Suggested changes to the Standard Specification to enhance performance and / or enhance the longevity of the vessel.
Spinnaker Pole and spinnaker Tack Point
[New Yacht] will be supplied with a hard point (probably a pad eye) on the deck ahead of the forestay, on the centreline. This is for tacking an asymmetric spinnaker or fastening Code 0 furling gear. I suggest the spinnaker tack line is run through a block shackled or lashed to this point. To make best use of the IRC rule, the spinnaker tack length (STL) should be specified on the location of this hard point, it is then imperative that the spinnaker pole is sized so that it fits to but does not exceed this STL.
Mainsheet Traveller
[Old Yacht] had inadequate mainsheet traveller control. It is possible that the tackle supplied will need to be changed to give more mechanical advantage.
Steering Wheels
The [New Yacht] is specified as standard with twin stainless steel steering wheels, I am lead to believe that [New Yacht] is to be supplied with Carbon Fibre steering wheels. If this is the case, covers will need to be supplied to protect the wheels from the effects of UV light when not in use. Carbon Fibre wheels are fragile and so may compromise reliability – even if they do look sexy!
Boom
The standard specification (aluminium) boom is equipped with single line reefing. This is unsuitable for racing, I suggest conventional horns or a separate luff puller at the tack reef points. Is a Carbon Fibre boom necessary? The negligible increase in performance does not warrant the added expense.
Mast
The Supplied mast will be an aluminium (probably Sparcraft) three spreader spar. The spinnaker halyards (two) will emerge at the mast head and then run down the front of the mast to pass through spectacles at the hounds. These spectacles should be moved to the masthead, the higher hoist (even with fractional rig sized spinnakers) will be faster. As an option, an additional third spinnaker halyard could be added at fractional hoist for a reaching asymmetric spinnaker but it really isn’t much lower and the added complication and weight may out-weigh any gains made by moving the centre of effort of the reaching asymmetric lower.
Headsail Furling Gear
The furling drum will be beneath the deck, it is likely to be a Facnor unit. The feeder for the foil must be of a racing model to ensure that headsails don’t pull out during hoists or peels, a Wichard style opening pre-feeder should also be fitted. Ideally a second forestay will be made up with a Tuff Luff of Harken head foil for racing, advantages are less weight and windage aloft and also the ability to hoist, drop & peel more easily.
Standing Rigging
The standard specification suggests rod rigging? Suggest the contract is checked.
Backstay
Will the supplied tensioner be hydraulic? Any conventional mechanical system will be too slow to operate under racing conditions. Weight aloft can be reduced by changing to a fibre backstay, this will improve performance.
Halyards
All halyards should be Spectra / Dyneema as a minimum specification & of adequate thickness to be effectively gripped in rope clutches.
Propeller
The fixed two bladed propeller should be changed for a folding or feathering design.
Feasibility study for Coded Headsails, against conventional Genoas
Advantages of Coded Headsails
IRC TCC reduction of approximately 10 points. Suggest a trial certificate to confirm.
Less sheet to pull in during tacking will result in faster tacks, especially useful when sailing in confined waters of the East Coast or Solent.
Headsails should last longer before replacements are needed as the fabric is not dragged over the shrouds and spreaders when tacking.
Battens can be fitted to the headsail leech thus improving shape stability and keeping the leech (exit) straighter.
The yacht is easier to sail for charterers and so will deliver a better experience.
Headsails will not need skirting over the guard rails during tacks thus saving time and keeping crew weight off the bow.
Disadvantages of Coded Headsails
The boat will feel under powered in lighter airs; this may extend up as far as 8 or 10 knots true wind speed.
The necessary fitting of headsail sheet barber haulers will complicate trimming.
Additional deck hardware will be needed for coded headsails.
Reaching or fetching performance will be compromised when a code 0 or small reaching spinnaker cannot be set.
Analysis of performance prediction through Parametric Study
Length Water Line / Displacement Ratio
This chart shows how light or heavy a yacht is for its length. The Dehler 44 is light for its length where as a First 45R is heavy. The [New Yacht] is lighter than the [Old Yacht] by approximately 1.3% for unit length.
Sail Area / Length Water Line Ratio
This chart shows how powerful a yacht is for its length. The Finngulf 43R has more sail area for unit length than the Elan 450. The [New Yacht] is more powerful than the [Old Yacht] by approximately 4.6% for unit length (overlapping genoa sail plan).
Sail Area / Displacement Ratio
This chart shows how powerful a yacht is for its displacement. The Finngulf 43R has more sail area for unit displacement than the Elan 450. The [New Yacht] is more powerful than the [Old Yacht] by approximately 1% for unit displacement (overlapping genoa sail plan).
The above analysis of the attached charts and spreadsheet shows that the [New Yacht] is a more powerful and so a faster yacht than the [Old Yacht]. Some of these figures, especially Sail Area / Length Ratio, are significantly different to show a marked improvement in performance.
When the [New Yacht] is compared to other similar yachts, she is neither particularly light nor heavy for her length. This will give an indication of the hull’s ability to surf or even plane and so is less of an indicator of the effects of reduced sail area whilst sailing to windward. It does however give some indication of how easily driven the hull is. It should be noted that the [New Yacht] compares favourably with the successful Farr designed First 45R.
The [New Yacht] carries significant sail area for her length; in fact she carries the most sail for her length (overlapping configuration) of any yachts studied. Even with coded headsails, the [New Yacht] is still in the top half and shows better figures than the Dehler 44, Grand Soleil 44 and J133. This figure gives an indication of straight line speed to windward however displacement must not be forgotten as it is a significant related factor.
Sail Area / Displacement Ratio will give an indication of potential acceleration. This is an important criterion on the start line and when tacking, especially in lighter airs. The [New Yacht] with overlapping headsails shows good numbers that are comparable with the Dehler 44 and J133 however when coded headsails are examined, the figure falls significantly. Once again, it should be noted that the [New Yacht] with coded headsails compares favourably with the successful Farr designed First 45R and Humphreys designed Elan 450.
The figures at the bottom of the charts, after the boat type, denote the % LP of that vessel.
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