The shaft rake: when this adjustment can become a winner

Have you ever heard a sailmaker, or a professional sailmaker, utter the word “shaft rake“? This term refers to the distance there is between the masthead and a point surveyed in the center of the boat’s transom, and is used to assess how the sail plan is centered.

In general, we can say that the more the mast is tilted toward the stern, the more the boat will have a sail center of gravity with a tendency to lazy. Working on the mast rake is critical to correcting boats that are overly gilt or, conversely, overly lean. Giving a practical example, with little wind if we want to get a lazy boat we will have to have a lot of rake at the mast, that is, a pronounced slope of the profile toward the stern.

How to change the shaft rake

There are basically two maneuvers that will cause us to modify the rake: the first is the forestay, the second is the mast foot (where modifiable). By collapsing the forestay, the masthead moves aft, thus increasing the tilt of the “pole” and the bearish tendency of the boat.

One way to act just as directly on the rake is by moving the mast foot: if we bring it forward, the head will move aft instead, and we will get a similar effect to letting go of the forestay. Balancing these two adjustments, and testing them in different wind conditions, will lead to the perfect balance.

Care must be taken not to confuse rake with preflexion: the latter is in fact the curvature of the mast and not its simple inclination towards the stern; they are two similar but different concepts, and two adjustments that are made differently. For pre-flexion in fact, the adjustment work will be to be done mainly on the loads applied to the shrouds.

Mauro Giuffrè