N-2NSPML (BW) RIRs 1-22 - Redacted
36 passages
- 1: Hardwoods 50 MW CT retired in 2022 - 2: 1 x 50 MW CT added - 3: Stephenville 50 MW CT retired in 2024 - 4: 2 x 50 MW CT added - 5: 3 x 50 MW CT added - 6: 4 x 50 MW CT added - 7: 5 x 50 MW CT added - 8: Portland Creek at 23 MW and new...
AI summary The document outlines the retirement and addition of combustion turbines (CT) and combined cycle combustion turbines (CCCT) in the energy sector, along with historical data on transmission line outages on the Avalon Peninsula due to icing events. A two-week repair window is used for outage analysis, with refined calculations based on observed icing events.
n observed icing events in one of the most heavily loaded sections of the HVdc route. For the refined icing event analysis the following periods are extracted for the annual load shape for evaluation: - Based upon the load shape presented...
AI summary The document discusses icing events on the HVdc route, analyzing exposure hours during specific periods (February, April, and December) and their impact on energy availability. The analysis shows that the Maritime Link significantly reduces exposure hours and increases availability when only icing load conditions are considered.
REFERENCES - 1. CSA Standard C22.3 No. 1‐06 Overhead systems published October 2006 by Canadian Standards Association - 2. National Standard of Canada CAN/CSA‐C22.3 No. 60826:06 Design criteria of overhead transmission lines published Octo...
AI summary The document lists several references, including standards and studies related to overhead transmission lines, HVDC systems, and transmission planning, all filed by Newfoundland and Labrador Hydro. These references are relevant to technical and regulatory considerations in power system planning and reliability.
Date: 10-Apr-2012 Prepared by: Peter Anderson Figi ure 2-1: Force ed Energy Unavailability (FEU) as reported by CIGRE 5
AI summary The document, dated April 10, 2012, includes a figure titled 'Force ed Energy Unavailability (FEU) as reported by CIGRE' and is prepared by Peter Anderson. The content appears to be related to energy unavailability metrics and is associated with the International Council on Large Electric Systems (CIGRE).
RELIABILITY & AVAILABILITY ASSESSMENT OF THE HVDC ISLAND LINK Revision Nalcor Doc. No.: ILK-SN-CD-8000-EL-SY-0004-01 B1 Date Page SLI Doc.: No. 505573-480A-47ER-0017 00 10-Apr-2012 A APPENDIX A
AI summary The document provides an appendix related to the reliability and availability assessment of the HVDC Island Link, with specific reference numbers and a revision history. It is part of a technical evaluation process.
NSD new stream-reach development AWIA American Water Infrastructure Act of 2018 O&M operations and maintenance Figure 37. HUC-2 water resource regions Figure 38. Annual deviations from average generation vs. percentage of area under drough...
AI summary The text provides a series of figures related to hydropower and pumped storage hydropower (PSH) generation, operational status, and capacity factors across various regions and time periods, with data sourced from the NERC Generating Availability Data System (GADS).
Correlation must also be considered among the failure modes (Haldar, 1985, 1988). This is rarely done in traditional design practice; DLS criteria needs to be understood in this context. DLS analysis may be sufficient if it can be shown th...
AI summary The text discusses the importance of considering correlation among failure modes in design practice, emphasizing the limitations of DLS criteria and the need for strength analysis and event tree analysis to assess potential progression to ULS conditions in the LIL system.
Figure 4.6 Setup of the WRF model simulations (The WRF4km domain is shown as the white rectangle and the two green rectangles show the two WRF500m domains) –EFLA (2021) The proposed load combinations of "Wind and Ice" and "Ice and Wind" as...
AI summary The document discusses the proposed load combinations of 'Wind and Ice' and 'Ice and Wind' used in the WRF model simulations, referencing CSA 60826-10 standards for ice load values and return periods.
Table 4.1 Proposed values of wind speed and ice load in a combination of wind and rime ice (EFLA, 2021). Load case Ice load Wind speed Wind and Ice 0.40 gR 0.80 VR Ice and wind gR 0.5 VR Assessment of LIL Reliability in Consideration of Cl...
AI summary The text presents Table 4.1, which outlines proposed values of wind speed and ice load combinations for wind and rime ice, as per the Energy & Capacity Agreement (EFLA, 2021). It also references an assessment of the reliability of the Long International Line (LIL) in light of climatological loads.
Table 4.2 Definition of combined loading with wind and ice in the CSA60826 Standard (reproduced from EFLA, 2020) Wind and Ice Ice and wind Ice load $0.40~g_l$ $g_l$ Wind speed (0.60 to 0.85) $V_{\rm R}$ (0.4 to 0.5) $V_{\mathrm{R}}$ Descri...
AI summary Table 4.2 defines combined loading with wind and ice according to the CSA60826 Standard, specifying ice load and wind speed values for different return periods. The table distinguishes between wind and ice loading and ice and wind loading, with associated return periods and descriptions.
Table 6.3 POF, Failure Rate Determined for Various Scenarios (ULS) RISK of EXC RISK of EXCEEDING ULS - CSA 60826 (5 and 50 Years) Scenario # POF- Annual 5 Years (%) 50 Years (%) Failure Rate (%) 1 0.00474 2 21 0.48 1A 0.00543 3 24 0.54 2 0...
AI summary The table compares the probability of failure (POF) under different scenarios for the Ultimate Load Specification (ULS) and the Design Load Specification (DLS). It highlights that POF under ULS is 43% of that under DLS in Scenario #1. The text also notes that a full ULS system reliability analysis has not been conducted and should be done before generation expansion planning.
7.2 Uncertainty on the topographical effect on LIL design Lines are normally designed for two primary classes of loads (1) reliability class and (2) security class. Under reliability class of loads, structures and major line components are...
AI summary The text discusses the impact of topographical effects on the design of Long International Line (LIL) transmission systems, highlighting how wind speed-up effects in hills, valleys, and mountains can significantly increase wind and combined wind-ice loads on support structures. Current design standards like CSA 60826-10 do not account for these topographic effects, which can lead to increased risk of failure. The study by Bitsuamlak et al. (2015) recommends assessing these effects for specific terrain configurations.
Table 7.1 Combined Wind and Ice and Ice and Wind Loads Ice + Wind Wind + Ice Reference Wind Type $g_{lf} + 0.4V_R$ $0.6 V_R + 0.4g_{lf}$ Type C (Zones 11&3a) , $g_{lf} + 0.5V_R$ $0.85 V_R + 0.4g_{lf}$ Type B (Zones 11&3a) $g_{lf} + 0.4V_R$...
AI summary Table 7.1 presents combined wind and ice loads for different reference wind types, including equations for Ice + Wind and Wind + Ice conditions. The table includes specific zones and load calculations for various scenarios.
- 2 December 2022, which caused damage to two OPGW top plates on two A3 towers. During this event, - 3 the top plate connections failed and caused deformation and damage to the top plate and the hanger - 4 bracket on two A3 towers. While t...
AI summary An icing event on 2 December 2022 caused damage to OPGW top plates on two A3 towers due to a design error. The ice load was below the design specifications, but the connection capacity was insufficient. Reinforcement work was completed in 2024, and recommendations from investigation reports are summarized in Appendix A.
Summary of all Failure Investigation Recommendations Document Number Report Title Recommendation Status Comments Monitor ice by line patrol Addressed Lines are monitored regularly during the winter by helicopter line patrol. Additional hel...
AI summary The document outlines recommendations from a failure investigation related to icing events and line damage in Labrador. Key actions include monitoring ice through helicopter patrols, installing real-time ice monitoring systems, and implementing procedures for mechanical ice management. The LIL Strengthening Capital Project is ongoing, and engineering consultants have been engaged to improve damper specifications.
Table 2: Wind & Weight Span Comparison for S4-502 (2469) Condition Total Wind Span Back Weight Span Ahead Weight Span Total Weight Span Existing 380 m 265 m 163 m 428 m One mid-span structure 256 m 140 m 158 m 298 m Change -124 m (33%) -12...
AI summary Table 2 compares wind and weight spans under different conditions for S4-502 (2469). It shows the existing spans and changes when one mid-span structure is introduced, with reductions in total wind span and weight spans, particularly in the back weight span.
