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?PUBLIC UTILITIES COMMISSION OF THE STATE OF CALIFORNIARail Safety DivisionRail Transit Safety BranchResolution ST-242December 17, 2020RESOLUTIONRESOLUTION ST-242 GRANTING THE LOS ANGELES COUNTY METROPOLITAN TRANSPORTATION AUTHORITY A VARIANCE FROM GENERAL ORDER 95 FOR THE MINIMUM OVERHEAD WIRE HEIGHT IN UNDERGROUND SEGMENTS OF THE CRENSHAW/LAX TRANSIT CORRIDOR PROJECTSummaryThis resolution approves the Los Angeles County Metropolitan Transportation Authority’s request for a variance from General Order 95 to allow a reduced minimum clearance from the 14-foot requirement to 13-feet-8-inches between the running rails and Overhead Conductor Rail in the underground segments of the Crenshaw/LAX Transit Corridor Project.BackgroundThe Los Angeles County Metropolitan Transportation Authority (LACMTA or Metro) rail operations consist of the Metro Rail A, B, C, D, E, and J Lines. LACMTA rail system carries approximately 344,000 passengers per weekday, with annual ridership of approximately 108 million in 2018.The Crenshaw/LAX Transit Corridor Project is a new light rail alignment that will service four cities (Los Angeles, Inglewood, Hawthorne, and El Segundo), as well as unincorporated areas in the Los Angeles County. The project consists of eight new stations over its 8.5-mile length. The project will provide a link from E Line (formerly Exposition Line) Exposition/Crenshaw Station to C Line (formerly Green Line) LAX/Aviation Boulevard Station. An additional at-grade station is included in the project at 96th Street and Aviation, known as the Airport Metro Connector (AMC). The AMC will connect to the Los Angeles International Airport (LAX) future automated people mover (APM) system currently under construction. The AMC Station that connects the Crenshaw Line with the LAX APM will be constructed after the Crenshaw line has initiated revenue service.The Crenshaw/LAX Transit Corridor Project alignment is comprised of a double track right-of-way consisting of a mix of sections that will run at-grade in-street, at-grade within exclusive railroad right-of-way, on aerial structures, and below grade. The three underground segments, Underground Guideway #1 (UG1), Underground Guideway #3 (UG3), and Underground Guideway #4 (UG4), are grade-separated and thus in an “Exclusive” alignment classification as described in General Order (GO) 143-B, Section 9.04(a).GO 95, Rule 37, Table 1 establishes the basic minimum allowable vertical clearance of wires above railroads. Rule 74.4E allows a reduction of the contact wire height to a minimum of 14 feet above railroads for subways, tunnels or bridges, and for 0-750 volt conductors within exclusive and semi-exclusive rights-of-way as defined by Alignment Classification in GO 143-A Section 9.04. GO 95 Figure 74-1 illustrates Rule 74.4E.By letter dated July 9, 2020, LACMTA requested to deviate from the 14-feet minimum clearance requirements of GO 95, Rule 74.4E, Figure 74-1, and Rule 77.4B to allow a minimum clearance of 13-feet-8-inches between the running rails and Overhead Conductor Rail (OCR) in a portion of UG1, a portion of UG3, and the cut and cover portion of UG4 and Leimert Park Station.The approximate percentages of UG1 northbound and southbound track with OCR clearances under 14 feet are 80% (2,125 ft) and 83% (2,224 ft), respectively. The approximate percentages of UG3 northbound and southbound track with OCR clearances under 14 feet are both 74% (3,126 ft). The approximate percentages of UG4 northbound and southbound track with OCR clearances under 14 feet are 19% (1,571 ft) and 12% (979 ft), respectively.LACMTA’s request letter specified that the OCR system consists of a continuous aluminum rail bracket, supported by insulated brackets affixed to the tunnel soffit or walls, that clamps copper contact wire under zero tension. The OCR remains electrically isolated from the ceiling supports by insulators (“cones”) and an insulated support rod. The Overhead Contact System (OCS) approach spans are graded to accommodate the profile changes in the non-compliant OCR segments.LACMTA’s design-build contractor, Walsh Shea Corridor Constructors (WSCC), originally designed the height of OCR from Top of Rail (TOR) to comply with the required 14-feet minimum clearance. Due to a miscalculation of grade elevations and the absence of construction tolerances in the design of the cut-and-cover structures, the design clearance from TOR to concrete ceiling was not maintained after the direct fixation track was installed. In effect, there was not enough clearance for the 14-feet minimum height from TOR to OCR, 9-inch conductor rail assembly height, and 3-inch electrical clearance from the conductor rail to the surface of the supporting structure. The 3-inch clearance is required by American Railway Engineering and Maintenance-of-Way Association (AREMA) Chapter 33 Part 2 Table 33-2-2, Metro Rail Design Criteria (MRDC) Section 9.18.8.D.9.d, and CPUC GO 95, Rule 37, Table 1, Case 9.LACMTA considered several alternatives to maintain the 14-feet clearance but concluded that none were feasible or practicable. LACMTA Safety, Operations, Maintenance, and Engineering staff performed safety evaluations of the reduced height of the OCR system, and determined that it would not negatively impact the safety of the public, passengers, or employees, since the OCR would remain out of reach to present a hazard to someone at track level. LACMTA also could not identify any safety impacts on maintenance of the OCR system or vehicle pantographs.To further justify