Statement of Work.pdf

Statement of Work Preservation and Stabilization of

Engineering Officers’ Quarters & Front 4 Curtain Magazine Fort Jefferson, Garden Key Dry Tortugas National Park

Scope: Engineering Officers’ Quarters (EOQ)

The objective of this project is to Preserve the structure through stabilization. Given the existing condition and character of the Engineers’ Quarters ruin, stabilization will require significant intervention beyond simple repointing of the structure’s masonry. In its current condition, the structure is stable but vulnerable to failure in the extreme conditions of the region and therefore measures must be taken to secure the standing walls to ensure preservation. A second condition contributing to the instability of the structure is the presence of corroding metals, specifically the lintels supporting the masonry over the fireboxes. The steel lintels have corroded, deformed and are no longer able to support the masonry above. Cracking and displacement of the brickwork above the lintels has occurred.

Treatment to address these conditions shall consist of the following:

• Ensure limbs of adjacent tree are trimmed so as not to contact ruin during wind events.

• Repoint areas were mortar has deteriorated or lost it binding qualities. Develop compatible repair mortars based on results of materials analysis. The pointing mortar used at the Engineers’ Quarters was determined to be a lime and natural cement mix (EOQ-Historic Structures Report-Appendix C).

• Repair/reconstruct minor areas where bricks have collapsed or fallen from the walls.

There are several instances of this condition at building corners. Repair using salvaged brick that matches the existing in dimension, color and physical characteristics. Maintain coursing, joint width and tooling.

• Implement structural repairs, including o Based on Code wind loading, it is determined that framing at the original joist level as well areas of plan bracing is required to recreate diaphragm action, bracing the walls and providing a lateral load path. See drawings for details (Engineers_Quarters_Drawings_FINAL).

o Provide new joists, as interpretive elements to reflect original construction as well as provide supplemental support to the remnants of the original building walls.

The end detailing at the joist pocket into the masonry wall and choice of materials is critical, to prevent moisture infiltration and subsequent deterioration of the new joists.

o At the door opening in the interior EOQ wall, there is an arched brick lintel and bearing pockets for a missing flat timber lintel. Repoint and reset the arched bricks that are loose.

o At the door and window openings at the exterior walls, there are stone lintels at the exterior and pockets for missing timber lintels at the interior.

o Above the fireplace opening there is a 3”x3/8” thick iron bar “lintel” that is heavily corroded and is causing the outer wythe of brick above to push out upwards of 2 inches. The iron piece appears to have been originally curved upward as permanent form and protection of brick from heat at fire box. The iron bar and brick above are to be removed and rebuilt from lintel level to +/- 12 inches.

o Repair broken stone lintels.

Refer to Historic Structure Report (Engineers Officers Quarters FINAL Report), drawings (Engineers_Quarters_Drawings_FINAL), and project specifications (DRTO_TBD_FINAL_Specifications and) for additional details about the treatment and structural repairs.

All work shall be conducted under the guidance and in accordance with the Secretary of the Interior's Standards for Treatment of Historic Properties.

Scope: Front 4 Curtain Magazine

The objective of this project is to Repair and Restore selected features to expand and enhance the interpretive program. The NPS is planning on using the Front 4 Curtain Magazine as a stopping points on the established tour route where ordinance storage will be discussed.

Treatment of the Front 4 Curtain Magazine shall focus on repairing existing conditions and making improvements that will enhance the interpretive value of the space. Repairs to the existing fabric are anticipated to be minor as no condition issues were identified that require significant intervention. Restorative actions will focus on selected elements, such as flooring, doors, and windows.

Treatment shall include the following:

• Reconstruct wood floor structure and finish boards in magazine passageway.

• Design and install new wood door and window for openings leading from passageway to magazine interior. Design is based on information found on original drawings for doors at similar locations. (See Bastion Curtain Magazines HSR-Appendix A& C).

• Repair or replace the stone covers at the cistern access points.

• Repoint deteriorated masonry along the parade face of the magazine, the interior passageway walls, and passageway ceiling. Develop repair mortars based on findings of materials analysis.

• Replicate ribbon pointing to match existing historic treatment; new work shall blend and match historic work.

Refer to Historic Structure Report (Bastion_Curtain_Magazines_FINAL_Report), project drawings (Curtain_Magazine_Drawings_FINAL), and project specifications (DRTO_TBD_FINAL_Specifications) for additional details about the treatment and structural repairs.

All work shall be conducted under the guidance and in accordance with the Secretary of the Interior's Standards for Treatment of Historic Properties.

Performance Period: The work of this Task Order shall be completed from approximately July to November 2020, July to November 2021, and July to November 2022. Exact timing of work shall be coordinated with COR and will be based on availability of government housing.

