2022 Routine Inspection Report.pdf

ROUTINE INSPECTION REPORT

2022 ROUTINE INSPECTION

OF THE

VERTICAL LIFT RAILROAD BRIDGE

OVER THE

CAPE COD CANAL

BOURNE, MA

Final Report: April 2022

PREPARED BY:

US ARMY CORPS OF ENGINEERS

PHILADELPHIA DISTRICT

2022 Routine Inspection of the Vertical Lift Railroad Bridge

THIS PAGE IS LEFT BLANK INTENTIONALLY

VERTICAL LIFT RAILROAD BRIDGE

2022 ROUTINE INSPECTION REPORT

i

Table of Contents

1. Executive Summary

2. General Information

3. Inspection Procedure

4. Summary of Inspection Findings

4.1 Substructure (Overall Rating of Good Condition = 7)

4.2 Channel and Channel Protection (Overall Rating of Good Condition = 7)

4.3 Superstructure (Overall Rating of Fair Condition = 5)

4.4 Deck (Overall Rating of Good Condition = 7)

ii

1. Executive Summary The 2022 Routine Inspection of the Vertical Lift Railroad Bridge was performed by Structural Engineers from the Philadelphia District (NAP) and New England District (NAE) of the US Army Corps of Engineers (USACE) during the period of November 14th to November 18th, 2022.

The inspection and this report are based on the following regulations, guides and manuals:

a) USACE Engineering Regulation, ER 1110-2-111 (Errata 1), USACE Bridge Safety Program, 31

January 2020.

b) USACE Engineering Manual, EM 1110-2-1102, Inspection and Evaluation of USACE Bridges, 31 January 2020.

c) USACE Engineering Manual, EM 385-1-1, Safety and Health Requirements Manual, 30

November 2014 and all updates.

d) AASHTO, Manual for Bridge Evaluation, 3rd Edition, 2018.

e) AASHTO, Manual for Bridge Element Inspection, 2nd Edition, 2019.

f) Department of Transportation, Federal Highway Administration (FHWA) Reports:

(1) FHWA NHI 12-049, Bridge Inspectors Reference Manual, December 2012.

(2) FHWA-IP-86-26, Inspection of Fracture Critical Bridge Members, September 1986.

g) AREMA, Manual for Railway Engineering, 2015.

The purpose of this inspection was to determine the physical and functional conditions of the bridge, identify any problems and/or changes from the previous recorded conditions and to recommend corrective measures as necessary so the structure continues to satisfy present service requirements. The previous routine inspection, performed in November of 2020, served as the baseline for comparison.

The overall condition of the Vertical Lift Railroad Bridge has not changed since the previous inspection.

The deck, superstructure and substructure remain in good, fair and good condition, respectively. The paint system remains mostly intact. The deck is in good condition with localized split, rotted and missing sections of the timber railroad ties. The superstructure is in fair condition due to truss members with significant arrested section loss with localized corrosion holes. The substructure is in good condition with localized edge spalls in the coping seats and missing pointing between the masonry stones.

No significant changes in section loss to the primary members of the trusses, floor system and towers were noted during this inspection in comparison with the information presented in tables 2-1 through 2-4 of the 2004 Routine Inspection Report.

The most significant inspection findings for the deck, superstructure and substructure are as follows:

♦ Crack in connection plate of upper chord lateral bracing at U7 of east truss – Corrosion in this area has reactivated and extent of previously noted crack is difficult to accurately obtain due to location and coating condition.

♦ Deteriorated timber railroad ties – Six timber railroad ties exhibit splits/rot with missing sections up to 10'-0" long by up to 6" high by up to 4 1/4" wide along the bottom edges. In addition, one of the rotted ties in the south approach span between the 2nd and 3rd catwalk support channel south of floorbeam 1 has one of four screw spikes exposed.

♦ Truss members with significant section loss – There are several approach span truss vertical and diagonal members with up to 1/4" deep arrested section loss by up to the full width of the interior face of one channel web, with corrosion beginning to re-activate in some areas. In addition, there are localized truss members with areas of moderate to heavy arrested section loss including corrosion holes as follows:

South Approach Span

• East truss, L3L4 at truss joint L4: There is heavy section loss to the exterior face of both web plates and up to 3/4" wide corrosion holes to the outstanding legs of the bottom flange angles. A similar but less severe condition exists at the same location on the west truss. Some areas exhibit paint failure with active corrosion.

Lift Span

• West Truss:

o L9U9 at truss joint U9: There is a 1'-3" high by 2" wide area with as little as 1/16" remaining thickness with three, 1/8" diameter pinholes in the outstanding leg of the southeast flange angle crevice corrosion along the plate. Crevice corrosion has begun to reactivate.

o L4'U4' at truss joint U4': There is a 3" high by 2 1/2" wide area of heavy section loss with multiple pinholes in the outstanding leg of the southeast flange angle.

North Approach Span

• West Truss:

o L2U1 near truss joint U1: There is moderate arrested section loss to the interior face of both channel webs with a 2" high corrosion hole in the east channel web.

o L3U3 near truss joint U3: There is heavy section loss with a 1/4" wide corrosion hole in the outstanding leg of the southeast flange angle.

• East Truss:

o L1U2 near truss joint L1: There is heavy arrested section loss to the exterior faces of both channel webs with two, up to 1" wide corrosion holes in the east channel web.

