The University of Southampton provided a technical report to Gwynt y Môr OFTO plc to support its Exceptional Event claim to Ofgem regarding failures on Subsea Export Cable 3 (SSEC3). The report concluded it was probable the fibre-optic cables had defective semicon sheaths and that it was very likely the 2015 hotspot repair joint, or its installation, created a weakness in the spare fibre-optic cable that subsequently led to a second fibre-optic cable break and main power core failure.