http://www.legislation.gov.uk/nisr/2012/381/section/19/madeTHE ELECTRICITY SAFETY, QUALITY AND CONTINUITY REGULATIONS (NORTHERN IRELAND) 2012Dangerous animalsElectrical installation and servicingenGovernment Printer for Northern Ireland2014-10-07ELECTRICITY These Regulations replace the Electricity Supply Regulations (Northern Ireland) 1991 (S.R. 1991 No. 536) and the subsequent amendment (S.R. 1993/21). PART 5 19 1 Every support carrying a high voltage overhead line shall, if the circumstances reasonably require, be fitted with devices to prevent, so far as is reasonably practicable, any unauthorised person from reaching a position at which any such line would be a source of danger. 2 Every support carrying a high voltage overhead line, and every support carrying a low voltage overhead line incorporating bare phase conductors, shall have attached to it sufficient safety signs complying with Schedule 1 of such size and placed in such positions as are necessary to give due warning of such danger as is reasonably foreseeable in the circumstances.