F-33 - NEW FEATURES

By Ian Farrier

February, 2003

Like the F-27, the F-33 represents a major step forward from all my previous designs, the F-27 introducing such things as the low rocker main hull, molded carbon fiber beams, vertical joined floats, simpler parallel lower folding struts, single bar style upper folding strut, and a simplified molded beam bulkhead system. The vertical joined floats did not last on the F-27 due to difficulties in production, but these problems have now been solved, and the clean vertical joined seamless floats are back with the F-33, along with an improved beam and folding system, and this, plus some other significant innovations are detailed below.

BEAMS AND FOLDING SYSTEM

The 'Farrier Folding System' is now well proven, with over 2000 boats using it very successfully world wide. However, I felt there was still room for improvement and hence the F-33 beams are more advanced over what has been used before.

'Pretty' Open 60 or F-36 style rounded 'gull wing' style beams (originally developed by Australia's Lock Crowther) have always been a good start and look good, and I have gone this way in the past, as far as could be achieved in a production beam. However, such beams can be difficult and expensive to make in their ideal form, and production versions have to have compromises, resulting in a number of drawbacks.

I thus set out to solve these problems with the F-33, with the aim of providing more practical beams that offer some real advantages such as:

1. Easier to make - which makes them more reliable, and of a lower cost. Trying to achieve the ideal rounded shape on earlier production beams, meant overlapping join flanges on the beam sides, but these proved difficult in a production environment. This is because the overlapping top sides tended to scrape the glue off the bottom sides as the beams come together, which can make the glue join somewhat unreliable at times The production process then has to be properly and very carefully supervised, and such joins frequently checked. The F-33 join flanges were thus made horizontal, and wide for simple, reliable, and easy assembly. 'One off' beams such as those for the F-9A/F-82/F-36/F-39 beams don't have join flanges and they can be molded into the ideal shape with foam fairings on the front, but this is not practical with production beams.

2. Beam Recesses Eliminated - these are the notches into the main hull where the beams are normally bolted in my older designs. Drawbacks are they take up interior room, plus they can be a nuisance when the boat is folded, and they add weight. A complete rethink and redesign eliminated them altogether by moving the beams completely outside the main hull, which also made them shorter (lighter and with a lower trailering height). It is also now much easier to fit and maintain the required mounting plates and compression pads, while the only thing left in the main hull is a small slot for the upper folding strut.

View of Forward Beam Bulkhead area - no intrusion by the folding system or beams, only the
Upper Folding Strut pivot pin cover plate being visible inside.

3. Drier - this was probably the most important aspect that I wanted to improve. The F-31 for instance is a very dry boat at normal or even above normal monohull speeds, but over 15 knots, and in a chop, then it can get rather wet at times. Main culprits are the leeward folding struts and beam outer ends, which can generate spray when they hit wave tops. This spray can be shot up vertically, and find its way into the cockpit, and also force itself through gaps under the aft beams where they connect to the main hull.

To improve matters, lower folding struts were moved higher, by anchoring inside the beams rather than below. A close look was then taken at the beam shape, particularly the aft beam outer ends near the floats, which could frequently hit wave tops and send water flying in all directions. Beam was reshaped to direct this water downwards, while the horizontal join flanges were made oversize and right above the initial contact area to catch any spray that may still head upwards, and slam it back down again.

The ideal production beam shape? Outer ends are set high with sides angled to deflect wave tops
down, while large overlapping join flanges make it difficult for any spray to escape upwards.

The beam to hull connection had already been moved completely outside the main hull, to eliminate beam recesses, and this had the additional benefit of eliminating any gaps between the beam and hull in the coaming area where water could force its way through into the cockpit.

4. Brackets and Bolts Eliminated - the F-33 is intended to be an ocean capable boat, and thus I wanted to eliminate all the aluminum brackets and stainless steel bolts that go into the carbon fiber beams. These have to have special treatment to ensure 100% long term reliability when bolted through the carbon fiber used in the beams, and thus require special supervision in the production environment. Eliminating these removes ninety six (yes, 96) 1/2" stainless steel bolts and 32 aluminum brackets (heavy and labor intensive). They have been replaced by 100% integrated carbon fiber anchors, which destruct tests have shown to be enormously strong, while also eliminating any point loading and potential leak problems.