Table 3: Maximum Structure Usage Comparison for S4-502 (2469) Load Case Exi isting One Mid-Sp Reinforcing Existing Tower Load Case Maximum Usage % Element Label Maximum Usage % Maximum Usage Difference Maximum Usage % F1 LC70 AS UBI G 50mm...
AI summary Table 3 presents a comparison of maximum structure usage percentages for different load cases and elements under S4-502 (2469), highlighting differences between existing structures and reinforcing options.
Table 4: Wind & Weight Span Comparison for S4-576 (2543) Condition Total Wind Span Back Weight Span Ahead Weight Span Total Weight Span Existing 478 m 274 m 234 m 508 m One mid-span structure 365 m 156 m 235 m 391 m Two mid-span structures...
AI summary Table 4 compares wind and weight spans under different conditions for S4-576 (2543), showing reductions in span lengths when mid-span structures are added. The table highlights the impact of structural changes on wind and weight spans, with the most significant reductions observed when two mid-span structures are added.
Table 5: Maximum Structure Usage Comparison for S4-576 (2543) Exis sting One Mid-Span Structure Two Mid-Span Structures Reinforcing Existing Tower Load Case Maximum Usage % Element Label Maximum Usage % Maximum Usage Difference Maximum Usa...
AI summary Table 5 presents a comparison of maximum structure usage percentages for different load cases and reinforcement scenarios, including the use of mid-span structures and reinforcing existing towers. The data highlights differences in usage percentages between various configurations.
Table 6: Wind & Weight Span Comparison for S4-598 (2565) Condition Total Wind Span Back Weight Span Ahead Weight Span Total Weight Span Existing 392 m 153 m 368 m 521 m One mid-span structure 316 m 154 m 238 m 392 m Change -76 m (19%) 1 m...
AI summary Table 6 compares wind and weight spans under different conditions for S4-598 (2565). The existing configuration has a total wind span of 392 m, while adding a mid-span structure reduces the total wind span by 76 m (19%). The total weight span decreases by 129 m (25%) with the addition of the structure.
Table 7: Maximum Structure Usage Comparison for S4-598 (2565) E xisting One Mid-Sp an Structure Reinforcing Existing Tower Load Case Maximum Usage % Element Label Maximum Usage % Maximum Usage Difference Maximum Usage % F1 LC70 AS UBI G 50...
AI summary Table 7 compares maximum structure usage for S4-598 (2565) under various load cases, showing percentages for existing structures, one mid-span structure, and reinforcing existing towers. Similar to other structures, local overstresses were observed in peak braces and legs under new unbalanced ice loading conditions, as depicted in Figure 2.
Newfoundland and Labrador Hydro Landon Exis sting One Mid-Span Structure Two M Struc Reinforcing Existing Tower Load Case Maximum Usage % Element Label Maximum Usage % Maximum Usage Difference Maximum Usage % Maximum Usage Difference Maxim...
AI summary The document discusses overstressed members in existing structures due to various load cases, such as unbalanced ice loading on OPGW and electrodes, heavy ice events, and broken wire scenarios. Adding mid-span structures can reduce overstresses, but reinforcement is still necessary. The reinforced A1 tower showed no overstresses.
Back Weight Ahead Weight Condition Total Wind Span Back Weight Span Ahead Weight Span Total Weight Span Existing 392 m 112 m 298 m 410 m One mid-span structure 273 m 114 m 204 m 318 m Change (1 Structure) -119 m (30%) 2 m -94 m -92 m (22%)...
AI summary The document presents a comparison of weight spans under different conditions for a power line structure. Adding a mid-span structure reduces the total weight span but only slightly, due to topographical constraints. The structure S1-370a is noted as the tallest available option, achieving a modest reduction in weight span.
Table 11: Maximum Structure Usage Comparison for S1-370 (371) Exis sting One Mid-Sp an Structure Reinforcing Existing Tower Load Case Maximum Usage % Element Label Maximum Usage % Maximum Usage Difference Maximum Usage % F1 LC70 AS UBI G 5...
AI summary Table 11 presents a comparison of maximum structure usage percentages for different load cases and elements in the context of a mid-span structure addition report for S1-370 (371). The table includes various load cases, element labels, and usage percentages for existing structures, one mid-span structure, and reinforcing existing towers.
Table 12: OPGW Wind & Weight Span Comparison for S1-307 (308) Condition Total Wind Span Back Weight Span Ahead Weight Span Total Weight Span Existing 337 m 265 m 56 m 321 m One mid-span structure 225 m 151 m 57 m 208 m Change (1 Structure)...
AI summary Table 12 compares the wind and weight spans for S1-307 (308) under different conditions, including the existing configuration and the addition of one mid-span structure. The data shows reductions in wind and weight spans when a mid-span structure is added, with the most significant decrease in total wind span by 33%.
Table 14: Load Cases Comparison for S4-576 (2543) (As built VS Envelope I Loads) LCA/Set name Load direction Envelope forces (kN) As built forces (kN) Difference (kN) V (Vertical) 31.2 34.7 -3.5 G T (Transverse) -0.2 0 -0.2 L (Longitudinal...
AI summary Table 14 compares load cases for Tower S4-576 under different conditions, showing differences in vertical, transverse, and longitudinal forces between the as-built and Envelope I scenarios. The section highlights that the reinforced model for Tower S1-307 (308) may be overstressed.
As shown in Table 13, the reinforced model shows overstress with a ratio of 102.3%. Similar to tower S4-576 (2543), the overstresses are seen due to the discrepancy between the envelope load cases and the as built load cases. Figure 11 sho...
AI summary The text discusses overstress in a reinforced model with a ratio of 102.3%, caused by discrepancies between envelope load cases and as built load cases. Overstresses occur in the upper chord of the guy cross arm (GA136-137-2), similar to tower S4-576 (2543). The governing load case involves a broken wire scenario for sets E2 and P2, leading to increased loads and overturning moments.
7.0 LONGITUDINAL LOAD REDUCTION An assessment of longitudinal load reduction was completed to determine the benefit of the insulator lengthening of option 2. The following procedure was completed to compare the existing condition to the im...
AI summary A longitudinal load reduction assessment was conducted to evaluate the benefits of insulator lengthening in option 2. The procedure involved changing insulator lengths in PLS-CADD models and comparing load cases. The average relative change in load reduction across inspected tower locations was 10%.
Table 1: Relative Change for Insulator Lengthening Option 2 Tower No. Long. Load Before (N) Long. Load After (N) Relative Change 335 16020 14226 11.2% 340 19779 17429 11.9% 343 20320 18408 9.4% 362 16209 14497 10.6% 363 21330 19415 9.0% 36...
AI summary Table 1 presents the relative change in longitudinal load for various towers under Insulator Lengthening Option 2. The data shows a consistent reduction in load across all towers, with an average relative change of 10.0%. Newfoundland and Labrador Hydro is mentioned as an entity in the context.
LIL Engineering Study - Calculations for OPGW Reinforcement Tetra Tech REV. NO ISSUE DATE DATE PREPARED BY REVIEWED BY APPROVED BY DESCRIPTION OF REVISION 00 July 21, 2025 Tarek Ghazal Julien Dupas Greg Sheppard Issued for Use PREPARED BY...
AI summary This document outlines the LIL Engineering Study focusing on calculations for OPGW reinforcement. It includes a table of contents with sections on methodology, material properties, loading, meshing, and results, as well as figures illustrating various aspects of the engineering analysis.
NL Hydro provided design loading drawings for each tower family listed below: - Tower A2 - ILK-SN-CD-6200-TL-DD-0070-01 - o ILK-SN-CD-6200-TL-DD-0070-02 - Tower A4 - ILK-SN-CD-6200-TL-DD-0199-01 - Tower B1 - ILK-SN-CD-6200-TL-DD-0066-01 -...
AI summary NL Hydro provided design loading drawings for various tower families, including Tower A2, A4, B1, and B2. Four maximum loading cases were identified and studied: maximum vertical, positive transverse, negative transverse, and longitudinal load cases, applied at the insulator suspension vang in different directions.
