Clew: Lower Aft Corner of a Sail
The clew is the lower aft corner of a sail, a key point where control lines attach to help trim and adjust the sail’s shape and angle to the wind. On mainsails, the outhaul is attached to the clew to control the sail’s foot tension and draft, while on headsails like genoas and jibs, the clew serves as the attachment point for sheets, enabling sailors to adjust the sail’s position relative to the wind. Properly managing the clew helps maintain optimal sail shape and control, ensuring efficient sailing performance.
Importance and Function of the Clew in Sail Trim
The clew plays a critical role in shaping the sail’s lower section, affecting the boat’s power, speed, and balance. On a mainsail, the outhaul is used to pull the clew along the boom, flattening or loosening the foot of the sail depending on wind conditions. Tightening the outhaul, for example, flattens the sail for stronger winds, reducing drag and maintaining control, while easing the outhaul creates a deeper draft for added power in lighter winds. This adjustment impacts not only speed but also the boat’s handling and ability to point upwind.
On headsails, such as genoas and jibs, sheets are attached to the clew to control the sail’s angle and trim. When the sheet is pulled tighter, the sail’s angle to the wind decreases, which is beneficial when sailing upwind. Easing the sheet opens up the sail angle, improving efficiency on a reach or downwind course. This control over the clew provides sailors with the flexibility to adjust the sail for optimal performance on various points of sail, making the clew a crucial component for responsive sail management.
Historical Context of the Clew
The concept of the clew dates back to early sailing practices, as traditional square-rigged vessels required a system to manage large sails effectively. The term “clew” has historical roots in Old English, relating to the idea of a “ball” or “mass,” which refers to the clew’s function in gathering and tying off parts of the sail. On square-rigged ships, clew lines allowed the crew to gather and secure the lower corners of the square sails, adjusting or furling them as needed. This early innovation laid the groundwork for modern sail control systems, emphasizing the clew’s importance in trimming and managing sail shape.
Today’s sailboats, particularly modern racing and cruising yachts, continue to use the clew as an essential control point for managing sail tension, shape, and angle. With advancements in sail materials and rigging, the clew has maintained its relevance in modern sailing, allowing for precise adjustments and efficient sailing in a wide range of conditions.
Components Associated with the Clew
Several key components interact with the clew to facilitate sail control:
- Outhaul: Attached to the clew on mainsails, the outhaul is used to tension or ease the foot of the sail along the boom, helping sailors adjust sail shape to suit wind conditions.
- Sheets: On headsails, sheets attach to the clew, providing the means to trim the sail’s angle to the wind. Headsail sheets can be adjusted to improve performance based on the point of sail, making the clew an integral part of headsail trim.
- Clew Ring or Cringle: The clew ring, or cringle, is a reinforced ring at the clew, serving as the attachment point for the outhaul on mainsails or sheets on headsails. This ring is built to withstand the strain exerted on the clew during sailing.
- Clew Strap or Webbing: To provide extra reinforcement, many sails use a strap or webbing around the clew to distribute load and reduce wear on the sailcloth, enhancing the durability and lifespan of the sail.
Frequently Asked Questions about the Clew
How does the clew affect sail shape?
The clew is instrumental in adjusting the lower portion of the sail, impacting both draft and tension. For mainsails, pulling the clew aft with the outhaul flattens the sail, reducing power and drag, which is beneficial in strong winds. Easing the outhaul allows the sail to develop a deeper curve, increasing lift and power in lighter wind. On headsails, adjusting the sheets affects the sail’s angle and twist, enabling sailors to trim the sail for optimal performance on different points of sail.
What is the difference between a clew on a mainsail and a headsail?
The clew serves a similar purpose on both mainsails and headsails in that it is used to control sail tension and angle. However, on mainsails, the outhaul attaches to the clew to adjust the foot’s tension along the boom. In contrast, on headsails like genoas and jibs, the clew is attached to the sheets, allowing for side-to-side trimming that adjusts the sail’s angle to the wind.
Why is the clew reinforced?
The clew is heavily reinforced because it endures significant load, especially in strong winds. Constant trimming and tension place strain on this point, which can lead to wear over time. Reinforcing the clew with webbing, layers of sailcloth, or additional stitching helps distribute the load evenly and prevents tearing, extending the sail’s life and performance.
Best Practices for Managing the Clew
Understanding and properly adjusting the clew is crucial for maintaining sail efficiency and handling. Here are some best practices:
- Inspect Regularly: Check the clew and its attachments, such as the clew ring, outhaul shackle, or sheet knots, for signs of wear or corrosion. Reinforcement and hardware should be intact and securely fastened to prevent failures during sailing.
- Adjust for Conditions: Use the outhaul and sheets to adjust the clew tension based on wind conditions. In lighter winds, a fuller sail shape (eased outhaul) adds power, while in heavy winds, flattening the sail (tightened outhaul) reduces heeling and improves control.
- Prevent Overloading: Avoid excessive tension on the clew by ensuring appropriate sheet and outhaul adjustments. Overloading the clew can lead to premature wear and even damage, especially on older sails or sails not designed for high loads.
- Use Quality Hardware: Invest in high-quality hardware like stainless steel rings, shackles, and reinforced straps or webbing at the clew to ensure durability and reliability. Strong, corrosion-resistant materials are essential to withstand the constant load placed on the clew.
The Clew’s Role in Modern Sailing
The clew is one of the most critical points on any sail, serving as the connection between the sailor and the sail’s shape, power, and angle. It provides the leverage needed to control sail performance, allowing adjustments that directly impact speed, handling, and efficiency. Mastering clew management and understanding its role in different wind conditions helps sailors maintain optimal sail trim, contributing to smoother, faster, and safer sailing experiences.
In sum, the clew remains an integral part of sail control, embodying centuries of sailing evolution. Its function has expanded with advancements in materials and rigging, but its purpose remains largely unchanged—to provide sailors with the control necessary to harness the wind’s power effectively. Whether racing, cruising, or simply enjoying a day on the water, the clew is essential in achieving the best performance and safety in any sailing environment.