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Updating the AASHTO LRFD Movable Highway Bridge Design Specifications (2021)

Chapter: Appendix B Survey Response Data

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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
×
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
×
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
×
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
×
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
×
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
×
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
×
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
×
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
×
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
×
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
×
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
×
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Suggested Citation:"Appendix B Survey Response Data." National Academies of Sciences, Engineering, and Medicine. 2021. Updating the AASHTO LRFD Movable Highway Bridge Design Specifications. Washington, DC: The National Academies Press. doi: 10.17226/26395.
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92 A P P E N D I X B Survey Response Data MOVABLE BRIDGE OWNER INTERVIEWS Bridge Owner: Palm Beach County, FL Date: 8/21/18 Movable Bridge Importance and Availability Survey Questions 4. Can the waterways crossed by movable bridges be classified within the following categories? Check acceptable classifications. Are there other categories you recommend considering? ☒Port Entry ☐Commercial ☒Mixed Use ☐Recreational 5. The following factors are being considered as potential modifiers in establishing design wind pressure. Check acceptable factors. Do you have any other factors you believe should be considered? ☒Evacuation Route ☐Strategic or Military Route ☒Detour Length (miles) ☒Vehicle and/or Truck Usage • (ADT / ADTT) ☒Number of Bridge Openings • (number per year) ☐Combined Hwy/Rail Use • Others: Mixed Use covers all their movables. Others: One bridge has 22 mile detour.

93 6. Does your agency place movable bridges in lockdown or otherwise render them inoperable, under specific warnings of impending high winds (e.g., gale force winds, tropical storm warning, etc.)? If so, provide specifics of the conditions that initiate bridge closure including wind speed. Also include time of advance warning in the table below (“OD” for on demand). MOVABLE BRIDGE OPERATING RESTRICTION DATA BRIDGE(S) WATERWAY(S) OPERATING RESTRICTION(S) ALL GT 40 mph sustained wind or projected hurricane – no operation 6 of 8 (newer design) OK w/ operation up to 60 mph ALL Intermittent winds GT 40 mph (thunderstorm) – delayed opening Existing Movable Bridge Reliability Survey In responding to the questions below disregard equipment failures due to abnormal conditions such as vessel or vehicle impact, submergence or vandalism1. 8. How would you rate the reliability of movable bridge support machinery2 systems and components (trunnions, rolling lift track/tread, center bearings, etc.) on your movable bridges: ☒Excellent ☐Good ☐Satisfactory ☐Fair ☐Poor 9. How would you rate the reliability of movable bridge drive machinery systems and components on your movable bridges: ☒Excellent ☐Good ☐Satisfactory ☐Fair ☐Poor Notes on particular elements:  Components usually give a “warning” (noises, etc.) before failure.  Trunnion issue on one bridge – initial construction / alignment problem. Notes on particular elements:  Hydraulic – shorter life (20-25 yrs), but easier to replace components.  Hopkins frame type have been very reliable.

94 10. How would you rate the reliability of movable bridge locking (live load transfer) devices3 (center locks, tail locks, end/center wedges, etc.) machinery on your movable bridges: ☒Excellent ☐Good ☐Satisfactory ☐Fair ☐Poor 11. How would you rate the reliability of movable bridge electrical power and control systems on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor • • 12. How would you rate the reliability of movable bridge traffic control (gates, signals) systems on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor 13. Approximately how many movable bridges are included in the above assessment? 9 Notes on particular elements:  Span Locks (more problems in 1980’s): • Upgrade to “Cushion Locks” very reliable (all bascules upgraded) • Initial installation is critical Notes on particular elements:  Control System: 90% relay-based (more reliable than PLC and less susceptible to power fluctuation / spikes).  PLC good for monitoring and trouble-shooting.  3 span motors replaced in 20 yrs. (rebuild and reinstall in few days). Notes on particular elements: Traffic gates:  Simple design.  Typical problems are with limit switches and cams.  After vehicle impact, need to tweak for proper operation.

95 14. How would you rate the routine maintenance these bridges have received over their service life? ☒Excellent ☐Good ☐Satisfactory ☐Fair ☐Poor Supplemental Questions: 13. What is your inventory of bridges? Number, Types:  8 Bascule o 3 Rolling Lift o 5 Trunnion Bascule o 2 Single Leaf o 6 Double Leaf o 2 with Tail Locks  1 Swing o Hand-operated  6 Mechanical, 2 Hydraulic, 1 Hand-Operated 14. How frequent do your bridges open?  Up to 1,200 operations per month (for bridges with about 6 ft clear)  Manual swing ranges from 5 to 20 per month. 15. How often do you experience failures that prevent operation?  1 to 2 per month (total) for the eight bascules (not including bridge tender work- arounds / bypasses). 16. What causes more of your disruptions in operation, electrical or mechanical issues?  Almost always an electrical problem (typically limit switches) or operator error.  90% electrical and 10% mechanical.  Limit switches are easy to fix but are not always easy to diagnose (can be intermittent problems).  Mechanical issues are typically brakes. Span locks (cushion locks) have been pretty reliable. Notes on maintenance:  Fortunate to have adequate funding / staffing (3 electricians and 5 mechanics currently dedicated to movable bridge maintenance).  Maintenance has a monthly checklist.  Yearly amperage readings taken.  Modern drives and sequencing (controls) have been very beneficial for “smoothing-out” operations (i.e. avoid operator caused impact loads).

