Case Study: SuedLink

SuedLink is a ~700 km HVDC underground cable system transporting up to 4 GW of renewable energy from northern to southern Germany. As one of Europe’s largest underground energy infrastructure programmes, it demands tightly controlled work-front release, multi-authority approvals, and consistent compliance across multiple federal states.

INFRA JV was appointed to deliver archaeological evaluation, mitigation, and construction-phase support across approximately 450 km of the southern corridor (more than half of the total archaeological scope). Delivery is fully integrated within a Tier-1-led mega-programme environment, requiring archaeology to progress in parallel with live construction while protecting safety, environmental compliance, regulatory confidence, and programme certainty.

INFRA JV embedded archaeology within Tier-1 governance via a single client-facing Programme & Planning Lead, supporting consistent escalation, rapid resequencing, and predictable work-front release across dispersed regions. Permanent regional and local delivery bases were established along the corridor to enable responsive mobilisation and reliable construction-phase support at scale.

Our methodology followed a structured progression:

• Pre-construction evaluation via trial trenching (620 trenches / c.157,000 m²), with reports completed and approved by the client and relevant heritage authorities.
• UXO watching briefs supporting safe delivery during ground investigations (250+ supervised interventions).
• Open-area excavation across 50+ areas covering 150+ ha, including mitigation triggered by discoveries during live construction.
• Construction-phase watching briefs across work fronts totalling c.729 ha within the programme footprint.
• Digital and GIS-enabled delivery, including corridor-wide integration of archaeology, UXO, environment, access and civils interfaces to support a “single view of the route”.

Safe, consistent delivery was maintained across a multilingual workforce scaling from approximately 50 to 300+ staff. Project-wide SHEQ controls included RAMS, OH&W governance, and multilingual competence frameworks (including a RAMS-driven Language Concept and Language Risk Assessment).

Quality and data reliability were ensured through a single digital recording standard (with authority-specific annexes), project-wide QA governance for context data, drawings, GIS and reporting, and clear escalation routes and audit trails. Environmental compliance was managed proactively under inspection-led regimes, with dynamic resequencing or suspension where required to maintain compliance and protect programme outcomes.

SuedLink is generating extensive new archaeological datasets across a highly dispersed linear corridor. Mitigation activity includes responses to discoveries made during live construction, with excavation reporting and synthesis studies in preparation to support future research and stakeholder value.

• Achieved 100% delivery of evaluation and approximately 25% delivery of mitigation to date, supporting construction milestone confidence.
• Delivered high-productivity construction-phase oversight across the active programme footprint, including strong progress in Baden-Württemberg (pre-construction open-area excavation and c.95% of construction-phase watching briefs).
• Maintained robust safety performance with zero serious incidents recorded over 350,000+ hours worked to date.
• Strengthened authority and client confidence through disciplined QA governance, consistent technical sign-off, and clear audit trails.
• Enabled transparent, programme-ready decision-making through integrated GIS delivery and predictable work-front release.

Our role on SuedLink demonstrates INFRA JV’s ability to operate as a low-risk, predictable delivery partner within Tier-1 governance on nationally critical infrastructure programmes. Clients choose INFRA JV for: