🔍 Key Concepts

• Yard and stay rig geometry – how the two booms and their heads form a triangle with the load and the topping lifts/falls • Horizontal vs. vertical stress components – how the angle of the falls changes the side (horizontal) pull on the boom heads for the same weight • Vector resolution of forces – how a single load is shared between two stays and how their angles affect the horizontal component

💭 Think About

• Imagine a fixed load weight and slowly move it so the angle of each fall to the horizontal changes – when would the sideways (horizontal) pull between the two boom heads be the greatest? • Think about how the same weight can create larger tension in the falls when the falls are more horizontal vs. more vertical – what does that do to the horizontal component at the boom heads? • Compare the extreme cases: almost straight up and down vs. spread wide out – in which case would the booms be pulled hardest toward each other?

✅ Before You Answer

• Be clear on the difference between tension in the falls and the horizontal component of that tension at the boom heads • Visualize or sketch the force triangle between the two boom heads and the load – identify where the horizontal pull acts • Verify which angle condition causes the largest side pull between boom heads, not just the largest total tension in each fall