Choosing the right offshore container is critical for safe and compliant transportation in oil & gas, marine, and offshore wind projects. Many buyers struggle to understand the differences between DNV 2.7-1 and DNV 2.7-3, leading to costly mistakes or compliance risks.
This guide explains everything you need to know—from standards to selection criteria—so you can confidently choose the right offshore container for your project.
What Is an Offshore Container?
An offshore container is a specialized cargo unit designed for transporting equipment and materials to and from offshore installations such as oil rigs, drilling platforms, and marine vessels.
Unlike standard shipping containers, offshore containers must withstand:
● Harsh marine environments
● Dynamic lifting conditions
● Strict safety regulations
They are commonly used for:
● Tools and spare parts
● Hazardous materials
● Bulk cargo and equipment
What Is DNV 2.7-1?
DNV 2.7-1 is the most widely used certification standard for offshore containers.
Key Features:
● Applies to cargo carrying units (CCUs)
● Focuses on design, lifting, and structural integrity
● Ensures safe handling during offshore lifting operations
Typical Use Cases:
● Offshore cargo baskets
● Mud skips
● Standard offshore containers
● Tool boxes and equipment containers
If your container is lifted by cranes between vessel and platform, DNV 2.7-1 is usually required.
What Is DNV 2.7-3?
DNV 2.7-3 applies to offshore service modules, not cargo containers.
Key Features:
● Covers portable offshore units with equipment inside
● Includes electrical systems, HVAC, and safety systems
● Focuses on operational safety in hazardous areas
Typical Use Cases:
● Offshore workshop containers
● Laboratory modules
● Accommodation modules
● Pressurized cabins
● MWD/LWD cabins
If your container includes people or active equipment, DNV 2.7-3 is required.
DNV 2.7-1 vs 2.7-3: Key Differences
| Feature | DNV 2.7-1 | DNV 2.7-3 |
Type | Cargo containers (CCU) | Service modules |
Function | Transport goods | Support operations |
Human occupancy | Not allowed | Allowed |
Electrical systems | Minimal | Fully integrated |
Safety scope | Structural & lifting | Full system safety |
Typical examples | Baskets, skips, containers | Workshops, labs, cabins |
How to Choose the Right Offshore Container
1. Define the Purpose
Ask yourself:
● Is it used for cargo transport? → Choose DNV 2.7-1
● Is it used for operations or personnel? → Choose DNV 2.7-3
2. Check If Equipment Is Installed
If your container includes:
● Electrical systems
● HVAC (especially explosion-proof AC)
● Control panels
Then it likely falls under DNV 2.7-3
3. Consider Hazardous Area Requirements
For oil & gas environments:
● Zone 1 / Zone 2 → Requires explosion-proof design
● May require:
■ ATEX / IECEx certification
■ Pressurized modules
These are typically DNV 2.7-3 modules
4. Evaluate Lifting and Transport Needs
All offshore units must handle:
● Crane lifting
● Sea transport
● Impact loads
Both standards apply, but:
● 2.7-1 focuses on lifting safety
● 2.7-3 includes operational safety
5. Check Client or Project Specifications
Major operators (e.g., oil companies, EPC contractors) often specify:
● Required certification
● Additional standards (ISO, EN, ATEX)
Always align with project specs before purchasing.
Common Mistakes to Avoid
Using DNV 2.7-1 for equipment modules
→ Not compliant, high safety risk
Ignoring hazardous area classification
→ Explosion risk + project rejection
Choosing standard containers instead of offshore-certified ones
→ Structural failure during lifting
Real Application Examples
Case 1: Offshore Drilling Project
● Requirement: Transport drilling tools
● Solution: DNV 2.7-1 cargo container
Case 2: Mud Logging Unit
● Requirement: Equipment + personnel workspace
● Solution: DNV 2.7-3 service module
Case 3: Hazardous Area Workshop
● Requirement: Maintenance in Zone 2
● Solution: Pressurized DNV 2.7-3 module
FAQ
What is the difference between DNV 2.7-1 and 2.7-3?
DNV 2.7-1 applies to offshore cargo containers used for transporting goods, while DNV 2.7-3 applies to offshore service modules used for operations, often including equipment and personnel.
When should I use a DNV 2.7-3 container?
You should use DNV 2.7-3 when the unit includes equipment, electrical systems, or is intended for human occupancy or operational use.
Are offshore containers required to be DNV certified?
In most offshore oil & gas projects, DNV certification (especially 2.7-1 or 2.7-3) is required to ensure safety and compliance.
Can a DNV 2.7-1 container be converted into a module?
No. Once equipment and systems are integrated, the unit must comply with DNV 2.7-3 requirements.
Conclusion
Choosing between DNV 2.7-1 and DNV 2.7-3 depends on one key factor:
Transport vs Operation
● Transport cargo → DNV 2.7-1
● Support operations → DNV 2.7-3
Making the right choice ensures:
● Safety compliance
● Project approval
● Long-term reliability
Get Expert Support
If you're unsure which offshore container or module fits your project, our engineering team can help you:
● Select the right certification
● Customize container solutions
● Meet offshore and hazardous area standards
Contact us today to get a tailored solution and quotation.