96 17. What is the average time to restore operation with electrical issues? Mechanical Issues?  Typical time to restore operation is about 1 hour. 18. Span Locks – how often to you service span locks?  Not often. 19. Do your bridges have PLC or Relay System Controls? Which do you see as more reliable?  1 with PLC control and relay backup.  1 manual operation.  7 with relay control and PLC monitoring / data logging.  Relay system is more reliable, less susceptible to power surge and obsolescence. 20. Do your bridges have generators for backup power?  All have backup generator – sized for normal operation. 21. Do you have bridges with redundant systems, such as: dual power supply: none dual motor/drives:  Palmetto Park – only two cylinders per leaf.  New hydraulic bridges – four cylinders per leaf.  Most older mech drives NOT redundant and have single main motor.  Ocean Ave has redundant gearboxes and motors. 22. Are there any movable bridge systems that are inherently problematic that you don’t recommend?  Rolling Lift not recommended  Older Hopkins type could be under-powered. 23. Are there any bridge types you think are more or less reliable than others?  Rolling Lift not recommended: o Track and tread issues (corrosion - can’t lubricate) o Less precise alignment o Walking can happen at nose 24. Any suggestions for changing movable bridge design requirements?  New bridges have gotten better.  Stay with standard components when possible.  Heavier, more substantial lock bars are an improvement.  Bypasses should be used only with keys and maintenance authorization.  Use portable HPU for backup.

97 MOVABLE BRIDGE OWNER INTERVIEWS Bridge Owner: New York City DOT Date: 8/21/18 Movable Bridge Importance and Availability Survey Questions 1. Can the waterways crossed by movable bridges be classified within the following categories? Check acceptable classifications. Are there other categories you recommend considering? ☒Port Entry ☒Commercial ☐Mixed Use ☐Recreational 2. The following factors are being considered as potential modifiers in establishing design wind pressure. Check acceptable factors. Do you have any other factors you believe should be considered? ☒Evacuation Route ☒Strategic or Military Route ☒Detour Length (miles) ☒Vehicle and/or Truck Usage • (ADT / ADTT) ☒Number of Bridge Openings • (number per year) ☒Combined Hwy/Rail Use • Others: Port Entry: Roosevelt Island and Shore Rd. Commercial: covers all other movables. Others: Estimate that 20 of 23 bridges have at least one of these factors. Pelham and Greenpoint Ave are only bridges with frequent operations (1,000 to 2,000 per year). NYCDOT website has log of openings.

98 3. Does your agency place movable bridges in lockdown or otherwise render them inoperable, under specific warnings of impending high winds (e.g., gale force winds, tropical storm warning, etc.)? If so, provide specifics of the conditions that initiate bridge closure including wind speed. Also include time of advance warning in the table below (“OD” for on demand). MOVABLE BRIDGE OPERATING RESTRICTION DATA BRIDGE(S) WATERWAY(S) OPERATING RESTRICTION(S) ALL GT 40 mph wind gusts – no operation but can be lower with ice/snow. Based on wind reports from Verrazano Bridge. Some Bridges Do not open during very hot weather sue to history of “jamming” due to thermal expansion. Existing Movable Bridge Reliability Survey In responding to the questions below disregard equipment failures due to abnormal conditions such as vessel or vehicle impact, submergence or vandalism4. 1. How would you rate the reliability of movable bridge support machinery5 systems and components (trunnions, rolling lift track/tread, center bearings, etc.) on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor 2. How would you rate the reliability of movable bridge drive machinery systems and components on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor Notes on particular elements:  No particular bridge-type problems. Notes on particular elements:  No hydraulic bridges, all electro-mechanical.

99 3. How would you rate the reliability of movable bridge locking (live load transfer) devices6 (center locks, tail locks, end/center wedges, etc.) machinery on your movable bridges: ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor 4. How would you rate the reliability of movable bridge electrical power and control systems on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor • • 5. How would you rate the reliability of movable bridge traffic control (gates, signals) systems on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor 6. Approximately how many movable bridges are included in the above assessment? 23 7. How would you rate the routine maintenance these bridges have received over their service life? ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor Notes on particular elements:  Span Locks: • Most issues with older bridges, especially adjustments / shimming.  Tail Locks: o Some issues with shimming and adjustment. Notes on particular elements:  PLC learning curve was very steep with many bugs to work out.  Limit switches can be a problem.  Backup generators have previously been installed in flood- prone locations. Notes on maintenance:  Better lately, but budget restraints in past decades led to poor maintenance. Notes on particular elements: Traffic gates:  No notable issues.

100 Supplemental Questions: 1. What is your inventory of bridges? Number, Types:  11 Bascule o 3 Rolling Lift o 8 Trunnion Bascule o 2 Single Leaf o 9 Double Leaf  7 Swing o Mix of rim-bearing and center-bearing types  2 Retractable  3 Vertical Lift  All electro-mechanical, hydraulic only for emergency backup 2. How frequent do your bridges open?  Most are very infrequent (most openings for monthly maintenance).  2 bridges (Pelham and Greenpoint) have frequent operations of 1,000 to 2,000 per year. 3. How often do you experience failures that prevent operation?  On average one failure per week.  Problems increase in winter. 4. What causes more of your disruptions in operation, electrical or mechanical issues?  Mechanical more problematic. o Usually with older bridges. o Major problems typically related to span locks and tail locks.  Electrical problems are typically limit switches. 5. What is the average time to restore operation with electrical issues? Mechanical Issues?  Typical time to restore operation is 6 to 8 hours. If bypass solution can be used, operation is restored much faster. 6. Span Locks – how often to you service span locks?  As-needed, other than monthly lubrication. 7. Do your bridges have PLC or Relay System Controls? Which do you see as more reliable?  Have been changing over to PLC controls. There has been a steep learning curve for this. 8. Do your bridges have generators for backup power?  All have backup generator.

101 9. Do you have bridges with redundant systems, such as: dual power supply:  All Harlem River Bridges have redundant power supplies. dual motor/drives:  Many have dual motors. 10. Are there any movable bridge systems that are inherently problematic that you don’t recommend?  Span locks and tail locks are most problematic. 11. Are there any bridge types you think are more or less reliable than others?  Vertical Lift is least favorite. Bascule and swing bridges are okay. 12. Any suggestions for changing movable bridge design requirements?  Add redundancy when possible (dual power feeds and motors).  Avoid concrete filled gratings as they turn into potholes.  Verify adequate maintenance access space.