Table 2: Loading Cases for Each Tower Family Group Tower Family /LC Max. Vertical Load (kN) Load Max. Positive Transverse Load (kN) Max. Negative Transverse Load (kN) Max. Longitudinal Load (kN) V Т L V Т L V Т L V Т L A2 -89.9 3.5 0.0 -31...
AI summary Table 2 presents loading cases for different tower family groups, detailing maximum vertical, transverse, and longitudinal loads in kilonewtons. The table includes various tower families (A2, A4, B1, B2) and their respective load values. Section 2.5 discusses meshing, which is likely related to structural or engineering analysis.
Line L3501/2 is the 350 kV HVdc overland transmission line portion of LIL traversing a distance of approximately 1,100 km through three major meteorological loading zones: average, alpine and eastern. The HVdc line has two poles, one OPGW,...
AI summary The document describes the 350 kV HVdc overland transmission line (L3501/2) of the Labrador-Island Link (LIL), which spans approximately 1,100 km through three major meteorological loading zones. The line includes two poles, an OPGW, and two electrode conductors for a portion of the line. The corridor is divided into 19 loading zones based on meteorological, pollution, and geographic factors, and eleven tower types were designed to meet specific loading requirements.
Table 1- Summary of Electrode Damage All Events Damaged Components Damaged Components Structure Number Crossarm Crossarm Conductor Conductor Structure Crossarm Crossarm Conductor Conductor EL1 EL1 EL1 EL2 Number EL1 EL1 EL1 EL2 127 507 X 1...
AI summary Table 1 summarizes electrode damage events across various structures, including details on damaged components such as crossarms and conductors, with specific structure numbers and failure dates noted.
4. Summary, Conclusions, and Recommendations There have been a number of failures on the L3501/2 transmission line due to ice events over the past 4 years. The electrode crossarms and the electrode conductor are two components that are oft...
AI summary Over the past four years, the L3501/2 transmission line has experienced failures due to ice events, primarily caused by unbalanced ice loads. Removing the electrode conductor from towers and running it parallel on a wood pole line could reduce damage. Analysis shows significant benefits, especially for ice loads of 70 mm, with some sections showing greater improvements under higher ice loads.
Table 2 - Difference in Percentage Without and With the Electrode Conductor Difference between Without Electrode and With Electrode Load Case All Sections Str. 113 - 132 Str. 222 - 243 Str. 328 - 370 Str. 424 - 467 Str. 498 - 542 Str. 1209...
AI summary Table 2 presents the differences in percentage between load cases with and without the electrode conductor under various ice and UBL load conditions. The data highlights the impact of the electrode conductor on different sections, showing varying percentages depending on the load case.
N-4NSPML (IG) RIRs 1-26 - Redacted
94 passages
NSPML Responses to Industrial Group Information Requests 1 Request IR-09: 22 knowledge to the extent the responses relate to the Labrador Island Link and 23 Labrador Transmission Assets. 24 25 For part (b), NSPML's understanding is that th...
AI summary NSPML responds to information requests regarding the Labrador Island Link and Labrador Transmission Assets, stating that outages on non-LIL lines did not impact the assets required to deliver energy from Muskrat Falls to Nova Scotia. The response references pages 21-22 and Footnote 26 of the N-01 Application.
3 For the section of line containing str. 1218–1228 and 1232, sections of the electrode conductor will be removed from the towers for installation on wood poles, and reinforcement will be completed for the OPGW peaks. 4 & quot;Quarterly Re...
AI summary The text discusses the removal of sections of electrode conductor from towers for installation on wood poles and reinforcement of OPGW peaks. It also references quarterly reports on asset performance from Newfoundland and Labrador Hydro for the periods ending March 31, 2025, and December 31, 2025.
1 and securing the OPGW to allow for tower repairs. Repair work which allowed the LIL to 2 return to monopole operation began on April 10, 2024. All repair work, which included 3 replacement of tower steel and electrode conductor, was comp...
AI summary The text discusses repair work on the Lower Island Link (LIL) involving the securing of the OPGW to allow for tower repairs. The repair work, which included replacement of tower steel and electrode conductor, was completed by April 19, 2024, and resulted in a reduction of 26,513 MWh in Base NS Block deliveries.
Appendix A: Summary of all Failure Investigation Recommendations Appendix B: LIL Engineering Study – Mid-Span Structure Addition Report Appendix C: LIL Engineering Study – A1 Electrode Suspension Assembly Appendix D: LIL Engineering Study...
AI summary The document includes appendices summarizing failure investigation recommendations and engineering studies related to the Lower Island Link (LIL), including mid-span structure additions, electrode suspension assemblies, OPGW peak reinforcement calculations, wood pole and mid-span cost estimates, and analysis of removing an electrode conductor.
2.0 Background - Line L3501/2 is the 350 kV High Voltage direct current ("HVdc") overland transmission line portion of the - LIL, traversing approximately 1,100 km through three major meteorological loading zones, referred to as - average,...
AI summary The document provides background on Line L3501/2, a 350 kV HVdc transmission line as part of the LIL project. It traverses 1,100 km through three meteorological loading zones, with specific tower designs and configurations, including electrode conductors and different tower types.
Table 1: Tower Types Deflection Angle Tower Structure Insulator Limit Type Type Assembly Type (degree) A1, A2, A3, A4 Guyed Suspension 0–1 B1 Guyed Suspension 0–3 B2 Self-Support Suspension 0–3 C1, C2 Self-Support Dead-End 0–30 D1, D2 Self...
AI summary Table 1 lists various tower types used in power transmission, including their structure type, insulator assembly type, and deflection angle limits. The table includes categories such as Guyed and Self-Support towers with different insulator types and deflection angle ranges.
3.0 Investigation Overview Issues with components of the LIL during ice events over the past five years have primarily caused damage to the electrode crossarms, OPGW tower peaks, and the electrode conductor. Investigations determined that...
AI summary The document discusses issues with components of the Lower Island Link (LIL) caused by ice events over the past five years, primarily affecting electrode crossarms, OPGW tower peaks, and the electrode conductor. Root causes include overloading from ice accumulation and unbalanced ice loads, with some failures attributed to galloping. A capital project is planned for 2026 to address these issues.
Number of Date Location Number of Damaged EL Crossarms Locations of Damaged EL Conductor Number of Damaged OPGW Peaks Number of Damaged OPGW Top Plates Approximate Radial Equivalent Ice Thickness (mm)4 Approximate Weight of Ice on EL Condu...
AI summary The document presents a table detailing the number of damaged electrical crossarms, conductor locations, and optical ground wire (OPGW) peaks and top plates in various regions of Labrador and Newfoundland between January 2021 and January 2025, along with approximate ice thickness and weight on conductors.
Summary of all Failure Investigation Recommendations Document Number weather, and new equipment was installed in Q3 of 2025 to continue monitoring and required for the damper study. The equipment experienced issues due to severe Determine...
AI summary The document outlines recommendations and actions taken following a failure investigation related to OPGW and tower structures. Key actions include redesigning top plate connections, installing air spoilers to reduce galloping, and modifying electrode insulator assemblies to address structural and performance issues.
2.0 STUDIED TOWER LOCATIONS Six tower locations were inspected for potential candidates for mid-span structure additions. Locations were chosen to have unique characteristics that may represent a good sample space for potential highly load...
AI summary Six tower locations were inspected for potential mid-span structure additions. The locations were selected for their unique characteristics and represent a good sample space for highly loaded tower positions. The tower names are based on PLS-CADD models provided by NL Hydro on January 15, 2025.
Table 1: Studied Tower Locations Tower Location Structure Number Reason for Selection S4-502 2469 Large span imbalance, back span coincident with a wet, low-lying area. No electrode strung. S4-576 2543 Long weight spans both sides of the t...
AI summary Table 1 lists several tower locations with specific structural numbers and reasons for selection, including factors like span imbalance, terrain challenges, and load conditions. The methodology section introduces the approach used for the analysis but does not provide detailed information.
Table 2: Wind & Weight Span Comparison for S4-502 (2469) Condition Total Wind Span Back Weight Span A Total Weight Span Existing 380 m 265 m 163 m 428 m One mid-span structure 256 m 140 m 158 m 298 m Change -124 m (33%) -125 m -5 m -130 m...
