Floyd_Bennett_Field_Manhole_Investigation_20161220.pdf

Jamaica Bay Unit of Gateway National Recreational Area

Manhole Investigation at Floyd Bennett Field

National Park Service

Manhole Investigation Report Draft

December 20, 2016

NPS Contract No. P15PC00008 Task Order No. P16PD03809

Jamaica Bay Unit of Gateway National Recreational Area – Floyd Bennett Field Manhole i

Contents Introduction

Investigation

Findings

Appendix A - Floyd Bennett Field Primary Electrical Cables Plan View

Appendix B - Areas of Concern

Appendix C - Manhole Observations

Introduction Floyd Bennett Field, a historic district of approximately 1,400 acres, is the primary year-round center for park operations in the Jamaica Bay Unit of Gateway National Recreation Area. The

Jamaica Bay Unit encompasses about 18,560 acres in southern Brooklyn and Queens and contains the largest contiguous area of open space in New York City. Public use of Floyd Bennett

Field is estimated to be about one million visits per year.

The existing primary electrical cabling system at Floyd Bennett Field has had multiple failures due to its age. Most of the cabling dates from the early 1940s when the Field was converted for use as a Naval Air Station during World War II. The remaining cabling is a mix of the original cables from the 1930s when the Field was in use as the first airport for the City of New York and cables that were recently replaced during the first phase of the project. The cabling provides primary electrical service to 95% of the buildings on Floyd Bennett Field. Areas served by the cables include the Jamaica Bay Education Campus, Historic Hangar Row including the Ryan

Visitor Center, the Jamaica Bay unit maintenance shop and headquarters, and headquarters for the USPP (United States Park Police) New York Field Office. This phase of this project will complete the replacement of the deteriorated, underground electrical cable at Floyd Bennett

Field.

Investigation Based on the Schematic Design for this project, the cable replacement project includes the use of existing electrical manholes at Floyd Bennett Field to route and splice cables. An investigation of these manholes was performed to document their conditions and to note any areas of concern with the reuse approach.

The manhole investigation at Floyd Bennett Field was performed by HDR on November 14th, 16th, and 17th, 2016 to inspect 41 manholes and to document the existing conditions of each structure noting any areas of concern observed during this process. To facilitate the investigation, the National Park Service (NPS) maintenance staff for Floyd Bennett Field located all the manholes a week prior, marked them with long metal bars embedded in the ground, spray painted orange on the covers for visibility and pumped the water out of the manholes.

Some of the manholes were located in areas overgrown with weeds, trees, and shrubs that required excavation and the use of heavy machinery. During the investigation, HDR was accompanied by the maintenance staff to aid in locating each structure, to remove each structures cover, and pump out any additional water if encountered.

The investigation included verifying each structure’s designation number, documenting the cover/access details, determining if there appeared to be any surface drainage problems that would cause surface water to flow into the manhole based on the surrounding surface grade, reviewing the structural condition, verifying code compliance, and determining the constructability for new ductbanks. To facilitate a safe investigation and avoid shutting down any facilities by de-energizing circuits in the manholes, a camera was lowered into each manhole. The camera was attached to a medium voltage insulated fiberglass pole with a lighting attachment for increased visibility of the manholes. The camera was remotely controlled from a tablet and these devices were connected through a wireless connection. The camera transmits a high-resolution video feed to the tablet for the investigation and each side of the structure was photographed in high-resolution to help determine if there were any areas of concern. A plan view of the manhole locations is located in Appendix A, a photo log of areas of concern in

Appendix B, and manhole observations in Appendix C.

Findings The investigation revealed that three different types of construction methods were used for the manholes. The first and most common method of construction is cast-in-place (CIP) concrete walls with a CIP roof slab, which comprised 34 of the reviewed structures. The second most common construction method, found in 6 of the structures, was all brick walls with a CIP roof slab. The third construction method was one manhole that was built with CMU (concrete masonry unit) block walls and a CIP roof slab. Most of the manholes (regardless of construction type) had collars built of brick to elevate the manhole lid up to the appropriate elevation. Most of the manholes are constructed in a square shape although a few of the CIP structures were constructed in an octagonal shape.

The structural condition of the manholes, even though the inside of the structures have been discolored over the years, are in remarkably good shape, no cracks were found in any of the CIP walls or roof slabs and all of the brick and CMU walls were in good shape, with a few areas of concern listed below:

Manhole No. 8 has a lid that is chipped (See Photo B-1).

Manhole No. 9X has a rectangular roof hatch with rusted away hinges (See Photo B-2).

This manhole is located in the front of an occupied residence and its lid can easily shift and fall into the manhole creating a safety hazard.

