TenneT TSO bv

Requirements of  Service scope of O&M Survey 2025 tender; TenneT TSO B.V. (hereafter: Client) is appointed by the Dutch government as the offshore grid operator for The Netherlands. In order to operate and maintain the assets, Client is by law responsible for assets monitoring. The various connections that are developed and are in operation require survey works for cable routes and platforms.  This EU-Tender shall consist of 3 lots, a) Borssele, b) 700MW cables and the c) interconnectors Cobra&NorNed. All lots shall have the minimal requirements as set out in this tender. Requirements are the following, TenneT minimum requirements, HSE, offshore  The objectives of the services are to: 1.    Perform the O&M survey by means of MBES, SSS and airborne survey or other solution to cover landing/tidal area according to technical specification listed above. 2.    Establish the bathymetry and topography of the seabed to understand the level of it and identify the obstructions in the corridor with the specified quality as minimum. 3.    Establish the seabed features of the seabed to identify the obstructions in the corridor and identify any possible cable exposures or freespans. Resolution of the SSS is described in SPE.06.380-OG and shall be such that the cable if exposed shall be identified using this method (cable diameter ~ 0.2 m). Below defined locations and quantities are currently indicative. Exact routes and amounts shall be published in the second phase, the ITT (Invitation To Tender). LOT 1 - Borssele: Survey of Cables and Areas Summary 1. Export Cables (BSA1, BSA2, BSB1, BSB2)   - Quantity in meters: 255,000 / width 20 meters (amount n.a.)   - Coverage: 200%   - O&M TVU/THU   - Lines in reciprocal directions 2. Export Cables Extended (BSA1, BSA2, BSB1, BSB2)   - Quantity in meters: 255,000 / width 40 meters (amount X2 – two times)   - Special Order TVU/THU   - Overlap as per specification 380   - Coverage: 40m each side of the primary corridor (total of 50m) 3. Platform Area (BSA, BSB)   - Quantity: 500m X 500m each (amount X2 – two times)   - Special Order TVU/THU   - Overlap as per specification 380 4. Crossing Structures   - Quantity: 100m X 100m (amount X14 – fourteen times)   - Coverage: 200%   - O&M TVU/THU   - Lines in reciprocal directions 5. P2 Spijkerplaat Extended Area   - Quantity: 1,600m X 750m (amount X1 – one time)   - Special Order TVU/THU   - Overlap as per specification 380   - No SSS 6. Honte Extended Area   - Quantity: 1,100m X 750m (amount X1 – one time)   - Special Order TVU/THU   - Overlap as per specification 380   - No SSS 7. Export Cable Corridor within Spijkerplaat and Honte   - Quantity: 800m X 20m  (amount n.a.)   - Coverage: 200%   - O&M TVU/THU   - Lines in reciprocal directions 8. Spijkerplaat Extended Area   - Quantity: 1,600m X 750m (amount X1 – one time)   - Special Order TVU/THU   - Overlap as per specification 380   - No SSS 9. Honte Extended Area    - Quantity: 1,100m X 750m (amount X1 – one time)   - Special Order TVU/THU   - Overlap as per specification 380   - No SSS LOT 2 – 700MW Cables: 1. Export Cables: BSL (GNB), HKZ, HKN, HKWa. HKWb, and      Export Cables: Interlinks: BSL-BSB, HKZa-HKzb, HKWa-HKWb   - Length: 725,000 m X 20 m (amount n.a.)   - MBES Requirement: 200% coverage, O&M TVU/THU, lines in reciprocal directions 2. Export Cables Extended (BSL GNB)   - Length: 212,000 m X 40 m (amount X2 – two times)   - MBES Requirement: Special Order TVU/THU, overlap as per specification 380, no SSS 3. Crossing Structures   - Length: 100 m X 100 m  (amount X85 – eighty five times)   - MBES Requirement: 200% coverage, O&M TVU/THU, lines in reciprocal directions 4. Platforms (HKZa, HKZb, HKN, HKWa, HKWb)   - Length: 500 m X 500 m (amount X5 – five times)   - MBES Requirement: Special Order TVU/THU, overlap as per specification 380 LOT 3 – Interconnectors Cobra and NorNed: 1. NorNed - NL (Inside the Wadden Sea)   - Approx. Length: 30,000 m X 120 m (amount n.a.)     - MBES Requirement: Exclusive order TVU/THU, overlap as per specification 380 2. NorNed - NL (Outside the Wadden Sea)   - Approx. Length: 18,000 m X 120 m (amount n.a.)     - MBES Requirement: Exclusive order TVU/THU, overlap as per specification 380 3. NorNed – DE (Optional)   - Approx. Length: 222,000 m X 60 m (amount n.a.)     - MBES Requirement: Exclusive order TVU/THU, overlap as per specification 380 4. Cobra (NL) + DE - Optional   - Approx. Length: 250,000 m X 60 m (amount n.a.)     - MBES Requirement: Exclusive order TVU/THU, overlap as per specification 380  Export Corridor: For the Export Corridor and crossings structures 200% MBES coverage is required. O&M THU/TVU for this survey is based on IHO S-44 with a value from Table B-c13, and b value from table B-d9. Data shall not be trimmed to provided surveys corridor, but all acquired data to be provided in raw and processed files. Calibrations and Verifications: Calibrations and verifications shall be performed in the port closest to survey area, unless differently agreed with Client. These shall cover, but not limited to: position check (in the project coordinates system), absolute Z depth check (should be less than 5cm), F-test (3x3 lines of 30m length,200% overlap), Z-test, USBL spin test. Contractor shall provide mobilization, calibration and demobilization port(s) information in the proposal. Once the data is final it shall be provided on 2 copies of HDD and uploaded by Contractor to Azure cloud on the location specified by TenneT.

The TenneT TSO bv. (TenneT) business unit Grid Field Operations (GFO) also internally know as Offshore - Area West (GFO-O-XW) is the organizational unit managing the operations of the Dutch Offshore High Voltage Substations (OHVS) including associated export cables from sea to land, also called a Grid Connection System (GCS). For this CTV tender we are interest in one party that can provide the services to the following grid connections/platforms: - Borssele Alpha - Borssele Beta - Hollandse Kust Zuid Alpha - Hollandse Kust Zuid Beta - Hollandse Kust Noord Alpha - Hollandse Kust West Alpha - Hollandse Kust West Beta The platforms OHVS’s are remote operated and normally unmanned, and. The planned maintenance will be based on relative short periods, i.e., several sequential days. This means that the maintenance teams of maintenance engineers including equipment and spares require a fast and reliable means of transport, with extensive excellent and proven vessel capabilities in relation to weather conditions. Operators that are exceeding operating in compliance with the current standards for CTV's, or who are preparing a fleet of vessels in compliance with the current standards including IMO MSC 418(97), a resolution that is already implemented by the Dutch government in 2019, will be taken into serious considerations as these new standards will best fit the TenneT design concept. Providers that are operating CTVs conform the latest standards in relation to transport industrial personnel (PAX) and equipment safe, quick, and efficient are particularly seen as crucial as part of the installation operations and maintenance phase of the offshore sections of the grid connection systems GCSs in the Dutch North Sea. The CTV will work in close cooperation with the installation unit/Offshore Installation Manager (OIM) or a designated project GCS manager and will transfer the client’s industrial personnel, including spares and equipment as well as third party industrial personnel. Pending on the area of operation, the main ports / logistics hubs will be Vlissingen, Scheveningen or IJmuiden, with the Rotterdam area and Scheveningen as potential substitutes. Other harbours can be announced by the Client. In this case mobilization and demobilization will be paid separately. A CTV might also be required for unscheduled deployments. As highlighted, apart from industrial personnel it also shall be used to transport minor spares and equipment including dangerous goods. As the platforms OHVS’s are designed to be operate unmanned, everything transported to the platform must be returned via the CTV. This also means that any waste (usually packed in transport units, e. g. big bags) will have to be brought back. One or two 10 feet containers might have to be transported to the sites, being loaded with components and equipment for the installation and servicing of the platform or installation units. From an operational perspective, the following factors are seen as crucial and will be considered during the technical evaluation. The list is presented from highest valued factor to lowest: 1. Safety standards from step-over in port, offshore and during the voyage, as our personnel's health and safety are of highest priority. 