AI summary Table 2 compares wind and weight spans for S4-502 (2469) under different conditions, showing reductions in span lengths when a mid-span structure is introduced. The data highlights changes in total wind span, back weight span, and total weight span, with percentages indicating the reduction in each scenario.
Table 3: Maximum Structure Usage Comparison for S4-502 (2469) Load Case Ex isting One Mid-Sp Reinforcing Existing Tower Load Case Maximum Usage % Element Label Maximum Usage % Maximum Usage Difference Maximum Usage % F1 LC70 AS UBI G 50mm...
AI summary Table 3 presents a comparison of maximum structure usage percentages for different load cases under S4-502 (2469), showing the existing usage, usage after adding a mid-span, reinforcing the existing tower, and the difference in usage.
Table 4: Wind & Weight Span Comparison for S4-576 (2543) Condition Total Wind Span Back Weight Span Ahead Weight Span Total Weight Span Existing 478 m 274 m 234 m 508 m One mid-span structure 365 m 156 m 235 m 391 m Two mid-span structures...
AI summary Table 4 compares wind and weight spans for different conditions on S4-576 (2543). The data shows the impact of adding mid-span structures on wind and weight spans, with reductions in span lengths as more structures are added.
Table 5: Maximum Structure Usage Comparison for S4-576 (2543) Existing One Mid-Span Structure Two Mid-Span Structures Reinforcing Existing Tower Load Case Maximum Usage % Element Label Maximum Usage % Maximum Usage Difference Maximum Usage...
AI summary Table 5 compares the maximum structure usage percentages for different scenarios involving mid-span structures and reinforcing existing towers under various load cases. The data shows the impact of adding mid-span structures and reinforcing towers on reducing maximum usage percentages.
3.3.1 Wind and Weight Span Table 6: Wind & Weight Span Comparison for S4-598 (2565) I able U. vviilu Q VVCIUIT ODAIT Companion 101 04-030 (2000) Condition Total Wind Span Back Weight Span Ahead Weight Span Total Weight Span Existing 392 m...
AI summary This section discusses the wind and weight span comparison for S4-598 (2565), including the impact of adding a mid-span structure. The existing spans are compared to the spans after the change, with reductions in wind and weight spans noted.
Table 7: Maximum Structure Usage Comparison for S4-598 (2565) E xisting One Mid-Sp Reinforcing Existing Tower Load Case Maximum Usage % Maximum Usage % Maximum Usage Difference Maximum Usage % F1 LC70 AS UBI G 50mm 50/100%,C NA+ 151.6 GW21...
AI summary Table 7 compares maximum structure usage percentages for different load cases under various reinforcement scenarios for S4-598 (2565). The table shows that reinforcing existing towers reduces maximum usage percentages, with differences ranging from -2.8% to -19.7%. Similar issues were observed in other towers under new unbalanced ice loading conditions.
Table 9: Maximum Structure Usage Comparison for S1-318 (319) Load Case Existing One Mid-Span Structure Two Mid-Span Structures Reinforcing Existing Tower Load Case Maximum Usage % Element Label Maximum Usage % Maximum Usage Difference Maxi...
AI summary Table 9 presents a comparison of maximum structure usage percentages for different load cases under various scenarios, including the addition of mid-span structures and reinforcing existing towers. The data highlights the differences in usage percentages across these scenarios for specific elements.
Newfoundland and Labrador Hydro LandOnn Existing One Mid-Span Structure Two Mid-Span Structures Reinforcing Existing Tower Load Case Maximum Usage % Element Label Maximum Usage % Maximum Usage Difference Maximum Usage % Maximum Usage Diffe...
AI summary The existing configuration of the structure shows overstressed members under peak load conditions, including unbalanced ice loading on the OPGW and electrodes, heavy ice events, or broken wire scenarios. While adding mid-span structures can reduce overstresses, reinforcement is still required. The reinforced A1 tower does not show overstresses.
3.5.1 Wind and Weight Span Similar to tower S1-318 (319), the OPGW and electrode wind & weight spans were found to be similar so only the OPGW is presented.
AI summary The wind and weight spans for OPGW and electrode are similar to those of tower S1-318, so only the OPGW is presented in detail.
Table 10: OPGW Wind & Weight Span Comparison for S1-370 (371) Condition Total Wind Span Back Weight Span Ahead Weight Span Total Weight Span Existing 392 m 112 m 298 m 410 m One mid-span structure 273 m 114 m 204 m 318 m Change (1 Structur...
AI summary Table 10 compares wind and weight spans for a power line under different conditions. Adding a mid-span structure reduces the total weight span by 92 meters, but the reduction is limited due to topography, with the weight span ratio decreasing from 2.4 to 1.8.
Table 11: Maximum Structure Usage Comparison for S1-370 (371) Exi sting One Mid-Sp an Structure Reinforcing Existing Tower Load Case Maximum Usage % Element Label Maximum Usage % Maximum Usage Difference Maximum Usage % F1 LC70 AS UBI G 50...
AI summary Table 11 presents a comparison of maximum structure usage percentages for different load cases and structural elements in the context of a mid-span structure addition and reinforcing existing towers. The data shows varying percentages of usage across different elements and load scenarios.
3.6.1 Wind and Weight Span Similar to tower S1-318 (319), the OPGW and electrode wind & weight spans were found to be similar so only the OPGW is presented.
AI summary The section discusses the similarity between the OPGW and electrode wind & weight spans, noting that only the OPGW is presented due to their similarity to tower S1-318 (319).
Table 12: OPGW Wind & Weight Span Comparison for S1-307 (308) Condition Total Wind Span Back Weight Span Ahead Weight Span Total Weight Span Existing 337 m 265 m 56 m 321 m One mid-span structure 225 m 151 m 57 m 208 m Change (1 Structure)...
AI summary Table 12 compares the wind and weight spans for S1-307 (308) under different conditions, including existing, one mid-span structure, and the change resulting from adding a structure. The data shows reductions in wind and weight spans when a mid-span structure is added.
Table 13: Maximum Structure Usage Comparison for S1-307 (308) Exis sting One Mid-Sp an Structure Reinforcing Existing Tower Load Case Maximum Usage % Element Label Maximum Usage % Maximum Usage Difference Maximum Usage % F1 LC70 AS UBI G 5...
AI summary Table 13 presents a comparison of maximum structure usage percentages for different load cases and structural elements, including existing structures, one mid-span structure, and reinforcing existing towers. The table includes various load cases and their corresponding maximum usage percentages, differences, and reinforced usage percentages.
3.7.1 Tower S4-576 (2543) Reinforced Model Overstresses As shown in Table 5, the reinforced model shows overstresses with a ratio of 100.2%. This scenario is encountered if no mid-span structures are added and only reinforcing of the exist...
AI summary The reinforced model of Tower S4-576 (2543) shows overstresses of 100.2% due to a discrepancy between the envelope load cases provided for tower A1 reinforcement and the as-built load cases obtained from PLS CADD. The overstress is observed in one of the peak diagonals (GW217), caused by an increase in vertical load under the governing load case F1 LC70 AS UBI G 50mm 50/100%,C NA+.
As shown in Table 13, the reinforced model shows overstress with a ratio of 102.3%. Similar to tower S4-576 (2543), the overstresses are seen due to the discrepancy between the envelope load cases and the as built load cases. Figure 11 sho...
AI summary The text discusses overstress in a reinforced model with a 102.3% ratio, similar to tower S4-576 (2543). Overstresses occur due to discrepancies between envelope load cases and as-built load cases, specifically in the upper chord of the guy cross arm (GA136-137-2). The governing load case involves a broken wire scenario for sets E2 and P2, leading to increased loads and overturning moments.
Table 15: Load Cases Comparison for S1-307 (308) (As built VS Envelope Loads) LCA/Set name Load direction Envelope forces (N) As built forces (N) Difference (kN) V (Vertical) 29.2 21.6 7.6 P1 T (Transverse) 1.3 0.0 1.3 L (Longitudinal) 0.0...
AI summary Table 15 presents a comparison of load cases for S1-307 (308), showing differences between envelope loads and as-built forces in vertical, transverse, and longitudinal directions for various load cases (P1, P2, E1, E2, GP). The data highlights discrepancies in force measurements across different load scenarios.
