David McKee's Guide to
Faster Flying Fifteens

The Flying Fifteen will give you back what you put into your sailing. If you are fit with energy to burn, this boat will reward you with its performance, giving the thrill of sailing in a planing hull under an efficient rig. For those who prefer to rely on tactical skill rather than brawn, the Flying Fifteen’s one design rules make the racing close and the boat responsive to tuning. Although over 50 years old, a constant and controlled development has enabled the class to remain fresh and modern, both in construction and appearance.

The basic set up and fit out is simple. Boat speed is generally quite even and therefore there are rewards available to those who put effort into their hiking up wind and for those able to use the rig controls to maximise performance.

One of the features of the Fifteen is the freedom to develop our rigs and control systems to make the boats easier and more satisfying to sail. This is one of the challenges of modern racing sometimes forgotten in the new strict one designs.

THE BOAT

In recent years measurement tolerances have been tightened and this has resulted in a stable period of hull and keel shape. Boats are mainly constructed in epoxy foam sandwich. Well maintained boats up to ten years old can remain competitive. A recently introduced rule allows boats to be re-weighed annually and as many boats have weight correctors it should be possible to maintain minimum weight for many years to come.

The keel should also be of minimum weight (169 kg). If yours is overweight, I would recommend drilling it out, in accordance with the class rules, to achieve the minimum. The keel should be to the maximum sideways profile allowed by the class. It may be necessary to fill and fare to achieve the optimum profile.

Modern rudders optimise the tolerances to give a more vertical leading edge and therefore a more balanced feel. The rudder should be of minimum weight (3.8 kg). Most shafts are of stainless steel passing through nylon bearings at bottom and top of the shaft. These tend to wear with time, resulting in wobble and vibration. When this occurs, the bearings should be replaced.

The hull, keel and rudder should be smooth, fair and kept clean.
 

THE RIG

The most common masts are the Super Spar M2 and the Proctor Epsilon. For lighter crews (under 24 stone), the Super Spar M7 is an alternative that can be de-powered more readily. The mast foot is generally 3,777mm from the aft face of the transom to the rear mast foot bolt. Rake is measured by attaching a tape measure to the main haliard and setting it to read 6,248mm at the black band by the goose neck. Set in this position, rake is then measured to the centre of the transom. With the genoa hoisted with 350lbs of rig tension, rake should be approximately 7,570mm (24ft 10in). For light crews in high winds, rake can be increased to 7,500mm (24ft 7in).

Of the two sail makers heavily involved with the class, Goacher favours a slightly straighter mast with less rake. Alan Bax of Pinnell & Bax uses slightly more rake and pre-bend. Both set-ups have similar performance around the race course so it’s a matter of making your choice and applying the basic set-up recommended by your sail maker.


EQUIPMENT

To achieve optimum set-up and trim of the sails, it is necessary for all control systems to run freely, to have appropriate purchase, to be calibrated and fall readily to hand. The principal requirements are as follows:

Mainsheet

Most boats now use an aft bridle mainsheet. This incorporates a split tail anchored each side of the aft deck lead along the boom and to a central mainsheet jammer. On windy days, an additional purchase in the centre of the boat can be added to assist control of the large mainsail. The advantage of the stern mainsheet is the ability to centre the boom in light and medium winds. There is a risk of over sheeting and hooking the leach with this system so you should use care when applying tension to the sheet, watch your leach teltails.. This arrangement is not so effective for regulating leech tension with the boom off the centre line. In windier conditions, a good kicking strap is needed to apply downward pressure on the boom.

Jib Cars

With a large over lapping genoa, the positioning of the cars and sheet tension is critical to performance. Basic car positions can be obtained from your sail maker. The sheeting tension should be regulated to ensure that the luff teltails lift at the same time in normal wind conditions. When windy the upper teltails should stall out first.

The most recent trend is the adoption of ball tracks/cars that can be altered when hiking from the windward rail. It is always helpful in big winds to move the cars back progressively as the wind builds to prevent the slot between genoa and main becoming congested as the main is eased in the gusts. The positioning of the jib cars is crucial to performance and in big winds can make all the difference between fighting the boat and being able to concentrate on racing and race tactics. I move the jib cars back as much as 6 ins in the biggest winds.

