Skip to main content

Cable Anchor Force


 

Cable Anchor Force (Single Cable at Angle) Formula

  • If a load \(W\) is supported by a single cable with angles \(\theta\).

\( T \;=\;  \dfrac{ W  }{  sin(\theta) } \)     (Tension Cable)

\( W  \;=\;   T \cdot sin(\theta)  \)
Symbol English Metric
\( T \) = Tension \(lbf\) \(N\)
\( W \) = Cable Weight \(lb\) \(kg\)
\( \theta \) = Angle of the Cable Measured from the Horizontal \(ft\) \(m\)

Cable anchor force, abbreviated as \(CAF\), is the mechanical load exerted on an anchoring point due to the tension in a cable.  This force is important because it ensures that the cable remains in place and structurally secure, especially in overhead installations, such as aerial fiber-optic cables, coaxial cables, or telephone lines.   

Key Factors Affecting Cable Anchor Force
Cable Tension  -  The tension within the cable, caused by factors like cable weight, external environmental forces (wind, ice, etc.), and temperature fluctuations, directly contributes to the anchor force.
Span Length  -  The distance between two support structures (poles or towers) determines how much force is exerted on the anchoring points.
Cable Weight  -  Heavier cables, such as those with additional reinforcement, will exert more force on the anchor points.
Environmental Conditions  -  Wind load, ice accumulation, and temperature changes can increase the tension in the cable, thus increasing the anchor force.
Anchoring Equipment  -  The quality and specifications of the anchors (dead-end anchors, guy grips) must be designed to handle the calculated force without failure.
 

Cable Anchor Force (Two Sided Cable Equal Angle) Formula

  • If a load \(W\) is supported by a two-sided cable forming equal angles \(\theta\) from the horizontal.

\( T \;=\;  \dfrac{ W  }{ 2 \cdot sin(\theta) } \)     (Tension Cable)

\( W  \;=\;  2 \cdot T \cdot sin(\theta)  \)
Symbol English Metric
\( T \) = Tension \(lbf\) \(N\)
\( W \) = Cable Weight \(lb\) \(kg\)
\( \theta \) = Angle of the Cable Measured from the Horizontal \(ft\) \(m\)

Piping Designer Logo 1

 

 

 

 

 

 

 

 

 

 

Cable Anchor Force (Two Cables Unequal Angle) Formula

  • If a load \(W\) is supported by two cables with different angles \(\theta_1\) and \(\theta_2\).

\( T_1 \;=\;  \dfrac{ W \cdot sin(\theta_2) }{  sin ( \theta_1 + \theta_2 )  } \)     (Tension Cable 1)

\( T_2 \;=\;  \dfrac{ W \cdot sin(\theta_1) }{  sin ( \theta_1 + \theta_2 )  } \)     (Tension Cable 2)
Symbol English Metric
\( T \) = Tension \(lbf\) \(N\)
\( W \) = Cable Weight \(lb\) \(kg\)
\( \theta \) = Angle of the Cable Measured from the Horizontal \(ft\) \(m\)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Cable Anchor Force (Parabolic Sag) Formula

  • For cables with span \(L\), total sag \(d\) (vertical distance from supports to lowest point) and uniform load per horizontal length \(w\) (weight of cable + any ice or distributed live load).

\( H \;=\;  \dfrac{  w \cdot L^2  }{  8 \cdot d  } \)     (Horizontal Component of Tension)

\( T \;=\;  \sqrt{ H^2 + V_a^2  } \)     (Tension Maximum Tension at the Anchor (Support))
Symbol English Metric
\( H \) = Horizontal Component of Tension (Constant Along Cable) \(lbf\)  \(N\) 
\( w \) = Width \(ft\) \(m\)
\( L \) = Cable Span \(ft\) \(m\)
\( d \) = Total Sag \(ft\) \(m\)
\( T \) = Maximum Tension at the Anchor \(lbf\) \(N\)
\( V_a \) = Vertical Reaction at each Support = \(wL / 2\)  \(lbf\) \(N\) 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Random Articles