LIL Engineering Study – A1 Electrode Suspension Assembly Newfoundland and Labrador Hydro O SI VI RE Y R O T S HI N Tetra Tech REV. No. ISSUE DATE PREPARED BY WED BY REVIE APPROVED BY DESCRIPTION OF REVISION 00 June 10, 2025 Julien Dupas Ta...
AI summary The document outlines an engineering study conducted by Tetra Tech for Newfoundland and Labrador Hydro, focusing on the permissible length increase and design options for the LIL (Labrador-Island Link) electrode suspension assembly. The study includes sections on work completed, permissible length increases, longitudinal articulation angles, design options, load reduction, and conclusions.
7.0 LONGITUDINAL LOAD REDUCTION An assessment of longitudinal load reduction was completed to determine the benefit of the insulator lengthening of option 2. The following procedure was completed to compare the existing condition to the im...
AI summary An assessment of longitudinal load reduction was conducted to evaluate the benefits of insulator lengthening in option 2. The procedure involved comparing existing and improved conditions by modifying insulator lengths and analyzing structure loads. The average relative change in load reduction was found to be 10% at tower locations with known electrode cross-arm damage during ice events.
Table 1: Relative Change for Insulator Lengthening Option 2 Tower No. Long. Load Before (N) Long. Load After (N) Relative Change 335 16020 14226 11.2% 340 19779 17429 11.9% 343 20320 18408 9.4% 362 16209 14497 10.6% 363 21330 19415 9.0% 36...
AI summary Table 1 presents the relative change in longitudinal load for various towers under Insulator Lengthening Option 2. The data shows a consistent reduction in load, with an average decrease of 10.0% across all towers listed.
LIL Engineering Study Calculations for OPG ment W Reinforce Newfoundland and Labrador Hydro O SI VI E R Y R O T S HI N Tetra Tech REV. NO ISSUE DATE PREPARED BY WED BY REVIE APPROVED BY DESCRIPTION OF REVISION 00 July 21, 2025 Tarek Ghazal...
AI summary The document outlines an engineering study conducted by Tetra Tech for the Labrador-Island Link (LIL) project, focusing on the reinforcement of optical ground wire (OPGW) structures. It includes a table of contents detailing the methodology, material properties, loading cases, and results of the study.
Table 2: Loading Cases for Each Tower Family Group Tower Family /LC Max. Vertical Load (kN) _ Max. Positive Transverse Load (kN) Max. Negative Transverse Load (kN) Max. Longitudinal Load (kN) V Т L V Т L V Т L V Т L A2 -89.9 3.5 0.0 -31.9...
AI summary Table 2 presents loading cases for different tower family groups, showing maximum vertical, transverse, and longitudinal loads in kilonewtons. The table includes data for Tower Families A2, A4, B1, and B2, with values for various load types and directions.
Line L3501/2 is the 350 kV HVdc overland transmission line portion of LIL traversing a distance of approximately 1,100 km through three major meteorological loading zones: average, alpine and eastern. The HVdc line has two poles, one OPGW,...
AI summary The 350 kV HVdc transmission line (L3501/2) of the Labrador Island Link (LIL) spans approximately 1,100 km through three major meteorological loading zones. It includes two poles, an OPGW, and two electrode conductors. The line uses 11 tower types designed for specific wind and ice loads, with sections using wood poles and a separate right of way for electrode conductors.
e ice at a density of 0.9 g/cm 3 (20.6 to 21.6 kg/m), and the damage likely occurred due to unbalanced ice loads from ice shedding. There were no other components damaged in this icing event. In March 2024 there was an icing event in south...
AI summary Multiple icing events between 2024 and 2025 caused damage to electrode crossarms and conductors in Labrador. Ice shedding led to unbalanced ice loads, resulting in failures at various locations. The damage was documented in Table 1, with a total of 30 electrode crossarms and 56 conductor locations affected.
4. Summary, Conclusions, and Recommendations There have been a number of failures on the L3501/2 transmission line due to ice events over the past 4 years. The electrode crossarms and the electrode conductor are two components that are oft...
AI summary The L3501/2 transmission line has experienced multiple failures due to ice events over the past four years, primarily caused by unbalanced ice loads. Removing the electrode conductor from towers and running it parallel on a wood pole line reduces failures, especially under high ice loads. The greatest benefits are observed for 70 mm ice loads, with some sections showing significant improvements.
Table 2 - Difference in Percentage Without and With the Electrode Conductor Difference between Without Electrode and With Electrode Load Case All Sections Str. 113 - 132 Str. 222 - 243 Str. 328 - 370 Str. 424 - 467 Str. 498 - 542 Str. 1209...
AI summary Table 2 presents the differences in percentage between scenarios without and with an electrode conductor under various load cases and ice/UBL conditions, highlighting variations in impact across different sections of the line.
9.1 Ice Loading - As discussed in Section [6.0,](#page-158-1) reports from site estimate the ice thickness at the location of the failures at - approximately 120–140 mm of radial thickness. The sample of ice that fell from the OPGW was - m...
AI summary This section discusses ice loading on power lines, analyzing the failure of towers due to excessive ice thickness. Modeling was conducted with various ice thicknesses and densities, revealing that failures occurred at specific ice thickness ranges. The results suggest that electrode crossarm failures could be caused by radial ice between 90–100 mm.
Table 4: Comparison of Field Damage and Modeling Results for Ice Loading Field Damage Modeling 9 90 mm Modeling 100 mm Crossarm EL Crossarm EL Crossarm Dan nage OPGW Tower Damage OPGW Damage OPGW Tower EL1 EL2 Peak (% Utilization) Tower Pe...
AI summary Table 4 compares field damage observations with modeling results for ice loading on various structures, including towers and crossarms, under different ice thickness scenarios (9 mm and 100 mm). The data includes utilization percentages and damage indicators for specific poles and electrodes.
Table of contents Executive summary ii Figure 1-1: Google map provided by NL Hydro [1] showing the general compass directions of the segments of the transmission lines between Tower #1200 and Tower #1229. The map also shows the reported di...
AI summary The text provides a table of contents with references to figures illustrating transmission line failures, conductor specifications, and analysis of failed components. It includes details about the location of failures, conductor configurations, and images of damaged equipment.
3.1 Dimensional Characterization of Failed Conductor EL-1 Wire Strands Table 3-1 contains a summary of wire strand diameter ranges for the 6 layers associated with the failed conductor EL-1 (the detailed measurement results have been provi...
AI summary This section discusses the dimensional characterization of failed conductor EL-1 wire strands, including diameter ranges for aluminum and zinc-coated steel strands, and the variation in zinc coating thickness observed. The measurements are compared to ASTM B-232 standards for a Grackle ACSR 54/19 conductor.
Wire Strand Diameter Ranges (mm) Outer Aluminum Strands Outer Aluminum Strands Layer 1 Layer 2 Layer 3 Layer 4 Layer 5 Layer 6 Conductor EL-2 3.43-3.68 3.56-3.71 3.66-3.71 2.18-2.26 2.16-2.24 2.24 Figure 3-3: SEM backscatter image of a rep...
AI summary The document presents a table showing wire strand diameter ranges for conductor EL-2 and includes a figure depicting a scanning electron microscope (SEM) backscatter image of a zinc-coated steel reinforcing strand from the failed conductor EL-2, highlighting the variation in zinc coating thickness.
Wire Strand Diameter Ranges (mm) Oute Outer Aluminum Strands Oute er Aluminum Strands Layer 1 Layer 2 Layer 3 Layer 4 Layer 5 Layer 6 Intact Conductor 3.71-3.76 3.71-3.76 3.71-3.73 2.21-2.24 2.21-2.24 2.21 Figure 3-4: SEM backscatter image...
AI summary The text describes a table and an image related to the wire strand diameter ranges of an intact conductor and provides a backscatter image of a zinc-coated steel reinforcing strand, highlighting variations in zinc coating thickness.
Table 4-1: Semi-quantitative SEM EDS analysis results for the strand to strand fusing observed in conductor EL-1. Figure 4-5 shows the locations of the EDS analyses. Chemical Composition (wt%) Position Fe Si Zn Al O P S A1 ND ND 93.40 3.40...