Manhole No. 113, 11W, and H2 have roof slabs with exposed rebar around the opening

(See Photos B-3, B-4, and B-5) with Manhole No. 113 exhibiting concrete honeycombing

(See Photo B-3).

Manhole No. 3 has two cracks in its brick collar (See Photo B-6).

Manhole No. 9-2 and 14-2 have a collar that is slightly offset from the roof opening (See

Photos B-7 and B-8).

Appendix A - Floyd Bennett Field Primary Electrical Cables Plan View

Appendix B - Areas of Concern B-1 Photo – Manhole No. 8

B-2 Photo – Manhole No. 9X

B-3 Photo – Manhole No. 113

B-4 Photo – Manhole No. 11W

B-5 Photo – Manhole No. H2

B-6 Photo – Manhole No. 3

B-7 Photo – Manhole No. 9-2

B-8 Photo – Manhole No. 14-2

B-1 Photo – Manhole No. 8

Area of Concern:

The manhole cover is chipped and can fall into the hole.

B-2 Photo – Manhole No. 9X

Area of Concern :

The hinges of the rectangular roof hatch has completely rusted away. This manhole is located in the front of an occupied residence and its lid can easily shift and fall into the manhole creating a safety hazard.

B-3 Photo – Manhole No. 113

There are several pieces of exposed rebar around the roof opening along with concrete honeycombing.

B-4 Photo – Manhole No. 11W

There is exposed rebar in the roof opening. The exposure is minor.

B-5 Photo – Manhole No. H2

There is exposed rebar on the underside of the roof.

B-6 Photo – Manhole No. 3

There are two cracks in the brick collar.

B-7 Photo – Manhole No. 9-2

Collar is slightly offset from the roof opening.

B-8 Photo – Manhole No. 14-2

Collar is slightly offset from the roof opening.

Appendix C - Manhole Observations 1-14 ....................................................................................................................................... 13 Manhole No.

2 ............................................................................................................................................ 14 Manhole No.

2-1 ......................................................................................................................................... 15 Manhole No.

3 ............................................................................................................................................ 16 Manhole No.

4 ............................................................................................................................................ 17 Manhole No.

5 ............................................................................................................................................ 18 Manhole No.

5AW ....................................................................................................................................... 19 Manhole No.

5BW ....................................................................................................................................... 20 Manhole No.

6 ............................................................................................................................................ 21 Manhole No.

6W ......................................................................................................................................... 22 Manhole No.

7 ............................................................................................................................................ 23 Manhole No.

7W ......................................................................................................................................... 24 Manhole No.

8 ............................................................................................................................................ 25 Manhole No.

8-1 ......................................................................................................................................... 26 Manhole No.

8-2 ......................................................................................................................................... 27 Manhole No.

8W ......................................................................................................................................... 28 Manhole No.

8X .......................................................................................................................................... 29 Manhole No.

9 ............................................................................................................................................ 30 Manhole No.

9-1 ......................................................................................................................................... 31 Manhole No.

9-2 ......................................................................................................................................... 32 Manhole No.

9W ......................................................................................................................................... 33 Manhole No.

9X .......................................................................................................................................... 34 Manhole No.

10 .......................................................................................................................................... 35 Manhole No.

10W ....................................................................................................................................... 36 Manhole No.

11W ....................................................................................................................................... 37 Manhole No.

14 .......................................................................................................................................... 38 Manhole No.

14-1 ....................................................................................................................................... 39 Manhole No.

14-2 ....................................................................................................................................... 40 Manhole No.

15-5 ....................................................................................................................................... 41 Manhole No.

17 .......................................................................................................................................... 42 Manhole No.

22 .......................................................................................................................................... 43 Manhole No.

23 .......................................................................................................................................... 44 Manhole No.

24 .......................................................................................................................................... 45 Manhole No.

44 .......................................................................................................................................... 46 Manhole No.

44B ........................................................................................................................................ 47 Manhole No.

45 .......................................................................................................................................... 48 Manhole No.

46 .......................................................................................................................................... 49 Manhole No.

47 .......................................................................................................................................... 50 Manhole No.

113 ........................................................................................................................................ 51 Manhole No.

H1 .......................................................................................................................................... 52 Manhole No.

H2 .......................................................................................................................................... 53 Manhole No.

1-14 Manhole No.

North Wall East Wall

South Wall West Wall

Manhole Observations

Cover/Access Type: Cast Iron/Round

Cover/Access Size: 37.5” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

Code Compliance for New Ductbanks: Adequate size

Constructability for New Ductbanks: No noted concerns

2 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

2-1 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

3 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

4 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

5 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition:

Good, no cracks, spalls or rust damage. No roof damage noted. Two cracks in the brick collar (See Photo B-6, Appendix)

Code Compliance for New Ductbanks: Adequate size

Constructability for New Ductbanks: No additional concerns noted. Collar cracks should not affect ability to install new ductbanks.

