The 14 class has adopted some rule changes that are designed to increase the performance of thier boats. Some of the changes have been analised in the following article. The analisis is crude, but hopfully it will quantify the changes and allow us to understand and compare them. The most cost efficient conversion options can then be assessed. Assumptions have been stated however a lot of the maths has been left out to condense the article. Due to the immensely complicity of the problem I can not prove any of my theories to be correct, and fortunately no one can prove me wrong, but there accuracy is clearly questionable. Therefore the following is meant only to be a rough guide and so a pinch of salt may be required before any money is spent on conversions. As an aside, a similar analysis could be the basis for a handicapping system.
| Table 1 | Old rule | New Rule |
| Approximate distance from crews feet to center of gravity | 40" | 40" |
| Distance from feet to center line of boat | 33" | 36" |
| Totals | 73" | 76" |
The righting moment will increase by 4%. Assuming that in over powered conditions an increase in righting moment of 4% will allow the sails to produce 4% greater driving force. This will accelerate the boat until the drag has increased by 4%. Assuming that resistance is proportional to V2, and the coefficients of drag (C) are constant for small changes in speed.
\dV = C.dR /2
Therefore there is a potential increase in speed of 2% in overpowered conditions.
An increase in crew weight of 4% will increase the righting moment and therefor the sail driving force by 4%. This increase has to be offset against the increase in resistance of the boat mom to it’s larger displacement. Assuming hull resistance is proportional to displacement a 4% increase in crew weight will increase the displacement by 2.3%, (see table 2). Assuming the hull resistance to be half the craft’s total resistance, (dodgy assumption) then there will be an offset resistance of 1.15%. When over powered there is therefore the potential to increase the resistance by 2.85%. This will relate to a speed increase of 1.4%.
If both crew were to lower themselves by 25° to the horizontal, there will be a 5.5% increase in righting moment. This translates to a 2.7% increase in speed.
| Table 2 | Old rule | New rule |
| hull | 190 lb | 165 lb |
| rig | 40 lb | 40 lb |
| foils | 22 lb | 22 lb |
| crew | 350 lb | 350 lb |
| Totals | 602 lb | 577 lb |
Assuming table 2 to be accurate the reduction in displacement will be 4.15%. As before assuming hull resistance to be half total resistance and proportional to displacement, the increase in speed will be 1%.
Assuming the reduction in weight of a carbon mast to be 10 lb, the total reduction in displacement is 1.7%. As before the speed will increase by 0.4%.
The other advantages of a lighter mast such as, reducing pitching inertia and the center of gravity height have to be considered before any sweeping conclusions about carbon masts can be drawn.
To analyze this rule change in isolation we shall assume that the sail area does not change only the aspect ratio increases. An increase in luff length of 12% relates to an increase in aspect ratio of 25%. Assuming that rig induced drag is 1/4 of the total craft’s drag (very dodgy assumption ), and that induced drag is inversely proportionally to aspect ratio. The potential increase in speed in under-powered conditions is (25/4/2) 3.1%.
The white sail area will increase by 5%. Assuming that 5% more sail area will allow 5% more driving force. There will also be a 5% increase in rig drag, this drag shall be assumed to be 1/3 of the total craft drag ( dodgy). The potential speed increase in under-powered conditions is 1.7%.