2018 Colorado City Major Storm Event - ONCOR ELECTRIC RESTORATION EFFORT

2018 Colorado City Major Storm Event
  ONCOR ELECTRIC RESTORATION EFFORT

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INTRODUCTION
• Brandon Campbell
  – Senior Engineer (Oncor)
• Jerry Murphree
  – M&C Supervisor (Oncor)
• Josh Holder
  – Project Manager (Primoris)

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MAJOR STORM EVENT
• Snyder, Loraine, & Colorado City                          TX-84
• Began @ 11pm on June 7th, 2018                 SNYDER

• 85-120mph wind speeds recorded
                                                                    I-20
   – Straight-line; no tornadoes reported
                                                              LORAINE
• 10” of rain causing flash flooding        COLORADO CITY

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MAJOR STORM EVENT

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MAJOR STORM EVENT

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OVERALL IMPACT
• 6x Oncor T-lines tripped to lock out w/in 47
  min
• 170x str.’s damaged
• Miles of downed wire
  – CR’s, I-20, & UPRR
• Major D-line impact

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RESPONSE
•   FCC’s from other regions rendered aid
•   160 const. contract personnel mobilized
•   Numerous internal groups utilized
•   Temporary kitting yard/emergency office est.
    in Colorado City, Texas

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• The 4-69 kV line designs, were all similar, single pole and a total of 50 structures
  were replaced. Also all were located beside a paved roadway.
• No conductor was damaged during this event

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9-138 kV structures had to be replaced with 65’ wood poles and 30’ steel cross arm
These structures were located in an open field and very wet conditions

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TONKAWA – MORGAN CREEK
           • 21.3 miles of 345 kV line
           • (2) 795.9 ACSR & 2x 3/8”
             EHS Shield wire
           • H-frame lattice towers
             – height range = 72’ - 87’
           • Constructed in 1982
           • Kickers (16)/storm guys
             (2) installed in 2005
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TONKAWA – MORGAN CREEK
                   WITH KICKERS

        ORIGINAL

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TONKAWA – MORGAN CREEK
• 17.3 miles initially effected

• 92x structures damaged
  – 87x failed; 5x long. deflection

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345 kV INVESTIGATION
• 138 kV line (S. of I-20)
  tripped approx. 30 sec.
  after 345 kV
• ≈ 500 ft/sec fall rate
• Mode = Leg buckling
• AHF3 (TESCO-1961)
   – NO longitudinal load
     requirements from
     NESC (5th Edition)

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RESTORATION
• 6919X-family lattice towers
   • Developed during CREZ
• 959.6 ACSS/TW/HS “Suwannee”
• 48-count OPGW & 7/16” EHS

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TONKAWA – MORGAN CREEK
       POWER SECURE

                 PRIMORIS

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RESTORATION EFFORT

Primoris T&D Services is one of 22 well-funded companies within Primoris Services
               Corporation, with approximately 1,800 employees.                     tsdos.org

PROJECT SEQUENCING - BEGAN WITH MOBILIZATION & WRECK OUT
  Mobilization: June 8th, 2018
  • Dispatching, crews were sent for initial assessment after
    notification of the event
  • Scope, Construction procedures were determined
  • Crew/equipment assignment
  • ROW installation
  Wreck out, Removals
  •   Road clearing to allow traffic to flow on roadways
  •   Disassembly, removal of retired structures
  •   Haul off, removing steel from ROW
  •   Disposal of retired steel
  •   Retired foundation removal

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Project Sequencing Continues

Foundations:
•   Engineering designs received
•   Vendors notified
•   Material ordered
•   Material Receiving
•   Rebar assembly
•   Drilling
•   Crews: set up, pouring, and wreck out
•   Production expectation

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Project Sequencing Continues
Steel
•   Engineering designs received
•   Material Receiving
•   Hauling
•   Assembly crew make up
•   Structure setting
•   Production rates

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Project Sequencing Completed – Project Success

Wire
• Engineering
• Material receiving
• Material Spotting
• Wire stringing efforts
• Fiber stringing efforts
• Production rates

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Project Sequencing Completed – Project Success

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OVERALL PROJECT SUCCESS!

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345 kV Hardening Initiative
• 230 miles of existing H-frames
• Complete by end of 2021
• Tier 1: Major Highway/RR
   – 2x deadends
• Tier 2: Minor Highways
   – 1x deadends
• Tier 3: 10-mi. sections
   – 1x deadends

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LESSONS LEARNED
•   Importance of communication
•   Cascading failure mechanisms
•   Material procurement details
•   Focused training necessary for
    better overall understanding

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LESSONS LEARNED
        • Residual tension retained
          in “failed” structure
        • Proximity of still-standing
          structures
        • Amount of recoil when cut
        • Location/direction to snub-
          off

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CONCLUSION & QUESTIONS

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