♦ Deformation of approach span gusset plates due to pack rust – There are approach span gusset plates at the mid-height intersection of the diagonal members with minor bowing along the free edges due to pack rust between the truss diagonal member and gusset plate as follows:

• South approach span at west truss joint H: The north free edge of both gusset plates exhibits outward bowing due to 1/4" thick pack rust between the diagonal member and the bottom north corner of the gusset plate.

• North approach span at west truss joints H and G: The south free edge of both gusset plates exhibits outward bowing due to 1/4" thick pack rust between the diagonal member and the bottom north corner of the gusset plate.

♦ Significant section loss to stringers and isolated floorbeams – The stringers typically exhibit corrosion holes up to 1/2" wide at the edge of the outstanding legs of the top flange angle directly below the timber railroad ties. The paint at a majority of these locations is starting to fail with corrosion beginning to reactivate. Floorbeam 0 at the connection to the east truss in the north approach span exhibits a localized 1 1/4" high corrosion hole in the bottom of the web plate.

♦ Tower diagonal and horizontal members with scattered corrosion holes – There are isolated diagonal and horizontal members on the east and west sides of each tower with up to 2 1/2" diameter corrosion holes in the channel webs and flanges.

of the Vertical Lift Railroad Bridge

♦ Fatigue sensitive details (FSD's) on fracture critical members (FCM's) – There are scattered FSD's on FCM's in the form of welded attachments, weld remnants from removed attachments, steel rolling defects with jagged edges, gouges in the base metal and flame cut holes with jagged edges.

♦ Missing pointing between masonry stones – The corners of the abutment breastwalls exhibit areas of missing pointing between the top two courses of masonry stones, up to 6'-0" long by 3'-0" wide with penetrations up to 1'-8" deep. In addition, the noses of both pier walls exhibit similar but less severe areas of missing pointing.

Some additional general inspection findings are as follows:

♦ The main truss members exhibit minor pack rust between the riveted built-up components with associated plate warping and localized section loss on individual components. This pack rust and section loss is typically arrested by the current paint system, with localized areas of active corrosion.

The built-up riveted floorbeams and stringers exhibit localized areas of arrested section loss to the lower portion of the web plates, typically at the ends of the member. The section loss exhibited by the main truss members, floorbeams and stringers is typically 1/8" deep.

♦ The built-up riveted tower columns typically exhibit areas of 1/8" deep arrested section loss to the web plates, most notably throughout the landside tower columns. There are localized areas of up to 1/4" deep arrested section loss to the interior web plate along the full length of the utility support angles that are intermittently attached throughout the full height of the landside tower columns.

♦ A painting program was completed in 2016, which included cleaning and spot-painting select areas throughout the bridge, where the existing paint coating had failed, and active corrosion was present.

Overall, the paint system on the Vertical Lift Railroad Bridge is in fair condition. All section loss to primary structural members is typically arrested by the paint system. There are several areas throughout the bridge where rust is bleeding through the paint and is starting to crack/blister with active corrosion. A majority of these areas with signs of paint failure are at recently spot-painted areas.

♦ In certain wind conditions the lift span rail extensions make hard contact with the approach rail centering device when lowered due to miss-alignment. A project is underway to adjust the centering device wear plates to prevent such contact.

The elevator shafts were not inspected in this inspection, or the 2020 inspection. The 2024 inspection must include a plan to inspect the elevator shafts either by rope access, or by use of protected climbing using the ladders.

It is recommended to perform a load rating update to account for the as-inspected conditions of the truss members, floor system members and the tower members throughout the bridge since the previous rating was performed in 2000. See appendix A for additional recommendations and improvements.

2. General Information The Vertical Lift Railroad Bridge is one of three Cape Cod Canal crossings and carries a single track of the Massachusetts Coastal Railroad across the Cape Cod Canal in the neighborhood of Buzzards Bay in Bourne, MA (see Photo 1 through Photo 12 for general views of the bridge). The bridge, constructed in 1935 under the direction of the United States Army Corps of Engineers, is a three-span bridge with one main lift span which is flanked by a tower/approach span at each end. The spans are designated as the south approach span, lift span and north approach span from south to north. The substructure is labeled abutment A, pier B, pier C and abutment D from south to north.

The total length of the bridge is 806 feet from center-to-center of abutment bearings and supports a single railroad track on an open timber tie deck. All spans are composed of riveted steel through trusses. The main lift span is 544 feet, center-to-center of live load bearings. The approach spans are 128 feet long from center of abutment bearings to center of tower bearings. The main lift span in the raised position provides a vertical clearance of 136 feet above mean high water. See Appendix D, sketches D-1 through D-9 for location map, general plans, elevations, and cross sections.

The bridge has served the New York, New Haven and Hartford Railroad Company, the New York Central Railroad, the Penn Central Railroad, and the Consolidated Railway Corporation. The approach tracks are owned by the Commonwealth of Massachusetts. The Mass Coastal Railroad utilizes the bridge to haul waste from Cape Cod typically six days a week. The Massachusetts Bay Transportation Authority (MBTA) provides passenger rail service (the Cape Flyer) on weekends during the summer months from Boston to Hyannis. The passenger train requires the vertical lift bridge to operate six times per week from June to September. The Otis company also runs a train twice a week carrying construction waste and scrap. The bridge is owned, operated, and maintained by the United States Army Corps of Engineers, New England District.