102 MOVABLE BRIDGE OWNER INTERVIEWS Bridge Owner: Michigan DOT Date: 8/20/18 Movable Bridge Importance and Availability Survey Questions 1. Can the waterways crossed by movable bridges be classified within the following categories? Check acceptable classifications. Are there other categories you recommend considering? ☒Port Entry ☒Commercial ☒Mixed Use ☒Recreational 2. The following factors are being considered as potential modifiers in establishing design wind pressure. Check acceptable factors. Do you have any other factors you believe should be considered? ☒Evacuation Route ☐Strategic or Military Route ☒Detour Length (miles) ☒Vehicle and/or Truck Usage • (ADT / ADTT) ☒Number of Bridge Openings • (number per year) ☐Combined Hwy/Rail Use Port Entry: 8 bridges Commercial / Mixed Use: 3 bridges Recreational: 1 bridge Others: All categories acceptable. Those that are checked are applicable. The vertical lift bridge is the only vehicular access to an island.

103 3. Does your agency place movable bridges in lockdown or otherwise render them inoperable, under specific warnings of impending high winds (e.g., gale force winds, tropical storm warning, etc.)? If so, provide specifics of the conditions that initiate bridge closure including wind speed. Also include time of advance warning in the table below (“OD” for on demand). MOVABLE BRIDGE OPERATING RESTRICTION DATA BRIDGE(S) WATERWAY(S) OPERATING RESTRICTION(S) All Port of Entry and Commercial On Demand Recreational Scheduled All Open for AASHTO design wind loading (approximately 50 mph) Existing Movable Bridge Reliability Survey In responding to the questions below disregard equipment failures due to abnormal conditions such as vessel or vehicle impact, submergence or vandalism7. 1. How would you rate the reliability of movable bridge support machinery8 systems and components (trunnions, rolling lift track/tread, center bearings, etc.) on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor 2. How would you rate the reliability of movable bridge drive machinery systems and components on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor Notes on particular elements:  Most of their movables are over 50 years old.  Recently finding problems with Rolling lift tracks and treads. Notes on particular elements:  There is expected wear and tear consistent with typical bridge age.

104 3. How would you rate the reliability of movable bridge locking (live load transfer) devices9 (center locks, tail locks, end/center wedges, etc.) machinery on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor 4. How would you rate the reliability of movable bridge electrical power and control systems on your movable bridges: ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor • • 5. How would you rate the reliability of movable bridge traffic control (gates, signals) systems on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor 6. Approximately how many movable bridges are included in the above assessment? 12 7. How would you rate the routine maintenance these bridges have received over their service life? ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor Notes on particular elements:  Span Locks: • Most of their bridges have passive span locks common on rolling lifts and have had little problem with them.  Tail Locks: o Common on Rolling Lifts, but no reported problems. Notes on particular elements:  Overall satisfactory.  Incoming Power – Good (redundant power or b/u generator).  Control Sys – Satisfactory (3 PLC, others relay)  Limit Switches – Fair / Poor Notes on maintenance:  Over last 25 years – Good (with dedicated movable bridge maintenance crew).  Prior – Fair / Poor Notes on particular elements: Traffic gates:  Only notable problems is when they are hit.

105 Supplemental Questions: 1. What is your inventory of bridges? Number, Types:  11 Bascule o 11 Rolling Lift o 10 Double Leaf o 1 Single Leaf  1 Vertical Lift.  9 electro-mechanical.  3 hydraulic cylinder. 2. How frequent do your bridges open?  Most are seasonal, but some can have several operations each day. 3. How often do you experience failures that prevent operation?  On average one failure per week (total for all bridges) during the boating season. 4. What causes more of your disruptions in operation, electrical or mechanical issues?  Electrical more problematic. o “Always limit switches!” o Typical limit switch life is 2 to 5 years. No “warning signs” for impending failure. Program started to just replace all limit switches every 2 years. Replacements are “heavy duty” whenever feasible. o Acknowledged that a lot of salt used in winter.  Mechanical problems are typically hydraulic. o Hydraulic leaks. o Hydraulic pump / hydraulic motor failures.  Electro-mechanical drive issues: o Couplings (rare). o Tail locks – typically operator error issue. o Brakes – adjust settings due to wear. 5. What is the average time to restore operation with electrical issues? Mechanical Issues?  Typical time to restore operation is a few minutes, but bridge crew may be 2 hours away. 6. Span Locks – how often to you service span locks?  All bascule bridges have passive span locks. Just regular greasing.

106 7. Do your bridges have PLC or Relay System Controls? Which do you see as more reliable?  3 PLC and the rest are relay-based. No comment on preference. 8. Do your bridges have generators for backup power?  All have either redundant power feed or backup generator. 9. Do you have bridges with redundant systems, such as: dual power supply:  All have either redundant power feed or backup generator. dual motor/drives:  Some have dual motors or emergency drive. 10. Are there any movable bridge systems that are inherently problematic that you don’t recommend?  No response. 11. Are there any bridge types you think are more or less reliable than others?  No response. 12. Any suggestions for changing movable bridge design requirements?  Add redundancy when possible (dual power feeds and motors).  Require more reliable electrical equipment.  Verify adequate maintenance and repair access.

107 MOVABLE BRIDGE OWNER INTERVIEWS Bridge Owner: North Carolina DOT Date: 8/15/18 Movable Bridge Importance and Availability Survey Questions 1. Can the waterways crossed by movable bridges be classified within the following categories? Check acceptable classifications. Are there other categories you recommend considering? ☒Port Entry ☒Commercial ☒Mixed Use ☒Recreational 2. The following factors are being considered as potential modifiers in establishing design wind pressure. Check acceptable factors. Do you have any other factors you believe should be considered? ☒Evacuation Route ☒Strategic or Military Route ☒Detour Length (miles) ☒Vehicle and/or Truck Usage • (ADT / ADTT) ☒Number of Bridge Openings • (number per year) ☒Combined Hwy/Rail Use Port Entry: 2 bridges Commercial: 8 bridges Mixed Use / Recreational: 2 bridges Others: All categories acceptable and applicable. All have detours available, but some would be problematic.

108 3. Does your agency place movable bridges in lockdown or otherwise render them inoperable, under specific warnings of impending high winds (e.g., gale force winds, tropical storm warning, etc.)? If so, provide specifics of the conditions that initiate bridge closure including wind speed. Also include time of advance warning in the table below (“OD” for on demand). MOVABLE BRIDGE OPERATING RESTRICTION DATA BRIDGE(S) WATERWAY(S) OPERATING RESTRICTION(S) SE Division (Wilmington area) – 4 brs Port of Entry 1 VL and 1 Basc – Less than 40 mph wind 1 Swing (eq arm) & 1 Basc – Less than 30 mph NE Division – 4 brs 35 mph except one older br is 30 mph Central Division No response Existing Movable Bridge Reliability Survey In responding to the questions below disregard equipment failures due to abnormal conditions such as vessel or vehicle impact, submergence or vandalism10. 1. How would you rate the reliability of movable bridge support machinery11 systems and components (trunnions, rolling lift track/tread, center bearings, etc.) on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor 2. How would you rate the reliability of movable bridge drive machinery systems and components on your movable bridges: ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor Notes on particular elements:  None. Notes on particular elements:  Most problems on swings, but these are typically 100 years old.

109 3. How would you rate the reliability of movable bridge locking (live load transfer) devices12 (center locks, tail locks, end/center wedges, etc.) machinery on your movable bridges: ☐Excellent ☐Good ☐Satisfactory ☒Fair ☐Poor 4. How would you rate the reliability of movable bridge electrical power and control systems on your movable bridges: ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor 5. How would you rate the reliability of movable bridge traffic control (gates, signals) systems on your movable bridges: ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor 6. Approximately how many movable bridges are included in the above assessment? 12 7. How would you rate the routine maintenance these bridges have received over their service life? ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor Notes on particular elements:  Span Locks: • “These are the headache items.” • Most problems relate to obtaining limit switch signal: o Bad limit switch o Shimming issue • Generally undersized. Notes on particular elements:  Nothing remarkable.  All bridges going to PLC o Helps to remove operator error, which can cause as much damage as anything else.  Most bridges have generators that do get used. Notes on maintenance:  NE and Central Divisions - now contract out maintenance & operation.  SE Division – state still does maintenance and operation (better).  Spending a lot of money on rehabs to improve reliability and maintenance. Notes on particular elements: Traffic gates:  Maintenance personnel would likely score fair.

110 Supplemental Questions: 1. What is your inventory of bridges? Number, Types:  6 Bascule (1 to be replaced by fixed by EOY). o 0 Rolling Lift o 6 Trunnion Bascule o 5 Double Leaf o 1 Single Leaf  1 Vertical Lift  5 Swing (1 to be replaced in-kind next year)  All electro-mechanical. 2. How frequent do your bridges open?  No response. 3. How often do you experience failures that prevent operation?  Old swing bridge has been problematic.  Newer bridges have been acceptably reliable but have had limit switch failures / required adjustments and have also had software bugs. 4. What causes more of your disruptions in operation, electrical or mechanical issues?  Electrical more problematic on day-to-day basis.  Mechanical problems are less frequent, but more impactful. o Recent shear-key failure on swing shut bridge for 2 days. 5. What is the average time to restore operation with electrical issues? Mechanical Issues?  Typical time to restore operation is a few minutes for electrical problem, but bridge crew (electricians) may be a few hours away.  Mechanical repairs are typically longer (sometimes days). 6. Span Locks – how often to you service span locks?  No response. 7. Do your bridges have PLC or Relay System Controls? Which do you see as more reliable?  All bridges are PLC or will go to PLC. 8. Do your bridges have generators for backup power?  All have backup generators.

111 9. Do you have bridges with redundant systems, such as:dual power supply:  All have backup generators. dual motor/drives:  Some have dual motors or emergency drive. 10. Are there any movable bridge systems that are inherently problematic that you don’t recommend?  No response. 11. Are there any bridge types you think are more or less reliable than others?  No response. 12. Any suggestions for changing movable bridge design requirements?  No response.

112 MOVABLE BRIDGE OWNER INTERVIEWS Bridge Owner: Multnomah County, OR Date: 8/15/18 Movable Bridge Importance and Availability Survey Questions 1. Can the waterways crossed by movable bridges be classified within the following categories? Check acceptable classifications. Are there other categories you recommend considering? ☐Port Entry ☒Commercial ☒Mixed Use ☐Recreational 2. The following factors are being considered as potential modifiers in establishing design wind pressure. Check acceptable factors. Do you have any other factors you believe should be considered? ☒Evacuation Route ☐Strategic or Military Route ☐Detour Length (miles) ☒Vehicle and/or Truck Usage • (ADT / ADTT) ☒Number of Bridge Openings • (number per year) ☒Combined Hwy/Rail Use All categories acceptable Commercial / Mixed Use: 4 bridges Users include: party boats, barges, commercial, pleasure / sail boats, and one bridge has ocean-going ships for grain and Fleet Week. Others: All categories acceptable. Those that are checked are applicable. Lowest bridge (Hawthorne) operates 2 or 3 times per day.

113 3. Does your agency place movable bridges in lockdown or otherwise render them inoperable, under specific warnings of impending high winds (e.g., gale force winds, tropical storm warning, etc.)? If so, provide specifics of the conditions that initiate bridge closure including wind speed. Also include time of advance warning in the table below (“OD” for on demand). MOVABLE BRIDGE OPERATING RESTRICTION DATA BRIDGE(S) WATERWAY(S) OPERATING RESTRICTION(S) All Willamette Performing study that will recommend restrictions for sustained winds of approximately 30 mph. Existing Movable Bridge Reliability Survey In responding to the questions below disregard equipment failures due to abnormal conditions such as vessel or vehicle impact, submergence or vandalism13. 1. How would you rate the reliability of movable bridge support machinery14 systems and components (trunnions, rolling lift track/tread, center bearings, etc.) on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor 2. How would you rate the reliability of movable bridge drive machinery systems and components on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor Notes on particular elements:  All of their movables are over 75 years old.  Strauss CWT trunnion froze on one leaf. Likely grease issue.  VL had sheaves replaced (original casting defects). Notes on particular elements:  No gearing / shaft failures.  Only bearing replacement due to wear after many years of service.

114 3. How would you rate the reliability of movable bridge locking (live load transfer) devices15 (center locks, tail locks, end/center wedges, etc.) machinery on your movable bridges: ☐Excellent ☐Good ☐Satisfactory ☒Fair ☐Poor 4. How would you rate the reliability of movable bridge electrical power and control systems on your movable bridges: ☐Excellent ☐Good ☐Satisfactory ☒Fair ☐Poor 5. How would you rate the reliability of movable bridge traffic control (gates, signals) systems on your movable bridges: ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor 6. Approximately how many movable bridges are included in the above assessment? 4 7. How would you rate the routine maintenance these bridges have received over their service life? ☐Excellent ☒Good ☒Satisfactory ☐Fair ☐Poor Notes on particular elements:  Span Locks: • Morrison Trunnion Bascule uses sliding eccentric locks - problematic. • Broadway Rall Bascule uses bar locks that have a lot of issues / wear, especially with streetcar passage. • Burnside Strauss Bascule (CWT under) uses jaw type l k d Notes on particular elements:  Wiring – Aging / problematic. Also, NEC allows too many wires per conduit.  Power – Good (b/u generators used, either permanent or portable).  Control Sys – PLC problems after 18 yrs (should probably replace every 12 years +/-).  Limit Switches – Have gone to prox switches (have finite life of about 10 yrs) Notes on maintenance:  Good since mid 1980’s.  Poor / intermittent prior to that. Notes on particular elements: Traffic gates:  Limit switch problems typical.  Rotary cam limit switch boxes replace on all with prox switches.

115 Supplemental Questions: 1. What is your inventory of bridges? Number, Types:  3 Bascule o 0 Rolling Lift o 1 Chicago Trunnion Bascule o 1 Rall Trunnion Bascule o 1 Strauss Trunnion Bascule (CWT under) o 3 Double Leaf o 0 Single Leaf  1 Vertical Lift  4 electro-mechanical. 2. How frequent do your bridges open?  Busiest (VL) operations 2-3 times each day.  Others are about 1-2 times per day. 3. How often do you experience failures that prevent operation?  No response. 4. What causes more of your disruptions in operation, electrical or mechanical issues?  Electrical more problematic. o Control system (1). o Wiring faults (2).  Mechanical: o Locking system (3) 5. What is the average time to restore operation with electrical issues? Mechanical Issues?  Typical time to restore operation is a few hours.  Mechanical issues such as stuck locks can require a few days. 6. Span Locks – how often to you service span locks?  As-needed other than regular maintenance (greasing). 7. Do your bridges have PLC or Relay System Controls? Which do you see as more reliable?  All PLC. No comment on preference. 8. Do your bridges have generators for backup power?  All have either permanent or portable backup generator.

116 9. Do you have bridges with redundant systems, such as: dual power supply:  All have backup generator. dual motor/drives:  Some have dual motors or emergency drive. 10. Are there any movable bridge systems that are inherently problematic that you don’t recommend?  No response. 11. Are there any bridge types you think are more or less reliable than others?  No response. 12. Any suggestions for changing movable bridge design requirements?  Like jaw-type locks.  Recommend / require scheduled pro-active electrical equipment replacement (especially PLC’s).  Careful with FRP decks, as they have been problematic.  Streetcar catenary systems add complexities / problems.

117 MOVABLE BRIDGE OWNER INTERVIEWS Bridge Owner: FDOT D4 Date: 8/16/18 Movable Bridge Importance and Availability Survey Questions 1. Can the waterways crossed by movable bridges be classified within the following categories? Check acceptable classifications. Are there other categories you recommend considering? ☐Port Entry ☒Commercial ☐Mixed Use ☐Recreational 2. The following factors are being considered as potential modifiers in establishing design wind pressure. Check acceptable factors. Do you have any other factors you believe should be considered? ☒Evacuation Route ☒Strategic or Military Route ☒Detour Length (miles) ☒Vehicle and/or Truck Usage • (ADT / ADTT) ☒Number of Bridge Openings • (number per year) ☒Combined Hwy/Rail Use All categories acceptable. Commercial: Most of the 37 bridges fall under commercial. The marine industry pushes for the waterways to be classified as commercial. Others: All categories acceptable and applicable. All have detours available, and only a few would be long. Evacuation Route: More critical for operation. 15-20 operations / day typical. Some with more.

