Project record

Zeevonk phase 1 foundation installation

Fugro Synergy geotechnical vessel conducting seabed investigation work for the Zeevonk offshore wind project

Vattenfall; project-specific Zeevonk seabed-investigation image

Zeevonk has awarded DEME the foundation transport and installation package for the first 1 GW phase of its Dutch North Sea wind farm. The contract covers intermediate monopile transport, marshalling of primary and secondary steel, transport and installation of 69 monopile foundations, and placement of a filter layer for scour protection. The owner plans phase 1 for 2029, but has not published the marshalling port, fabrication split, installation vessel or offshore start date.

Project signal

Award in Netherlands

Treat foundation installation as awarded, not mobilised or completed. The contract fixes a 69-foundation marine package and its logistics boundary. The installation vessel, foundation fabricators, marshalling base, final scour-protection build-up, cable installer, offshore start, first foundation and accepted completion remain undisclosed or unproven.

Current status DEME holds the transport and installation contract for 69 monopile foundations; offshore mobilisation has not been announced Source confidence Confirmed

Location

Netherlands / Europe

Segment

Offshore wind foundations

Status

DEME holds the transport and installation contract for 69 monopile foundations; offshore mobilisation has not been announced / Confirmed

Evidence reviewed

20 July 2026

Controlled taxonomy

Related sectors

The detailed segment above is the primary work classification. These broader sector links connect the project to related delivery and market research.

Knowledge context

Related knowledge topics

Continue through the topic collections to compare this record with related projects, evidence guides, briefs, articles, reports, and performance records.

Project anatomy

Scope, counterparties, and execution logic

Client / authority
Zeevonk, a joint project of Vattenfall and Copenhagen Infrastructure Partners
Delivery parties
DEME - intermediate monopile transport, marshalling services, transport and installation of 69 monopile foundations, and filter-layer placement, TKF - separate supply contract for approximately 162 km of 66 kV inter-array cable, Fugro - geotechnical and geophysical investigation partner identified by Vattenfall
Contract route
Zeevonk awarded DEME a substantial transport and installation contract for the phase 1 foundations. DEME uses 'substantial' as a value category but did not disclose the price. Zeevonk separately awarded TKF the design, manufacture, testing and delivery of the 66 kV inter-array cables; that announcement does not name the cable installation contractor.
Execution window
Vattenfall schedules the first 1 GW phase for completion in 2029. A second 1 GW wind phase and 500 MW of system-integration capacity are planned for 2032. The DEME release does not publish the foundation fabrication, marshalling, mobilisation or offshore installation dates.
Works package
Intermediate transport of monopiles, marshalling services for primary and secondary steel, transport and installation of 69 monopile foundations, and installation of a filter layer for scour protection. The package sits within a 1 GW first phase located 63 to 84 km off Bergen aan Zee. It does not, on the published evidence, include monopile fabrication, turbine installation, inter-array cable installation, the TenneT platform or the onshore hydrogen facilities.
Marine interfaces
The foundation sequence must join fabrication delivery, a still-unannounced marshalling base, intermediate transport, offshore lifting and piling, secondary-steel handling and filter-layer placement. Site investigations found strong currents, large sand formations and artificial seabed obstacles; Vattenfall also planned a 2026 unexploded-ordnance survey. The 69 turbine positions then need to connect through approximately 162 km of 66 kV inter-array cable to the TenneT offshore substation.
Commercial read
The core foundation installation opportunity is no longer open at owner level. Remaining visible interfaces include fabrication and port logistics disclosures, vessel and feeder strategy, survey and UXO work, noise and ecological controls, cable installation, remaining scour-protection layers, as-built survey and acceptance. No source reviewed for this record publishes package value, installation productivity, port allocation or subcontract awards.
Next milestone
Confirmation of foundation fabrication and marshalling arrangements, followed by vessel assignment, offshore mobilisation and installation of the first monopile and filter layer.

Material change register

What changed, when, and what it proves

Only source-bound events that alter phase, scope, counterparties, delivery, completion, commissioning, or acceptance are listed. A change can advance the record without proving the next gate.

DEME won the 69-foundation transport and installation package

The award fixes the principal offshore foundation contractor and includes marshalling, intermediate transport and filter-layer placement. Port, vessel, fabrication and mobilisation details remain unpublished.

Read controlling source

TKF received the phase 1 inter-array cable supply contract

The separate award covers about 162 km of 66 kV cable and accessories. It establishes the cable supply chain but does not identify the offshore installer.

Read controlling source

The amended IJmuiden Ver Beta permit became irrevocable

The amended permit supports the two-phase delivery sequence now used by the owner: 1 GW in 2029, followed by a further 1 GW and system-integration capacity in 2032.

Read controlling source

Delivery watch

Evidence needed next

Confirmation of foundation fabrication and marshalling arrangements, followed by vessel assignment, offshore mobilisation and installation of the first monopile and filter layer.

Decision watchpoints

  • Monopile and secondary-steel fabrication awards
  • Marshalling port and intermediate transport plan
  • Installation vessel, feeder spread and mobilisation date
  • UXO investigation and clearance status
  • Foundation installation method and underwater-noise controls
  • First monopile and filter-layer placement
  • Inter-array cable installation award and route preparation
  • As-built survey, scour completion and foundation acceptance

Related records 2

Project availability status

This public project page is a tracked market record rather than a tender notice, contractual commitment, or commercial instruction. Use the status, confidence label, evidence-review date, and source note together when judging how much weight to place on the signal.

Read featured analysis Review methodology Submit stronger evidence or a correction Open project tracker

Record control

Evidence reviewed date is not a project-event date.

IMWO changes phase, participants, scope, completion, or acceptance wording only when a dated source establishes the change. The review date records when the evidence set was checked; it does not claim that physical work changed on that date.

Evidence reviewed 20 July 2026 Sources in this record 6

Source record

DEME's 20 July release is the controlling source for the 69-foundation installation award and exact package boundary. Vattenfall's project page provides the two-phase programme and 2029 phase 1 target. Its May cable award confirms about 162 km of 66 kV inter-array cable supply without identifying the installer. The Dutch RVO record confirms Zeevonk II as the IJmuiden Ver Beta permit holder and the amended permit as irrevocable from 17 October 2025. Vattenfall's seabed-investigation account supplies the site-condition and survey context; it is not installation evidence.

Phase: award. Evidence reviewed: 20 July 2026.

Project sources 6