JA-1_Architectural_Narrative_3.10.15.pdf

EXISTING CONDITIONS

Hangar 1335 houses maintenance functions for aircraft at Eielson AFB, Alaska. The aircraft hangar was completed in 1988, and is a mission-critical hangar designed to house and maintain either (2) F-16 Fighting Falcons or one A-10 Thunderbolt aircraft in each hangar bay (4 bays total in hangar).

The door operating systems have been in service for over 20 years and have experienced wear of the pulleys, sheaves, cables, rollers assemblies, counterweights, etc. Many of the components are difficult to procure or no longer manufactured. The 354th Fighter Wing has deemed it necessary to replace the hangar door system and assemblies.

Each bay has two opposing large tilt-up hangar doors (eight doors total). Each hangar door weighs approximately 16,000 pounds (design weight). The hangar doors measure 77 feet 6 inches wide by 24 feet 0 inches tall. Hangar doors are constructed of 24 gauge 1-1/2 inch by 12 inch wide flat exterior metal panels over two foot by four foot treated wood sub-girt on eight inch steel girt with nine inches of semi rigid mineral fiber insulation on vapor retarder on 1-1/2 inch by 12 inch wide flat interior metal panel. The bottom 12 feet on the exterior side of the door is covered with 1/4 inch steel plate. The door operating system consists of a floor mounted, chain driven electric motor and dual counterweights through a sheave and cable system. The concrete counterweights weigh approximately 8,000 pounds each and are located at each side of the door opening. The counterweights are connected to four wire rope cables threaded through a series of sheaves and rollers to the tilt-up hangar doors. The door operating motor consists of a floor mounted motor assembly capable of manual crank door operation.

CORRECTIVE ACTION

Hangar Door and Door Operating Systems Base Bid Work

1. New tube steel bracing to existing door track support beams and existing channel supports (4 per door).

2. New overhead guide tracks and support angles/clips to existing beams (4 per door).

3. New adjustable swivel sheave housing assemblies with tapered roller bearings, located directly above each pickup point on the doors (4 per door). Align with new swivel sheave assemblies at new counterweight tower (item number 19 in base bid scope).

4. New self-adjusting top roller assembly with safety chain/cable at each door guide track (4 per door).

5. New wire rope with swaged clevis assembly at door pickup bracket and wire rope clips at counterweight pickup points (4 per door).

6. New structural steel counterweight tower assemblies (1 per door), new steel counterweight tubs (concrete filled), and new chain drive assemblies.

7. New counterweight guide track beam assembly at counterweight tower.

8. New continuous door head, sill and side jamb seals (weathering) on hangar doors. Weathering shall be arctic grade gasket rubber (for mitigating air penetration).

9. New continuous jamb seal rub plates.

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EIELSON AFB, ALASKA

ATTACHMENT JA-1

ARCHITECTURAL NARRATIVE

10. Provide measures/adjustments to ensure bottom of door seals tight to the floor. No daylight should be visible under the seal.

11. Repair of door sill wind locks at door and lock plate in concrete – add divider bar to all (4 per door).

12. New floor mounted door operator enclosure and access door (1 per door). Ensure design of enclosure allows for all necessary maintenance of items/equipment contained within the confines of the enclosure (ensure access to all grease points and other necessary maintenance areas). Ensure that drawings indicate the necessary coordinate system numbers (currently on enclosures) that should be stamped/imprinted/adhered to the new enclosures.

13. New pre-wired electrical control panel with lockable disconnect with separate constant pressure open/close pushbutton control station mounted on face of operator enclosure (1 per door). If logic controllers are used, provide software (AC Lenze or approved equal) and one laptop portable operating terminal.

14. New floor mounted door operator motor assembly with double reduction chain drive and solenoid operated brake with manual operation (hand crank) capability (1 per counterweight).

15. Gasoline powered portable drills with custom socket head matching fitting on exposed staff of electric motor for operating doors in emergencies (at least 2 total for the project - coordinate with user on amount/number required).

16. Manual hand crank with custom socket head matching fitting on exposed staff of electric motor for operating doors in emergencies.

17. New floor mounted motor operator base assembly for each new motor.

18. New swivel sheave housing assembly, with swivel sheaves at the top of the counterweight tub guide track assembly (4 per door).

19. New full height exterior insulated metal wall panels with concealed fasteners on exterior of hangar door with matching prefinished metal trim. Ensure all exterior metal fasteners meet specifications for climate coated (galvanized.), TEK 3 or TEK 5.

20. Remove hangar door and inspect for and repair faults prior to re-skinning exterior and rehanging door. Repair or replace damaged of rotten areas (insulation, wood strips, door vapor barrier, etc.) of door as necessary to result in a proper functioning door. Replace wood strips (with appropriately sized angle). Minimize use of wood products in hangar door repair. Ensure door components are all adjusted tightly so as to prevent foreign object debris (FOD) issues in the future.

21. Weighing of refurbished hangar door and balancing of hangar door with new counterweight (or counterweights) by the addition or subtraction of steel plate to the steel tub concrete filled/ballasted counterweight.

22. New 1/8 inch aluminum diamond tread plate scuff panels installed on the face of the door operator cabinets.

23. Replacements of personnel doors (salvage serviceable doors and turn over to the Eielson AFB Structures Shop). New personnel door hardware (closures, locksets, thresholds, hinges, weather stripping/seals, exit signs).

24. Repair reinforcement of hinge plates (new hinge anchor plates will be installed) and repair of existing personnel door frames.

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EIELSON AFB, ALASKA

25. New warning horns and warning signs on the exterior of the buildings (2 per door). New horn to be tied into circuit for new interior warning horn and is to run while the door is moving either upward or downward.

26. New interior warning horns (2 per door).

27. Painting of all new work, painting of personnel doors and frames in hangar door, painting of hangar door sill (inside and out), and grit texture non-skid pad at personnel doors inside and out.

28. Refurbishing, reinstallation of flashing and painting of port doors in hangar doors.

29. Rerouting of existing electric power supplies to new door operators and control panels from existing junction boxes.

30. New limit switches (open, close, slow down limits) mounted on counterweight tower (4 per door/tower). Salvage and turn over old limit switches to the Eielson AFB Structures Shop.

31. All equipment required for a complete and operational system at each hangar door, to include but not be limited to devices, boxes, conduit, switches and control wiring. Door contractor is to provide all electrical work including but not limited to all devices, boxes, conduit, switches and control wiring for a complete and operational system.

32. Reroute existing electric power supplies to new door operators and control panels. Ensure electrical ties are properly made.

33. Move existing light fixtures, fire suppression system components or other building elements as needed to facilitate new system operating properly and so that nothing interferes with the routing of the new hangar door sheave cables. Provide and install all associated equipment (e.g., conduit, conductors, and supports) for continued proper, reliable, and safe functioning of the equipment. Accomplish work so that the amount of electrical conductor splices is not increased from existing.

34. New instructional and regulatory safety signage (exterior and interior as required).

35. Paint all new work.

36. Include any work deemed necessary on the recessed stop plates in the floor.

37. Provide thread locking material on all exposed threaded fasteners (both self-taping and bolted connections).

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EIELSON AFB, ALASKA