Does my crane still have a declaration of conformity after a third party repairs the boom?

by | Sep 15, 2026 | Crane Repair

Certified inspector examining a weathered mobile crane boom with visible repair welds in an industrial workshop.

If your crane boom has been repaired by a third party, one of the first questions that comes up is whether the crane’s declaration of conformity is still valid. It’s a fair concern, and the answer isn’t always obvious. The rules around CE marking and crane certification after a repair depend on several factors, including who did the work, how they did it, and what documentation followed. Here’s what you need to know.

What the declaration of conformity actually covers

A declaration of conformity is the manufacturer’s formal statement that a machine meets all relevant EU directives and harmonised standards at the time it was placed on the market. For mobile cranes, this typically falls under the Machinery Directive (2006/42/EC). The document confirms that the crane, as originally built and configured, complies with the essential health and safety requirements set out in that directive.

Importantly, the declaration of conformity covers the crane as a whole system, not individual components in isolation. The boom is part of that system, and it plays a central role in the crane’s structural integrity and load-bearing capacity. Any significant intervention on the boom, such as welding, structural repair, or modification, can raise questions about whether the original conformity still holds.

How boom repairs affect CE certification status

A repair does not automatically void the CE marking or the declaration of conformity, but it can do so if it is not carried out correctly. The key distinction is between a repair that restores the original specification and one that alters the crane’s design, capacity, or structural behaviour. If a repair changes the crane in a way that affects its safety-relevant characteristics, the machine may effectively be treated as a new product under EU law, requiring a fresh conformity assessment.

When a boom repair is performed to the original specification, using appropriate materials, qualified welders, and documented procedures, the crane can retain its CE status. This is only possible when the repair meets the same technical standards the manufacturer applied during original production. For high-grade steel booms, such as those made from 960 or 1100 N/mm² steel, this is a particularly demanding requirement.

The risk of losing CE certification rises when repairs are carried out without proper documentation, without verified welding procedures, or by personnel who lack the relevant qualifications. In those cases, the legal and operational consequences can be significant, including the crane being taken out of service until compliance is re-established.

Why the repairing company’s qualifications matter

Not every workshop that can weld steel is equipped to repair a crane boom in a way that preserves conformity. The repairing company needs to demonstrate that it operates within a recognised quality management system, uses certified welders, and applies welding procedures that are formally documented and validated for the specific materials involved.

For mobile crane boom repair, the materials used are often ultra-high-strength steels that require specialised knowledge. Standard welding procedures do not apply. The company carrying out the repair must have developed and qualified welding procedure specifications (WPS) for the exact grade of steel in question. Without this, the structural integrity of the repair cannot be guaranteed, and neither can the crane’s certification.

There are a few things to verify before handing over a boom for third-party repair:

  • Does the company hold ISO 9001 certification or an equivalent quality management accreditation?
  • Are their welders certified to the relevant EN or equivalent standards for the materials being welded?
  • Do they have documented WPS procedures for high-grade steels, including 960 and 1100 N/mm² grades?
  • Can they involve a Notified Body for independent testing when required?
  • Do they provide a formal repair report and guarantee after the work is completed?

These are not bureaucratic boxes to tick. They are practical indicators that a repair will hold up, both structurally and legally.

Post-repair testing and documentation to retain

Once a boom repair is complete, the documentation you receive is just as important as the repair itself. This paperwork is what allows you to demonstrate continued compliance to inspectors, insurers, and clients. Without it, even a technically sound repair can create problems during audits or incident investigations.

After a qualified repair, you should expect to receive the following:

  1. A detailed repair report covering the scope of work, materials used, welding procedures applied, and all measurements taken before and after the repair.
  2. Non-destructive testing (NDT) results, such as magnetic particle inspection (MPI) or ultrasonic testing reports, confirming that all new welds are free from cracks or inclusions.
  3. Photographic records of the repair process, including pre-repair condition, in-progress work, and final inspection results.
  4. A certificate or statement from the repairing company confirming that the repair was carried out in accordance with the original specification and applicable standards.
  5. A written guarantee covering the repair for a defined period, which provides additional assurance for your own records and risk management.

If a Notified Body was involved in independent verification, their report should be included as well. Keep all of this documentation together with the crane’s original technical file and declaration of conformity. If questions ever arise about the crane’s compliance status, this paper trail is your evidence that the repair was done properly and that CE certification remains valid.