5. Compression Pads Improved - No More Creaking! A very high inwards compression force is generated in the beams while sailing, and this has to be absorbed into the main hull via compression pads. These need to be adjusted properly otherwise there can be a slight in and out movement of the beams, which, while usually harmless, can sometimes generate an annoying creaking noise. Twin compression pads are now used, both of which are easily accessible and adjustable, virtually eliminating any chance of creaking. SHADOWFAX has not creaked once since launching.

6. Wingnet lashings Covered - another problem always present with earlier beams was the danger of stepping too near the beams in the wing net lashing area. One's foot could go through this gap, if not careful, with painful results. This possibility has now been eliminated by the lashing being concealed under the beam join flanges, making it virtually impossible for a foot to slip through. The beams themselves now also offer a nice wide and safe walking area.

7. Disassembly Possible - Fully integrated beams that are permanently attached to the float look nice, but they have proved to be impractical, as they make it very difficult to replace a beam or a float, raising repair and insurance costs. It is also impossible to disassemble the boat to where it can be fitted inside a container for easy shipping. Thus the F-33 beams are bolted into molded sockets in the floats, making disassembly easy and practical.

8. All epoxy construction - as throughout the F-33, only epoxy resin is used in the beam construction, which is the toughest, most durable, most fatigue resistant, and most waterproof resin available.

The new beams are thus significantly better, being stronger, lighter, shorter, more reliable, and drier. They are much safer to walk on, or around, the flanges give something to hang on to while sitting, and there is no intrusion into the main hull, with the nuisance beam recesses completely eliminated.

KICK-UP DAGGERBOARD RUDDER

Kick-up rudders have been used successfully for years, where the rudder blade is pivoted in the case and will swing back. But they come with one annoying problem - they are just about impossible to steer with when swung back to reduce draft for shallow water. Daggerboard rudders solve this problem by lifting vertically, and have also been around for years, but also come with a problem - they cannot kick back. Thus if one hits anything the rudder can be destroyed, or worse, ripped off the transom.

The only way to solve this was by developing a new kick up daggerboard rudder, which has now been done with the F-33.

SHADOWFAX at Southport Yacht Club, on the delivery trip, awaiting better weather. The new
daggerboard style rudder case is visible here, rudder blade being on port wing net

Blade in place, and retracted - this can give excellent control in shallow waters, coupled with a light helm,
something a swing back style kick up rudder does not do well. The rudder can also be retracted in lighter
airs for less drag.

Rudder sleeve shown kicked back - this built in 'kick back' ability will help avoid any damage or
even complete loss should rudder hit anything, which has always been the the main concern with
such daggerboard rudders.

Rudder case and blade are of epoxy glass/carbon composite construction, and rudder assembly will be attached to boat with CNC machined aluminum transom brackets. Fully integrated carbon fiber transom brackets will be optional (standard on the F-33R) and these are shown. Special Teflon filled acetal rudder bearings are then fitted in embedded G10 fiberglass bushings to give a totally slop free rudder, with a very smooth feel.

Rudder fully down. This new style rudder system can also be bolted on to F-9A and F-31s, using the same
gudgeon bolt holes, the old stainless steel gudgeons being replaced by new aluminum gudgeons with the
Teflon/acetal bearings, eliminating all metal to metal contact (and slop). A similar 'bolt on' rudder system
will also be developed for F-24s, F-25Cs, F-82s, and F-28s when time permits.

MAST STEP

The F-33 mast step is another new and improved feature. There's no need to insert any pins when attaching the mast base to the deck/step which can be an awkward and time consuming task. The mast base has two slots which instead just slide over a pin in the step. The sheaves are also in the mast base itself, so that once the mast is raised, there is no need to thread the halyards through any sheaves in the deck step, which is another awkward job eliminated, all of which makes the mast raising process faster and easier.

The mast raising pole yoke (which is now very compact) is held to the mast base by one pin. One then removes this and inserts it through the mast step to lock the mast to the deck step, to ensure the mast cannot jump off the step.

Better still, on the F-33 you can remove the daggerboard without having to unbolt the step from the deck, as with earlier designs, a process which can take some time. The F-33 mast step will also allow the mast to lean over sideways in any direction, without breaking the step, which is another important factor while folding the boat or raising the mast.

Mast step area with new step - note also the concealed/flush daggerboard control lines

BOW WING

The bow wing increases bow net area to make foredeck wider and safer. It also provides an external area on the side of the bow to mount or set the anchor from. Eliminates the awkward and difficult task of setting anchor forward under headsail or through pulpit, where space is very constricted, particularly with headsail lowered.

The bow wing while sailing - anchor roller on starboard side.

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