118 3. Does your agency place movable bridges in lockdown or otherwise render them inoperable, under specific warnings of impending high winds (e.g., gale force winds, tropical storm warning, etc.)? If so, provide specifics of the conditions that initiate bridge closure including wind speed. Also include time of advance warning in the table below (“OD” for on demand). MOVABLE BRIDGE OPERATING RESTRICTION DATA BRIDGE(S) WATERWAY(S) OPERATING RESTRICTION(S) All Intracoastal Waterway (ICW), New River Shut down upon USCG notice of winds > 40 mph. Secure bridges, remove gates, lock tender house. Most On Demand Hillsboro Hillsboro Inlet (to ocean w/ 13 ft clear when closed) Every 20 minutes SR 84 New River (21 ft vert clear when closed) 24 hr notice Existing Movable Bridge Reliability Survey In responding to the questions below disregard equipment failures due to abnormal conditions such as vessel or vehicle impact, submergence or vandalism16. 1. How would you rate the reliability of movable bridge support machinery17 systems and components (trunnions, rolling lift track/tread, center bearings, etc.) on your movable bridges: ☒Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor Notes on particular elements:  Excellent: Rolling Lift  Good: Trunnion (problems with cantilever trunnions)

119 2. How would you rate the reliability of movable bridge drive machinery systems and components on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☒Fair ☐Poor 3. How would you rate the reliability of movable bridge locking (live load transfer) devices18 (center locks, tail locks, end/center wedges, etc.) machinery on your movable bridges: ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor 4. How would you rate the reliability of movable bridge electrical power and control systems on your movable bridges: ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor • 5. How would you rate the reliability of movable bridge traffic control (gates, signals) systems on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor Notes on particular elements:  Hopkins Frames: some were problematic. Most repaired / replaced.  Hydraulics have been bad experience for D4: o Design o Component quality o Prefer not to use hydraulic cylinder  Gear boxes have had problems. Would like to go to LSHT hydraulic motors.  Ratings: o Good: Hydraulic motors and Gear drives o Fair: Hydraulic cylinders Notes on particular elements:  Live Load Shoes: problematic and a better design is needed.  Span Locks: require adjustments nearly every year following inspection. • Adjustments require traffic shut-downs. Notes on particular elements:  VFD’s: have been good.  Some bridges are PLC control, but most bridges relay logic with PLC monitoring.  Relay is more reliable than PLC (easier to maintain relays). Notes on particular elements:

120 6. Approximately how many movable bridges are included in the above assessment? 37 7. How would you rate the routine maintenance these bridges have received over their service life? ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor Supplemental Questions: 1. What is your inventory of bridges? Number, Types:  37 Bascule o 2 Rolling Lift o 35 Trunnion Bascule o 33 Double Leaf o 4 Single Leaf  0 Vertical Lift  0 Swing  Most electro-mechanical. 2. How frequent do your bridges open?  Most bridges average 15-20 operations per day.  Hillsboro Inlet is every 20 min between 7 am and 6 pm, then OD. 3. How often do you experience failures that prevent operation?  No response. 4. What causes more of your disruptions in operation, electrical or mechanical issues?  Electrical more problematic. o Most problems are with control system. o They use lever-arm style limit switches for better resolution and easier adjustment. o Noted that proximity switches are sealed and may last longer.  Mechanical problems are less frequent, but more impactful. o Longer delays experienced if item is non-redundant. 5. What is the average time to restore operation with electrical issues? Mechanical Issues?  Typical time to restore operation is typically within a few hours for electrical problems.  Mechanical repairs are typically longer, especially for non-redundant items. Notes on maintenance:  Maintenance has been better under Asset Management (contractors), Poor / Fair in past.

121 6. Span Locks – how often to you service span locks?  Part of regular maintenance. Shimming and adjustment seems to occur yearly following inspection. 7. Do your bridges have PLC or Relay System Controls? Which do you see as more reliable?  Most are relay with PLC monitoring. Relay is more reliable. 8. Do your bridges have generators for backup power?  All have backup generators except SR 84, which is on a 24-hour notice for operation. 9. Do you have bridges with redundant systems, such as: dual power supply:  All have backup generators. dual motor/drives:  Some have dual motors or emergency drive.  Redundant system should be designed to operate up to the restricted loading (40 mph wind). 10. Are there any movable bridge systems that are inherently problematic that you don’t recommend?  Have not had good experience with hydraulic cylinders.  Span locks require adjustment too frequently.  Live Load Shoes should be redesigned. 11. Are there any bridge types you think are more or less reliable than others?  Rolling lift is less maintenance prone. 12. Any suggestions for changing movable bridge design requirements?  No response.

122 MOVABLE BRIDGE OWNER INTERVIEWS Bridge Owner: FDOT D1 & D7 Date: 8/14/18 Movable Bridge Importance and Availability Survey Questions 1. Can the waterways crossed by movable bridges be classified within the following categories? Check acceptable classifications. Are there other categories you recommend considering? ☐Port Entry ☒Commercial ☒Mixed Use ☒Recreational 2. The following factors are being considered as potential modifiers in establishing design wind pressure. Check acceptable factors. Do you have any other factors you believe should be considered? ☒Evacuation Route ☒Strategic or Military Route ☒Detour Length (miles) ☒Vehicle and/or Truck Usage • (ADT / ADTT) ☒Number of Bridge Openings • (number per year) ☐Combined Hwy/Rail Use All categories acceptable. 85% of traffic is Mixed Use on ICW.  Traffic is Recreational or Commercial Others: All categories acceptable and applicable. Detours available except 1 bridge. Typical detour is 15 miles, but one is 40 miles. Evacuation Route: Many. 15-20 operations / day typical. Some with more.