2. Crew welfare: As our personnel have limited hands-on tool time, it is seen as crucial that they arrive on location as fit as possible. Meaning least affected by vessel motion during the voyage. 3. Vessel speed: As our personnel have limited hands-on tool time, effective traveling time is seen as a major factor as this will significantly affect the work. The vessel must be able to meet the minimum speed of 24 kts against eco-speed. 4. Cargo capability: Vessel must be capable of receiving at least 1 x 10 feet container in port and transport this safely to the offshore location where it can be safely offloaded by the OHVS crane or other equivalent. 5. Vessels must be able to meet the minimum TenneT operational workability, and therefore must be able to carry 12 PAX and are to comply with the above. Vessels capable of carrying 24 PAX will receive a higher-ranking score. 6. Vessels with the lowest Co2 emissions against highest efficiency will receive a higher-ranking score Main area of operation will be the Dutch North Sea off the west coast. It should be noted that the offshore assets could be fully or partly located outside the 12-mile Dutch Exclusive Economic Zone (EEZ). • Cargo crane on board the vessel with a safe working load of min. 1000 kg @ 5 m to (off)load minor equipment and big bags from the quay and back. • Operator is responsible for loading facilities such as a crane to load any cargo within the limits of a 10 feet container on board the CTV and back to shore • Deck area of min. 10 m² with a deck load of min. 1,25 t/m2 / 5 t capacity for cargo. Weather Requirements / operational capabilities: The Client will provide weather data for the relevant job locations to the Contractor on a 6 hourly base, if necessary. The Contractor guarantees that the operational capabilities of its vessels’ can perform the requested transfer of personnel and/or cargo operations up to the weather limits listed below. The below mentioned wind and wave criteria are set as the operational limits for the transfer of people by CTV (live data from platform to be used as reference): Transfer of personnel: Depending on the vessel operational capabilities, as a minimum figure a CTV should be able to operate within the range of Hs = 1.,5 – 1,75 m. Higher figures will lead to a higher ranking, where vessels with a proven track record will be ranked higher compared to vessels that only come with design criteria. Cargo transfer at offshore location (by means of OHVS crane): Equal to crew transfer limits, i.e. Hs= 1.5 – 1,75 m, higher figures will lead to a higher ranking.

Requirements of Service scope of O&M Survey 2025 tender; TenneT TSO B.V. (hereafter: Client) is appointed by the Dutch government as the offshore grid operator for The Netherlands. In order to operate and maintain the assets, Client is by law responsible for assets monitoring. The various connections that are developed and are in operation require survey works for cable routes and platforms. This EU-Tender shall consist of 3 lots, a) Borssele, b) 700MW cables and the c) interconnectors Cobra&NorNed. All lots shall have the minimal requirements as set out in this tender. Requirements are the following, TenneT minimum requirements, HSE, offshore The objectives of the services are to: 1. Perform the O&M survey by means of MBES, SSS and airborne survey or other solution to cover landing/tidal area according to technical specification listed above. 2. Establish the bathymetry and topography of the seabed to understand the level of it and identify the obstructions in the corridor with the specified quality as minimum. 