HT-2022-000090 - [2025] EWHC 723 (TCC)

A number of conclusions reached by Mr Alyah related to what original ‘unauthorised’ works, and he fairly accepted that if (as I have concluded) SEPD has not established that these works are themselves representative of the wider Modus work, then they are not directly relevant to the matters to be decided. Mr Alyah also fairly accepted that some of the photographs may not show the works as they had been when first exposed, if for example they were taken out of ‘trefoil’ configuration for the purposes of inspection. Mr Alyah’s report included a criticism that the jointing of the three cables for each circuit did not appear to have been carried out at 500mm distances, but Mr Alyah conceded that the rectification works were also not carried out this way, under SEPD’s direct supervision, and that it was not a point which concerned SEPD at the time, nor raised in the contemporaneous reports as a problem which, for example, played any part in the choice of rectification method. Clearing away these tangential criticisms, it is clear that Mr Alyah’s focus was on the quality of the joints which had been inspected in the EA Report, and the reasonableness of extrapolating the results of that inspection to substantiate a legitimate concern about the quality of the circuits as a whole.

At paragraph 117 of his report, on the basis of his review of the EA Report, Mr Alyah tabulated the nature and type of defect within the joints which were inspected, as follows:

Mr Alyah then explained how each defect was a failure of industry standards and/or the jointing instructions and/or other appendices forming part of the Adoption Agreement. None of this was challenged in cross-examination, no doubt because it was either accepted or Modus did not have any competing evidence to the contrary. I accept Mr Alyah’s description of the defects as found in the table above and that, as he explained, the workmanship in each case fell below the standards required and/or was a breach of the specific requirements of the various aspects of the jointing instructions or other appendices he referred to in 116 to 184 of his report.

In the same section of his report, Mr Alyah identified the implications of each of the 11 types of defect which were identified, often by reference to footnoted literature or manuals. None of this was subject to challenge from a technical perspective, either. This is important evidence which underlies Mr Alyah’s conclusions about (a) what might be discerned as to the extent of other defects and (b) the future risk of degradation of the cable. I summarise Mr Alyah’s evidence as to the impact of the defects, which I accept, as follows:

Mr Alyah then explained his analysis of all the data touching upon the sheath testing undertaken during the investigations and prior to the remedial works, some of which have been referred to in the narrative above. Mr Alyah tabulated the results of that analysis at Appendix 4 to his report, and I accept that he did so accurately (not least in the absence of any suggestion that he had not done so). Mr Alyah’s conclusion was that, on the records available, there were 178 tests of different phases, in the two circuits performed on different occasions. Of those faults were identified during four tests. A ‘fault’ was when the insulation around the energised core fails such that the electrical energy is allowed to come out of the core of the cable and go to ground. The tests results met the specification requirements during 67 tests or slightly more than 37% of the time while the tests results failed to meet the requirements of 10MΩ @ 5kV in 107 tests or just over 60% of the time. On the basis of this, Mr Alyah’s conclusion that the two circuits failed to meet the requirements by SEPD which were part of the SSEN specifications listed in the Adoption Agreement including schedules and appendices was plainly justified, and was not, in fact, subject to challenge.

However, the further importance of the test results goes beyond merely establishing a continuing breach of the specification even after the 10 joints had been replaced and during the period when no actual ‘faults’ (as defined above) happened. As explained by Mr Alyah, and which evidence I accept as cogent, the very purpose of the sheath test is to check whether the cable sheath has not been damaged during installation. A lower value indicates that there is damage in the sheath somewhere along the cable. The continued low results, after the 10 joints were replaced, indicates that there remained damage to the sheaths at unknown locations along the cables in both circuits, and undermines Modus’ contention (albeit, for the reasons explained, not supported by expert evidence) that it is not possible to extrapolate from the 10 joints inspected. I do not accept the contention, not supported by expert evidence for the reasons given, that it was necessary to carry out ‘partial discharge’ (or ‘PD’ testing) in order to reach this conclusion. The conclusion is sufficiently established from the inspections and testing that was carried out as described above.

All of the defects described in the EA are workmanship defects. Their number and type are seemingly fairly arbitrary across the different joints, as is often the nature of poor workmanship. Without a particular explanation (for example – that all the relevant joints were carried out by a particular jointing team that it could be shown were not responsible for any other joints), it might be instinctively surprising even to a layman if the poor workmanship was limited to these 10 joints. Putting the instinctive surprise of a layman to one side, Mr Alyah’s expert evidence on the basis of his experience was, and I accept, that the amount of defects within each of the samples was so great that it is very likely that they exist in other locations as well. Crucially, however, he considered this in tandem with what he described as the ‘really really high percentage’ of test results in which the reduced specification for resistance could not be met. Indeed, in my judgment the continuing test failures after the joints which ‘faulted’ were replaced are only sensibly explained by the existence of similar defects in other parts of the cable which combine to reduce the efficacy of the insulation and therefore resistance (albeit not (yet) to the point of complete failure). Indeed, no other explanation was provided for the continuing failure to pass sheath tests (even on the reduced specification) other than the existence of the type of poor workmanship which was displayed on each of the 10 joints that was inspected. I am left in no doubt that Mr Alyah’s evidence that the types of defects identified within the EA report are likely to be widespread across both circuits is correct.