123 3. Does your agency place movable bridges in lockdown or otherwise render them inoperable, under specific warnings of impending high winds (e.g., gale force winds, tropical storm warning, etc.)? If so, provide specifics of the conditions that initiate bridge closure including wind speed. Also include time of advance warning in the table below (“OD” for on demand). MOVABLE BRIDGE OPERATING RESTRICTION DATA BRIDGE(S) WATERWAY(S) OPERATING RESTRICTION(S) D7 Barrier Islands ICW, Rivers, All Shut down upon 8-hour advanced notice from USCG of winds > 40 mph. Secure bridges, remove gates, lock tender house. Existing Movable Bridge Reliability Survey In responding to the questions below disregard equipment failures due to abnormal conditions such as vessel or vehicle impact, submergence or vandalism19. 1. How would you rate the reliability of movable bridge support machinery20 systems and components (trunnions, rolling lift track/tread, center bearings, etc.) on your movable bridges: ☒Excellent ☐Good ☐Satisfactory ☐Fair ☐Poor 2. How would you rate the reliability of movable bridge drive machinery systems and components on your movable bridges: ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor Notes on particular elements:  No known problems on their bridges. Notes on particular elements:  Hopkins Frames (about 50% of inventory): have inherent problems. o Rehabs are only lasting about 10-15 years.  Reducer seal leakage. o Typical span drive machinery failures give “warning signs” allowing at least some time to prepare.  Lift Bridge (constructed in 1939): span drive has been problematic (operating ropes).  H d li G d

124 3. How would you rate the reliability of movable bridge locking (live load transfer) devices21 (center locks, tail locks, end/center wedges, etc.) machinery on your movable bridges: ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor 4. How would you rate the reliability of movable bridge electrical power and control systems on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor 5. How would you rate the reliability of movable bridge traffic control (gates, signals) systems on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor 6. Approximately how many movable bridges are included in the above assessment? 26 Notes on particular elements:  Limit Switches: most problematic component.  Span Locks: overall problematic: o Cushion Locks no good - springs wear out o Adjustable shim deign preferred. Adjustment req’d every 2-3 years.  Birds on Live Load Shoes is problem Notes on particular elements:  Incoming power: Good.  All but 1 have generator (Taylor Creek).  PLC Control: o Good once set-up and bugs worked out. o Difficult to operate bridge if they fail (must operate from MCC). o PLC’s and Drives last about 15-20 years. o Approximately 20 bridges with PLC operation. They have relay backup, except John’s Pass.  Relay Control: o More reliable than PLC and preferred for new designs. o Preferred for backup.  Limit Switches: o Are the cause of many problems (brakes, gates, span locks). o Prefer lever-arm type. Greater flexibility to adjust and better resolution than plunger type. Notes on particular elements: Good other than on John’s Pass, which has gate problems.

125 7. How would you rate the routine maintenance these bridges have received over their service life? ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor Supplemental Questions: 1. What is your inventory of bridges? Number, Types:  25 Bascule o 1 Rolling Lift o 24 Trunnion Bascule o 21 Double Leaf o 3 Single Leaf  1 Vertical Lift  0 Swing 2. How frequent do your bridges open?  D1 – 7 to 218 per month.  D7 – 3 to 351 per month. 3. How often do you experience failures that prevent operation?  No response. 4. What causes more of your disruptions in operation, electrical or mechanical issues?  Electrical more problematic. o Most problems are related to limit switches, are small and can be resolved in a few minutes.  Mechanical problems. o Usually span locks won’t pull / drive. o Pigeon on LLS: will not obtain “fully seated indication”, and interlocking will disallow next step (typically to drive span locks). o VL Bridge has jammed, causing long outage. o Span lock pin fell off Clearwater Bridge. Notes on maintenance:  Maintenance has been very good / excellent since 2003 when contract Asset Management started.

126 5. What is the average time to restore operation with electrical issues? Mechanical Issues?  Time to restore operation is typically within a few minutes to a few hours for electrical problems.  Mechanical repairs are typically longer and are measured in hours. 6. Span Locks – how often to you service span locks?  Part of regular maintenance. Shimming and adjustment approximately every 2-3 years. 7. Do your bridges have PLC or Relay System Controls? Which do you see as more reliable?  Approximately 20 of 26 are PLC control. Relay is more reliable. 8. Do your bridges have generators for backup power?  All but 1have backup generators. 9. Do you have bridges with redundant systems, such as: dual power supply:  All but one have backup generators. dual motor/drives:  No response. 10. Are there any movable bridge systems that are inherently problematic that you don’t recommend?  Hopkins Frame type bascules seem to have inherent design flaws. 11. Are there any bridge types you think are more or less reliable than others?  Hopkins Frame type bascules seem to have inherent design flaws. 12. Any suggestions for changing movable bridge design requirements?  Verify adequate line-of-site from operator’s house. Cameras are not always sufficient.  Take extra precautions in tourist areas that may have nearby bars.

127 MOVABLE BRIDGE OWNER INTERVIEWS Bridge Owner: LaDOTd Date: 9/14/18 Movable Bridge Importance and Availability Survey Questions 1. Can the waterways crossed by movable bridges be classified within the following categories? Check acceptable classifications. Are there other categories you recommend considering? ☒Port Entry ☒Commercial ☒Mixed Use ☒Recreational 2. The following factors are being considered as potential modifiers in establishing design wind pressure. Check acceptable factors. Do you have any other factors you believe should be considered? ☒Evacuation Route ☒Strategic or Military Route ☒Detour Length (miles) ☒Vehicle and/or Truck Usage • (ADT / ADTT) ☒Number of Bridge Openings • (number per year) ☒Combined Hwy/Rail Use All categories acceptable. Vast majority of bridges fall into the Commercial and Mixed Use categories. All categories acceptable and applicable. Others: Consider bridges that access remote locations and may be the sole access. May be able to include this in detour length.

