory or logistics center and becomes empty after devanning. If a nearby company has export cargo, the most efficient option may appear obvious: load that cargo into the available container.

This is the basic idea of CRU.

In practice, however, the following situation often arises:

  • the import container is owned or controlled by Shipping Line A; and
  • the exporter has booked its shipment with Shipping Line B.

Under conventional practice, Line A’s empty container is returned to a location designated by Line A. At the same time, an empty container supplied by Line B is transported from Line B’s container yard or depot to the exporter.

The result may be two separate empty-container movements, even though a physically usable container is already available near the export cargo.

2. The SOC-based CRU Concept

One possible way to overcome the shipping-line boundary is authorized free use.

With the express approval of the container-owning shipping line, an empty container generated after import delivery may be made available to a third party for a specified route, period and purpose. The exporter loads cargo into that container and books it with another shipping line as an SOC (Shipper’s Own Container).

After arrival at the overseas destination and devanning, the empty container is returned to a depot, container yard or other location designated by its owner.

Basic flow

  1. A container owned or controlled by Shipping Line A arrives in Japan with import cargo.
  2. The cargo is devanned at a factory or logistics facility.
  3. The empty container becomes available near an export shipper.
  4. Shipping Line A authorizes its free use under agreed conditions.
  5. Nearby export cargo is loaded into the container.
  6. Shipping Line B accepts and carries the loaded container as an SOC.
  7. The container is transported to the overseas destination.
  8. After devanning, the empty container is returned to a location designated by Shipping Line A.

This arrangement does not transfer ownership of the container. It is also different from an interchange in which shipping lines exchange equipment. The container remains the property or controlled equipment of its original owner and is used only with that party’s authorization and under agreed conditions.

3. Turning Empty Repositioning into Revenue-generating Cargo Transport

Container imbalances are unavoidable. Some regions accumulate empty containers after imports, while other regions need equipment for exports. Shipping lines therefore reposition empty containers by truck, rail or vessel.

Empty repositioning is necessary asset management, but an empty container carries no paying cargo. It still requires inland transport, terminal handling, vessel space, tracking and administration.

SOC-based CRU creates the possibility of combining two requirements:

  • an exporter needs a container and transport to a particular destination; and
  • the container owner needs its empty equipment repositioned toward that destination or region.

If these needs can be matched, a movement that would otherwise reposition an empty container may be carried out while the container is transporting revenue-generating export cargo.

ESCOT refers to this as a form of free positioning: repositioning equipment at lower operational and environmental cost by combining it with a loaded cargo movement.

4. Potential Benefits for Each Party

Export shippers

  • Shorter empty-container pickup distances;
  • lower inland transport costs;
  • shorter lead times;
  • greater flexibility when a required container is not locally available; and
  • lower CO₂ emissions from unnecessary empty transport.

Inland transport operators

  • Fewer long-distance empty-container trips;
  • reduced fuel consumption;
  • shorter driver working and waiting times;
  • improved vehicle utilization; and
  • more capacity available for revenue-generating transport.

The shipping line carrying the SOC

  • Revenue from carrying loaded export cargo, even when the equipment is owned by another line;
  • no need to supply one of its own empty containers for that shipment; and
  • no obligation to add the container to its own equipment inventory after devanning, provided that the agreed return procedure is followed.

The container-owning shipping line

  • A possible alternative to repositioning the container empty;
  • reduced empty handling and transport requirements;
  • movement of equipment toward a location where it is needed; and
  • continued ownership and control under agreed free-use and return conditions.

Society and the environment

  • Fewer unnecessary truck movements;
  • reduced congestion and driver workload;
  • more efficient use of existing containers and transport capacity; and
  • lower fuel consumption and CO₂ emissions.

5. A Concept Previously Tested in Actual Transport

NPO ESCOT has previously participated in container-sharing trials based on this concept. In those trials, the container-owning shipping line and the shipping line carrying the export cargo were different.

