SOW - Tower.pdf

NIWC – ASR-8 Radar Tower June 2019

37’ ASR-8 Radar Tower Fabrication

The selected Contractor shall furnish and install all materials, supplies, equipment and services necessary to design, fabricate, and deliver a 37 ft. radar tower. New tower shall meet all FAA and OSHA requirements. Contractor must furnish a complete, galvanized steel, self-supporting radar tower including, but not limited to: stairway, antenna interface, antenna tie down provisions, platforms, radome ring, protective grounding, obstruction lighting, lightning protection and all other hardware essential for erecting the tower.

The following items are a summary of the project and are provided solely for the purpose of describing the general nature of the work. The Contractor is responsible for accomplishing all items of work identified in the applicable specifications and provisions of the contract:

A. General

1. This contract is for design, fabrication, and delivery of the tower only. Assembly will be completed by a separate organization.

2. Inspection of materials prior to shipment is required unless specifically authorized by the FAA representative.

3. The Contractor shall provide a tower that is ready to install. Packaging and labelling parts is required to assist in assembly.

B. Shipment Location

1. The contract includes shipping of the tower components to Charleston, SC. Exact address to be provided prior to shipment.

C. Work Description

1. Radar Tower

a. Design and fabricate new Radar Tower. Tower must have a 24 ft. x 24 ft.

nominal platform at the top level for mounting and servicing the radar antenna, including the accommodation of a radome. Tower members must be fabricated from pipe, angular or solid stock. Tower must be fabricated to conform to a standard ASR-8 legacy design. Tower must be designed for field erection with structural bolts only. Tower height must be not less than 37 ft. Minimum tower height must be measured from foundation to top of the main platform floor. The Basis-of-Design tower shall be an FAA standard ASR-8 design.

Figure 1: Basis of Design

i. Tower shall support ASR-8 radar antenna assembly and radome.

Weights are provided below. Ensure tower is capable of mounting antenna on the platform. Additional capacity should be added to support a radome.

Item Weight (lbs) Reflector and Support Assembly 1970 Dual Feed Assembly 56 Pedestal Assembly 1418 Drive Assembly 622 Rotary Joint 87 Beacon Omni Antenna 3 Beacon Directional Antenna 330

ii. Radome to be installed is a L3-Essco SO35-64. Upper Platform shall be designed to accomidate and mount this radome.

iii. Tower shall meet all FAA guidelines regarding obstruction marking and lighting Advisory Circular AC 70/7460-1K.

iv. Provide and Install lighting into the stairway, platform, and structural lighting as required.

v. Provide lightning protection and per FAA-STD-019F.

vi. Tower shall have 4 each duplex power receptacles installed on the platform, one per side.

vii. Provide and Install waveguide supports up the tower as needed to prevent wind damage to the antenna waveguides.

b. Tower Design must be approved and sealed by a registered structural engineer. Design must be in accordance with established engineering practices, TIA-222-G and all FAA specifications and OSHA requirements.

Loading must meet or exceed TIA-222-G, section 2. Stresses must meet or exceed TIA-222-G, section 3, while supporting a ASR-8 radar unit.

c. The floor of the platform must support 250 pounds concentrated load over any one square foot area in addition to a live lead of 20 pounds per square foot over the entire platform. Platform floor shall be anti-slip or grating.

The guardrail must meet or exceed OSHA 1910.23.

d. The tower must be designed for 150 mile per hour wind gust and no ice and 100 mile per hour wind and 1/2 inch of radial ice per TIA-222-G & ASCE-7 to support the radar antenna and the platform with the guardrail and include the following:

i. Obstruction lighting — dual bulbed LED

ii. Grounding

iii. Lightning protection system with dual down conductors

iv. Anchor bolts

v. 500 lb. rated electric hoist

vi. Stairway with lighting at each landing level

vii. Platform lighting with four duplex-type convenience outlets

viii. Waveguide pathway through tower center.

ix. Radome: L3-Essco SO35-64

e. Grounding must meet or exceed FAA-STD-019F and E1A-222-F, section 12.

Earth electrode system must not be included in the design. Design must include, but not be limited to, air terminals, down conductors, fasteners, clamps and ancillary items.

f. Dual bulb LED obstruction lighting system must be in accordance with "Red Obstruction Lighting Standards" of FAA AC-70/7460-1, FAA AC-150/5345-43, NFA 70 and NFPA 780.

g. Provide all necessary conduits, including 2 - 2” conduit runs up the tower for radar antenna power and controls.

h. Provide Waveguide brackets for supporting waveguide on completed tower.

Waveguide is IGCE, and is not included as part of this contract.

D. Submittals

1. Drawings - All drawings must be legible B-size drawings, 11 in. x 17 in. Electronic drawing files must be submitted in .pdf format.

a. Tower design drawings must include, but not be limited to, plan and elevation views, overall dimensions and control dimensions, member sizes and coatings, steel types, hardware coatings, platform details and dimensions, details for safety door, stairway, antenna arid beacon mounts, grounding system, and any pertinent notes.

b. Erection drawings must indicate member location, bolt sizes and numbers, antenna mounts and all other information to clearly depict requirements for field erection. Parts list -showing member -number, size and length must be provided in erection drawings. Recommended erection procedure must include, but not be limited to, basic sequence of assembly, temporary bracing, shoring and related information necessary for erection of tower. Installation drawing must be provided for obstruction lighting system.

2. Calculations — Calculations must include, but not be limited to, structural design calculations for the tower. All design calculations must be indexed and arranged in an orderly manner, with appropriate sketches, so that any element can be easily identified. Complete structural calculations are required covering all parts of the structure and related items, Tower twist, sway, and displacement must be determined by an analytical method. All design loads must be identified; design methods and assumptions must be indicated. When computer printouts form a portion of the design calculations, the manufacturer must include all input diagrams and information needed to relate printout to design elements. Computer programs utilized must be identified and a brief description of each must be included.

3. Certificates, guarantees and warranties.

4. Other data as necessary to clearly describe design, materials, sizes, layouts, details, fasteners, and erection.

E. QUALITY ASSURANCE

1. The antenna tower must be the product of a recognized tower manufacturer having substantial experience acceptable to the Government and Contracting Officer in design and fabrication of antenna towers. All structural steel tower members must be hot-dipped galvanized after fabrication and conform to the requirements of ASTM Al23, The finish must be guaranteed not to flake, peel, crack or rust for a period of at least twenty (20) years. Unless otherwise specified, all tests and inspections must be performed by the manufacturer and will be subject to the Government's observation or observation. The COR must be notified ten (10) days prior to shipment to allow for a shop inspection by the Government.

The shop inspection will be at the COR's discretion.

2. The radar antenna is a precision electronic mechanism built to close tolerances.

Extreme care must be taken when around/handling this unit. There is no possibility of making field repairs to damaged parts. The Contractor will be responsible for the costs of any delays and/or replacement of any components damaged due to damage or carelessness on his or her part or on the part of any subcontractor when around this Government furnished and installed unit.