BEST OF 2015 – ” Make it run fast. To win, listen to your boat.”

We briefly summarize the last two installments devoted to the method of technical development in racing. In the first one we looked at how to set up a racing project and organize boat and crew; in the second one we looked at how to optimize our vehicle and conduct it to the best of our ability. In this third lesson we will look at how to focus on boat speed, improving mast setting, perfecting sail shape and developing a table of speed and angle targets in all gaits.

To cover this topic we will also rely on the experience of a close Phi!Number collaborator: Matteo Polli, a boat designer specializing in ORC and IRC optimizations, which will help us understand how to improve the tonnage certificate by highlighting the key parameters to work on in the ORC world by arriving at the trade-off between rating, speed on the water, and technical ability of the crew.

1. HOW TO WORK.
Following a working method is necessary to improve performance without wasting time. Initially, if possible, it will be wise to choose days with average winds around 8-13 knots. Once a good speed in this range has been achieved, one will move on to training with little wind and stiff wind and wave. In the first stage it will be sufficient to go out to sea without sparring partners, later it would be good to be joined by a boat and team with performance equal to or better than ours. We will go out with a setting that we consider to be suitable for the wind and sea conditions, and gradually make adjustments to reach an optimal setting (only one of the two boats will go to modify its set), until we notice a concrete improvement in speed.

2. WORKING TOOLS
In this speed-finding work, it is essential to have a notebook where you can keep track of feelings, data, measurements, changes and any improvements in performance. That is why a tensiometer (if there is one of the right size for the boat), a metric wheel, a caliper, and a well-stocked toolbox should not be missing.

3. TREE AND SAILS.
Regarding mast adjustment, first it will be important to find proper lateral symmetry (there are various methods, the most widely used one being to hoist a metric batten to the mainsail halyard by taking measurements at lateral points on the deck from the masthead). Then you will find the best rake (longitudinal tilt of the mast), adjusting it so that the rudder is neutral or slightly bearish when the boat has the right angle of upwind heel.

The rake is also critically important for boat speed at the breakers. With the rake fixed, it will be time to work on the shrouds to get the right prebend (amount of mast bend) thus perfecting the mainsail shape and making the backstay adjustment more efficient. The backstay will define the amount of forestay catenary and the deflection of the top of the mast (in fractional arms) by acting on the shape and fatness of the sails.

4. HOW TO CREATE A TABLE OF ADJUSTMENTS
With a view to the future, to make adjustments more straightforward and to avoid losing the results obtained, it will be good to have a table available showing the changes in forestay and shroud loads with respect to different wind ranges. It will be convenient to mark on the chart the number of turns to pull and/or let go in the hairpins to achieve the desired set, starting, for example, from a basic setting for winds around 8-10 knots.

If we have worked well during training, more and more specific data will be added: the adjustments of vang, cunningham and backstay in all wind and wave conditions or the ranges of use of various sails. Also, it is useful to apply marks on sheets, halyards, etc. to have adjustment references. However, the table we will have produced will not take into account the wave and/or wind fluidity.

5. BLOCK COMMUNICATION
Training to communicate is critical to navigating fast. That is why the helmsman will have to transfer feelings about the load on the rudder (the boat’s main restraint) to the upwind mainsailer, while with little wind in the upwinds the tailer will guide the helmsman by communicating changes that could cause the boat to lean.

6. OPTIMIZE WITH CRITERION
Improving the ORC certificate does not simply mean optimizing and pulling our means to the maximum. The technical capabilities of the crew must also be taken into consideration: if we are not facing a professional team, the goal of a well-done optimization will have to be to make the hull easier to carry. There is no point in “pulling” a boat to the maximum if you then lack the technical skills to take advantage of this optimization work. Let’s take an example: racing boats are born with little surface area in the appendages, commonly recognized as a brake for speed.

However, by reducing the appendages, the boat is more difficult to carry and especially to make the boat accelerate when, for whatever reason (e.g., a badly caught wave), it slows down. Potentially reducing the area of the appendages leads to an increase in top speed: but what good is that if the crew cannot carry the boat adequately to the modifications made? Instead, by increasing the lateral surface area of the appendages, the boat is more manageable in re-accelerations, resulting in an increase in average hull speed and greater ease of handling.
Taken from the June 2015 GdV