Survey services

Tender description

Lot 1: Tower Steelwork Assessment: NIE Networks have a requirement to carry out refurbishment works to overhead lines on an on-going basis. Part of these works can include replacing corroded steel bars on towers due to corrosion, or to strengthen towers to carry larger conductors. In order to facilitate these works, it is necessary to individually assess the condition of tower steelwork. It is envisaged that the method of survey will be via helicopter or an Unmanned Aerial Vehicle(UAV) Drone. This contract relates to single and double circuit towers operating at 275kV, 110kV and 33kV. Lot 2: LiDAR: NIE Networks carries out refurbishment works to overhead lines on an on-going basis and occasionally builds new overhead lines according to business needs. Part of these works can include a LiDAR survey of the existing structures, ground profile, vegetation and other objects. Works are to be carried out in accordance withNIE Networks Specification 205-26. NIE Networks has a requirement to carry out steelwork inspection and assessment of lattice towers. This relates to single and double circuit towers operating at 275 kV, 110 kV and 33 kV. NIE Networks intends to carry out refurbishment works to overhead lines on an on-going basis. Part of these works can include replacing corroded steel bars on towers due to corrosion, or to strengthen towers to carry larger conductors. In order to facilitate these works, it is necessary to individually assess the condition of each bar on the tower. Towers are graded 1-6 in accordance with National Grid Specification 3.04.31. The appointed contractor shall provide a complete service, whereby each individual bar is surveyed and photographed on site and assessed in terms of its condition. Data shall then be presented in summary for the tower as a whole. It is envisaged that the method of survey will be via helicopter or an Unmanned Aerial Vehicle (UAV) Drone. The tenderer should detail their proposed method. NIE Networks has no preference to which method is selected; however the tenderer should note Section 1.7 Inaccessible Bars within this specification and satisfy themselves that bars which cannot be fully surveyed will be taken into account during the evaluation process of the tenders. It is assumed that the assessment element will be carried out in a desk-based environment using the images obtained in the field at an earlier date. Bidders must have at least 3 years’ experience of carrying out similar condition based assessments on lattice steel towers for other UK or Ireland electricity network operators. Previous experience must include assessment of at least 50 structures (or equivalent circuit length). The contractor shall also hold all required licences, authorisations, training certificates and insurances to operate the drone/helicopter and to survey electricity equipment. As a minimum, this shall include either: 1) Valid CAA Standard Permission for flying small unmanned aircraft and provide CAA ID number; 2) CAA Exemption for low level powerline patrols by helicopter. NIE Networks have a requirement for Aerial LiDAR surveys of existing overhead lines or proposed new overhead line routes. NIE Networks carries out refurbishment works to overhead lines on an on-going basis and occasionally builds new overhead lines according to business needs. Part of these works can include a LiDAR survey of the existing structures, ground profile, vegetation and other objects. Works are to be carried out in accordance with NIE Networks Specification 205-26. The appointed contractor shall provide a complete service, whereby the LiDAR survey will be carried out, the data processed and a PLS-CADD (.bak) file produced. It is envisaged that the method of survey will be by fixed wing aircraft or drone. The tender should detail their proposed method. Bidders have at least 3 years experience of carrying out similar LiDAR survey and processing work for other EU electricity network operators. The contractor shall also hold all required licences, authorisations, training certificates and insurances to operate the aircraft/drone and to survey electricity equipment. As a minimum, this shall include either: 1) Valid CAA standard permission for flying small unmanned aircraft and provide CAA ID number; 2) CAA exemption for low level powerline patrols. It is the sole responsibility of the successful contractor to obtain written clearances from the Civil Aviation Authority (CAA), in relation to restricted zones located adjacent to NIE networks overhead transmission lines. The contractor should also consult with relevant authorities such as, but not limited to, the CAA, prison service, highways agency, infrastructure NI, Northern Ireland Rail, etc. to ascertain any restrictions which may apply depending on the successful contractors intended survey method. Under no circumstances must the successful Contractor commence a survey or mobilise to site until they have received clearances from NIE Networks or any relevant authorities.