Deck and Superstructure The main lift span has eighteen panels; the southern and northern most panels are 30'-3" long and all other panels are 30'-2 5/8" long. The center-to-center distance between through trusses is 27'-0". The truss joints in the lift span are labeled symmetrically about the midspan at joint 9 with the joints to the north differentiated with a "prime" designation. From south to north, these truss joints are designated 0 to 9 then 8' to 0'.

The south and north approach spans each have four panels with all panels 31'-10" long. The center-to-center distance between through trusses is 33'-0". The truss joints are designated 0 to 4 from the pier to the abutment. In each truss panel, the diagonal members intersect at the midpoint and are designated as truss joints F, G, H and K from the abutment to the pier.

The floor system in all spans consists of two steel built-up riveted stringers supported by steel built-up riveted floorbeams located at each truss joint. The stringers, labeled as east and west, are spaced at 6'- 6" on-center and support timber ties, typically spaced at 1'-1 7/8" on-center. There is an open steel grated walkway, supported by transverse support channels cantilevered off the east stringer in all spans.

The approach spans frame into built-up riveted towers at each pier. Each tower consists of four columns and associated bracing with four, 43'-5 1/4" high panels. The canal side tower joints are labeled vertically L0, U0, and A0 through C0 from the pier to the top of the tower column. Similarly, the land side tower joints are labeled vertically L1, U1 and A1 through C1 from the lower chord of the truss to the top of the tower column. The towers support the lift span, sheave girders, sheaves, counterweights/cable ropes, machinery house, electrical motors, machinery, spire and messenger cables/brackets. At the top of each tower, there are eight built-up riveted longitudinal sheave girders supported by a transverse girder at the front (canal side) and rear (landside) sides of each tower. The longitudinal sheave girders are numbered 1 through 8 from west to east.

Substructure Both abutments and piers are constructed of reinforced concrete and faced with granite blocks on the upper portions and capped with a reinforced concrete coping seat. The abutments and piers are founded on oak piles.

Fracture Critical Members The fracture critical members on this bridge are the truss lower chords, truss vertical tension members, truss diagonal tension members and floorbeams. See Appendix D, sketches D-3 & D-5 for identification of fracture critical members.

Miscellaneous There are messenger cables that span the canal on either side of the lift span in the raised position. The cables on each side are suspended over the canal by a pair of 1 1/4" diameter steel cables, supported by built-up welded catenary brackets attached to the upper portion of each canal side tower column. The backstay portion of these cables is anchored in reinforced concrete blocks embedded into the ground approximately 60 feet beyond each abutment.

Navigation lights are mounted to the topside of the pier coping seat at both piers and to the lift span truss lower chords. There is a single aviation light atop each tower spire.

The vertical lift span is a tower-drive type operated by two 200 horsepower, DC electric motors (one in each tower). An additional 200 horsepower motor exists in each tower as a redundant unit. A 750-kilowatt diesel generator is located at the north approach and is available to furnish emergency power.

The main rails are 115-pound rails and the inner guard rails are 100-pound rails. The track gage is standard width. The track structure is examined once a week by a railroad track supervisor and the running rails are tested periodically by a rail detector car.

The current speed limits on this bridge are 15 mph for freight trains and 20 mph for passenger trains.

Maintenance and Repair History The following table lists the improvements to the structure since 1935:

MAINTENANCE AND REPAIR HISTORY

Year Work Performed

1940-1941 Cleaning and painting of superstructure.

1950-1952 Cleaning and painting of superstructure.

1954 Railroad tie replacement work. Installation of new diesel auxiliary generator begun.

1955 Railroad tie replacement work, construction of new generator house, installation of new diesel auxiliary generator completed, and installation of new power cables begun.

1956 Installation of new power cables completed, and generator house remodeled.

1957 Installation of fence around generator house.

1958-1960 Painting of superstructure.

1960-61 Replacement of all main counterweight cables.

MAINTENANCE AND REPAIR HISTORY (CONTINUED)

Year Work Performed

1966 Installation of new elevators and enclosures.

1967 Painting of superstructure.

1973-1974 Painting of superstructure.

1976-1977 Miscellaneous structural, electrical and mechanical repairs, modifications and rehabilitation. Replacement of main and secondary messenger cables. Repair of south backstay anchorage concrete.

1981-1982 Painting of superstructure.

1996-1997 Installation of new 750-kilowatt standby generator and power system.

Installation of new elevators.

2001 Installation of new rail miter joints.

2001-2003 Phase 1 Contract – Structure metalwork repairs and blast cleaning and painting.

Phase 2 Rehabilitation Contract – Replaced track system, catenary brackets, messenger cables, main and auxiliary counterweight ropes and main sheave bearings; installed computerized DC drive system and motors, new cabinets containing "state of the art" circuitry and a new control panel.

2014 Mechanical repairs including:

• Measure and adjust the tension of the lift span support ropes

• Measure and adjust the span balance

• Adjust the clearance of two span guide rollers

• Replace the south tower elevator support beam

2016 Painting of superstructure.

2018 Elevator replacement at North and South towers.

2020 Operators house roof replacement

2022 Repairs to the tower spire members and ladders; Damaged USACE right-of-way fence on the northwest embankment at abutment has been repaired; top concrete surface of piers B and C repaired; replacement of lower span lock motor/gear drive assembly; replacement of wear plates located on centering castings; replacement of southeast pier guide roller assembly.

Recent Inspection History The last underwater inspection of the piers was performed in October 2020. The next underwater inspection is scheduled for 2025. The last routine inspection was performed in November 2020. The next routine inspection is scheduled for November 2024.

