City of Berkeley, CA Streetlight Condition Assessment · the inventory from the ity’s LED...

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CITY OF BERKELEY, CA | STREETLIGHT CONDITION ASSESSMENT | TANKO LIGHTING

City of Berkeley, CA

Streetlight Condition Assessment

Project Background The City of Berkeley contracted with Tanko Lighting to evaluate the condition of the City’s metal streetlights

and develop a plan to remediate or replace problematic poles within the City. Tanko Lighting determined

a sampling method, dispatched field staff to evaluate the poles, then analyzed the data to determine

appropriate treatment/replacement recommendations and remaining useful pole life.

This report summarizes the findings of Tanko Lighting’s investigation and provides pole

treatment/replacement recommendations based on pole condition, type, and location within the City,

along with timelines for replacement. This report also includes secondary findings that the City may wish

to act upon, including locations where poles have sustained acute damage, mobile bolt covers are still

present, or handhole covers are missing.

Methods Tanko Lighting developed a custom survey for field staff to complete at each pole (Appendix A), and used

the inventory from the City’s LED streetlight conversion to direct field staff to all known metal pole locations

within the City. Data points were compiled at the end of the field assessment, pole types were standardized

(Appendix B), and various analyses were performed to determine which pole groups were experiencing

chronic rust or corrosion and how these issues should be addressed (see Results & Recommendations

section below). The data set was further reviewed for any scenarios requiring immediate attention, after

which an estimated remaining useful pole life was determined for each pole. The remaining pole life was

estimated based on pole type and level of damage (if any) observed in the field. The data set was also

mapped to allow the City to visualize where various issues are occurring. The complete, final data set was

converted into an Excel spreadsheet (Appendix C), allowing the City to view specific information collected

for each pole.

Results & Recommendations Tanko Lighting assessed 3,105 metal poles within the City of Berkeley. Appendix C (Excel spreadsheet) lists

Tanko Lighting’s complete findings, including the exact location of each pole assessed, various types of

damage encountered, recommended action, suggested prioritization, and estimated remaining useful pole

life. Below is a summary of the main scenarios discovered in the field and the recommended action for

each:

Immediate Action Required (12 poles): Tanko Lighting found twelve poles in the field for which immediate

action is recommended. Two of these poles have open cracks, elevating the risk that the pole will fall over.

One appears intact but was noted to be swaying in the wind. One was partially crushed and slightly leaning.

The remaining eight fixtures had rusted so much that the structural integrity of the pole appeared to be

compromised. Details on the locations of these poles can be found in Appendix C by searching the Priority

column for “Immediate Action Required”. See Map 1 for the locations of all poles recommended for

replacement or removal (Priority of “Immediate Action Required”, “High – Replace”, or “High – Remove”).

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High Priority – Replacement or Removal (137 poles): In addition to the poles requiring immediate action,

Tanko Lighting found 137 poles of various types that are recommended for replacement (136 poles) or

removal (1 pole). The majority of these poles are either Type 1a/1b – Simplex Ball-Top or Type 2 – Davit.

Additional results specific to pole type can be found below.

Type 1a and 1b – Simplex Ball-Top (71 poles): Tanko Lighting recommends replacing 67 of these poles and

removing the single pole with a barn light/gum drop fixture. These poles currently show a range of visible

rust levels, but due to the age of the poles, uncertainty as to whether interior rust is present, and previous

failures of this pole type, Tanko Lighting recommends replacing the majority of them. The remaining three

poles of this type that Tanko Lighting is not recommending for replacement appear to be a newer vintage

and are acceptable to remain with routine maintenance. See Map 1 for the locations of all poles

recommended for replacement or removal (Priority of “Immediate Action Required”, “High – Replace”, or

“High – Remove”).

Type 2 – Davit Poles (1,627 poles): The majority of poles experiencing major rust are Davit poles (61 poles).

These poles have been individually reviewed and either recommended for maintenance (2 poles) or

replacement (59 poles), depending on the amount of metal still intact combined with any other damage

found on the pole. There are additional Davit poles experiencing intermediate rust (82 poles) or minor rust

(868 poles), which can simply be cleaned, sanded, and painted. See Map 2 for the locations of Davit and

other poles experiencing major rust issues.

Type 10h – Codornices Rd Contempo (2 poles): These poles appear to be thick and sturdy. Therefore,

cleaning, sanding, and painting is recommended for all poles regardless of rust level. Additionally, it is

recommended that the luminaires on these poles be changed out for Type 10e – Capped Acorn (LED).

Type 18 – Rose Walk Globe (3 poles): These poles appear to be thick and sturdy. Therefore, cleaning,

sanding, and painting is recommended for all poles regardless of rust level.

Type 20 – Trolley Line Cobra Head (3 poles): These poles appear to be thick and sturdy. Therefore, cleaning,

sanding, and painting is recommended for all poles regardless of rust level.

Other Poles with Major Rust or Corrosion (28 poles, various types): These poles have been individually

reviewed and either recommended for maintenance or replacement, depending on the amount of metal

still intact combined with any other damage found on the pole. See Map 2 for the locations of all poles

experiencing major rust issues.

Mobile Base Covers (105 poles): Tanko Lighting recommends removing all mobile base covers found in the

field, then cleaning and inspecting the portion of pole and base plate underneath. Since these covers are

not sealed to the pole, they may trap moisture against the bottom of the pole and the base plate,

shortening the lifetime of the pole and, over time, increasing the likelihood of the pole falling over. The

locations of the mobile base covers found during the assessment can be found in Appendix C in the “Mobile

Base Cover” column, or viewed in Map 3.

General: Tanko Lighting recommends that any new poles purchased by the City be hot-dipped galvanized

steel, such that any paint issues that develop will only impact the aesthetic and not the integrity of the pole.

Tanko Lighting examined some painted galvanized steel poles and found their paint condition to be

comparable or better than painted steel poles. Galvanized steel will protect both the interior and exterior




of the pole, regardless of whether paint is being maintained or not. This protection is particularly important,

as pole paint does not appear to be maintained consistently across the City.

Tanko Lighting found that pole quality was generally dependent on the level of rust present. Poles were

categorized into Major Rust (100 poles), Intermediate Rust (98 poles), Minor Rust (1,218 poles), or No Rust

(1,690 poles). This designation was the major factor in determining priority level and recommended action

when no acute damage was present (see Appendix C, columns titled: “Priority”, “Tanko Recommendation”,

and “Rust/Corrosion Status”). Poles with Major Rust were reviewed individually to determine if the pole

can be sanded and repainted or if it needs to be replaced, as well as to determine the priority of replacing

or maintaining the pole. Poles with Intermediate Rust and Minor Rust are generally listed as medium and

low priority, respectively, and both categories are recommended for cleaning, sanding, and painting. Spot

painting may be a suitable alternative to full-pole painting for poles with Minor Rust. Poles with No Rust

are simply recommended to have standard maintenance and inspection and have no priority.

Note on Painting: Tanko Lighting observed that many problematic poles had been painted without first

having rust and older paint removed, and in some cases, it appeared that tape and band ties had been

painted over. This lack of pole preparation prior to painting seemed to be causing paint to peel prematurely,

leaving poles vulnerable to further rust or corrosion. Tanko Lighting recommends that steel poles be fully

cleaned, sanded, and prepped prior to future painting, hopefully increasing the life of the pole and

decreasing the frequency of painting required. Painted galvanized steel poles seemed to be less impacted

by these painting issues, presumably because the poles themselves were not degraded beneath the paint

(band ties and tape were still an aesthetic painting issue). Galvanized steel poles will also be less expensive

to paint in the future, as they will not require pole preparation to remove rust prior to painting.

Remaining Useful Pole Life: Tanko Lighting estimated the remaining useful pole life of each pole based on a

variety of factors and under the assumption that poles are properly maintained*. A general estimate for

each pole type was first determined based on the estimated age of the poles and general condition of poles

of that type (see Table 1). Poles where immediate action is required were given an estimated life of zero

years, as the pole needs to be replaced immediately. High priority poles were examined individually to

assign a useful remaining life appropriate to the level of damage. Poles flagged as high priority for

replacement had no more than five years of remaining life, and the majority had only one year. Poles

flagged as high priority for maintenance had between 12 and 50 years of useful life remaining. Poles flagged

as medium priority for maintenance were assigned useful life by removing ~25% from their pole type’s

general estimate of useful remaining life. Poles flagged as low priority or no priority were assigned their

pole type’s general estimate of useful remaining life. See Appendix C for complete results.

*The assumption that poles are properly maintained is critical to the remaining useful pole life estimates

provided. If pole maintenance does not increase from its current level and poles remain in the field

unmaintained, the remaining useful life will be significantly less than listed here (on the order of a 50%

reduction).




Table 1

Pole Type Estimated Remaining Useful Pole Life (years)

Type 1a – Simplex Ball-Top Cobra Head 0-3 (replace) / 60-75 (new)

Type 1b – Simplex Ball-Top Barn Light 0-3 (remove)

Type 2 – Davit Cobra Head 60-75

Type 3 – Flat Bracket Cobra Head (CalTrans Type 15) 100+

Type 4a – Center St Fluted Cobra Head 25

Type 4b – MLK Park Fluted Pendant 25

Type 4c – Allston Way Fluted Cobra Head 50-75

Type 5 – Round Bracket Cobra Head 3

Type 6a – Bay Trail Cobra Head 25

Type 6b – John Hinkel Park Cobra Head 60-75

Type 6c – Telegraph Ave Cobra Head 60-75

Type 6d – Sojourner Truth Ct Cobra Head 60-75

Type 6e – Pinnacle Path Cobra Head 60-75

Type 7a – Marina Pendant 25+

Type 7b – Marina Contempo 50 (assuming galvanized)

Type 7c – Marina Contempo, Square Pole 50 (assuming galvanized)

