This is an engineering note on how Phase 1 of THG1 was designed. We are publishing the headlines now and the deeper write-ups in instalments through the year. The goal is to give prospective tenants and their advisors enough visibility into the design choices to make a properly informed siting decision — not just a glossy capacity number.
The brief
1.75 MW live in Phase 1, 1.75 MW reserved for Phase 2, 3.50 MW gross at full build. Up to 20 kW per cabinet. Distributed 2N+1 from the utility hand-off through to the cabinet, on both the electrical and mechanical sides. VRKI 2.0 Class 4 security envelope. Open carrier-neutral connectivity into a metro fabric we control.
The site itself is a retrofit of a building with prior data center use, which constrained some of the floor-plate decisions and unlocked others (existing concrete-slab loading, existing utility tie-in).
Electrical: four generators, three UPS clusters, three ATSes
The distributed 2N+1 topology has four diesel generators on-site, drilled monthly, on a four-hour refuelling SLA. Three independent UPS clusters with hot-swappable battery modules feed the cabinets via three ATSes that hand the load cleanly between utility and genset. Distributed (rather than centralized) 2N+1 means a single fault on any one ATS, UPS, or generator does not constrain the workload on cabinets fed from the other two paths. The bus topology is documented in the under-NDA pack on request.
Mechanical: sealed cold-aisle, ASHRAE allowable, N+1 CRAC
The cooling design is sealed cold-aisle containment with N+1 CRAC redundancy at the perimeter and room-level humidification held inside the ASHRAE allowable envelope. The default cabinet design point is 20 kW air-cooled, which is enough headroom for everything short of dense GPU workloads. The mechanical design is distributed 2N+1 alongside the electrical so a single CRAC fault, a single chilled-water leg, or a single humidification path does not cascade into a thermal incident.
Fiber: six paths, three carriers, diverse meet-me areas
THG1 has multiple diverse fiber points of entry into the building, with the paths landing in independent meet-me areas. The in-building dark fiber suppliers (Verizon, Eurofiber, Relined) each have redundant routes — six discrete fiber paths out of the building. We chose the carrier set with two criteria in mind: redundancy in the literal physical sense (different conduits, different cable plants, different cities of origin) and geographic reach (NL incumbent, NL+BE metro, NL rail-side dark fiber).
Security: VRKI 2.0 Class 4, RC4 envelope, EN 50131 Grade 4
The security plan is signed off by the insurer at VRKI 2.0 Class 4. The envelope is RC4 under NEN-EN 1627 (doors, fittings, glazing), the intrusion detection is EN 50131 Grade 4, and the alarm transmission is dual-path, supervised, into a certified PAC. The full controls catalogue is documented in the under-NDA security pack for tenants who need it for their own audit work.
What we are publishing next
Over the next quarter we will be releasing the deeper write-ups: how the bus topology is laid out, what the failure-mode analysis looked like, how we sized the CRAC plant against the design density, and where the trade-offs went. If there is a specific design question you want answered first, drop us a line and we will move it up the queue.
For tour or engineering deep-dive bookings, see the tour page or reach out via the contact page.