128 3. Does your agency place movable bridges in lockdown or otherwise render them inoperable, under specific warnings of impending high winds (e.g., gale force winds, tropical storm warning, etc.)? If so, provide specifics of the conditions that initiate bridge closure including wind speed. Also include time of advance warning in the table below (“OD” for on demand). MOVABLE BRIDGE OPERATING RESTRICTION DATA BRIDGE(S) WATERWAY(S) OPERATING RESTRICTION(S) All Shut down upon tropical force winds hitting coastline. Secure bridges (including removal of traffic arm if manageable) and evacuate upon USCG coordination. Most The Operator’s Manual for most Districts allow the operator to not open if wind exceeds 35 mph. A few Some bridges with known operational difficulties may be limited to 25 mph wind for operation. Existing Movable Bridge Reliability Survey In responding to the questions below disregard equipment failures due to abnormal conditions such as vessel or vehicle impact, submergence or vandalism22. 1. How would you rate the reliability of movable bridge support machinery23 systems and components (trunnions, rolling lift track/tread, center bearings, etc.) on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor 2. How would you rate the reliability of movable bridge drive machinery systems and components on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor Notes on particular elements:  Old center bearing designs had no seal provision, but new designs include.  Occasional problems with center bearings, trunnion assemblies, tread plates. Notes on particular elements:  Generally exceed life expectancy for electro-mechanical systems.  Hydraulics – Recent systems much better, especially with better seals. Reliability similar to E/M systems.

129 3. How would you rate the reliability of movable bridge locking (live load transfer) devices24 (center locks, tail locks, end/center wedges, etc.) machinery on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☒Fair ☐Poor 4. How would you rate the reliability of movable bridge electrical power and control systems on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☒Fair ☒Poor 5. How would you rate the reliability of movable bridge traffic control (gates, signals) systems on your movable bridges: ☐Excellent ☒Good ☐Satisfactory ☐Fair ☐Poor 6. Approximately how many movable bridges are included in the above assessment? 102 “on system” & 42 “off system” (Port / Parish / Levee District / Other) 7. How would you rate the routine maintenance these bridges have received over their service life? ☐Excellent ☐Good ☒Satisfactory ☐Fair ☐Poor Notes on particular elements:  Bascule center and tail locks: Good  Swing bridge wedges: Good (mostly hydraulically operated)  VL locks: Fair (newer designs better) Notes on particular elements:  Power and Control: Good  Limit Switches: Fair/Poor and account for approximately 90% of service calls (adjustment or replacement required). Notes on maintenance:  Limited Budget / Personnel  Maintenance primarily done in-house.  Bridge operator’s work directly for state. Notes on particular elements:  Inherently susceptible to insect (ant) infiltration and other environmental factors such as rain.

130 Supplemental Questions: 1. What is your inventory of bridges? Number, Types:  15 Bascule o 2 Rolling Lift o 13 Trunnion Bascule o ? Double Leaf o ? Single Leaf  46 Vertical Lift  70 Swing  13 Pontoon  Most electro-mechanical. 2. How frequent do your bridges open?  Low: Some only operate a few times per year to exercise and for maintenance.  High: 900 plus times per month.  Most are near the middle of this range. 3. How often do you experience failures that prevent operation?  Low: 2 times per year (per bridge)  High: 24 to 36 per year (per bridge). 4. What causes more of your disruptions in operation, electrical or mechanical issues?  Electrical more problematic. o Most problems are with limit switches.  Mechanical problems are less frequent, but more impactful. o Noted problems with broken couplings on vertical lift bridges. 5. What is the average time to restore operation with electrical issues? Mechanical Issues?  Limit switches: 1-2 hours.  Mechanical repairs are typically longer. The worst case noted was a trunnion failure that resulted in an outage of a few weeks. 6. Span Locks – how often to you service span locks?  Just regular maintenance (usually monthly).  No significant problems with span locks, but noted they only have a few bascules. 7. Do your bridges have PLC or Relay System Controls? Which do you see as more reliable?  Only a handful of PLC controlled bridges (approximately 5). o Port of New Orleans has one and is reportedly not happy with performance. o Maintainers not trained and requires vendors to service. o Significant concerns over lightning strikes. Cited bridge in Monroe that had problems for months due to lightning strike.  All others (vast majority) are relay controlled. o Very happy with reliability and maintainability. 8. Do your bridges have generators for backup power?  Most critical bridges (on evacuation routes) have backup generators.  After hurricane Katrina, raised elevation of generators if possible.

131 9. Do you have bridges with redundant systems, such as: dual power supply:  This is uncommon.  For “critical” bridges, typically just use backup generator(s). dual motor/drives:  Vertical Lifts: Most vertical lifts are older tied-tower type. More recent tower-drive vertical lift designs typically include independent drives that can operate bridge in restricted winds with single motor (in each tower).  Swings: More recent designs tend to have redundant motors / drives / pumps. 10. Are there any movable bridge systems that are inherently problematic that you don’t recommend?  Nothing in particular, but for control, relay is preferred.  Starting to more seriously consider VFDs. 11. Are there any bridge types you think are more or less reliable than others?  Owner believes that reliability has more to do with specific design of a particular bridge rather than bridge type, however, Pontoon bridges are more problematic (increased maintenance). 12. Any suggestions for changing movable bridge design requirements?  No drastic changes suggested, and as a whole satisfied with existing.  Noted that LaDOTd has their own Bridge Design and Evaluation Manual (BDEM II) that is available on their website. It includes a movable bridge section. Other:  Movable bridge replacement and rehab approach? o Usually, replacement stems from structural issues such as functional obsolescence or insufficient rating. o Previously, they did very few major rehabs. In last 15 years, they have started with major rehabs at 40 to 50 yrs (bridge age). Once bridge exceeds 40 years, they are having more problems, especially electrical. o Busy / Urban bridge repair takes priority. Also, political pressure can be driver. o Replacement of movable with fixed will be considered, but many times impractical due to various constraints.

Next: Appendix C Auburn University Report of Reliability-Based Methodology for Mechanical Design with Design Examples »
Updating the AASHTO LRFD Movable Highway Bridge Design Specifications Get This Book
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There are approximately 1,000 movable highway bridges in the U.S. inventory.

The TRB National Cooperative Highway Research Program's NCHRP Web-Only Document 314: Updating the AASHTO LRFD Movable Highway Bridge Design Specifications allows bridge owners the option of employing site-specific conditions to develop the design wind speed and provides other general updates to previous research from 2000 that reflects changes in design practice and other standards.

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