Airfield Blast Shield

1.1 PROJECT DESCRIPTION: 1.1.1 Work under this project shall consist of providing all plant, labor, equipment, appliances, materials, and performing all operations required to cover the fabrication and erection of new Blast Deflector Fences for the B1-B. All work shall comply with the contract specifications and shall be in accordance with the latest International Building Code (IBC), National Fire Codes, Unified Facilities Criteria (UFC), Engineering Technical Letters (ETL’s), and all applicable Federal, State and local regulations/codes. 2.1 GENERAL: 2.1.1 The blast deflector shall be of the curved, non-perforated, galvanized, corrugated type, with corrugations running in a horizontal direction. The Lynnco Type GS-20-2 as manufactured by Blast Deflectors, Inc shall be considered as the standard for this work. At the option of the Contracting Officer, alternate types of blast deflectors may be considered provided the drawings and specifications of alternate types are approved by Contracting Officer. The blast fence shall be furnished and installed by a manufacturer/contractor with blast fence experience. The blast fence shall be capable of withstanding the afterburner throttle at 30,000 lbs thrust of a B1-B Bomber engine nozzle 90 ft/ (min.) from front of deflector foundation. Extrapolated temperature is approx. 1400 ? velocity @ 900 MPH. 2.1.2 Haul Route: Approved haul route is from the Tye Gate, Third Street, Ave E, Second Street, to Flightline. Haul Route subject to change based on Flightline Restrictions. Contractors are required to use the Tye Gate for all access. 2.1.3 Construction Storage Yard & Contractor Limits: Contractor shall store all equipment and material within the designed laydown yard. Contractors shall restore this area to pre-construction conditions. Regardless of the area, the yard shall be fenced. Contractor shall keep the fence well maintained and the site clean and mowed. Contractor shall obtain approval for any project limits changes prior to construction commencement from 7 CES through the Contracting Officer. The approved laydown yard will be provided at the pre-construction meeting. 2.1.4 Contractor shall provide material submittals for all materials & products used in the project on an AF Form 3000. All PDFs shall be from original electronic documents; no scans allowed due to file size. 2.1.5 Work is located in a restricted area. The contractor shall submit a two-week schedule to the Escort POC at least one week prior to work starting to ensure escorts are assigned. The schedule should include start/end times for each day, crew sizes, and work locations. 3.1 BLAST DEFLECTOR CONTRUCTION: 3.1.1 Structural frames which support the deflecting surface will be of structural shapes, rolled, punches, and prefabricated for bolting together at site. Deflecting surface will be of galvanized corrugated steel with a minimum of 2 oz. zinc coating per Fed. Spec. WW-P-00405. Sheets shall have a section modulus of not less than 0.0163 inches curbed per inch and shall be of corrosion resistant material with yield point in 50,000 psi range. 3.1.2 All bolts subject to blast temperatures shall be of SAE 1038 steel, heat treated. All nuts, except on anchor bolts, shall be made of all-steel, self-locking type. 4.1 BLAST DEFLECTOR ANCHORAGE 4.1.1 Blast Deflectors shall be installed on existing concrete. Existing concrete has a minimum thickness of 16”. Lynnco "Epoxy-Locked" anchors, with Lynnco No. 22 Epoxy Resin were used to lock in place the existing blast deflectors. 5.1 BLAST DEFLECTOR ASSEMBLY: 5.1.1 All components will be assembled by bolting together with flat washers, under heads and nuts. Welding, brazing or burning of holes is not permitted. All nuts and bolts will be tightened to torques specified by manufacturer. 6.1 BLAST DEFLECTOR FINISH: 6.1.1 All bolts, nuts and washers will be cadmium or zinc plated. All structural members, parts, and corrugated metal will be hot dip galvanized with a minimum coating of 2.0 oz. zinc per square foot of surface. Painting of galvanized surfaces is not required, but any galvanized surface badly scratched or marred, will be re-galvanized or otherwise repaired to the satisfaction of the Contracting Officer. 6.1.2 Contractor shall paint the corresponding aircraft parking position number on the front of the blast deflectors. The Contactor shall provide a 2’x2’ number sign mounted 15’ above the concrete at the midpoint on the backside of the blast deflector. Markings/sign shall follow details 2 and 8 on sheet C2 of the attached drawings. 7.1 BLAST DEFLECTOR ALTERNATIVES: 7.1.1 At the option of the Contracting Officer, and as specified in Paragraph 2, the Contractor may substitute an alternate type of blast deflector, providing that the following information and data is submitted, prior to the time of bid opening and approved in writing. 7.1.2 Contractor will submit for approval a tabulation of results of full-scale instrumented field tests witnessed and certified by an accredited testing laboratory, in which proposed alternate is subject to the intermediate throttle power of similar engines totaling # 30,000 afterburner thrust @ approx. 90 feet distance from the leading edge of the deflector measured along centerline of bast impingement. Tabulation must show the maximum pressure in psi, temperature in degrees F., vibration frequency in CPS, and vibration amplitude in inches, taken at the centerline of blast impingement on deflector. The results of all such readings may not be greater than the readings submitted for the specified deflector, for each corresponding item. 7.1.3 Contractor must submit results of smoke-pot tests behind similar deflectors, demonstrating that smoke and gases are deflected in a vertical direction, with no evidence of smoke dispersal behind deflectors. 7.1.4 Contractor must submit evidence of satisfactory operation for at least two (2) years in actual field service for continued testing of similar aircraft and jet engines. 7.1.5 Contractor must submit detailed design analysis, showing loads and stresses in structural members, deflecting surface and bolted joints, using the maximum pressure measured in Paragraph 7.1.2, as the average pressure for load calculations. Welds subjected to tension or vibration may not be used; all bolts must be heat treated if subjected to blast temperatures. 7.1.6 Because of thermal shock and cavitation effects, which results in cracking and spalling, concrete deflectors may not be used as an alternate. Perforated deflecting surfaces are not acceptable for this use.