Published 2026-09-12 · Event 2024-11-18

C-Lion1 lands in Helsinki, Hanko and Rostock; a Swedish EEZ fault is not a Swedish landing

Cinia’s C-Lion1 page names endpoints in Helsinki and Rostock, a backup landing in Hanko, a length of 1,173 km and a total capacity of 144 Tbit/s. The 18 November 2024 fault notice places the cut in the Swedish exclusive economic zone, east of the southern tip of Öland, about 700 km from Helsinki. A fault location is not a cable-landing station and not a Swedish hall.

Cinia’s C-Lion1 project page is the operator description used here. It lists endpoints Helsinki and Rostock, a backup landing at Hanko, a cable length of 1,173 km, eight fibre pairs and a total capacity of 144 Tbit/s. Installation from Helsinki toward Rostock began in autumn 2015 and was completed on schedule in early 2016. Those are landing, length and capacity sentences. They do not name a Swedish beach.

The 18 November 2024 notice is the dated incident paper. It says a fault was detected at 4:04 a.m. Eastern European Time and that services provided over C-Lion1 were down. The cause of the cable fault is unknown. Cinia submitted a request for investigation to Finland’s National Bureau of Investigation on 19 November 2024. This article does not supply a perpetrator, a ship name or a legal conclusion the operator page did not publish.

The geography sentence is the load-bearing distinction. The location of the cable cut is in the Baltic Sea, in the Swedish exclusive economic zone, east of the southern tip of Öland, about 700 km from Helsinki. An exclusive-economic-zone coordinate is a maritime location. It is not a landing station in Kalmar County, not a Gotland meet-me room and not a reason to pin a hall on Öland.

The same notice says Finland’s international telecommunication connections are routed via multiple routes, and that the impact of a single cable failure depends on the resilience of service providers’ connections. That is a resilience sentence. It is not a published diverse-entry drawing for a Swedish campus. C-Lion2 planning papers stay on their own row. Microsoft Natick remains an underwater-hall experiment, not a landing-station file.

DataCenterSweden records C-Lion1 as a Finland–Germany cable with named Finnish and German landings, and 18 November 2024 as a fault in the Swedish EEZ. No Swedish project identifier is attached. The next update would need a later primary source that names a Swedish landing or a different fault state. Until then, Öland is a fault coordinate, not a site pin.

Why it matters

A Baltic cable fault inside Sweden’s EEZ is easy to rewrite as a Swedish landing or a Swedish outage campus. The November notice is usable only if Helsinki, Hanko and Rostock stay the landings — and if Öland stays a cut coordinate.

What remains unknown

The operator papers do not name a Swedish landing station, do not publish a repaired-capacity certificate, and do not assign the cable to a hall in this register.

Sources