Galvanised steel ground anchor SPIRALE

Presentation
To avoid impacts on high-value marine ecosystems (protected habitats, notably Posidonia seagrass meadows and associated benthic fauna), ANCR’EST has developed a range of ecological spiral anchors.

Function and uses
The ecological spiral anchor is a screw-type wire anchor designed to provide effective anchorage against traction and horizontal loads. Systems are adapted to project needs. For mooring applications, anchors can be equipped with an eyelet.

Spiral anchors can be shared via anchorage points. This option ensures stability for large units, in particular vessels over 30 metres.

For support of pontoons or structures, custom mounting plates with adjustable height are available.

Advantages of screw piles
These foundations offer many benefits compared with concrete deadweight anchors. Installation of a foundation on a spiral anchor does not require heavy lifting equipment: it is rapid and can be completed in a few minutes.

Installed systems are available for immediate use. The reduced footprint also provides more options for restricted areas.

Its lower carbon footprint, limited impact on Posidonia meadows (surface impact limited to the anchor's footprint) and reversibility compared with deadweight anchors make the spiral anchor an environmentally relevant solution.

These aspects also improve maritime safety, the visibility of regulated sensitive areas and their protection.

Materials and protection
The steels used comply with European standards and welders are qualified to NF EN ISO 9606-1. Anchors can be protected against corrosion by galvanization or by a cathodic protection system that preserves them from soil corrosion.

Service
ANCR’EST’s engineering service can determine the type of screw pile adapted to each project.

Illustration
Tests of the impact left after unscrewing a spiral anchor from the seabed

Characteristics / technical specifications

• Type: ecological spiral anchor, wire/screw anchor
• Main functions: anchorage under traction and horizontal loads
• Options: eyelet for mooring; shared anchoring via anchorage points for large units
• Adaptations: custom adjustable plates for pontoon or structure supports
• Advantages: rapid installation without heavy equipment, immediate reuse after installation, reduced footprint, lower carbon footprint, reversibility (less impact than a deadweight anchor)
• Compliance: steels compliant with European standards
• Welding: welders qualified NF EN ISO 9606-1
• Corrosion protection: galvanization or cathodic protection
• Technical support: engineering service to choose the appropriate screw pile