AI summary Table 4-1 presents semi-quantitative SEM EDS analysis results for strand to strand fusing observed in conductor EL-1. The table lists chemical compositions of various positions (A1 to A4) with percentages of elements such as Fe, Si, Zn, Al, O, P, and S. The note indicates that ND means the element was not detected.
Table 4-2: Semi-quantitative SEM EDS analysis results for the clamp material immediately adjacent to the site of localized brinelling in conductor EL-1. Figure 4-6 shows the locations of the EDS analyses.
AI summary The text references a table and figure related to a semi-quantitative SEM EDS analysis of clamp material near localized brinelling in conductor EL-1, indicating a focus on material analysis and structural integrity assessment.
4.2 Metallurgical Characterization of Failed Conductor EL-2 Samples from several of the outer aluminum wire strands, which included the fracture surface associated with the strand failure were removed from conductor EL-2. The samples were...
AI summary This section discusses the metallurgical analysis of failed conductor EL-2, focusing on the fracture surfaces and fusing between strands. SEM and EDS analyses revealed ductile fracture mechanisms and the presence of zinc from steel reinforcing strands, which contributed to the failure.
Table 4-3: Semi-quantitative SEM EDS analysis results for the strand to strand fusing observed in conductor EL-2. Figure 4-11 shows the locations of the EDS analyses. Chemical Composition (wt%) Position Fe Si Zn Al O P S C1 ND ND 79.55 10....
AI summary Table 4-3 presents the semi-quantitative SEM EDS analysis results for the strand to strand fusing observed in conductor EL-2. The table provides chemical composition data for various positions (C1 to C6) with elements such as Fe, Si, Zn, Al, O, P, and S. The note indicates that 'ND' represents elements not detected.
Table C-1: Summary of the outer aluminum conductor and inner steel reinforcing wire strand diameter measurements for the failed section of conductor EL-2. Wire Wire Strand Diameter Ranges (mm) Strand Outer Aluminum Strands Inner Steel Stra...
AI summary Table C-1 presents the diameter measurements of the outer aluminum conductor and inner steel reinforcing wire strands for the failed section of conductor EL-2. The table includes measurements across multiple layers and notes that some strands were fused or distorted.
Annex D Dimensional Characterization of the Intact Service Exposed Section of ACSR Grackle (Zinc Coated) Conductor Table D-1 summarizes the outer aluminum conductor and inner steel reinforcing wire strand diameter measurements for the used...
AI summary Annex D provides dimensional measurements of the ACSR Grackle (Zinc Coated) conductor, including outer aluminum conductor and inner steel reinforcing wire strand diameters, as well as examples of zinc coating thickness on steel strands.
Table D-1: Summary of the outer aluminum conductor and inner steel reinforcing wire strand diameter measurements for the used intact service exposed conductor provided for uniaxial tension testing. Wire Wire Strand Diameter Ranges (mm) Str...
AI summary The text presents a table summarizing the diameter measurements of outer aluminum conductor and inner steel reinforcing wire strands for a used intact service exposed conductor tested under uniaxial tension. The data includes measurements across multiple strands and layers.
Figure D-1: SEM backscatter image of a representative example of a zinc coated steel reinforcing strand for the intact conductor. The image shows the significant variation in the thickness of the zinc coating observed around the circumfere...
AI summary The text presents three SEM backscatter images depicting zinc-coated steel reinforcing strands, highlighting the variation in zinc coating thickness around the circumference of the strands. These images are used to illustrate the condition of the conductor material.
Appendix A - Interconnection Facilities, Network Upgrades, and Distribution Upgrades Appendix B – Milestones Appendix C – Interconnection Details Appendix D – Security Arrangements Details Appendix E – Commercial Operation Date Appendix F...
AI summary The document outlines various appendices related to interconnection facilities, network upgrades, distribution upgrades, milestones, security arrangements, commercial operation dates, notice addresses, interconnection requirements for wind generating plants, and operating assumptions for generating facilities.
Interconnection Facilities, Network Upgrades and Distribution Upgrades Interconnection Facilities: 1. [insert Interconnection Customer'sInterconnection Facilities]: (a) (b) [insert Transmission Provider'sInterconnection Facilities]: 2. Net...
AI summary The text outlines sections related to interconnection facilities, network upgrades, and distribution upgrades, with placeholders for specific details. It references Appendix B to the Large Generator Interconnection Agreement (LGIA).
Item Component Item Component 1 Oil Duct 8 Anti-corrosion PE jacket 2 Conductor, self supporting 9 Antiteredo protection, Cu segmental strips of copper tapes 3 Conductor screen 10 Bedding 4 Insulation, paper tapes impreg nated with low vis...
AI summary The text provides a detailed description of a hollow conductor with slot-and-key shaped wires, including its components such as oil ducts, conductors, insulation, lead sheaths, and reinforcement materials. It also references a figure from Prysmian, Italy, illustrating the conductor's structure.
2.1.6 Conductor Resistance The electric resistance is the most important property of the cable conductor. The specific resistivity of the conductor material is temperature dependent: $$R_{\theta} = R_{20} \cdot (1 + \alpha(\theta - 20))$$...
AI summary The text discusses the factors influencing conductor resistance in cables, emphasizing the temperature dependence of resistivity, material purity, conductor design, and manufacturing processes. It highlights how specific resistivity and thermal coefficients vary for copper and aluminum, and how manufacturing processes like cold working affect resistance.
Operating temperature Short-circuit temperature LDPE XLPE 70◦C 90◦C 125◦C 250◦C EPR Mass-paper Oil-paper 90◦C 50–55◦C 85–90◦C 250◦C Table 2.2 Operational temperature of cable insulation materials
AI summary Table 2.2 outlines the operating and short-circuit temperatures for various cable insulation materials, including LDPE, XLPE, EPR, mass-paper, and oil-paper. The data provides key temperature thresholds for each material.
2.3.1 Lead Sheath Wheatstone and Cooke suggested lead sheaths for telegraph cables already in 1845. Lead extrusion was known since 1797, but it took the relentless efforts of some known and countless unknown cable engineers to arrive at th...
AI summary The text discusses the historical development and technical aspects of lead sheaths used in submarine cables. It highlights the evolution from early manufacturing methods to modern extrusion techniques, the importance of lead alloys for durability, and the challenges posed by mechanical and environmental stress on lead sheaths.
Table 2.3 Lead alloys and their constituents suitable for submarine cables. The table shows the designation according to EN 50307, and the conventional names for the nearest related alloy Alloy designation acc. to Alloy elements and percen...
AI summary The text discusses lead alloys suitable for submarine cables, referencing EN 50307 standards and their constituents. It also mentions a 1967 200 kV d.c. cable and a 138 kV gas-filled cable, highlighting the thermal expansion properties of cables.
Table 2.4 Properties of some armoring concepts Long lay-length (pitch) Short lay-length (pitch) Tensional stability ++ 0 Bending stiffness – + Torsional stiffness + 0 Possibility to coil the cable ++ + Properties of armoring of single-core...
AI summary Table 2.4 outlines the properties of different armoring concepts for cables, comparing long and short lay-length (pitch) configurations, including tensional stability, bending stiffness, torsional stiffness, and the possibility to coil the cable.
2.4 Armoring 35 The armoring lay-length must be optimized with respect to the expected tensional forces, the tension stability of the conductor and the torsional requirements of the cable and its installation. A cable with a unidirectional...
AI summary The text discusses the importance of optimizing armoring lay-length in cables based on tensional forces, torsional requirements, and installation conditions. It explains the benefits of double-layer armoring (DWA), counter-helical armoring for torque balance, and 'rock armor' for crush resistance. The text also notes the need for turntables in counter-helical cables and mentions a figure from ABB.
e cable with double-layer round wire rock armoring (Courtesy of ABB, Sweden) Phosphor bronze laying, high tensional forces in connection with unidirectional lay create considerable torsional forces. Flat armoring wires rather than round wi...
