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Projects: Projects for Investigator
Reference Number NIA_SPEN_0039
Title THOR Hammer
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 ENGINEERING AND TECHNOLOGY (Electrical and Electronic Engineering) 100%
UKERC Cross Cutting Characterisation Not Cross-cutting 100%
Principal Investigator Project Contact
No email address given
SP Energy Networks
Award Type Network Innovation Allowance
Funding Source Ofgem
Start Date 01 June 2019
End Date 01 December 2022
Duration ENA months
Total Grant Value £1,317,502
Industrial Sectors Power
Region Scotland
Programme Network Innovation Allowance
Investigators Principal Investigator Project Contact , SP Energy Networks (100.000%)
  Industrial Collaborator Project Contact , SP Energy Networks (0.000%)
Project Contact , UK Power Networks (0.000%)
Project Contact , Northern Powergrid (0.000%)
Web Site https://smarter.energynetworks.org/projects/NIA_SPEN_0039
Objectives Over the last ten years in partnership with Industry and Academia, Groundline Engineering has developed a seismic pole tester, “THOR” capable of non-destructively evaluating the in situ health of timber poles. The real value of this device is its simplicity of use – being as close as possible to the traditional hammer test that the linesmen are used to performing, while still providing the following potential outputs: Presence and extent of any internal decay, including below ground level without excavation; GPS-tagged measurement results provide confirmation of measurement location for auditing purposes; Predicted end of life for refurbishment investment planning; Accurate pole condition assessment, making pole climbing activities safer; and Pole embedment depth and foundation stiffness. At present, all results obtained are assessed using both qualitative and quantitative assessments. Qualitative assessment includes a review of the pole hammer input trace and its velocity (output) response in the time domain. The Quantitative Assessment of the pole is undertaken using parameters directly obtained from the THOR unit, and once real engineering units are applied, then mechanical impedance parameters such as hammer force input, duration, mobility and dynamic stiffness can be compared against similar pole populations to identify poles requiring further attention or identifying that poles are indeed healthy and sit within a normal admittance range. Poles tested to date have allowed for the building of a large database of poles and the establishment of health indices for the various parameters in determining if the pole is an “outlier” or outside of the norm. Barriers to business as usual application for the device, to be overcome during the project, include: Output given as a reduction of diameter; needs modifying to output reduction of strength to allow asset management decisions to be made; Detailed analysis is manual, time-consuming and reliant on a small number of people. The feature that enables embedment depth to be measured can only be obtained with detailed waveform analysis at a later date following the test. In addition, the on-site indication currently provided cannot be 100% relied upon so post-test analysis is recommended; The instrument was developed in Australia where a different type of wood is used for the pole (hardwood vs softwood) and different issues are encountered (e.g. termites). The technique and analysis parameters need measuring and confirming for GB standard wood poles, and the effectiveness of the technique needs to be proven; and The measured output then needs to be turned into something meaningful, i.e. integrated with existing asset management methodologies such as CNAIM. Currently, the device and service outputs the condition of the pole in terms of a reduction in diameter. In order for this to be integrated into the GB electricity industries current policy, this needs to be taken a step further and used to calculate a remaining RSV for the pole. This will be the first deliverable for the project.Further works are currently undertaken for the automation of pole analysis – preferably at the time of test. This could be achieved with machine learning approach. The machine learning technology will convert the conventional way of analysing or processing pole data in, to a faster and potentially accurate output in a timely manner for the industry. The deliverable will be a self-contained unit that provides all of the above analysis, automatically and at the time of test.Alongside the above, some consultancy work is required to review existing processes and the definition for an end of life pole, i.e. 80% remaining residual strength. The deliverable will be an agreed policy to use going forwards. Training and dissemination will then be undertaken followed by a period of monitoring to ensure a smooth transition into business as usual and that the expected benefits to the business have been realised. WP1: Data collection, initial data analysis and improvement of outputs 12 monthsThe existing THOR hammer units will be used to collect condition data on an initial 1,000 poles. The aim is to achieve a split of 300 waveforms from poles in good condition, 300 in