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A Mast Arm is a horizontal cantilever structure designed to extend over roadways for mounting traffic signals, signs, and luminaires. The arm features a tapered design that changes diameter at a uniform rate, incorporating essential mounting hardware and connection components for attaching various traffic control equipment. Mast Arms are engineered to meet specific wind load requirements and structural standards set by AASHTO specifications.
Mast Arms come in several configurations including single arm, dual arm, and combinations with luminaire attachments. The structure includes integrated cable management systems with holes and rubber grommets for signal cable routing to the attached equipment. Standard Mast Arms can support multiple traffic signals, overhead signs, traffic cameras, and vehicle detectors, with maximum standard span lengths typically reaching 78 足.
主な特長:
• Tapered design for optimal load distribution and structural integrity
• Integrated wire routing system with protective grommets
• Available in both curved and straight configurations
• Supports multiple attachment points for signals and signs
• Engineered to meet specific wind load requirements
• Galvanized coating for corrosion protection
mast arm drawing
よくある質問 (よくある質問)
What is the maximum span length for a standard Mast Arm?
Standard Mast Arm Assemblies have a maximum span length of 78 足. Arms exceeding this length require special design variations. The actual length depends on roadway edge location and desired signal head positioning, with typical lengths ranging between 30 に 70 足.
What is a Wind Damper and when is it needed?
Wind Dampers are devices installed within eight feet of the Mast Arm tip to reduce movement during high winds. They are typically required for signal arms longer than 25 feet to maintain stability and prevent excessive swaying.
How much sag is normal for a Mast Arm?
Mast Arm sag typically measures about 2% of the arm length. 例えば, a 50-foot mast arm will normally have approximately 1 foot of sag. The amount varies based on the arm’s stiffness and design specifications.
What is the taper rate for Mast Arms?
Mast Arms feature a tapered design where the diameter changes at a uniform rate of 0.14 inches per foot. This tapering provides optimal load distribution and structural integrity throughout the arm length.
How are Mast Arms protected from corrosion?
Steel Mast Arms receive galvanized coating for corrosion protection. Some installations may also include additional paint finishes in various colors (黒, brown, 緑) over the galvanized surface for enhanced aesthetics.