Questions_and_Answers_0001.pdf

EVERGLADES NATIONAL PARK – PMIS 343741 – REHABILITATE HM-69 NIKE MISSILE HANGER

ROLLING DOORS

8/05/2025

Prepared by: Jorge Balboa, AIA, LEED AP Historic Architect Everglades, Dry Tortugas and Biscayne National Park

CONTRACTOR QUESTION TO NPS WITH PARK RESPONSES

1. Are the entire a-frames to be replaced?

NPS REPSONSE: All “A”-frame metal pipe supports, including associated “X”-bracing, shall be fully replaced across all three Missile Shelters. Replacement shall be in-kind unless otherwise directed and shall conform to applicable structural standards, the HSR and historic construction documents.

2. Confirm that any abatement can be done onsite. They had mentioned that it might be best to remove the doors off site for abatement, would be expensive since they are an oversize load.

NPS RESPONSE: Lead-based paint abatement is required for all metal hangar doors and may be conducted on-site. In-place abatement using full containment measures may be a viable method; however, it must adhere to strict standards governing environmental control and worker safety. On-site execution will necessitate the construction of containment structures, the use of HEPA-filtered negative air systems, appropriate personal protective equipment, and procedures for the handling and disposal of hazardous waste. As part of the evaluation process, full removal of the doors for off-site abatement may also be considered as a comparative alternative in determining the most efficient and compliant approach.

3. If needed, can we work on more than 1 hangar at a time?

NPS RESPONSE: The NPS requires construction activities be limited to one Missile Shelter Hangar at a time. Sequential execution is required to ensure operational continuity, minimize disruption to surrounding resources, and maintain adherence to established site protocols.

NPS GENERAL COMMENT: All interventions shall respect the Cold War-era character-defining features of HM69, including above-ground launch configurations and original electrical installations. Work shall conform to the Secretary of the Interior’s Standards for Rehabilitation, with particular attention to Standards 2 and 5, which emphasize the retention and repair of historic materials and spatial relationships.

Questions For Electrical Work Scope

1. Is power currently working for the existing lights?

☐ Yes ☐ No x Not sure

2. Are the current lights on a switch, timer, or photocell?

x Manual switch ☐ Timer ☐ Photocell (turns on at dusk) ☐ Unknown

Fixture & Conduit Info:

3. How many existing fixtures need replacement?

(We understand there are 3 per hanger, please confirm)

NPS RESPONSE: There are currently three original Stonco-style industrial light fixtures in place. These fixtures may be eligible for reuse, provided they are found to be in good condition; however, some degree of refurbishment may be required. This determination will be made at the time of removal. For proposal purposes, please include an allowance for the replacement of each fixture with an in-kind equivalent.

4. Are the lights mounted directly to the building, or on an extension arm/bracket?

NPS REPSONSE: As observed during the site visit, the historic light fixtures are mounted to pre-bent galvanized extension arm conduits that penetrate the corrugated siding. This configuration must be replicated in exact detail, preserving the existing installation method as it currently stands. All work shall conform to the Secretary of the Interior’s Standards for the Treatment of Historic Properties, ensuring that character-defining features are retained without alteration.

☐ Flat mount x Bracket/Arm ☐ Not sure

5. What type of conduit is currently installed?

☐ EMT (metal pipe) ☐ Rusted/flexible/unknown

☐ PVC

x Not sure

6. Approximate total length of conduit to replace (from the power source to all 3 lights)?

☐ Under 20 ft ☐ 20–40 ft ☐ Over 40 ft X Not sure

Power Supply:

7. Where is the power source or panel located relative to the lights?

NPS RESPONSE: Although this should be field verified, the “as-built” construction documents provide show the location of the panel locations within the Missile Shelter.

Please refer to the electrical drawings with respect to the location of the electrical distribution centers.

(e.g., “inside the hangar,” “20 ft to the left of the lights”)

8. Do you want the lights to turn on automatically (photocell or motion sensor)?

☐ Yes – dusk to dawn (photocell) ☐ Yes – motion sensor x No – just a regular switch

Photos:

NPS RESPONSE: The site visit was made available to all prospective contractors to facilitate direct documentation of existing conditions across the Missile Shelters. This included the opportunity to conduct thorough visual assessments and capture photographic records as needed. At this time, the National Park Service does not assume responsibility for furnishing photographs to interested offerors.

9. Please send clear photos of the following (if possible):

• A full view of all 3 light fixtures

• A close-up of each light and conduit

• The electrical panel or switch that controls the lights

Questions for General Work:

NPS RESPONSE:

Paint Specification and Refurbishment Scope – Metal Structural Elements and Hangar Doors

In response to the contractor’s inquiry regarding the treatment of metal structural elements and the refurbishment of the hangar doors at the HM69 Nike Missile Base, the following specification is provided to guide all work in accordance with the Secretary of the Interior’s Standards for the Treatment of Historic Properties, applicable environmental regulations, and best practices for corrosion protection in sensitive environments.

