The Ninian Northern Platform stood 160 kilometres northeast of the Shetland Islands, in 141 metres of water in Block 3/03 of the UK Continental Shelf. Installed in June 1978, it produced at peak rate of 89,587 barrels of oil per day before ceasing production permanently in May 2017 after 37 years of operation.
In 2019, CNR International awarded the removal contract to Allseas. The tool selected for the topsides was Pioneering Spirit — at 382 metres long and with a single-lift topsides capacity of 48,000 tonnes, the largest offshore construction vessel ever built. The tool selected for the jacket was a system that did not yet exist in commercial form: the Jacket Lift System (JLS), a purpose-built set of two 170-metre beams being installed on Pioneering Spirit's stern in Rotterdam.
This created a sequencing dependency as absolute as the one on the Jamuna River. The topsides had to go before the jacket could be touched. And the jacket could only go when the JLS was ready — which it was not in 2020. The vessel would have to return.
Pioneering Spirit arrived at the Ninian field in August 2020, connected its lifting beams to the topsides, and executed the lift in seven seconds. The full offshore operation took approximately two hours. The vessel delivered the 14,200-tonne structure to the Peterson-Veolia yard at Dales Voe in Shetland, before sailing southeast to Rotterdam.
The jacket remained on the seabed. It would stay there for twenty months.
💡 The Core Insight
The Ninian Northern decommissioning was not a single operation — it was a sequenced campaign across two vessel mobilisations, separated by the development timeline of a new lifting technology. The topsides removal and the jacket removal shared one hard dependency: the jacket could not move until the topsides was gone. The gap between them — twenty months — was not a failure. It was planned.
Jacket waits on seabed — Pioneering Spirit undergoes JLS installation and commissioning in Rotterdam. Bespoke rigging fabricated.
Apr 2022
Jacket removed — 8,100 t, first commercial deployment of JLS. Lift executed 21 April. Delivered intact to Dales Voe for 98% steel reuse.
The decommissioning programme published by CNR International in March 2019 — a public document submitted to the Department for Business, Energy and Industrial Strategy — stated explicitly: "topsides removal commencing earliest 2020, and for the jacket which will be removed latest 2023." The programme was accurate. The jacket was removed in April 2022, within the planned window.
In 2023, the NSTA found that only 2 of 6 planned topsides removals were executed as scheduled. Only 4 of 8 planned substructure removals went ahead. Operators were described as "not engaging with the supply chain early enough" — the commercial translation of a sequencing failure.
The Pattern & The Question
Why this dependency failure repeats on every major offshore removal campaign — and the one question to put on every preparation review agenda.
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