AI summary The text discusses various types of cable armoring, including double-layer round wire rock armoring, flat armoring, and open armoring. It highlights the advantages and disadvantages of each type, such as material savings, mechanical protection, and eddy current losses in AC cables. Mild steel armoring is noted for causing magnetic field concentration and heat losses in AC submarine cables, with some strategies to mitigate these issues.
heat in a.c. submarine cables. In single-core a.c. submarine cables, the losses in the steel armoring can reduce the ampacity substantially. Some strategies have been developed to reduce these losses: 1. Armoring made from non-magnetic mat...
AI summary The text discusses the issue of heat loss in single-core alternating current (a.c.) submarine cables due to steel armoring and explores strategies to reduce these losses, including the use of non-magnetic materials like bronze, brass, copper, and aluminum, as well as stainless steel for superior but more expensive solutions.
Table 3.1 Resistance values for copper and aluminium conductors according to IEC 60228, class 2 Copper Aluminium Specific electric resistivity@20◦C, mm2/m 0.01786 0.02874 Thermal coefficient of the specific electric resistivity @20◦C, 1/K...
AI summary Table 3.1 provides resistance values for copper and aluminium conductors according to IEC 60228, class 2, including specific electric resistivity, thermal coefficient of resistivity, and conductor resistance for various conductor sizes.
Table 3.2 Thermal resistivity of cable design materials according to IEC 60287 Insulation Specific thermal resistivity K·m/W Paper insulation, oil-filled cables 5.0 Paper insulation, mass impregnated 6.0 (according to IEC 60287) PPL 5.5 Po...
AI summary Table 3.2 provides the thermal resistivity values for various cable insulation and outer serving materials according to IEC 60287. The table includes values for materials like paper insulation, polyethylene, PVC, and others, with some values estimated.
3.1.3.4 Thermal Resistivity of the Seafloor For good reasons, one of the prime objectives of any cable design is to avoid hotspots as they can jeopardize the availability of the link. It is therefore extremely 70 3 Design important to have...
AI summary The thermal resistivity of the seafloor is crucial for cable design to prevent hotspots and ensure reliability. Factors such as soil composition, humidity, and compaction influence thermal resistivity, with values ranging from 0.5 to 1.03 K·m/W. In-situ measurements are essential due to the variability of soil conditions along the cable route.
78 3 Design Table 3.8 Estimated utilization of submarine power cable links Type of submarine link Link utilization Supply of islands with residential demand According to island demand, 4380/8760 h Supply of G&O platforms 90% 7884/8760 h OW...
AI summary The document discusses the estimated utilization of submarine power cable links for various purposes, such as supplying islands and offshore platforms, and explores how using larger conductors can reduce cable heat losses and burial costs to meet the 2 K criteria.
Table 3.9 Comparison of tensional test values of Electra 171 and estimated maximum tensional forces in heavy weather Mass of the cable 29 kg/m Weight in water 209 N/m Laying depth 250 m Force attributed to bottom tension ( H in Eq. 3.35) 1...
AI summary Table 3.9 compares tensional test values of Electra 171 and estimated maximum tensional forces in heavy weather. It includes parameters like cable mass, laying depth, static and dynamic forces, and total tensional force. Section 3.2.3 discusses the distribution of mechanical stress between conductor and armoring.
In the following, the response of a single-core DWA submarine cable with steel armoring and copper conductor is discussed. The equations can easily be adapted to other armoring and/or conductor materials. When a tension is applied on the c...
AI summary This text discusses the mechanical behavior of a single-core DWA submarine cable under tension, presenting equations to calculate the elongation, tension distribution between the steel armor and copper conductor, and the stress in the conductor. It also explains how the total armoring tension is divided between inner and outer layers based on their cross-sectional areas.
cross section of the inner layer (mm2) AAO Total cross section of the outer layer (mm2). Now the tension in the inner and the outer armoring layer can be calculated from Eqs. 3.43, 3.44, and 3.45: $$F_{AO} = F \cdot \frac{A_{AO}}{A_{AO} +...
AI summary The text provides equations for calculating tension and mechanical stress in the inner and outer armoring layers of a cable, referencing lay angles and material properties. It discusses the practical considerations of using thicker wires in submarine cable projects to meet tensional bending tests.
3.2 Design of Mechanical Properties 85 Table 3.10 Guide values for mechanical properties of copper and steel. Steel grade values from European Standard EN 10257-2:1998 Breaking stress (N/mm2) Yield point (N/mm2) 120 70–80 min 210 1250 1450...
AI summary The text discusses the mechanical properties of copper and steel, referencing European Standard EN 10257-2:1998, and mentions the use of stronger armoring in certain projects for additional lateral protection.
Table 3.11 Armoring wire overlength as a function of the lay-length Lay-length as multiple of the diameter of the armoring layer Ratio of armoring wire length to cable length 10 1.048 15 1.022 17.5 1.017 20 1.012 25 1.008 3.2.4 Other Force...
AI summary Table 3.11 presents the relationship between lay-length and the ratio of armoring wire length to cable length, illustrating how the overlength of armoring wire changes with different lay-length multiples of the armoring layer diameter.
The armoring must withstand all forces that can be reasonably expected during installation and operation. The tensional forces that occur during installation can be predicted with a certain degree of accuracy. Other forces and impacts duri...
AI summary The text discusses the design considerations for cable armoring, emphasizing the need to withstand various forces during installation and operation. It mentions challenges such as overbending, impacts from edges or rocks, squeezing, and impacts from anchors and fishing tackle. It also outlines general rules of thumb for effective armoring design.
vide a better protection - double wire armoring is tougher than single wire armoring - a short-lay rock armoring provides a better protection against lateral impacts at the expense of tensional force. The optimum armoring wire thickness is...
AI summary The text discusses the effectiveness of different types of wire armoring for cables, noting that double wire armoring is tougher than single wire armoring, and that short-lay rock armoring offers better lateral impact protection but reduces tensional force. Wire thickness is influenced by external threats, manufacturer limitations, and impacts on cable weight, diameter, and laying schedules.
The American standard ICEA No. S-57-401/NEMA Standards Publication No. WC2 determines the required wire thickness for paper-insulated submarine cables Calculated diameter of cable under the armoring bedding mm Size of ar galvanize BWG mori...
AI summary The text outlines the American standard ICEA No. S-57-401/NEMA Standards Publication No. WC2, which specifies the required wire thickness for paper-insulated submarine cables. A table is provided showing the calculated diameter of the cable under the armoring bedding and the corresponding sizes of galvanized wires.
according to Table 3.12. However, the standard does not tell if this is valid for single or double-layer armoring, or both. The side-wall pressure impact (SWP) value is often required to know for the planning of the installation. Literally...
AI summary The text discusses the side-wall pressure impact (SWP) value for submarine power cables, its calculation, and the lack of literature values for maximum permissible SWP. It also notes that SWP is a force per unit length, not a pressure, and highlights the absence of standardized values for this parameter.
Link Armoring Insulation Test tension kN SWP kN/m References Morocco – Spain Italy – Greece Gulf of Aqaba Troll A DWA copper DWA steel DWA DWA LPOF MI LPOF Dc XLPE 353 471 500 375 70.6 94.2 100 75 [16] [16] [17] Table 3.13 SWP in some cabl...
AI summary The table lists various cable projects with their respective armoring, insulation types, test tension, SWP, and references. It includes projects such as Morocco – Spain, Italy – Greece, Gulf of Aqaba, and Troll A, with details on materials and specifications.
3.2 Design of Mechanical Properties 89 Cable span data Large cable Small cable Cable mass per meter, kg/m 40 20 Length of free span, m 20 40 Tension in the span, kN 10 2 Cable diameter, mm 110 80 Frequency of the basic natural frequency, H...
AI summary This section discusses the design of mechanical properties, focusing on cable span data, including parameters such as cable mass, length of free span, tension, diameter, natural frequency, and minimum flow velocity for the establishment of VIV (vortex-induced vibrations).
with n the mode number, Ta the tension of the cable, m the mass per length unit of the cable, and L the length of the free span [20]. The cable in free span is excited by the force from the leaving Karmán vortices with an oscillating frequ...