Photo 1: West elevation of the bridge.

Photo 2: East elevation of the bridge.

Photo 3: General view of the lift span looking north.

Photo 4: General view of the lift span looking South from the North tower spire (2020).

Photo 5: General view of the South approach span, looking North.

Photo 6: West elevation of the South approach span.

Photo 7: General view of the North approach span, looking south.

Photo 8: East elevation of the North approach span.

Photo 9: General view of the underside of the floor system in the lift span, looking south from North tower.

Photo 10: North elevation of the South tower and spire, with lift span in the lowered position.

Photo 11: General view of the canal, looking west from the lift span.

Photo 12: General view of the canal, looking East from the North Tower.

3. Inspection Procedure The 2022 Routine Inspection of the Vertical Lift Railroad Bridge was performed by Structural Engineers from NAP and NAE of USACE from November 14, 2022 through November 18, 2022. The routine inspection was a visual inspection with hands-on inspection performed on all fracture critical members.

Access to the bridge elements was achieved through a combination of rope access, protected climbing, boat, and on foot from the walkways throughout the structure (see Photo 13 through Photo 16). All personnel used 100% tie-off measures when working at heights greater than six feet. Communication between the Rope Access Team Leader and USACE Bridge Control was maintained via radio contact throughout the workday to ensure all personnel onsite were clear of hazards during moveable bridge operations.

Cape Cod Canal Operations staff provided safety boat and personnel to perform water rescues during all work over water.

All inspectors performing rope access work are Society of Professional Rope Access Technicians (SPRAT) Level I certified. Supervision was provided by a SPRAT Level III, with assistance by a SPRAT Level II rigger.

Details of inspection procedures as well as means of access for the various areas are as follows:

Lift Span The lift span trusses and associated secondary members were accessed by protected climbing and rope access. The lift span floorbeams were inspected via boat. Coordination with the with bridge operator was required in order to inspect the members while the lift bridge was down during a specific window of time.

For the lift span truss and secondary members, vertical lines were rigged to bracing members above each vertical member. Climbers transferred on and off ropes from the walkway and railroad ties. The fracture critical truss diagonal members were climbed utilizing protected climbing techniques. Diagonal members L5U5 and L5’U5’ have wider lacing bars than what can be accommodated by a snap hook, and therefore utilized rope-to-rope transfer. Permanent steel cable safety lines along the lift span upper chords provide access along the upper chords.

Approach Spans The approach span trusses, portals, and decorative members were accessed by protected climbing. The floorbeams, stringers, and floor system were accessed via boat.

Towers and Counterweight The tower and associated bracing members were accessed by descending each tower column from the machinery house walkway, down to the pier/truss lower chord utilizing rope access techniques. The spires on top of each tower are typically inspected from the access ladder within each spire while maintaining 100% tie-off. Due to ongoing repairs, active workers, and equipment the spires were not inspected during this routine inspection. A full inspection will be conducted during the next routine inspection in 2024. Due to prior deterioration of the spire members, inspection should not be conducted by climbing the spire itself until they are deemed secure/safe. The sheave girders at the top of each tower were visually inspected from the catwalk that runs transversely below the midspan of these girders. Access to this catwalk can be gained from within the sheave room.

The main counterweight connection to the lifting cables was inspected from the topside of the counterweight utilizing 100% tie-off. The lifting girders were visually inspected from the adjacent staircase and from tower bracing members utilizing protected climbing techniques. The main lifting cables were visually inspected while descending along the tower columns, from the topside of the counterweight and from the lifting girder.

Abutments, Piers and Bearings The abutments and associated bearings were inspected from the bridge seat and from the adjacent embankment with the protection of a personal floatation device (PFD).

The piers and associated bearings were inspected from the pier coping seat and boat with the protection of a PFD and visually inspected from the embankments.

Catenary Brackets, Backstays and Backstay Anchorages The catenary brackets were inspected from the platform adjacent to these brackets while maintaining 100% tie-off. Access to the platforms adjacent to these brackets can be gained from hatches in the machinery house walkway floor above each bracket. It should be noted that the handle for the southeast catenary bracket access hatch was missing during this inspection and additional means of opening this hatch were necessary.

The backstay cables were visually inspected from the ground, from the catenary brackets and from the lift span truss upper chords. The backstay anchorages were accessed from the ground.

Railroad Tracks and Ties The railroad tracks and railroad ties were inspected from the adjacent walkway and the top of the ties while maintaining 100% tie-off.

Photo 13: Inspection of north approach members utilizing rope access and protected climbing.

Photo 14: Inspection of north tower utilizing rope access climbing.

Photo 15: Inspection of north tower utilizing rope access climbing.

Photo 16: Rigging of lift span primary and backup lines; climber utilizing protected climbing.

4. Summary of Inspection Findings General The inspection findings for the Vertical Lift Railroad Bridge 2022 Routine Inspection are presented in detail in this section. The bridge element items are assigned a rating with the rating assessment based on the FHWA Condition Rating Guide on the following pages.

FHWA Condition Rating Guidelines The condition rating guidelines used in this report are adopted from the Bridge Inspectors Reference Manual (BIRM) dated December 2012 with additional information added to the guidelines to clarify the coding of fatigue sensitive detail specific deficiencies. Numerical condition ratings characterize the general condition of the component being rated in aggregate. They do not describe localized or nominally occurring instances of deterioration. Correct assignment of a condition rating considers both the severity of the deterioration and the frequency of occurrence. If a deficiency reduces the capacity or serviceability of a component, the rating of the component is reduced accordingly.