Ram

Control of the mast position at the deck has a big effect upon mast bend, sail shape and, therefore, performance. The current trend is to use a below the deck lever to both straighten the mast and act as a puller to introduce pre-bend. With the genoa hoisted, 350lbs rig tension and with the puller/ram free to move, I mark the neutral position that the mast naturally adopts on either side of the deck.

When both helm and crew are hiking, I ram the mast back approximately 10mm from this neutral position. When overpowered I return to the neutral position. With the crew sitting in the centre of the boat, I release the ram/puller altogether and as soon as the crew goes down to leeward or has to sit on the leeward deck, I use the puller to pull the mast almost to the front of the gate to introduce mast bend to flatten the sail, free up the leech and keep the boat moving

Rig Tension

Sail makers provide recommendations for rig tensions across the wind strengths. These tend to range (standard masts) from approximately 300lbs to 400lbs. It is important to have these rig tensions calibrated and the tension control easily operated from the rail. In severe winds, rig tension as low as 250lbs is effective. The settings recommended by the sail makers are good basic starting points. Sailing inland where conditions can vary considerably, I would recommend a good average tension of around 350lbs.

Out Haul and Kicking Strap

There are various systems for these controls. The important thing is that these are led readily to hand when sailing and with sufficient purchase to enable them to be easily adjusted.

CALIBRATION 

It is important that the main controls are calibrated. This provides a reference point to enable you to reproduce fast settings. You should mark main haliard, rig tension, jib cars, and pole height. I would also recommend calibration of the jib sheets as this helps the crew to readily set-up after a tack and produces consistent settings from one tack to the other. Many crews will naturally set the genoa differently from one tack to the other.

 
SAILING THE BOAT

If you sail predominantly on small to mid sized inland lakes, conditions will constantly vary. The wind may be gusty and under these conditions you should consider good average settings for most of the controls and concentrate on sailing the boat, tactics and strategy, rather than constantly tweaking the rig to optimise it through these fluctuations. The key controls in these conditions will be the kicking strap and sheet tension/settings.

The low aspect genoa is sheeted close to the centre line. The overlap at the bottom of the main is therefore large but this rapidly tapers to nothing and with the long top mast, there is a considerable area of main sail operating in free air, unaffected by the genoa.

This gives the characteristic twisted setting of the main sail, close to the centre line low down and freer leech high up above the slot area. As the rig becomes overpowered, it is necessary to de-power the main in a way which does not involve the boom moving too far off the centre line, thus avoiding back winding to the lower part of the sail. This is best achieved by use of the cunningham, rig tension, jib car position and kicking strap.

In light winds, the crew will have to sit on the leeward side deck and helm within the cockpit area to introduce a small amount of heel. The boom will be trimmed lightly perhaps 4” off the centre line, maximum puller on to induce mast bend and a flattish foot of the main sail. Rig tension can be reduced to assist mast bend at spreader height.

As the wind increases, the crew will move into the centre of the boat, rig tension can be increased to around 300-350lbs, the genoa cars moved to their standard position and the mast at deck rammed to the standard position. Care should be taken not to over-sheet the mainsail as hooking of the leech will slow the boat.

With a further increase in the wind, the helm and crew will be fully hiked, rig tension up towards the maximum of 350-400lbs and the mast rammed up to 10mm astern of the standard position.

As the wind increases further and the boat is overpowered, steps are necessary to reduce power. The rig tension should be reduced as the wind increases, the neutral mast bend position applied and the out haul and cunningham gradually tensioned. In extreme conditions the cars should be moved further back and you should consider applying further mast rake. In high winds over tensioning of the kicking strap can result in significant creases in the mainsail between the spreader position and the clew. This destroys the mainsail shape. Kicking strap tension should be reduced until the creases disappear.
 

CONCLUSION

Boat speeds in the Flying Fifteen class is generally quite similar producing close racing. Strategy and tactics play a large part in success. However, for those prepared to work hard to keep the boat flat, gain an understanding of the rig control settings and able to “change gear” with the conditions there are considerable rewards.


©David McKee 2001

 

 

 

 

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