5AW Manhole No.

Cover/Access Size: 33” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

5BW Manhole No.

Cover/Access Size: 33” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

6 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Poor, the surrounding area appears to slope down to the manhole

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

6W Manhole No.

Cover/Access Size: 33” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

7 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Poor, the surrounding area appears to slope down to the manhole

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

7W Manhole No.

Cover/Access Size: 33” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

8 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition:

Good, no cracks, spalls or rust damage. No roof damage noted. Area of concern regarding cover (See Photo B-1, Appendix B)

Code Compliance for New Ductbanks: Adequate size

Constructability for New Ductbanks: No additional concerns noted. Area of concern regarding cover should not affect ability to install new ductbanks.

8-1 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

8-2 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

8W Manhole No.

Cover/Access Size: 33” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

8X Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Poor, the surrounding area appears to slope down to the manhole

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

9 Manhole No.

Cover/Access Size: 32” Diameter

Surface Drainage: Poor, the surrounding area appears to slope down to the manhole

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

9-1 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

9-2 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition:

Good, no cracks, spalls or rust damage. No roof damage noted. Collar is slightly offset from the roof opening (See Photo B-7, Appendix B)

Code Compliance for New Ductbanks: Adequate size

Constructability for New Ductbanks: No additional concerns noted. Offset collar should not affect ability to install

9W Manhole No.

Cover/Access Size: 33” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

9X Manhole No.

Cover/Access Type: Cast Iron/Square

Cover/Access Size: 48”x50”

Surface Drainage: Good

Structural Condition:

Good, no cracks, spalls or rust damage. No roof damage noted. Area of concern regarding roof hatch (See Photo B-2, Appendix B)

Code Compliance for New Ductbanks: Adequate size

Constructability for New Ductbanks: No additional concerns noted. Area of concern regarding roof hatch should not affect ability to install new ductbanks.

10 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

10W Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

11W Manhole No.

Cover/Access Size: 33” Diameter

Surface Drainage: Good

Structural Condition:

Good, no cracks, spalls or rust damage. No roof damage noted. Exposed rebar (See Photo B-4, Appendix B)

Code Compliance for New Ductbanks: Adequate size

Constructability for New Ductbanks: No additional concerns noted. Exposed rebar should not affect ability to install new ductbanks.

14 Manhole No.

Cover/Access Size: 37.5” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

14-1 Manhole No.

Cover/Access Size: 37.5” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

14-2 Manhole No.

Cover/Access Size: 37.5” Diameter

Surface Drainage: Good

Structural Condition:

Good, no cracks, spalls or rust damage. No roof damage noted. Collar is slightly offset from the roof opening (See Photo B-8, Appendix B)

Code Compliance for New Ductbanks: Adequate size

Constructability for New Ductbanks: No additional concerns noted. Offset collar should not affect ability to install

15-5 Manhole No.

Cover/Access Size: 32”x32”

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

17 Manhole No.

Cover/Access Size: 37.5” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

22 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

23 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

24 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

44 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

44B Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

45 Manhole No.

Cover/Access Size: 27” Diameter

Surface Drainage: Good

Structural Condition:

Good, no cracks, spalls or rust damage. No roof damage noted. A large amount of dirt inside.

46 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

47 Manhole No.

Cover/Access Size: 29” Diameter

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

113 Manhole No.

Cover/Access Size: 31.5”x26”

Surface Drainage: Poor, the surrounding area appears to slope down to the manhole

Structural Condition:

Good, no cracks, spalls or rust damage. Exposed rebar and honeycombing (See Photo B-3, Appendix B)

Code Compliance for New Ductbanks: Adequate size

Constructability for New Ductbanks: No additional concerns noted. Exposed rebar and honeycombing should not affect ability to install new ductbanks.

H1 Manhole No.

Cover/Access Size: 32”x26”

Surface Drainage: Good

Structural Condition: Good, no cracks, spalls or rust damage. No roof damage noted

H2 Manhole No.

Cover/Access Size: 32”x26”

Surface Drainage: Poor, the surrounding area appears to slope down to the manhole

Structural Condition:

Good, no cracks, spalls or rust damage. Exposed rebar (See Photo B-5, Appendix B)

Code Compliance for New Ductbanks: Adequate size

Constructability for New Ductbanks: No additional concerns noted. Exposed rebar should not affect ability to install new ductbanks.