their request for deviation, LACMTA noted that CPUC inspected and approved a similar OCR system for the 2019 New Blue Improvement Project. The New Blue project involved improvements to the Blue Line, LACMTA’s oldest rail line, including replacing the OCS with OCR in the existing 7th/Metro tunnel. In a “New Blue OCR Safety Certification Review Team (SCRT) Meeting,” RTSB staff learned that due to the space limitations inside the tunnel, the OCR height had to be lower than the required 14 feet, with the minimum at 13-feet-8-inches. LACMTA asserted that they complied with the GO 95 requirements that were applicable for construction of the Blue Line, which began revenue service on July 14, 1990. RTSB staff determined that in 1990, the last modification to GO 95, Rule 74.4E was Decision No. 89022, which became effective on June 27, 1978. Subsequently, Rule 74.4E was modified to read as follows:A reduction of the clearances given in Table 1 to a minimum of 14 feet for trolley contact conductors is permitted for subways, tunnels or bridges, provided the railway does not operate freight cars where the vertical distance from the top of car or load to trolley contact conductor is less than 6 feet, except that for light rail transit systems, the minimum height shall be that set forth in General Order No. 143, “Rules for the Design, Construction and Operation of Light Rail Transit Systems Including Streetcar Operations”…In turn, GO 143 states:Overhead clearance shall conform to General Order 95 except that on Alignment Classifications 4.1 and 4.2.1, between crossings, and used exclusively for transit purposes the minimum contact wire clearance shall be 9 inches above the height of the LRV pantograph in the retracted position…LACMTA demonstrated that they complied with the aforementioned requirements by informing staff by email on August 5, 2019 that the OCR clearance exceeded the 13-feet-3-inch minimum requirement necessitated by the most restrictive seated pantograph height of 12-feet-6-inches. Affected LACMTA departments reviewed the OCR height condition and stated no objections, and the LACMTA Subject Matter Expert stated it was acceptable. RTSB staff witnessed the Live Wire Systems Integration Test in the 7th/Metro tunnel on July 20, 2019, whose objective was to verify proper electrical interface between the pantograph and OCR in the tunnel, including the crossover, and on approach to the tunnel. There was minor arcing observed at speeds between 25-45 MPH and at 15 MPH in the crossover, which the contractor subsequently addressed before revenue service began.Given the evidence of compliance, safety, and functionality, RTSB staff determined that the OCR system at a reduced height was acceptable. By letter dated August 22, 2019, CPUC approved the New Blue Improvement Project OCR Safety Certification Verification Report (SCVR) to allow revenue operations between 7th/Metro Station and Washington/Flower Junction with the introduction of the OCR on August 24, 2019.DiscussionThe OCR field measurement heights, the alternatives considered to maintain the 14-feet minimum height, the New Blue Improvement Project OCR Safety and Security Verification Report, and other supporting documents were reviewed by RTSB staff. For clarification and discussion purposes, RTSB staff held online meetings with staff from LACMTA, WSCC, and project subcontractors on September 14, 2020 and September 29, 2020.CPUC approval of the New Blue project is not relevant to Crenshaw/LAX. The underground portions of the Crenshaw/LAX Line are subject to amended versions of the General Orders that applied to the tunnel portion of the Blue Line, which opened in 1990. Staff approved the reduced OCR heights of the New Blue project considering that the reduced heights remained compliant with the clearance requirements that originally applied to the tunnel.Based on other supporting evidence, LACMTA has indicated that the reduced OCR clearances in Crenshaw/LAX will not negatively impact the safety of the public, passengers, or employees. Staff concurs with LACMTA’s assessment and recommends that the LACMTA request be granted based on the following:Five alternatives considered to maintain the required 14-feet clearance are either not effective, introduce more hazards, or are not able to be implemented. The options were to reconstruct the rail plinths (supports for direct fixation track) to a lower elevation, grind the concrete ceiling, install dielectric material above OCR supports to mitigate electrical clearance, procure a shallower OCR, and procure an insulating shroud to place over the OCR assembly. Reconstructing the rail plinths to a lower elevation may have achieved a 14-feet minimum height for some locations, and for other locations it would have extended the clearance 2 inches closer to the 14-feet minimum, but it would still be noncompliant. LACMTA explained that this option would create variable OCR heights, which would result in fluctuating pantograph motion, creating differential wear along the contact wire. If the wear is severe enough, the pantograph can lose contact with the wire, leading to electrical arcing, which further wears the wire. Additional maintenance would be required to address frequently worn wire, which would result in increased cost and possible disruptions to service. LACMTA rejected this option and maintained OCR profiles with the most consistent contact wire heights to reduce negative impacts to maintenance, operations, and ridership.Electrical hazard will be mitigated because the OCR will be electrically isolated from the ceiling