AI summary The text discusses the conditions under which cables in free span may experience vortex-induced vibrations (VIV) due to Karmán vortices, particularly when the exciting frequency matches natural frequencies. It introduces a formula for calculating the minimum flow velocity for lock-in and mentions the impact of marine growth on cable diameter and the effect of added-mass coefficients on natural frequencies.
Rated voltage (kV) Conductor size, (mm2) Nominal internal ac stress limit (KV/mm) Corresponding generic insulation thickness (mm) 69 wet 240–2000 4 16.5 69 dry 240–2000 6 12.0 115 400–2000 8 15.0 138 400–2000 8 18.0 161 400–2000 9 20.0 230...
AI summary The table provides stress limits and insulation thickness for extruded cables at various voltage levels, as referenced in [28]. It lists details such as rated voltage, conductor size, nominal internal AC stress limit, and corresponding insulation thickness for different cable configurations.
3.3.6 Impulse Stress For all cable types, there are test standards to demonstrate the impulse withstand level. Often, a Switching Impulse Withstand Level (SIWL) and a Lightning Impulse Withstand Level (LIWL) are defined. Table 3.17 lists t...
AI summary The section discusses impulse stress testing for power cables, including Switching Impulse Withstand Level (SIWL) and Lightning Impulse Withstand Level (LIWL). It notes that cable design impulse stress depends on factors like material purity and manufacturing quality, and highlights differences in test standards between IEC and Electra 189 for HVDC cables.
4.1.3 Miscellaneous Joint Designs Fluid-filled submarine power cables require joints with a continuous fluid duct in the hollow conductor. A tubular sleeve is often included into the duct to provide support before welding. The cable cores...
AI summary This section discusses various joint designs for submarine power cables, including fluid-filled joints, stop joints, and transition joints for connecting different cable types. It highlights the use of specialized joints to manage fluid flow, accommodate conductor size differences, and transition between different insulation and conductor materials in HVDC cable systems.
114 4 Accessories Flexible joint Rigid joints, tape insulated Rigid joints, pre-fab 1C mass-impregnated Yes, all voltages Yes, but no advantages No 1C paper-insulated Possible Possible No 1C extruded cables Up to 145 kV. In few cases 245 k...
AI summary The table outlines the application and properties of various joint concepts for different types of cables, including flexible and rigid joints, and their suitability for different cable types and voltages.
5.1.7 Storage of Submarine Cables It can be worthwhile to make some comments on the storage of submarine cables because it may involve the storage of a single product of 7000 tons in weight, without having the means of lifting the entire t...
AI summary The text discusses the challenges and methods involved in the storage of submarine cables, emphasizing the need for proper handling due to their significant weight and the potential for damage from improper coiling. It outlines storage methods, coiling requirements, and the importance of proper armoring direction to avoid kinks and loops.
Cables on coiling pads, outdoor turntables, trailers or cable laying vessels are frequently showered by rain, seawater spray, overflows and similar. In these situations Armoring lay orientation Coiling Single core cables with unidirectiona...
AI summary The text discusses the challenges faced by cables on coiling pads, outdoor turntables, trailers, and cable laying vessels due to exposure to rain, seawater spray, overflows, and similar environmental factors. It provides a table detailing the coiling direction for different types of cables based on their armoring lay orientation.
5.2.2 Type Tests Once a cable type has been developed or adopted to new applications, it will be subjected to a type test. As many large submarine cable projects require a tailored unique design, many purchase contracts also require the pe...
AI summary Type tests are conducted to qualify cable designs for specific applications, particularly for submarine power cables. These tests are often based on standards for underground cables due to the lack of specific submarine cable standards. The tests include material, electrical, and sometimes mechanical evaluations, and they add to project costs and timelines.
5.2 Testing 139 Table 5.3 Electric type tests for five generic cable types Cable type No 1 2 3 4 5 Rated voltage U0 33 kV a.c. 150 kV a.c. 420 kV a.c. 150 kV d.c. 450 kV d.c. Insulation XLPE XLPE Paper/oil Polymer Mass impregnated Mechanic...
AI summary This section outlines electric type tests for five generic cable types, specifying the rated voltages, insulation materials, and test sequences according to various international standards and technical brochures.
5.2.3.1 High-Voltage Routine Tests Manufacturing lengths are often given a high-voltage routine test either by standard requirement, by agreement, or as an internal test of the manufacturer (Table 5.5). The obvious reason is to exclude fau...
AI summary High-voltage routine tests are conducted on manufacturing lengths of cables to ensure quality and exclude faulty cores from further production, either by standard requirement, agreement, or as an internal manufacturer test.
Table 5.6 Test voltages for routine tests and after-installation tests Cable type No 1 2 3 4 5 Rated voltage U0 Insulation 33 kV a.c. XLPE 150 kV a.c. XLPE 420 kV a.c. Paper/oil 150 kV d.c. Polymer 450 kV d.c. Mass impregnated Applicable s...
AI summary Table 5.6 outlines test voltages for routine and after-installation tests for various cable types, including XLPE, paper/oil, and mass-impregnated cables, with specific values and applicable standards such as IEC 60840 and Cigré TB 219.
tribution from the ship size distribution in the cable route. Figure 8.4 shows the expected accumulated anchor size distribution, calculated for the Kadetrenden strait between Denmark and Germany [7]: It appears that about 98% of anchors a...
AI summary The text discusses the relationship between anchor size and the potential damage to submarine cables. It notes that 98% of anchors are 8000 kg or less, with over 60% below 4000 kg. Heavier anchors are more damaging due to greater mass, deeper penetration, and the force exerted by larger vessels. The text also mentions differences in anchor penetration based on seabed material.
Table 8.1 Relationship between ship size, anchor weight and penetration depth according to [9] Ship weight Anchor weight Penetration depth Penetration depth (tons) (tons) in mud in sand 1000 1.0 ~ 1.0 m ~ 0.5 m 5000 2.8 ~ 2.0 m ~ 1.0 m 15,...
AI summary Table 8.1 and Table 8.2 provide data on the relationship between ship size, anchor weight, and penetration depth in different ground types. The tables show how anchor penetration depth varies with ship weight and anchor type, and note that the data may underestimate actual anchor weights, as seen with the 'Queen Elizabeth II'.
Internal origin failures External origin failures All failures a.c. HPOF cables 0 0.7954 0.7954 a,c, LPOF cables 0 0.1189 0.1189 a.c XLPE cables 0 0.0706 0.0706 d.c. MI cables 0 0.1114 0.1114 d.c. LPOF cables 0.0346 0 0.0346 Table 9.1 Fail...
AI summary Table 9.1 presents failure rates for submarine power cables over 60 kV, distinguishing between internal and external origin failures. The data shows that most failures are attributed to external factors, with a.c. HPOF cables having the highest external failure rate.
Voltage (kV) 132 220 400 275 400 cable type 3-core 3-core 3-core SC SC No of cables for 1000 MW transmission 6 4 2 7 (1 spare) 4 (1 spare) Failures/year and cable 0.25 0.46 0.67 0.15 0.22 Table 9.3 Failure rates for different cable schemes...
AI summary Table 9.3 presents failure rates for different cable schemes used to connect a large offshore wind park (OWP) at various voltage levels. The table compares the number of cables required and their corresponding failure rates per year.
Table 9.4 Failure rates for different cable schemes to connect a large OWP Year Scheduled unavailability (%) Forced unavailability (%) Availability (%) 1995 3.14 0.82 96.04 1996 6.00 1.24 92.76 1997 1.49 1.40 97.11 1998 1.50 2.29 96.21 199...
AI summary Table 9.4 presents the failure rates for different cable schemes connecting a large offshore wind park (OWP) from 1995 to 2007, showing scheduled and forced unavailability percentages, as well as overall availability. The data highlights variability in performance across years, with notable drops in availability in 2000 and 2002 due to factors like cable repair delays.
1. Deschamps L et al. (1980). Development in France of High Voltage Cables with Synthetic Insulation, Paper Cigré 21–06. A Assembly time, 112 Emergency cutter, 170 Fluid-filled cable, 113, 125 Ems River, 6 Force EN 50307, 31, 129 dynamic,...
AI summary The document discusses the development of high-voltage cables with synthetic insulation in France, referencing technical details such as assembly times, cable types, environmental considerations, and various engineering terms related to cable design and performance.