With the owner’s authorization, the container was used for export cargo, carried by another shipping line as an SOC and returned after devanning to a location designated by the container owner.

This experience shows that SOC-based CRU is not merely a theoretical proposal. It has been tested in real transport operations, although every new case still requires individual commercial, operational, legal and technical approval.

6. Example of Inland Distance, CO₂ and Cost Reduction

In one previous matching case, an exporter was located approximately 400 km from the port container yard that would normally have supplied the empty export container.

After matching the export shipment with an empty import container available in the surrounding region, the empty-container movement was reduced to approximately 35 km.

The case study indicated:

  • Empty movement avoided: approximately 365 km per trip;
  • Estimated CO₂ reduction: approximately 4,680 kg per year; and
  • Estimated transport cost reduction: approximately JPY 1.6 million per year.

These figures represent one past case and must not be treated as a guaranteed result. The actual reduction depends on the original and revised routes, number of trips, vehicle type, fuel efficiency, load conditions and other operational factors.

The important principle is simple: the environmental benefit must be calculated from the empty-container movements actually avoided—not merely from the number of SOC containers used.

7. Potential Global GX Impact

Trade flows are structurally imbalanced. As a result, a substantial share of container movements worldwide consists of empty-equipment repositioning. Industry and international-organization publications commonly describe empty repositioning as a major cost and efficiency problem for liner shipping.

SOC-based CRU cannot eliminate all empty repositioning. However, even a limited conversion of empty movements into loaded export movements could create meaningful benefits at global scale.

The opportunity is to match:

  • a location where a container owner has surplus empty equipment;
  • export cargo available near that equipment;
  • a destination where the owner needs the container; and
  • a carrier willing and able to accept the loaded unit as an SOC.

In this way, the model combines:

Container Round Use + SOC + Authorized Free Use + Free Positioning

The objective is not simply to move a container. It is to reduce the empty movements required to transport the same amount of cargo.

8. Conventional Movement and SOC-based CRU

Conventional arrangement

Import side

Import delivery → devanning → Line A empty container → empty return to Line A’s designated CY or depot → possible empty repositioning to an overseas shortage area

Export side

Line B’s CY or depot → empty container supplied to exporter → cargo loaded → export shipment

This arrangement may create two inland empty movements and, depending on equipment imbalance, an additional overseas empty repositioning movement.

SOC-based CRU arrangement

Import delivery → devanning → Line A empty container → Line A authorizes free use → nearby export cargo is loaded → Line B carries the container as an SOC → overseas devanning → empty container returned to Line A’s designated location

The aim is to change:

“Returning an empty container” into “returning the container while it carries cargo.”

9. Conditions That Must Be Confirmed

The presence of a nearby empty container and nearby export cargo does not, by itself, make SOC-based CRU feasible.

At minimum, the parties must confirm:

  • location of the empty container;
  • container owner or controlling shipping line;
  • container number, size and type;
  • structural condition, cleanliness and cargo suitability;
  • valid inspection and certification status, including CSC requirements where applicable;
  • authorization for free use from the container owner;
  • permitted use period and route;
  • export cargo type, weight and destination;
  • acceptance conditions of the SOC-carrying shipping line;
  • booking and vessel capacity;
  • terminal and port acceptance;
  • customs and other regulatory procedures;
  • tracking and equipment-control arrangements;
  • overseas devanning location;
  • designated return location and return deadline;
  • responsibility for damage, repair, cleaning, detention, demurrage and other charges;
  • insurance and contractual allocation of risk; and
  • method for measuring the avoided empty movement and CO₂ reduction.

The most important prerequisite is clear:

The container-owning or controlling shipping line must expressly authorize the proposed use.

No container should be used outside the owner’s instructions or without the required approvals.

10. How Candidate Shipments Can Be Identified

The first step is to make two types of information visible:

  1. Where and when do empty import containers become available?
  2. Where are nearby export shipments going, and what equipment do they require?