supports via insulators and an insulated support rod. LACMTA confirmed to RTSB staff by email on August 5, 2020 that the double insulation is required by MRDC. Furthermore, power conductors secured to insulating supports are required by Section 6.4.3.2 of NFPA 130 2010 edition, which the Crenshaw/LAX project is required to follow, to provide isolation from the overhead contact system.As required by MRDC, AREMA, and CPUC GO 95, the 3-inch electrical clearance from the OCR to the surface of the supporting structure will be preserved, which will reduce the potential for undesired grounding of the energized rail.The Overhead Contact System (OCS) spans leading and trailing UG1, UG3, and UG4 are modified by properly grading down from the prescribed and compliant construction to accommodate the profile changes in the OCR non-compliant segments. LACMTA explained that the OCS grading complies with AREMA Table 4-1 “Maximum Wire Gradient versus Line Speed.” Since OCR is more widely used in Europe than in the United States, LACMTA designed OCR grading to comply with EN (European Standard) 50119 Table 11 “Contact wire gradients.” Both tables assign grading based on operating speed. At the meeting on September 29, 2020, LACMTA demonstrated to RTSB staff with OCS/OCR profile drawings that the OCS gradients leading and trailing the OCR comply with the AREMA table. LACMTA sent OCS/OCR documentation to RTSB staff for review. RTSB staff verified that LACMTA’s constructed design complies with the AREMA and EN tables, and therefore meets the requirements of GO 95 Rule 74.4E and Figure 74-1 for gradual grading of the contact conductor from the prescribed construction down to the reduced elevation.LACMTA evaluated the safety of the reduced OCR height from various perspectives (LACMTA Safety, Operations, Maintenance, and Engineering staff), all of which agreed that the lowered OCR system height is safe and acceptable for operations. Additionally, as exclusive alignment under General Order 143-Section 9.04, access to the underground tunnels is controlled and public access is prevented and monitored by intrusion detection systems connected to the LACMTA Rail Operations Center. Therefore, Staff finds there is minimal risk to the public by the 4-inch reduction in OCR height.The LACMTA request and this Resolution were sent to the Commission’s Electric Safety and Reliability Branch for review and concurrence. No concerns or objections were identified.NoticeOn November 13, 2020, this Resolution was published on the Commission’s Daily Calendar.////CommentsThe draft resolution of the Rail Safety Division in this matter was mailed in accordance with Section 311 of the Public Utilities Code and Rule 14.2(d)(1) of the Commission’s Rules of Practice and Procedure.No comments were received.FindingsBy a letter dated July 9, 2020, LACMTA requested to deviate from the 14-feet minimum clearance requirements of General Order 95, Rule 74.4E, Figure 74-1, and Rule 77.4B to allow a minimum clearance of 13-feet-8-inches between the running rails and Overhead Conductor Rail in a portion of UG1, a portion of UG3, and the cut and cover portion of UG4 and Leimert Park Station.The approximate percentages of UG1 northbound and southbound track with OCR clearances under 14 feet are 80% (2,125 ft) and 83% (2,224 ft), respectively. The approximate percentages of UG3 northbound and southbound track with OCR clearances under 14 feet are both 74% (3,126 ft). The approximate percentages of UG4 northbound and southbound track with OCR clearances under 14 feet are 19% (1,571 ft) and 12% (979 ft), respectively.The alternatives to maintain the required 14-feet clearance are either not effective, introduce more hazards, or are not able to be implemented.The location of the areas affected by this variance are within an exclusive alignment area, as defined by General Order 143-B, which are not accessible to the public.The OCR will be insulated from ceiling supports per MRDC and NFPA 130 2010 edition.The OCR will have 3 inches of electrical clearance from the surface of the supporting structure per AREMA, MRDC, and CPUC GO 95.There is proper grading of the OCS leading and trailing the OCR per AREMA, EN 50119, and CPUC GO 95.LACMTA Safety, Operations, Maintenance, and Engineering staff agreed that the lowered system height is safe, does not introduce a hazard, and is acceptable for operations.RTSB staff and LACMTA agree that the proposed minimum OCR height of 13-feet-8-inches will not adversely affect employee, public, or passenger safety.This Resolution was sent to the Electric Safety and Reliability Branch for review and concurrence. No concerns or objections were identified.//////Therefore, it is Ordered That:The Los Angeles County Metropolitan Transportation Authority is granted authority to deviate from the requirements of General Order 95 Rule 74.4E, Figure 74-1, and Rule 77.4B, and have a minimum Overhead Contact Rail height of 13-feet-8-inches instead of the required 14-feet height for the underground segments of the Crenshaw/LAX Transit Corridor Project as described in this Resolution.This resolution is effective today.I certify that the foregoing resolution was duly introduced, passed, and adopted by the Commission at its regularly scheduled meeting held on December 17, 2020. The following Commissioners voting favorably thereon: /s/ Rachel Peterson Rachel PetersonActing Executive DirectorMarybel BatjerPresidentMartha Guzman AcevesClifford RechtschaffenLiane M. RandolphGenevieve ShiromaCommissioners ................
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