FHWA Item 58 – Deck: The following FHWA general condition rating guidelines were used in the evaluation of the deck and the sub elements of the deck.

Code NBI Deck Condition Description N Not Applicable: Use for culverts, roadway tunnels, or filled spandrel arch bridges.

9 Excellent Condition: Deck is in new condition (recently constructed).

Very Good Condition: Deck has very minor (and isolated) deterioration.

• Concrete: minor cracking, leaching, scale, or wear (no delamination or spalling).

• Timber: minor weathering - isolated (minor) splitting.

• Steel: no corrosion (paint/protection system remains sound).

Good Condition: Deck has minor (or isolated) deterioration.

• Concrete: minor cracking, leaching, scale, or wear (isolated delamination, spalling, or temporary patches).

• Timber: minor weathering or splitting (no decay or crushing) - all planks are secure.

• Steel: minor paint failure or corrosion (no section loss) - all connections are secure.

Satisfactory Condition: Deck has minor to moderate deterioration (no repairs are necessary).

• Concrete: moderate cracking, leaching, scale, or wear (minor delamination or spalling).

• Timber: moderate weathering or splitting (isolated decay or crushing) - some planks may be slightly loose.

• Steel: moderate paint failure and/or surface corrosion (minor section loss) - some connections may have worked loose.

Fair Condition: Deck has moderate deterioration (repairs may be necessary).

• Concrete: extensive cracking, leaching, scale, or wear (moderate delamination or spalling).

• Timber: extensive weathering or splitting (moderate decay or crushing) - some planks may be loose, broken, or require replacement.

• Steel: extensive paint failure and/or surface corrosion (moderate section loss) - several connections may be loose or missing, but all deck components remain secure.

Poor Condition: Deck has advanced deterioration (replacement or overlay should be planned).

• Concrete: advanced cracking, leaching, scale, or wear (extensive delamination or spalling) - isolated full-depth failures may be imminent.

• Timber: advanced weathering, splitting, or decay - numerous planks may be loose, broken, or require replacement.

• Steel: advanced corrosion (significant section loss) - deck components may be loose or slightly out of alignment.

Serious Condition: Deck has severe deterioration - immediate repairs may be necessary.

• Concrete: severe cracking, leaching, delamination, or spalling - full-depth failures may be present.

• Timber: severe splitting, crushing or decay - majority of planks may need replacement.

• Steel: severe and section loss - deck components may be severely out of alignment.

2 Critical Condition: Deck has failed - it may be necessary to close the bridge until repairs are completed.

1 "Imminent" Failure Condition: Bridge is closed - corrective action is required to open to restricted service.

0 Failed Condition: Bridge is closed - deck replacement is necessary.

FHWA Item 59 – Superstructure: The following FHWA general condition rating guidelines were used in the evaluation of the superstructure and the sub elements of the superstructure.

Code NBI Superstructure Condition Description N Not Applicable: Use for culverts.

9 Excellent Condition: Superstructure is in new condition (recently constructed).

8 Very Good Condition: Superstructure has very minor (and isolated) deterioration.

Good Condition: Superstructure has minor (or isolated) deterioration.

• Steel: minor corrosion, little or no section loss.

• Concrete: minor scaling or non-structural cracking (isolated delamination or spalling).

• Timber: minor weathering or splitting (no decay or crushing).

• Masonry: minor weathering or cracking (joints have little or no deterioration).

Satisfactory Condition: Superstructure has minor to moderate deterioration. Members may be slightly bent or misaligned - connections may have minor distress.

• Steel: moderate corrosion (section loss or fatigue cracks in non-critical areas).

• Concrete: moderate scaling or non-structural cracking (minor delamination or spalling).

• Timber: moderate weathering or splitting (minor decay or crushing).

• Masonry: moderate weathering or cracking (joints may have minor deterioration).

Fair Condition: Superstructure has moderate deterioration. Members may be bent, bowed, or misaligned. Bolts, rivets, or connectors may be loose or missing, but connections remain intact.

• Steel: extensive corrosion (initial section loss in critical stress areas). Fatigue cracks (if present) have been arrested or are not likely to propagate into critical stress areas.

• Concrete: extensive scaling or cracking (structural cracks may be present), moderate spalling or delamination (reinforcement may have some section loss).

• Timber: extensive weathering or splitting (moderate decay or crushing).

• Masonry: extensive weathering or cracking (joints may have slight separation or offset).

Poor Condition: Superstructure has advanced deterioration. Members may be significantly bent or misaligned. Connection failure may be imminent. Bearings may be severely restricted.

• Steel: significant section loss in critical stress areas. Un-arrested fatigue cracks exist that may likely propagate into critical stress areas.

• Concrete: advanced scaling, cracking, or spalling (significant structural cracks may be present - exposed reinforcement may have significant section loss).

• Timber: advanced splitting (extensive decay or significant crushing).

• Masonry: advanced weathering or cracking (joints may have separation or offset).

Serious Condition: Superstructure has severe deterioration - immediate repairs or structural evaluation may be required. Members may be severely bent or misaligned -connections or bearings may have failed.

• Steel: severe section loss or fatigue cracks in critical stress areas.

• Concrete: severe structural cracking or spalling.