Type 8 – West Street Bike Path Pendant 50+

Type 9a – Sidewalk Pendant, Long Lens 50+

Type 9b – Sidewalk Pendant, Shallow Lens 50+

Type 9c – Sidewalk Pendant, LED 50+

Type 10a – Acorn, Fat Neck, Fat Base 75

Type 10b – Acorn, Thin Neck, Fat Base 50+

Type 10c – Acorn, Thin Neck, Thin Base 50+

Type 10d – Flagpole Twin Acorn 50+

Type 10e – Capped Acorn 50+

Type 10f – Narrow Acorn 75

Type 10g – Small Acorn 25+

Type 10h – Codornices Rd Contempo 50+

Type 11 – Round Sidewalk Shoebox 50

Type 12a – Square Sidewalk Shoebox 50

Type 12b – Tall Square Sidewalk Shoebox 50

Type 13 – New York City 50

Type 14 – Strawberry Creek Park Capped Acorn and Flood

75

Type 15 – Suspension Arm Cobra Head (CalTrans Type 10)

50

Type 16 – Beehive Pendant 25-50

Type 17 – College Ave Pendant 75

Type 18 – Rose Walk Globe 50

Type 19 – Willard Park Tennis Light 75

Type 20 – Trolley Line Cobra Head 25




Map 1: Poles recommended for replacement (148 poles) or removal (1 pole) based on rust and other damage found during Tanko Lighting’s Streetlight Condition Assessment in Berkeley. These lights are listed in Appendix C with Priority of “Immediate Action Required”, “High – Replace”, or “High – Remove”.




Map 2: Poles found to have major rust during Tanko Lighting’s Streetlight Condition Assessment in Berkeley. Recommendations differ by pole type, severity of rust, and other damage.




Map 3: Poles with mobile base covers found during Tanko Lighting’s Streetlight Condition Assessment in Berkeley. Tanko Lighting recommends removing all mobile base covers to extend the lifetime of the poles.




Appendix A – Streetlight Condition Assessment Survey

Question Available Answers

Coordinates (latitude, longitude) (auto-populated by application)

Pole Number(s) (free form)

Pole Type Type 1a – Simplex Ball-Top Cobra Head Type 1b – Simplex Ball-Top Barn Light Type 2 – Davit Cobra Head Type 3 – CalTrans/Flat Bracket Cobra Head etc.

Pole Material Galvanized Steel Painted Steel Aluminum Cast Iron

Pole Condition Good Rust Corrosion Paint Peeling/Missing Hand Hole Cover Missing/Damaged Pole Leaning Other (Comment)

Base Cover Mobile Immobile Bolt Caps Bolts Exposed Other (Comment)

Base Condition Good Anchor Bolts Damaged/Rusted/Corroded Concrete Base Damaged Base Plate Damaged/Rusted/Corroded Pole Under Base Plate Damaged/Rusted/Corroded Base Cover Damaged/Rusted/Corroded Bolt Cap(s) Loose/Missing Other (Comment)

Comments (free form) (If pole rusted/corroded, list percent of pole that is covered in rust)

Photos (photos of all damage observed in the field)




Appendix B – Pole Type Index

Pole Type Photo

Type 1a – Simplex Ball-Top Cobra Head

Type 1b – Simplex Ball-Top Barn Light

Type 2 – Davit Cobra Head




Type 3 – Flat Bracket Cobra Head (CalTrans Type 15)

Type 4a – Center St Fluted Cobra Head

Type 4b – MLK Park Fluted Pendant

Type 4c – Allston Way Fluted Cobra Head




Type 5 – Round Bracket Cobra Head

Type 6a – Bay Trail Cobra Head

Type 6b – John Hinkel Park Cobra Head

Type 6c – Telegraph Ave Cobra Head




Type 6d – Sojourner Truth Ct Cobra Head

Type 6e – Pinnacle Path Cobra Head

Type 7a – Marina Pendant




Type 7b – Marina Contempo

Type 7c – Marina Contempo, Square Pole

Type 8 – West Street Bike Path Pendant




Type 9a – Sidewalk Pendant, Long Lens

Type 9b – Sidewalk Pendant, Shallow Lens

Type 9c – Sidewalk Pendant, LED




Type 10a – Acorn, Fat Neck, Fat Base

Type 10b – Acorn, Thin Neck, Fat Base

Type 10c – Acorn, Thin Neck, Thin Base




Type 10d – Flagpole Twin Acorn

Type 10e – Capped Acorn

Type 10f – Narrow Acorn




Type 10g – Small Acorn

Type 10h – Codornices Rd Contempo

Type 11 – Round Sidewalk Shoebox




Type 12a – Square Sidewalk Shoebox

Type 12b – Tall Square Sidewalk Shoebox

Type 13 – New York City




Type 14 – Strawberry Creek Park Capped Acorn and Flood

Type 15 – Suspension Arm Cobra Head (CalTrans Type 10)

Type 16 – Beehive Pendant

Type 17 – College Ave Pendant




Type 18 – Rose Walk Globe

Type 19 – Willard Park Tennis Light

Type 20 – Trolley Line Cobra Head


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