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Projects: Projects for Investigator
Reference Number NIA_SHET_0017
Title Pole Reclassification System Evaluation
Status Completed
Energy Categories Other Power and Storage Technologies(Electricity transmission and distribution) 100%;
Research Types Applied Research and Development 100%
Science and Technology Fields PHYSICAL SCIENCES AND MATHEMATICS (Metallurgy and Materials) 50%;
ENGINEERING AND TECHNOLOGY (Electrical and Electronic Engineering) 50%;
UKERC Cross Cutting Characterisation Not Cross-cutting 100%
Principal Investigator Project Contact
No email address given
Scottish Hydro Electric Power Distribution plc (SHEPD)
Award Type Network Innovation Allowance
Funding Source Ofgem
Start Date 01 November 2015
End Date 01 May 2016
Duration 6 months
Total Grant Value £60,000
Industrial Sectors Power
Region Scotland
Programme Network Innovation Allowance
Investigators Principal Investigator Project Contact , Scottish Hydro Electric Power Distribution plc (SHEPD) (100.000%)
Web Site http://www.smarternetworks.org/project/NIA_SHET_0017
Objectives The overarching objective of this project is to ascertain if the strength of wood poles in service can effectively be improved through the use of the PRS system at a lower cost than would replacement with new poles of the relevant class. The project will be considered a success if it can determine the viability of using the PRS system to strengthen existing wooden poles on EHV circuits.
Abstract There is a considerable number of 132kV overhead line circuits mounted on wooden poles in various areas of GB. Wooden poles are more susceptible than steel lattice towers to adverse environmental conditions such as extreme wind speeds. Experience in Scotland has shown that greater than hurricane force winds can occur within GB. Such wind speeds exceed the expected design loadings of wood poles despite conformance with the standards applicable at the time of construction. As some work on climate change has indicated a higher probability of extreme weather events in the future, a review of the interventions available to network owners is now considered to be appropriate. The following are some of the options that are available: ; React to faults as and when they happen In the short term, this may be considered as the least cost option as it is difficult to effectively model the effect of low probability, high impact events with sufficient confidence to justify proactive intervention. However, this may also be considered as a high risk strategy as it still leaves the network vulnerable to the effect of extreme weather events as stated above. The potential impact resulting from the loss of several 132kV circuits in extreme weather is likely to be widespread disruption to supplies with significant impact on stakeholders. This first option would be most difficult to justify on the grounds of network security hence the following option can be considered: ; Replace poles on existing susceptible lines with higher classification ones or a different material of a higher specification This is probably the most effective technical intervention but it comes at an unacceptably high cost. As it would be difficult to justify this approach on the grounds of cost we need to consider another option: ; Reclassify or re-strengthen existing poles This option involves keeping the same poles, if their current condition is satisfactory, and providing a technical means of strengthening the poles so that they are deemed fit for purpose to meet more stringent loading requirements such as those expected to be imposed by extreme weather conditions. In GB, poles are classified as light, medium, stout or extra stout depending on their top and butt diameters. A pole classed as medium will be damaged by bending forces earlier than one classed as stout when subjected to the same forces so if a medium pole can be strengthened such that it can be reclassified as being in the ‘stout’ class, then that pole will be able to withstand the same constraints as does the naturally stout pole. This principle is the basis of the method being investigated in this project. This is a technical method to trial a solution called the Pole Reclassification System (PRS) which has potential to increase the strength of poles. The system has been successfully deployed in United States and is supplied by Laminated Wood Systems. The method involves attaching steel sections to most of the body of a wooden pole from below ground level to just below the crossarm using specialist tools. This project proposes to identify a representative extra high voltage (EHV) line of Trident construction at an offline site built to the same specification and conditions of existing lines in one of the worst affected parts of the country. The PRS systems will then be installed on the poles on the trial line section and the process of installation will be observed and evaluated. This willbe followed by tests which will be representative of the stresses imposed on typical poles in existence. The overall methodology will establish if: ; The PRS method is suitable for use on very hard foundations or those with baulks below ground; The PRS method can safely be deployed on lines in service; There is a demonstrable increase in the strength of poles after installation of the PRSA review of the entire project will be carried out after the demonstration and tests to ascertain if the method can be recommended for business as usual as well as to quantify the cost effectiveness of the method.Note : Project Documents may be available via the ENA Smarter Networks Portal using the Website link above
Publications (none)
Final Report (none)
Added to Database 09/10/18