a moderately degraded condition and 300 deemed to be end of life. The total volume tested may need to be increased in order to meet these minimum numbers.Groundline will be utilised to provide training and supervision to ensure that the data collected is of a high standard. The data collected will then be analysed. The analysed data will then be used to begin preparations for the pole autopsies which will be used to validate the accuracy of the device. Participating DNOs must ensure that poles required for autopsy are retained should they be taken out of service. Initial preparations for the machine learning process will also be undertaken.Alongside the above work will be undertaken to improve the analysis processes and algorithms. A key deliverable at the end of this work package will be the calculation of a RSV as an output: this can then be used immediately by the business when the existing THOR hammer unit is utilised. WP2: Data validation, development of automated waveform analysis, integration with unit and alignment with DNO systems of work 12 monthsFor the GB electricity industry to adopt the THOR hammer tester as a test method, an extremely high degree of confidence must be applicable to the results provided. While the work undertaken by Groundline to date has proved this in principle, the key output of the data validation tasks within this project will be to demonstrate this with real data. This will be achieved by undertaking pole autopsies on a selection of poles previously tested using the THOR hammer, to ensure that the output of the waveform analysis is consistent with what is found physically within the pole when it is dissected. Additional data validation will be undertaken by undertaking further in-situ tests using a previously proven technique: it is proposed that an experienced contractor will be utilised for this using a previously proven technology. Groundline will then utilise various machine learning and analysis techniques to develop an automatic analysis of the pole condition and embedment depth that can then be built into the unit, to enable the capability to provide this information at the time of test. This is a key deliverable. WP3: Policy and standards 12-18 monthsThe currently industry recognised standard is that a RSV of 80% is used as the criteria to “fail” a pole. This is what is written in DNO policies.The problem with this fixed value is twofold: It takes no account of the existing factor of safety, which will vary from one pole to the next depending upon factors such as the stoutness of the pole and the plant installed on it. The RSV for declaring a pole unsafe to climb will be significantly higher than the RSV at which the pole is likelyto have an unacceptable probability of failure in service. The THOR hammer has the potential to facilitate the accurate measurement of the RSV of poles across the network on a large scale. There is therefore the opportunity to use the RSV more within the asset management process, as such this project presents the ideal opportunity to revisit the values used within the policy.This would be undertaken using a combination of internal and external resource. WP4: Integration with DNO systems and CNAIM 24 - 36 monthsThere are two elements to the full integration with existing systems: obtaining the pole and network data prior to an inspection in order to allocate the results correctly; and uploading the results into the systems following an inspection.Full integration may require a second stage project as it is difficult to clearly define what would be required at this stage. However the minimum requirements that must be achieved within this project are as follows: Be able to import network data provided by the DNOs to form inspection plans. Accurately record results against the correct asset following the above data. Export the result data in an agreed format. SPEN (and other DNOs) can then manipulate this data and import into the relevant corporate IT systems. Outputs must be aligned with CNAIM requirements: primarily this will be the output of an accurate RSV. Deliverables: Calculation of RSV as an output. 12 months. Review the criteria for declaring poles fit for purpose using the RSV and update policy as required. 18 months, starting month 6. Full validation of the results obtained by THOR. 18-24 months. Algorithms to enable the automated analysis of results, providing required outputs at the time of test. 24 months. Integration as business as usual and monitoring of benefits. 36 months. Convert the existing output from the instrument (reduction in residual diameter) to reduction of residual strength value (RSV, as documented in BS1990-1), by determining and agreeing method and assumptions. Utilise machine learning to automate the detailed waveform analysis and provide the required outputs at the time of test. Use real data and destructive examinations to prove the accuracy of the technology on pole types common to the GB electricity industry.
Abstract This project will develop the THOR Hammer device to allow the consistent and accurate measurement and assessment of wood pole asset condition.
Publications (none)
Final Report (none)
Added to Database 02/11/22