It was accepted by the court that, in principle, electromagnetic interference could form the basis of a nuisance action. Railtrack, however, initially argued that the claim should not lie because the claimant's occupation was one that was abnormally sensitive.
Nuisance law has long been concerned with balancing competing interests and provides a protection against unreasonable interference. One principle developed in the nineteenth century to limit claims to what is or is not reasonable was to allow a defence where the claimant was considered unduly sensitive.
However, in the present case, the Court of Appeal noted that it had now clearly been established, especially since the Cambridge Water Company case in 1994, that for a claim to succeed in nuisance it was essential that the type of damage that resulted was reasonably foreseeable. That being so, the Court of Appeal doubted whether the concept of abnormal sensitivity had any further useful life in the modern law of nuisance. Reasonable foreseeability of damage was the key.
Looking at the question of foreseeability, British Rail, as it then was, had in 1991 received reports of electromagnetic interference affecting a rehearsal studio in railway arches which it rented. A report confirmed that the high currents were producing electromagnetic fields which were interfering with amplification equipment underneath the track.
This previous investigation had clearly influenced the judge in the court below, and he considered that as a result the defendants could no longer claim they had no idea that this sort of damage could occur.
However, in re-examining the expert evidence, the Court of Appeal concluded that this was not a reasonable inference to be drawn. The earlier complaints had concerned only property in arches directly below railway lines, and the technical evidence indicated that it was not reasonable to foresee interference as far as 80 metres from the track.
The case therefore failed to pass the hurdle of foreseeability, and it was not necessary for the court to consider whether section 122 of the Railways Act 1993 would have provided the defendants with a statutory defence in this case.
In giving its decision, the court was acutely aware that it was difficult to apply the law of nuisance in a world where the use of electronic and electrical equipment was all-pervasive. The competing claims of those who wish to use equipment giving rise to interference and those wishing to use equipment susceptible to interference were not easy to balance.
The court heard evidence that, increasingly since the mid-1990s, both the tolerance of equipment and the amount of interference that could be exported from equipment were now subject to standards laid down by EU legislation, and indeed that modern guitars subject to these standards would not encounter the problems in this case.
Clearly, the court felt this to be an area more suited for statutory regulation rather than individual decisions of the courts.
Nevertheless, the general approach taken will have wider implications. The principle of abnormal sensitivity has, for example, been raised in the context of organic farmers and possible liability claims for GM contamination. The Morris case indicates that the courts will now prefer to analyse such liability issues against the criterion of reasonable foreseeability, and that the boundaries between nuisance and negligence liability are increasingly ill-defined.
Richard Macrory, Professor of Environmental Law, University College London