Candidate cases can then be screened in two stages:

  • If the import and export movements use the same shipping line, consider conventional CRU.
  • If the shipping lines differ, examine whether owner-authorized free use and SOC carriage are possible.

ESCOT aims to connect information from importers, exporters, logistics companies, inland depots, ports and shipping lines so that containers previously moved empty can be used for cargo wherever practical.

Frequently Asked Questions

Q1. Does carrying an SOC displace the carrier’s own empty container from the vessel?

Not necessarily. An SOC in this model is not an additional empty unit. It is a loaded, revenue-generating export shipment booked for normal ocean carriage.

The SOC-carrying line can earn freight revenue without supplying one of its own empty containers to the exporter. After devanning at destination, the container is returned to the original owner’s designated location under the agreed procedure; the SOC-carrying line does not normally take it into its own equipment inventory.

Vessel capacity is, of course, limited. Acceptance remains subject to the carrier’s normal booking decision, including weight, stowage, route, port rotation, operational restrictions and available space.

Q2. Does using a nearby SOC container always reduce CO₂ emissions?

No. The use of an SOC is not automatically a GX achievement. The correct question is: Which empty-container movements were actually avoided?

If a truck must make a substantial detour to collect the proposed SOC container, the domestic benefit may be small or even negative. Likewise, if the owner does not need that container at the overseas destination, the shipment may not provide a repositioning benefit for the owner.

The GX effect should therefore be assessed separately in two areas:

  1. empty inland transport avoided in the origin country; and
  2. contribution to the container owner’s international equipment repositioning needs.

The strongest match occurs when:

  • an import container becomes empty close to an exporter; and
  • the export destination is a region where the container owner needs that equipment.

Q3. Who retains ownership of the container?

The original container owner retains ownership. The arrangement is a limited, authorized use for agreed cargo, route, period and return conditions. It is not a sale or permanent transfer of the equipment.

Q4. Is this the same as a container interchange between shipping lines?

No. The proposed model does not require the shipping lines to exchange ownership or permanently transfer equipment between their fleets. The carrying line accepts a loaded SOC shipment, while the original owner authorizes use of its equipment and specifies where it must ultimately be returned.

Q5. What happens if the container is damaged or returned late?

Liability, inspection, repair, cleaning, detention, demurrage, insurance and return procedures must be defined in advance by contract or written confirmation among the relevant parties. These conditions cannot be assumed and must be agreed for each project or standardized pilot scheme.

From “Empty Return Logistics” to “Cargo-carrying Return Logistics”

SOC-based CRU will not solve every container imbalance. It depends on the container owner’s approval, equipment condition, cargo compatibility, destination, timing, vessel space, customs procedures, overseas return arrangements and commercial agreement among the parties.

For that reason, the first step should not be to assume that a case is possible—or impossible.

The first step is to identify a potential match between an empty container and export cargo, quantify the movements that could be avoided, and then ask the relevant shipping lines and logistics partners to examine the case.

That is where practical logistics decarbonization begins.

Invitation to Shipping Lines and Logistics Partners

NPO ESCOT welcomes discussions with:

  • container-owning shipping lines;
  • shipping lines that accept SOC cargo;
  • importers and exporters;
  • freight forwarders and NVOCCs;
  • drayage and inland transport companies;
  • container depots and inland ports;
  • terminal operators;
  • research institutions; and
  • public authorities working on logistics decarbonization.

We are seeking practical pilot cases in which an import container available in Japan can be matched with nearby export cargo and, with the owner’s authorization, transported as an SOC to a destination that supports the owner’s equipment needs.

For each candidate, the environmental benefit should be measured transparently by comparing the empty-container movements before and after CRU.

Contact NPO ESCOT to discuss a candidate route, container or export shipment.

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Editorial note

The numerical case study above is based on ESCOT’s past matching materials. Before publication, confirm the displayed calculation assumptions and add links to the relevant Japanese case-study documents where appropriate.