The location of the project for which these services are contracted is Garden Key, Dry Tortugas National Park.

I. PROJECT BACKGROUND

Fort Jefferson is a 19th century “Third System” coastal defense fortification. Military engineers began construction on the fort in 1846 and stopped before it was completed in 1874. It was part of an organized effort by the United States government beginning in 1817 to generate a system of national defense. Each of these coastal defense works were designed to contain artillery, garrisons, and magazines of which could defend against an attack until further reinforcements could be dispatched. Fort Jefferson represents one of the highest achievements of 19th century American military architecture and engineering and is one of the largest Third System forts constructed. The hexagonal fortification has three tiers and surrounds a parade ground with auxiliary structures and ruins.

These auxiliary structures within the interior of the fort consist of a highly organized system of armament and ordinance supply including a hot shot furnace, multiple detached powder magazines at the ground level, and magazines on the first tier constructed within the fortification.

Additionally, there are quarters for officers and soldiers within the parade ground. Each of these structures individually has historic value and collectively are essential resources of the army period of significance at Dry Tortugas National Park. The NPS has received donation funding from the HTR Foundation to preserve and stabilize the Engineering Officers’ Quarters and the Front 4 Curtain Magazine. All of the structures included in this scope of work are identified as contributing historic features of Fort Jefferson which is on the National Register of Historic Buildings. The 1974 National Register documentation established that the fort and associated resources were significant in the areas of Military and Engineering.

Engineering Officers’ Quarters: The Engineers’ Quarters ruin is a two-story, 20-feet by 31-feet, brick masonry structure located in the northwest portion of the fort’s parade ground, within an area roped off from the public. The ruin is divided into two bays by a central chimney. The bays are mirrors of each other; 15-feet wide, a fireplace at the party wall, two windows in the opposite wall, and one window per bay along the longer walls. Today, the walls of the Engineers’ Quarters ruin rise just above the second floor granite window sills (two windows on the south elevation feature segmental brick arches), with scant bits of plaster still clinging to some of the inside corners. Remnants of joist pockets, first and second floor granite window sills, and two brick fireplace surrounds remain. A coral and cement foundation is visible within the interior of the ruin. The similar adjacent structures were reconstructed in the late1930s as part of a WPA program project. The reconstructions added porches to the buildings as well as a wood frame hyphen between them. No improvements were made to the Engineers’ Quarters and the structure has remained in a ruinous state since around the turn of the century.

Front 4 Curtain Magazine: The Front 4 Curtain Magazine encompasses two full casemates in the center of Front 4. The magazine interior is accessed through an arched masonry opening in the parade ground face that leads to a passageway aligned with the communicating arches. A central doorway and adjacent raised opening or window connect the passageway and magazine interior. The water filter niche, typically found between each casemate is present.

Originally a wood floor raised on a wood structure was present in the passageway and most likely the magazine also. It is probable that the walls of the magazine were also lined with wood.

No remnants of the wood flooring or wall lining remain. The walls and ceiling of the passageway were ribbon pointed. A decorative technique for finishing mortar joints found in various locations throughout the fort. The magazine storage area is rectangular in shape extending the width of two casemates. The magazine has a barrel vaulted ceiling. Due to the presence of the magazine, the embrasure openings in the scarp face have been infilled.

II. STANDARDS (See project Specifications for details)

All Research and Documentation shall comply with the standards outlined in:

• National Park Service Director’s Order #28: Cultural Resource Management Guideline

All treatment shall comply with the latest versions of the following:

• Dry Tortugas National Park Enabling Legislation

• The Secretary of the Interior's Standards for the Treatment of Historic Properties

• NPS DO #28: Cultural Resource Management Guidelines

• Project material specifications and drawings

DATA AND MATERIALS TO BE PROVIDED BY NPS:

• National Park Service Director’s Order 28 (NPS-28)

• Historic Structure Reports for Engineering Officers’ Quarters and Bastion/Curtain

Magazines, Lord Aeck Sargent; 2017 o Documents also include materials analysis data o Documents include structural recommendation of Engineering Officers’ Quarters

• Historic Photographs and Drawings of Fort Jefferson, and auxillary structures on file

• Revit files of modeled Engineering Officers’ Quarters for viewing with Autodesk Viewer

• Other applicable park planning documents as requested including but not limited to:

o Historic Structures Report (HSR), Edwin Bearss, 1983 o Historic Structures Report Amendment (HSR-A), LAS, 2006 o Dry Tortugas Cultural Landscape Report (CLR), Susan Hitchcock/Beth Byrd, o Long Range Interpretive Plan (LRIP), NPS-Harpers Ferry, 2003

• Local sand (un-sifted) and cistern water will be available for concrete/mortar mixing

III. GENERAL DESCRIPTION OF WORK:

The treatment of this project includes the preservation and stabilization of two separate structures; Engineering Officers’ Quarters (EOQ) and Front 4 Curtain Magazine.

