How Marauder commissioned Cranebank without the chaos.

The brief

Phoenix Digital briefed Marauder on a build that could not have a messy handover.

Cranebank is a £340M data centre on the edge of a brownfield site in the UK Midlands (fictional). Three halls, each three storeys, each floor divided into six pods — fifty-four commissioning units in total. The end-tenant, Meridian Cloud, requires Tier-IV uptime: fully redundant power and cooling, no single point of failure, proven under primary injection and live-load testing before handover.

Phoenix Digital's CIO, Krupa, had one non-negotiable: she would not receive a handover pack assembled at the wire. The commissioning record would be live, accessible, and independently witnessed throughout the build. She appointed Donnelly · Sentinel as independent commissioning authority (CxA) — outside Marauder's chain of command, reporting directly to her.

The challenge

54 pods. Multi-hall witness sequencing. OFCI-heavy Cx. Gateway-driven HRB compliance.

The commissioning programme on Cranebank was OFCI-heavy — Owner-Furnished, Contractor-Installed equipment across the UPS, cooling and generator packages meant that the commissioning chain crossed multiple procurement and warranty boundaries. Calibration instruments belonged to six different subcontractors. Witness tests required representatives from Apex Mechanical, Halloran Electrical, Shankar Civils, and the equipment OEMs — all on the same day.

The multi-hall sequencing problem was acute: a witness day lost in Hall 1 due to a sequencing conflict rippled into Hall 2 and Hall 3's commissioning calendar within 72 hours. On a conventional project, that sequencing risk is managed by a commissioning manager with a spreadsheet and a phone. On Cranebank, it was managed by the Cx Spine.

The Cx Spine in practice

L1 to L6. Witness testing live to the calendar. Calibration vault as the single source.

Every component on Cranebank was tagged at installation — L1 to L6, pod by pod, system by system. The L-level tag locked when the previous level was signed by a named, competent person. An L4 test could not be scheduled against a component whose L3 was unsigned. The system enforced the sequence; it did not merely record it.

Witness tests were booked directly against the commissioning programme calendar. When a test was booked, the invitations went out automatically to all required witnesses. When a witness confirmed, the confirmation was on the record. If a key witness could not attend, the test was automatically flagged for rescheduling before any logistics were mobilised. No day was wasted on an abortive witness visit.

The calibration vault was the single source of truth for every instrument used in commissioning. When an instrument's calibration certificate was due to expire, the vault flagged it before the next test it was booked for. No instrument with a lapsed certificate was used on a Cranebank witness test. The vault held 94 calibration certificates across six subcontractors. Every one current on the day of the handover audit.

The independent CxA

Donnelly outside Marauder. Immutable record. Phoenix read access from day one.

Donnelly · Sentinel's records sat on the Cx Spine under their own credentials. Not mediated by Marauder. Not summarised at handover. Every observation, every NCR, every witness signature, every L4 certificate — entered directly, immutable from the moment of entry. Marauder could see the CxA record and respond to NCRs through the workflow. They could not amend the observation that generated the NCR.

Phoenix Digital had read access to the CxA record from the day the Cx Spine went live on Hall 1. Krupa watched the commissioning in real time — pod by pod, L-level by L-level, NCR by NCR. When the handover certificate arrived, she had already seen the evidence behind every line on it. The handover audit took two hours. It would have taken two weeks.

The result in numbers