• Timber: severe splitting, decay, or crushing.

• Masonry: severe cracking, offset or misalignment.

Critical Condition: Superstructure has critical deterioration - primary structural elements may have failed (severed, detached or critically misaligned). Immediate repairs may be required to prevent collapse or closure.

1 "Imminent" Failure Condition: Bridge is closed - superstructure in no longer stable (corrective action might return the structure to restricted service).

0 Failed Condition - Bridge is closed - superstructure is beyond the point of corrective action.

FHWA Item 60 – Substructure: The following FHWA general condition rating guidelines were used in the evaluation of the substructure and the sub elements of the substructure.

Code NBI Substructure Condition Description N Not Applicable: Use for culverts.

9 Excellent Condition: Substructure is in new condition (recently constructed).

8 Very Good Condition: Substructure has very minor (and isolated) deterioration.

Good Condition: Substructure has minor (or isolated) deterioration.

• Concrete: minor cracking, leaching, or scale (isolated delaminations or spalls).

• Steel: minor paint failure and/or surface corrosion (little or no section loss).

• Timber: minor weathering or splitting (no decay or crushing).

• Masonry: minor weathering or cracking (joints have little or no deterioration).

Satisfactory Condition: Substructure has minor to moderate deterioration. Scour or erosion (if present) is minor and isolated. There may be slight movement or misalignment.

• Concrete: moderate scaling, cracking, or leaching (minor delamination or spalling).

• Steel: moderate paint failure and/or surface corrosion (minor section loss).

• Timber: moderate weathering or splitting (minor decay or crushing).

• Masonry: moderate weathering or cracking (joints may have minor deterioration).

Fair Condition: Substructure has moderate deterioration - repairs may be necessary. There may be moderate scour, erosion, or undermining. There may be minor settlement, movement, misalignment, or loss of bearing area.

• Concrete: extensive scaling, cracking or leaching (isolated structural cracks may be present) - there may be moderate delamination or spalling.

• Steel: extensive paint failure and/or surface corrosion (moderate section loss).

• Timber: extensive weathering or splitting (moderate decay or crushing).

• Masonry: extensive weathering or cracking (joints may have slight separation or offset).

Poor Condition: Substructure has advanced deterioration - repairs may be necessary to maintain stability. There may be extensive scour, erosion, or undermining. There may be significant settlement, movement, misalignment, or loss of bearing area.

• Concrete: advanced scaling, cracking, or leaching (significant structural cracks may be present) - there may be extensive delamination or spalling.

• Steel: advanced corrosion (significant section loss).

• Timber: advanced splitting (significant decay or crushing).

• Masonry: advanced weathering or cracking (joints may have separation or offset).

Serious Condition: Substructure has severe deterioration. Immediate corrective action may be required. Scour, erosion, or undermining may have resulted in severe settlement, movement, misalignment, or loss of bearing area.

• Concrete: severe spalling or structural cracking.

• Steel: severe section loss.

• Timber: severe decay or crushing.

• Masonry: severe cracking, offset or misalignment.

Critical Condition: Substructure has critical damage or deterioration (near the point of collapse)

- it may be necessary to close the bridge until corrective action is completed. Scour may have removed substructure support.

1 Imminent Failure Condition: Bridge is closed to traffic due to substructure failure - corrective action may restore the bridge to light service.

0 Failed Condition: Bridge is closed due to substructure failure - beyond corrective action (replacement required).

FHWA Item 61 – Channel and Channel Protection: The following FHWA general condition rating guidelines were used in the evaluation of the channel and channel protection.

Code NBI Channel Condition Description N Not Applicable: Bridge is not over a waterway.

9 Excellent Condition: There are no noticeable or noteworthy deficiencies.

8 Very Good Condition: Channel banks are protected (or well vegetated) - there is little or no erosion. Control structures and protection devices (if present) have little or no deterioration. Any drift or debris in the channel is incidental. Culvert barrel has little or no sediment.

Good Condition: Channel has no notable aggradation, degradation, or lateral movement. There is no notable scour around the bridge substructure. The banks may have minor erosion - bank protection (if any) may have minor deterioration. Control structures and/or protection devices may have minor deterioration. There may be minor drift or debris in the channel. Culvert barrel may have minor sediment.

Satisfactory Condition: Channel may have minor aggradation, degradation, or lateral movement.

The channel banks may have moderate erosion or slumping - bank protection may have moderate deterioration. Control structures and/or protection devices may have moderate deterioration. Drift or debris in the channel may be slightly restricting the channel. Culvert barrel may have moderate sediment.

Fair Condition: Channel may have moderate aggradation, degradation, or lateral movement, but the bridge and approaches have not yet been adversely affected. The channel banks may have extensive erosion - the bank protection may have extensive deterioration. Control structures and/or protection devices may have extensive deterioration but are functioning as intended.

Debris in the channel (or sediment in the culvert barrel) is restricting the channel and should be removed.

Poor Condition: Aggradation, degradation, or lateral movement of the channel may be adversely affecting the bridge and/or approaches. Channel banks may have severe erosion - the bank protection may have severe deterioration. Control structures and/or protection devices may be deteriorated to the extent that they are no longer functioning as intended. Large accumulations of debris or sediment are severely restricting the channel and should be removed immediately.

3 Serious Condition: Aggradation, degradation, or lateral movement has altered the channel to the extent that the bridge (or approach roadway) is threatened. Bank protection has failed. Control structures and/or protection devices have been destroyed.

