How does increasing the angle between two anchor legs affect load on each anchor?

How does increasing the angle between two anchor legs affect load on each anchor?

• A. A larger spread increases the load on each anchor; keep spread small to avoid overloading.
• B. A larger spread reduces the load on both anchors.
• C. A small spread increases load on one anchor.
• D. The angle has no effect on load if anchors are equal.

Answer: (C)

The main idea is that the forces on two anchor legs sharing a load are a matter of vector balance. When a load W is suspended between two anchors, the rope on each side carries a tension T. If the two legs form an angle θ between them at the load, and the setup is symmetric, each leg makes θ/2 with the vertical. Balancing vertical components gives W = 2 T cos(θ/2), so T = W / (2 cos(θ/2)). As θ increases (the spread between anchors grows), cos(θ/2) decreases, so T must increase. That means the load on each anchor grows with a larger angle. Conversely, a smaller spread (smaller θ) keeps T closer to W/2, sharing the load more evenly and with less peak force on each anchor. So increasing the angle between the two anchor legs increases the load on each anchor; keeping the spread small helps avoid overloading the anchors. Note that in asymmetric cases where one anchor ends up taking more than the other, the distribution can be uneven, but the general relationship for equal anchors is that larger spread raises the tension on each leg.

The main idea is that the forces on two anchor legs sharing a load are a matter of vector balance. When a load W is suspended between two anchors, the rope on each side carries a tension T. If the two legs form an angle θ between them at the load, and the setup is symmetric, each leg makes θ/2 with the vertical. Balancing vertical components gives W = 2 T cos(θ/2), so T = W / (2 cos(θ/2)).

As θ increases (the spread between anchors grows), cos(θ/2) decreases, so T must increase. That means the load on each anchor grows with a larger angle. Conversely, a smaller spread (smaller θ) keeps T closer to W/2, sharing the load more evenly and with less peak force on each anchor.

So increasing the angle between the two anchor legs increases the load on each anchor; keeping the spread small helps avoid overloading the anchors. Note that in asymmetric cases where one anchor ends up taking more than the other, the distribution can be uneven, but the general relationship for equal anchors is that larger spread raises the tension on each leg.