3. Establish the seabed features of the seabed to identify the obstructions in the corridor and identify any possible cable exposures or freespans. Resolution of the SSS is described in SPE.06.380-OG and shall be such that the cable if exposed shall be identified using this method (cable diameter ~ 0.2 m). Below defined locations and quantities are currently indicative. Exact routes and amounts shall be published in the second phase, the ITT (Invitation To Tender). LOT 1 - Borssele: Survey of Cables and Areas Summary 1. Export Cables (BSA1, BSA2, BSB1, BSB2) - Quantity in meters: 255,000 / width 20 meters (amount n.a.) - Coverage: 200% - O&M TVU/THU - Lines in reciprocal directions 2. Export Cables Extended (BSA1, BSA2, BSB1, BSB2) - Quantity in meters: 255,000 / width 40 meters (amount X2 – two times) - Special Order TVU/THU - Overlap as per specification 380 - Coverage: 40m each side of the primary corridor (total of 50m) 3. Platform Area (BSA, BSB) - Quantity: 500m X 500m each (amount X2 – two times) - Special Order TVU/THU - Overlap as per specification 380 4. Crossing Structures - Quantity: 100m X 100m (amount X14 – fourteen times) - Coverage: 200% - O&M TVU/THU - Lines in reciprocal directions 5. P2 Spijkerplaat Extended Area - Quantity: 1,600m X 750m (amount X1 – one time) - Special Order TVU/THU - Overlap as per specification 380 - No SSS 6. Honte Extended Area - Quantity: 1,100m X 750m (amount X1 – one time) - Special Order TVU/THU - Overlap as per specification 380 - No SSS 7. Export Cable Corridor within Spijkerplaat and Honte - Quantity: 800m X 20m (amount n.a.) - Coverage: 200% - O&M TVU/THU - Lines in reciprocal directions 8. Spijkerplaat Extended Area - Quantity: 1,600m X 750m (amount X1 – one time) - Special Order TVU/THU - Overlap as per specification 380 - No SSS 9. Honte Extended Area - Quantity: 1,100m X 750m (amount X1 – one time) - Special Order TVU/THU - Overlap as per specification 380 - No SSS LOT 2 – 700MW Cables: 1. Export Cables: BSL (GNB), HKZ, HKN, HKWa. HKWb, and Export Cables: Interlinks: BSL-BSB, HKZa-HKzb, HKWa-HKWb - Length: 725,000 m X 20 m (amount n.a.) - MBES Requirement: 200% coverage, O&M TVU/THU, lines in reciprocal directions 2. Export Cables Extended (BSL GNB) - Length: 212,000 m X 40 m (amount X2 – two times) - MBES Requirement: Special Order TVU/THU, overlap as per specification 380, no SSS 3. Crossing Structures - Length: 100 m X 100 m (amount X85 – eighty five times) - MBES Requirement: 200% coverage, O&M TVU/THU, lines in reciprocal directions 4. Platforms (HKZa, HKZb, HKN, HKWa, HKWb) - Length: 500 m X 500 m (amount X5 – five times) - MBES Requirement: Special Order TVU/THU, overlap as per specification 380 LOT 3 – Interconnectors Cobra and NorNed: 1. NorNed - NL (Inside the Wadden Sea) - Approx. Length: 30,000 m X 120 m (amount n.a.) - MBES Requirement: Exclusive order TVU/THU, overlap as per specification 380 2. NorNed - NL (Outside the Wadden Sea) - Approx. Length: 18,000 m X 120 m (amount n.a.) - MBES Requirement: Exclusive order TVU/THU, overlap as per specification 380 3. NorNed – DE (Optional) - Approx. Length: 222,000 m X 60 m (amount n.a.) - MBES Requirement: Exclusive order TVU/THU, overlap as per specification 380 4. Cobra (NL) + DE - Optional - Approx. Length: 250,000 m X 60 m (amount n.a.) - MBES Requirement: Exclusive order TVU/THU, overlap as per specification 380 Export Corridor: For the Export Corridor and crossings structures 200% MBES coverage is required. O&M THU/TVU for this survey is based on IHO S-44 with a value from Table B-c13, and b value from table B-d9. Data shall not be trimmed to provided surveys corridor, but all acquired data to be provided in raw and processed files. Calibrations and Verifications: Calibrations and verifications shall be performed in the port closest to survey area, unless differently agreed with Client. These shall cover, but not limited to: position check (in the project coordinates system), absolute Z depth check (should be less than 5cm), F-test (3x3 lines of 30m length,200% overlap), Z-test, USBL spin test. Contractor shall provide mobilization, calibration and demobilization port(s) information in the proposal. Once the data is final it shall be provided on 2 copies of HDD and uploaded by Contractor to Azure cloud on the location specified by TenneT.