ISO Shipping Container vs DNV 2.7-1 Offshore Container: What Is the Difference?

Short Answer

An ISO shipping container is designed mainly for intermodal freight transport. A DNV 2.7-1 offshore container is designed, built, tested and certified for repeated offshore lifting and handling between vessels and offshore installations. They can look similar, but they are not interchangeable.

For an offshore project, the question is not simply whether a container is strong enough to carry equipment. It is whether the complete unit—including its structure, lifting set, weld quality, markings, tests and documentation—meets the project’s offshore transport and lifting requirements.

What Is an ISO Shipping Container?

An ISO freight container is a standardized cargo unit used in road, rail and sea logistics. Its dimensions and corner fittings support global intermodal handling. A container carrying a CSC safety plate can be suitable for international transport under the International Convention for Safe Containers, subject to its condition and operating limits.

That does not make it an offshore lifting container. Offshore lifts can introduce dynamic effects, vessel motion, acceleration, impact and demanding corrosion exposure that are outside the normal design basis of a freight container.

What Is a DNV 2.7-1 Offshore Container?

DNV-ST-E271, commonly called DNV 2.7-1, is a standard for offshore containers and their lifting sets. It covers the approval and certification framework for design, manufacture, testing, marking, inspection and certification. EN 12079 is also widely specified for offshore-container applications.

A DNV 2.7-1 container may be a cargo-carrying unit, equipment container, workshop, laboratory, control-room module or another project-specific enclosure. The certification scope must be confirmed for the exact design and supplied configuration.

Why Offshore Lifting Changes the Design

The movement of a supply vessel relative to an offshore platform or rig can create dynamic loading during lifting. The container, lifting points and slings must therefore be assessed as a system for the intended offshore service.

An offshore container specification commonly considers:

structural framing, floors, doors, roof and equipment supports;
pad eyes, lifting sets and their certification;
lifting, impact and transport load cases;
welding procedures, material traceability and inspection;
corrosion protection for the operating environment;
load testing, non-destructive testing and final inspection; and
required marking, certificates and documentation.

The required details vary with the container type, payload, dimensions, lifting arrangement, project location and client specification.

Is a CSC Plate the Same as DNV 2.7-1 Certification?

No. A CSC plate is associated with the safety approval of a freight container for international transport. DNV 2.7-1 certification addresses offshore-container and lifting-set requirements. One approval does not automatically replace the other.

Some projects require both an offshore certification package and a CSC transport configuration. Buyers should state this explicitly rather than assuming that a freight certificate covers offshore use.

What Does DNV 2.7-1 Not Cover by Itself?

DNV 2.7-1 is vital for offshore structure and handling, but it is not a blanket approval for every system inside the module.

For example:

A-60 fire protection concerns the performance of a specified fire-rated boundary.
IEC 60079, ATEX or IECEx requirements concern equipment and installations in potentially explosive atmospheres.
Electrical protection, HVAC capacity, fire-and-gas systems and process equipment each require their own defined design and approval basis.

An offshore workshop or pressurised control room may need several coordinated compliance scopes. A technically credible quotation identifies each scope separately.

Which Container Should You Specify?

Specify an ISO freight container when the unit is intended for standard intermodal logistics and the project does not require offshore lifting certification.

Specify a DNV 2.7-1 offshore container when the unit will be lifted to or from an offshore installation, handled by offshore lifting equipment, or is required by the operator, classification society or project specification.

If the unit is a functional module, define its application as well: workshop, laboratory, MCC shelter, accommodation, refrigeration, ROV control or another purpose. The function determines the internal layout, utilities, safety systems and documentation required in addition to the offshore structure.

Questions Buyers Commonly Ask

Can a standard shipping container be converted for offshore use?

Not by adding pad eyes or repainting it. Offshore suitability must be evaluated against the applicable standard and certification process for the complete converted unit. The responsible manufacturer and certification body must confirm what is feasible.

Does every offshore container need A-60 fire protection?

No. Fire rating depends on the module’s function, location and project fire-safety requirements. It must be specified for the relevant boundaries and penetrations when required.

Are DNV 2.7-1 and EN 12079 identical?

They are both commonly referenced for offshore containers, but the project must state the applicable revision, certification basis and any client or class requirements. Do not rely on a generic statement that a unit is “offshore compliant.”

What documents should accompany an offshore container?

The required dossier is project-specific. It may include drawings, certificates, material traceability, load-test records, NDT reports, lifting-set certificates, inspection records, coating documentation, operating instructions and marking details.

What to Include in an Enquiry

Provide the intended service, payload and internal equipment; offshore installation location; required standards; maximum dimensions and weight; lifting arrangement; corrosion environment; fire or hazardous-area requirements; utility interfaces; target quantity; delivery location; and required documents or third-party inspection.

TLS designs standard and custom containerised solutions for offshore, energy, industrial and data-infrastructure projects. Its offshore container solutions can be engineered to project requirements including DNV 2.7-1 and EN 12079. Contact TLS with your application and specification for a project-specific review.