I. Lead-Based Paint Abatement

The hangar doors, approximately 12 feet in height and 30 feet in length, have been historically coated with lead-based paint applied by Army missile crews. Abatement is therefore a critical component of the scope. Note: Temporary tenting maybe required for lead abatement containment.

• Methodology:

o Utilize wet scraping and wet sanding techniques to suppress airborne lead dust.

o Employ HEPA-filtered vacuum systems for debris collection.

o Install containment sheeting extending a minimum of 5 feet beyond the work area.

o Comply with OSHA 29 CFR 1926.62 and EPA RRP (Renovation, Repair and Painting) standards.

o All personnel must be certified in lead-safe practices and equipped with appropriate PPE.

• Waste Handling:

o Collect and dispose of lead-contaminated materials in accordance with federal and state hazardous waste protocols.

o Submit documentation of disposal and abatement procedures as part of project closeout.

II. Surface Preparation – Metal Substrates

All metal surfaces shall be prepared to ensure optimal adhesion and long-term durability of the coating system.

• Standard:

o Achieve SSPC-SP2 or SP3 (hand or power tool cleaning) to remove loose paint, rust, and contaminants.

o Establish a uniform surface profile suitable for high-performance coatings.

o Ensure surfaces are dry and free of oil, grease, or other bond-inhibiting substances.

III. Coating System – Exterior Metal Elements

Given the harsh exposure and historic significance of the site, a high-performance, three-coat system is specified:

Layer Product Type Minimum DFT Function

Primer Zinc-rich epoxy or inorganic zinc 2.5–3.5 mils Corrosion resistance

Intermediate Epoxy mastic 4–6 mils Barrier protection

Topcoat Aliphatic polyurethane 2–3 mils UV stability and color retention

• Color: Final topcoat shall match the existing historic color or be approved by NPS cultural resource staff.

• Application: Brush, roller, or spray per manufacturer’s recommendations. Observe curing times and environmental conditions.

IV. Hangar Door Refurbishment

• Scope:

o Inspect doors for structural integrity and corrosion.

o Repair or replace damaged panels in-kind, preserving original hardware where feasible.

o Perform abatement and surface preparation prior to coating application.

o Repaint using the specified three-coat system.

V. Compliance and Documentation

• Submit product data sheets and MSDS for all coatings.

• Provide abatement plan and disposal documentation.

• Maintain daily logs of surface preparation, coating application, and environmental conditions.

• Coordinate with NPS staff for inspections and approvals at key milestones.

Should further clarification or site-specific adjustment be required, I remain available to coordinate directly with the contractor and field personnel. This specification is intended to uphold both the technical integrity and historical authenticity of the HM69 facility.

Can we use a spray machine to paint?

NPS RESPONSE: Application Methodology and Historic Sensitivity – Spray Coating Considerations

This addendum supplements the previously issued paint specification for the metal structural elements and hangar doors at the HM69 Nike Missile Base. It addresses the appropriateness of spray application in light of the site’s historic significance, environmental sensitivity, and the presence of lead-based coatings.

I. Overspray and Containment Risks

Spray application introduces a heightened risk of overspray onto adjacent historic materials, interpretive signage, and natural vegetation. Given the open-air nature of the site and its proximity to sensitive resources:

• Spray equipment shall not be used without approved containment measures, including full masking, drop cloths, and wind barriers.

• Overspray onto non-target surfaces will be considered a non-compliant action and subject to remediation at the contractor’s expense.

II. Lead-Based Paint Disturbance

Residual lead-based coatings on the hangar doors pose a significant hazard when disturbed by aerosolized methods:

• Wet methods and manual application (brush or roller) are preferred during abatement and priming stages to minimize airborne particulates.

• Spray application over surfaces with residual lead shall be prohibited unless abatement is complete and containment protocols are in place.

III. Preservation of Historic Character

The visual texture and finish of the hangar doors and structural elements contribute to the site’s historic integrity:

• Brush and roller application methods are strongly preferred for final topcoats to preserve the original appearance and avoid a modernized sheen or uniformity inconsistent with historic finishes.

• Where historic evidence suggests brush-applied coatings, replication of that method shall be prioritized.

IV. Conditional Use of Spray Equipment

Spray application may be considered for intermediate coats or inaccessible areas only under the following conditions:

• Contractor shall submit a detailed application plan including:

o Equipment specifications o Containment strategy o Environmental controls o Justification for spray use in specific areas

• Approval must be obtained from NPS cultural resource staff prior to mobilization.

V. Compliance and Review

All application methods shall conform to the Secretary of the Interior’s Standards, particularly:

• Standard 5: “Distinctive features, finishes, and construction techniques or examples of craftsmanship that characterize a property shall be preserved.”

Deviation from approved methods may result in work stoppage, corrective action, or withholding of payment until compliance is achieved.

What will the Payment schedule be like?

NPS RESPONSE: All questions regarding payment schedule questions to Will Vazquez, Contracting Officer.

Are there Paint Specifications?

NPS RESPONSE: See response above for Paint Guidance