2 Critical Condition: Aggradation, degradation, or lateral movement has altered the channel to the extent that the bridge is near a state of collapse. It may be necessary to close the bridge until corrective action is completed.

1 Bridge closed due to channel failure: Corrective action may restore bridge to light service.

0 Bridge closed due to channel failure: Replacement necessary.

4.1 Substructure (Overall Rating of Good Condition = 7)

The overall condition rating for the substructure is based on evaluation of the condition of the above water portions of the abutments and piers, as well as the backstay anchorages.

4.1.1 – Piers (Good Condition = 7) Both of the piers exhibit moderate marine growth on the granite blocks within the tidal zone (see Photo 17). There are areas of missing grout in multiple locations with voids up to 1’-6” deep (see Photo 19). The topside and vertical faces of the concrete coping seat exhibit scattered areas of hairline map cracking, some with light efflorescence.

Localized areas of heavy scaling and minor spalls in the concrete coping seat that were noted in the previous inspection have been repaired (see Photo 18).

4.1.2 – Abutments (Good condition = 7) Both abutments exhibit moderate to heavy marine growth on the granite blocks within the tidal zone and a minor accumulation of debris on the coping seats (see Photo 20). There are areas of missing pointing between the first and second courses of granite blocks from the top at the corners of both breastwalls, up to 6'-0" long by 3'-0" wide with penetrations up to 1'-8" deep (see Photo 21). Both abutment backwalls and coping seats are in good condition with small, localized areas of deficiencies as follows:

• At North back wall a utility clip has detached (see Photo 22).

• Hairline cracks in the Northwest wingwall at approximately 2’-0” on center.

• Northwest back wall grounding wire conduit is broken and has exposed the grounding wire (see Photo 23).

• Grounding cable conduit on west side of north abutment is broken at connector (see Photo 24)

Photo 17: North elevation of pier C with moderate marine growth.

Photo 18: Pier B areas of heavy scaling have been repaired.

Photo 19: Pier B North elevation, missing grout.

Photo 20: North elevation of abutment A with moderate marine growth.

Photo 21: Missing pointing at the east end of the abutment A breastwall.

Photo 22: Disconnected Utility clip at North backwall.

Photo 23: Broken grounding wire conduit with exposed grounding wire at north backwall.

Photo 24: Broken conduit connection at west side of north abutment.

4.1.3 – Backstay Anchorages (Good Condition = 7) There is moderate vegetation growth surrounding the backstay anchorage systems. There are isolated areas of peeling paint with light rust to the longitudinal anchorage beam, transverse channels and threaded rods for the backstay anchorage systems, heaviest at the southeast backstay (see Photo 25). A majority of the cotter pins for the pin at the clevis are not properly splayed, with only one leg of the pin splayed (see Photo 28).

Additional deficiencies to the backstay anchorage system are as follows:

Southeast Backstay Anchorage:

• The north transverse channel bottom flange is bent upwards 1" over a 2" length adjacent to a bolt.

• The bottom of the longitudinal anchorage beam is in contact with the ground (see Photo 25).

Northwest Backstay Anchorage:

• There is 1/8" deep by full height section loss with active corrosion to the interior face of the south transverse channel web adjacent to the west threaded rod (see Photo 26).

• There is 1/8" deep by 1" high active section loss for the full width of the exterior face of the north transverse channel web.

Northeast Backstay Anchorage:

• The cotter pin at the west clevis is not splayed.

The northeast backstay anchorage is surrounded by a rectangular pit composed of mortared concrete blocks (see Photo 27). The pit walls have several full height vertical cracks in the concrete blocks, up to 1/4" wide. There is a minor accumulation of debris and vegetation growth at the bottom of the pit. There are spalls in the concrete blocks at the top of the walls, above the ground level as follows:

• There is a 2'-4" long by 4" high by 7" deep spall in the interior face of the east wall.

• There is a full length by up to 6" high by up to full depth spall in the exterior face of the west wall, continuing 1'-9" onto the exterior face of the south wall and 2'-6" on the exterior face of the north wall.

• There is a 1'-0" wide by 6" high by 7" deep spall in the interior face of the north wall.

Photo 25: The bottom of the longitudinal anchorage beam is in contact with the ground at the southeast backstay anchorage. Note the peeling with light rust throughout the anchorage and debris/vegetation.

Photo 26: Active section loss to the interior face of the south traverse channel at the west threaded rod at the northwest backstay anchorage.

Photo 27: General view of the northeast backstay anchorage pit, showing cracked Concrete and spall at corner

Photo 28: Typical Improperly splayed cotter pin in backstay.

4.2 Channel and Channel Protection (Overall Rating of Good Condition = 7) The overall condition rating for the channel and channel protection is based on the evaluation of the condition of the embankments of the canal near the abutments.

4.2.1 – Embankments (Good Condition = 7) The embankments of the canal near the abutments are lined with dumped stone rip-rap, and have moderate vegetation growth beyond this rip-rap (see Photo 29 and Photo 30) . Areas of minor erosion along the embankments are as follows:

• The southwest embankment at abutment A exhibits small areas of missing rip-rap stones, exposing the gravel base course (see Photo 31).

• The southeast embankment near abutment A exhibits isolated displaced rip-rap stones with minor washout of the gravel base course (see Photo 32).

