welding, or threaded fasteners 300 mm 12 inches o.c. Where flat sheets are
attached as either exterior covering or interior liner sheets, the clear
unsupported area shall not exceed 2.5 square meters 25 square feet. Make
edges of exterior sheets weathertight with sealant.
2.2.2
Do not provide locking devices on motor-operated hangar doors.
2.2.3
Tractor Pulls
Provide tractor pulls so that leaves can be towed by a tractor or similar
equipment in the event of power failure. The tractor pull shall be
designed for drive force to tow door or 22240 N 5000 pounds whichever is
greater. Minimum thickness steel plate shall be 10 mm 3/8 inch.
2.2.4
Track Cleaners
Provide a device to clear debris from the rail head and wheel flange
grooves as the leaf is moved.
2.2.5
Insulation
Secure insulation to doors with clips, studs, or adhesive. Protect
insulation within 2400 mm 8 feet of floor with steel liner sheets secured
to framing 300 mm 12 inches o.c. at edges with zinc-coated, self-tapping
screws.
2.2.6
Cable System for Group Doors
The minimum size for the cable which interconnects the leaves shall be 10 mm
3/8 inch; the cables shall be improved plow steel with lubricated hemp
centers or wire rope cores. Sheaves over which the cables operate shall
have a diameter of at least 18 cable diameters and either sealed ball-or
roller-type bearings or graphite bronze bearings of a sufficient capacity
for the operating loads. Grease fittings shall be provided for the sheave
bearings unless permanently lubricated bearings are used.
2.3
OPERATION
**************************************************************************
NOTE: Type of operation will depend upon use and
configuration of the hangar. Delete inapplicable
paragraphs.
**************************************************************************
2.3.1
Hangar Door Types
Hangar doors shall be [unidirectional] [biparting] [as indicated.].
2.3.1.1
Individually Operated Doors
Each door leaf shall have a separate, traction-drive operating unit driving
one or more of the bottom wheels. Each leaf shall have a motor-mounted,
spring-set, solenoid-released motor brake. Each leaf shall move
independently of the other leaves. Provide doors that require operating
personnel to walk with the leaf as it moves.
SECTION 08342
Page 15
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