How Rusch Cranes helps with crane compliance after boom repair

We understand that compliance is not an afterthought. It runs through everything we do from the moment a boom arrives in our workshop or when we deploy to your location. Our repair process is built around preserving the full certification status of your crane, so you can put it back to work with confidence.

  • We prepare a formal Welding Procedure Specification and Repair Plan before any work begins
  • All new welds receive 100% visual inspection and 100% magnetic particle inspection
  • We involve third-party Notified Bodies for ultrasonic or X-ray testing when required
  • We provide full photographic records, NDT reports, and a written repair report
  • CE testing of the crane remains valid after our repairs, and we back every job with a one-year guarantee
  • We work with high-grade steels up to 1100 N/mm², making us one of only three companies in Europe with this capability for telescopic booms

Whether your crane is based in the Netherlands or anywhere else in the world, we can come to you. Get in touch with us to discuss your boom repair and what documentation you can expect to receive.

Frequently Asked Questions

Can the original crane manufacturer void our declaration of conformity if a third party repairs the boom?

The original manufacturer cannot unilaterally void a declaration of conformity simply because a third party performed a repair. However, if the repair was not carried out to the original specification, the manufacturer may legitimately argue that the crane no longer matches the product they certified. This is why ensuring the repairing company works to the same technical standards as the original manufacturer is so important — it removes any ambiguity about whether the original conformity still applies.

What happens if we put the crane back into service after a repair that wasn't properly documented?

Operating a crane after an undocumented or non-compliant repair creates serious legal and safety exposure. If an incident occurs, insurers may refuse to pay out, and the crane operator or owner could face liability under national health and safety legislation. Regulatory inspectors also have the authority to take the crane out of service immediately if they cannot verify compliance. The cost of getting documentation right before returning to work is always far lower than the consequences of operating without it.

How do we know if our boom repair counts as a 'substantial modification' that requires a new conformity assessment?

A repair crosses into substantial modification territory when it changes the crane’s design intent, load-bearing capacity, structural behaviour, or safety-relevant characteristics beyond what was covered in the original declaration of conformity. Restoring a damaged section to its exact original specification, using the correct materials and qualified procedures, is generally not considered a substantial modification. If you are unsure, the safest course is to consult a Notified Body before the repair begins, as they can provide a formal opinion on whether a new conformity assessment is required.

Is there a specific welding standard we should ask the repair company to work to?

For crane boom repairs in Europe, the relevant standard is typically EN 1090 (Execution of Steel Structures), combined with EN ISO 15614 for welding procedure qualification and EN ISO 9606 for welder certification. For ultra-high-strength steels in the 960–1100 N/mm² range, you should specifically confirm that the company holds qualified Welding Procedure Specifications (WPS) for those exact material grades, as standard structural welding qualifications do not cover them. Always ask to see the actual WPS documents before work begins, not just a general statement of capability.

How long should we keep the post-repair documentation, and where should it be stored?

Post-repair documentation should be kept for the entire operational life of the crane and ideally for a defined period beyond decommissioning, as national regulations and insurance requirements vary. Store it alongside the crane’s original technical file, declaration of conformity, and maintenance records so everything is accessible as a single compliance package. Digital backups are strongly recommended, as paper records can be lost or damaged — particularly for equipment that moves between job sites and jurisdictions.

Does the CE certification status affect our crane's insurability or the premiums we pay?

Yes, insurers increasingly scrutinise the compliance status of heavy lifting equipment, and a crane with a questionable or lapsed declaration of conformity can result in higher premiums, restricted coverage, or outright refusal to insure. Some insurers now require documented evidence of post-repair NDT results and repair reports as a condition of continued coverage. Maintaining a clean compliance paper trail after every repair is therefore not just a regulatory obligation — it is a practical financial consideration.

What should we do if we've inherited a crane with a boom repair and no documentation from the previous owner?

Start by commissioning a thorough structural inspection from a qualified crane inspection body or Notified Body, who can assess the current condition of the boom and identify any areas of concern. Depending on the findings, you may need to arrange additional NDT testing and have a competent engineer formally assess whether the crane meets the requirements of the applicable directive in its current state. In some cases, a new declaration of conformity may need to be issued before the crane can legally be placed back into service — your national market surveillance authority can advise on the specific requirements in your jurisdiction.

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