Tuning for safety

The rig is tuned for two reasons. Safety and speed. There are fundamental rules governing rig safety which apply to all rig types. Others are specific to fractional and masthead rigs respectively. Factors which have a positive effect on mast stability:Lateral • Correct adjustment of the lateral rigging. The aim is to achieve a straight mast in the lateral plane during sailing. A keel-stepped mast, however, must have an even curve. Masthead rig: Correctly tuned babystay or forward lower shrouds creating a positive pre-bend of the mast. This prevents inversion even if the backstay is slackened. Longitudinal In addition ... • A stiff hull which resists deformation. This prevents the tension in shrouds and stays being “wasted” in hull deformation. • Fractional rig: A tight (not necessarily tensioned) back-stay reduces the risk of the mast inverting. Inversion means that the mast creates a negative bend (the spreader area moving aft) until the mast buckles backwards. When the spreader area tries to move aft, the masthead wants to move forward, but this movement is prevented by a tight backstay.•
Mark the backstay with two pieces of tape at normal- and maximum load. The tape markers will enable you to re-tension the stay accurately. 30