• The northeast embankment along the full length of the abutment D wingwall exhibits a minor 2'-0" wide by 4" deep erosion trench.

4.2.2 – Navigation and Aviation Lights (Very Good Condition = 8) The navigation lights mounted to the pier coping seats and lift span truss lower chords as well as the aviation light atop each tower spire were functioning during this inspection.

Photo 29: General view of the northeast embankment.

Photo 30: General view of the southwest embankment.

Photo 31: Missing rip-rap stones with exposed aggregate along southwest embankment at abutment A.

Photo 32: Displaced rip-rap stones with minor washout of the gravel base course at the southeast embankment near the abutment A wingwall.

4.3 Superstructure (Overall Rating of Fair Condition = 5)

The overall condition rating for the superstructure is based on the evaluation of the condition of the bearings, trusses, truss gusset plates, truss bracing, truss portals, floorbeams, stringers and towers.

4.3.1 – Bearings (Good Condition = 7) Approach Span Bearings The approach span bearings at each abutment consists of two truss expansion bearings and a single rocker bearing supporting the midspan of floorbeam 4. The truss expansion bearing anchor bolts typically exhibit up to 1/16" deep arrested section loss by up to 3" high by the full circumference along the masonry plate (see Photo 33). Corrosion has re-activated on the abutment expansion bearing masonry plates, bearings, and anchor bolts and nuts (see Photo 34). Additionally, on one anchor bolt at the east expansion joint of Abutment A has heavy active corrosion that is delaminating. The floorbeam rocker bearings typically exhibit up to 50% section loss to the lower anchor bolt nuts for the masonry plate (see Photo 35).

The truss expansion bearing anchor bolts are bent towards the contracted position as follows:

• Abutment A, west truss bearing: Both west anchor bolts are bent up to 1" to the north (This condition was initially reported in 1984 and has not appreciably changed since then.).

• Abutment A, east truss bearing: All anchor bolts are bent 3/8" to the north.

• Abutment D, west truss bearing: Both west anchor bolts are bent up to 1 1/2" to the south (This condition was initially reported in 1984 and has not appreciably changed since then.) (see Photo 36).

The positions of the abutment expansion bearings were measured, and the results are tabulated in Appendix D, sketches D-14 & D-15 of this report. The data indicates that the magnitude of span movement with respect to temperature change is consistent with previous measurements. All bearings appear to be functioning properly with no evidence of restricted movement. The benchmarks for measuring the expansion and contraction of the bearings have significantly deteriorated over the years, becoming nearly unreadable, and should be marked again.

The bearings for the approach spans at each pier consist of fixed bearing supporting each stringer and a fixed rocker bearing supporting each truss and tower column at truss joint L0. The stringer bearings typically exhibit small areas of peeling paint with light rust. There is up to 90% section loss to all bottom anchor bolt nuts for the east stringer bearing at pier B in the south approach span (see Photo 37).

Tower Bearings There are rocker bearings at the base of each canal side tower column. These tower bearings typically exhibit peeling paint with light rust, moderate rust staining, and minor section loss at the interface of the masonry plate and bearing rocker (see Photo 38). In addition, there is typically up to 1/4" thick pack rust with minor debris accumulation between the masonry plate and the rocker on the north and south sides (see Photo 39).

Lift Span Bearings The lift span bearings at each pier consist of two truss expansion bearings at the north end, two truss fixed bearings at the south end and a single floorbeam bearing at the midspan of each floorbeam. There is typically peeling paint with light rust and minor section loss to the masonry plates and anchor bolt nuts for the truss and floorbeam bearings (see Photo 40 and Photo 41).

Photo 33: Arrested section loss to the lower portion of the east anchor bolts for the east truss bearing at abutment A in the south approach span.

Photo 34: Corrosion re-activation with paint failure, blistering, and section loss of the north approach span abutment D east bearing bolt.

Photo 35: Up to 50% section loss to the lower anchor nut for the masonry plate at the floorbeam 4 rocker bearing at abutment A in the south approach span.

Photo 36: Anchor bolts bent to the south at the west side of the west truss expansion bearing at abutment D in the north approach span.

Photo 37: Section loss to the lower anchor bolt nuts for the east stringer bearing at pier B in the south approach span.

Photo 38: Peeling paint with minor section loss to the rocker bearing at the interface of the masonry plate at the west for the north tower at pier C.

Photo 39: Pack rust minor debris between the masonry plate and rocker on the south side of the west bearing for the south tower at pier B

(2020 photo).

Photo 40: Peeling paint with light rust to the west truss span bearing at pier B.

Photo 41: Peeling paint with light rust to the masonry plate for the east truss lift span bearing at pier C.

4.3.2 – Structural Steel

4.3.2.1 – Approach Spans 4.3.2.1.a – Approach Span Truss Upper Chords (Good Condition = 7) The upper chords in the approach spans exhibit localized areas of peeling/cracked paint system with light active corrosion. Pitting and section loss of the lower lacing bars remains largely arrested. There are corrosion holes in the batten plates on the approach span upper chord members as follows:

• South approach span, east truss, U1U2 at U1: A 3" long by 3" wide corrosion hole in the top batten plate with active corrosion (see Photo 42).

• North approach span, west truss, U2U3 at U2: Two, up to 2" long by 1/2" wide corrosion holes in the top batten plate (see Photo 43), with active corrosion throughout the vicinity.

Other notable areas of deterioration include:

• South approach span, east truss, U1U2 at U1: Previously arrested…