Offshore container certification failures are more common than most project teams expect, and more often than not, they are not structural failures. The container is structurally sound. The failure is a documentation failure — the evidence presented to the certification body does not demonstrate compliance with the standard’s requirements, or does not do so completely enough for the reviewer to be confident.
Understanding where offshore container projects go wrong is the first step to avoiding it.
Why Offshore Container Certification Failures Happen
The certification body reviews a package of evidence, not the container itself. They look at the structural calculations to verify the design, the drawings to verify what was built, the material certificates to verify the properties of the steel, the weld records to verify fabrication quality, and the test records to verify that the as-built container performs as designed.
If any element of that evidence package is missing, inconsistent, or does not clearly connect to the container being certified, the reviewer cannot close out the certification. The structure may be fine — but the evidence is not there to prove it.
This distinction matters for how projects approach offshore container certification. Engineering and procurement teams that treat certification as a final inspection, rather than a process running alongside engineering and fabrication, consistently end up with evidence gaps. The time to build the certification evidence is during design and fabrication, not at the end.
The Most Common Failure Modes
Incomplete or inconsistent design calculations. The structural calculations cover certain load cases but miss others. The load cases in the calculations do not match the load cases described in the design brief. The analysis method used is not the method specified in DNV 2.7-1 or EN 12079. These gaps are common when calculations are produced by engineers unfamiliar with the specific requirements of the standard. The fix requires additional engineering — which takes time.
Material traceability gaps. The certification body requires evidence that the materials used in the primary structural members meet the specified requirements. This means mill certificates traceable to the specific heats or batches of material used in the fabrication. Common failures: certificates are not provided, provided for the wrong material grade, or the material is not uniquely identified in the fabrication records so the certificate cannot be linked to the specific component.
Weld procedure qualification records not covering the actual welding carried out. DNV 2.7-1 requires that welding is carried out using qualified procedures, by qualified welders, on qualified material combinations. In practice, offshore container projects fail because the welding procedure specification (WPS) submitted for review does not cover the actual joint configuration or material thickness used in fabrication. These are straightforward to manage if the manufacturer prepares the records during fabrication. They are very difficult to fix after the fact.
Pad eye design not accounting for the full range of sling angles. The lifting arrangement analysis submitted during design approval uses specific sling angles. If the lifting arrangement on the vessel uses angles outside the approved range, the pad eye design may be operating outside its certified capacity. This is a common problem when the lifting analysis is done without knowledge of the vessel’s crane geometry.
As-built drawings not reflecting what was actually fabricated. DNV 2.7-1 design approval is based on the design drawings. Certification is based on what was actually built. If the as-built drawings do not match the fabrication — a bracket fabricated differently, a penetration repositioned, a weld detail changed — the certification body cannot confirm the as-built structure matches the approved design.
Testing carried out without a surveyor present at the required hold point. The standard requires certain tests to be witnessed by the certification body’s surveyor. If a test is carried out without the surveyor present, it must be repeated. For proof load testing of lifting arrangements, this can mean re-rigging and re-loading the offshore container — a significant logistical exercise on a fabrication yard.
The Consequences of an Offshore Container Certification Failure
The direct consequences are cost and schedule.
Delay. Rework, re-inspection, and re-submission add weeks to the certification timeline. A design review failure requiring additional calculations might add 3 to 4 weeks. A hold point failure requiring re-testing might add 2 to 3 weeks plus re-mobilisation costs.
Cost. Additional engineering fees, surveyor re-inspection fees, and potentially re-testing costs. On a North Sea project, a 4-week certification delay carries day-rate costs that typically dwarf the original offshore container engineering fee.
Contractual exposure. If the container is part of a larger offshore campaign, a certification delay can delay the entire mobilisation.
In the worst case, an offshore container cannot be certified as designed and requires redesign — typically when a structural member is found to be undersized during as-built review, or when a material substitution does not meet the specified requirements.
How to Avoid Offshore Container Certification Failures
Avoiding certification failures requires treating DNV 2.7-1 certification as a process running from the start of engineering, not a step at the end.
Engage the engineering firm and the certification body before fabrication begins. Agree the scope of the certification, the standards that will be applied, the hold point schedule, and the documentation requirements. This alignment — held before any fabrication — prevents the misalignment that causes most offshore container certification failures.
Establish the hold point schedule with the manufacturer from the outset. The certification plan identifies when the surveyor is required. The manufacturer needs to plan their fabrication sequence around those requirements, not treat them as an add-on.
Use an offshore container engineering firm experienced in managing DNV and LR submissions. Structural design competence and certification management competence are different skills. A firm that knows what a DNV reviewer looks for in a design submission will produce a submission that clears review faster than one that produces technically correct work in a format the reviewer finds difficult to navigate.
Ingeniat has managed DNV 2.7-1 certifications across multiple projects. We know what certifiers look for in a design submission — and how to structure the evidence so review cycles move faster.
Share your project requirements below. We’ll review your specifications and respond with a detailed engineering proposal.