Project work includes all delivery and removal of construction materials, equipment, power generation, supplies, project debris, and domestic trash; all scaffolding delivery, assembly, disassembly required for access to work site, any and all safety barricades required as well.

• Site Visits:

o Due to the remote location, specific site logistics, and challenging working conditions of any project at the Dry Tortugas a site visit may be required prior to submission of your proposal. Site visits can be used to collect or verify measurements and quantities, quantify materials, establish construction methods, and to have site familiarity. Site visits shall be rendered by the COR assigned to the project under this SOW. The NPS reserves the right to limit site visits to those which the CO or the COR determines to be sufficient.

o Site visits prior to award will not be reimbursable by the government.

o Transportation to Dry Tortugas is offered daily by two separate commercial operations: Yankee Freedom III ferry; roughly 2.5 hours each way, 0800 departure from Key West to Dry Tortugtas and a 1430 departure from Dry Tortugas to Key West. Key West Seaplane Adventures offers multiple seaplane departures from Key West to Dry Tortugas Daily. Travel time is roughly 45 minutes each way. Contractor shall verify all transportation logistics with vendors directly.

• Park Housing:

o Park housing will be made available to contractor for a crew of up to ten (10) individuals. Park housing is a shared living situation. See project specifications for more detailed information. A walk through can be completed with a site visit and/or more information can be provided upon request.

Housing rates are $45/person/night to be paid to park at the end of each month of occupation.

• Telephone/Internet:

o The internet provided to transient quarters is very limited, with capability for texting and browsing webpages. Very strict usage rules apply as it is a community system.

o No government-provided phone service will be available to the contractor.

o Contractor will be responsible for all telecommunications needs and systems beyond the capabilities of what is provided currently by the NPS. This must be heavily coordinated with the designated CO as options for phone and internet are incredibly limited on Garden Key.

• General Treatment o Delivery all materials, supplies, personnel, and equipment required to complete the scope of work including but not limited to barricades, safety equipment, power generators, sand screeners, scaffolding, water pumps/containers, materials, tools, food, drink, recreation equipment.

https://www.drytortugas.com/ http://keywestseaplanecharters.com/ o Assemble scaffolding in accordance with all applicable state and federal requirements o See project drawings and specifications for scope details, material and workmanship requirements o Remove all materials, supplies, and equipment from Dry Tortugas National Park upon completion of the project

• Documentation o Contractor shall follow all project specifications for documentation, which includes at a minimum daily project reporting, photographic documentation, “As- Built” drawings, and Operations and Maintenance procedures/plan. All documentation shall be submitted to the park COR at close out.

IV. SCHEDULE AND SUBMISSIONS

A. Schedule This work season(s) for this project is from July to November of any calendar year from 2020 to 2022 (July to November 2020, July to November 2021, July to November 2022); however, timing of the work shall be coordinated with the COR and will be based on the availability of government housing. Dry Tortugas National Park is subject to seasonal Atlantic Hurricane conditions from June to November. Contractor will be responsible for planning, scheduling, and executing any temporary closures or shutdowns of the work site due to severe weather; any time of the year, but particularly during the hurricane season. Evacuations and seasonal shutdowns may be required. See Project Specifications for schedule submittals and day to day work schedule restrictions. No official contract work shall begin until after award and a Notice to Proceed have been provided by the Contracting Officer.

B. Final Submissions-Project Close Out:

Reference the Project Specifications Section 01 77 00-Close Out Procedures and Submittal List.

Produce and submit to NPS the final documents on computer disks in the current versions of MicroStation or AutoCAD format for drawings, MS-Word format and PDF (Adobe Acrobat portable document format) for texts in order to comply with DOI (Department of the Interior) e-commerce requirements, MS-Excel for spreadsheets, or other format as directed by the Contracting Officer. All PDF files are to be generated directly from the electronic files--scanning printouts is unacceptable.

All files shall be unprotected (no required passwords). Organization of CAD files on compact disks, and organization of drawing levels within the CAD files shall comply with the Denver Service Center CADD User's Guide.

Submission of the final documents shall include:

• Two electronic copies on compact disks of all graphic and text files

• Three sets of manufacturers' cut sheets of all critical products and equipment; double-sided bound on 8½" × 11" white paper

• All original project photographs in .jpeg format

• As-Built drawings The Contracting Officer may allow electronic transfer on computer files in lieu of compact disks