freddies Perfect Boat ...one step of thought forward

Ah the perfect boat,.....

well here are the must and should haves

planing in 14 - 16 knots wind
27/28 foot 8.1/8.3m
4 crew or 5 crew payload 440 kg max
4 to six berths
lifting keel
EU trailer legal 2.52m W
Inboard or Platu/Impala solution or DE combi
Assymetric spinnaker
Performance on IRC

A hard ask? Especially when you think of making anything go on IRC, and thinking about the rating the J88 has got, 1.037 - 1.039, faster than the 105 , 109 and j92s!!

Well IRC can be fixed a bit because there is a sweet point at a slightly lower SA-D ratio, more akin to the Bene Platu 25 and the First Class 8m which have quite kind IRC ratings, and could go on SBR in those days too. Sail area can be reduced, and by running with a heavier airs design of sail for one design sailing, so can the handicap be standardised and the boat be OD ready without odd sails in the wardrobe.
LP

The concept is also quite a lot like the j125 - a relatively heavy ballast ratio, with a lot in the bulb/lower keel. The ballast may well be up to 800-900kg in order to reduce crewing from 5 / 6 to optimal with 4 big chaps or 5 smaller, with the bouyant lever being less than many boats, althoiugh not silly sinny when compares to the Farr-Mumm 30 , the Tarac 33 or the j125 at 3.23 m for a 42 foot boat ! Engine, batteries and fuel tank considered as hull ballast and opti ised in design. Total displacement would need to be somewhere under two tonnes plus 440kg max lard aided ballast ie crew payload. I am thinking then about 1.6-1.8 tonnes, giving it a 48% ballast ratio and a SA / D ratio of around 32 I guess.

Upwind sails- a main with a high aspect, preferable with a spitfire round roach than square top, and either with a long crane-batten solution or maybe a backstayless rig ( twin spreaders, carbon inner tapered tube top section, hydraulic forestay contolled from pit). I would say around 25- 26 sqm. Use of a jib-oa at 115-120% to lower COE while adding upwind punch at about 16 sqm, with an H2 -j2at the same foot but with hollow to depwoer the main in 22 to 25 knts TWS. WkJ3 for IRC rating a about 13 sqm.
Inhaulers, optimised tracks with haulers.

Offwind Sails and Pole . given a total payload of about 2.4 t, the boat will need some woomf if itbisnto have sports performance offwind, with atleast 80 sqm and more like 90-95 sqm on the A1 vmg deep. I may favour twin halyards and twin tack lines-blocks for change downs to the A2 reacher, or a second halyard point. For IRC i guess we are down in the realms of 55-65 sqm, with the addition of a collar perhaps for the pole, shortening J measure too.

The concept is pretty firmly racer sleeper with a chemical heads, and perhaps a water boiler or microwave solution. I would tip this boat to be diesel generator - electric drive, with inverted 240AC being useable at 13 amps for auxilliaries when the prop is not in use.  Engine counts as ballast weight, 14 hp / 10 kw.

Trailer sailor? Well that is really one of the very few gaps in the market in the EU-USA-Can. .....a trailer sailor which can sleep all her crew meaning that deliveries go at 45 knts and there isnt a nasty hotel bill or late taxi in the morning to worry about. People are very used to a lifting keel, although the 707 shows otherwise, there being so many more 3 tonne + lift cranes on lorries these days. It would probably draw 2m or a little more depending on the need for righting lever to make up for the quite narrow hull.

Lift Keel ? And a useable cabin ? Seem like a contradiction? The aussies have been doing lift keel for some time and we have the Slovenian Europe 8m to look back to , all be that with a mistake in the keel design which lead to mid speed cavitation at around 14 knts and wipe out! Given that we are making no real concessions to cruising, then the cabin top can be quite small, so think of a melges 24 stretched with the keel then moving forward three feet, thus being in the cabin gangway, and thus covered by the step into the cabin. This is then to just above waterline, and sealable, with some better securing mechanism than a strop, perhaps even keel bolts. or a wedge sealing with a worm gear to secure this and release it under precise control   before and after hoisting with a special cran tool as in many boats, or by the lift crane.

Behind this is then the engine and perhaps sail drive if an electric outboard and hull hatch /moon pool solution is not taken into account. 14 hp with a 3 phase AC motor or a stepped DC motor is achievable in quite a small CC high speed generator, off the peg, with possibly a dry exhaust and radiator to air cooling not being assisted any further than on the standard unit. These are considerably cheaper and lighter than the heavy torque marine engines and the 'hyrbid' set up also allows for batteries around midships as ballast verus carrying much fuel. Getting in and out of Marina by el-drive. Plug in hybrid capability, minimising engine use.  I think the hull hatch on stb side like the platu and the Impala is pretty optimal in terms of weight and cost compared to an electric sail drive style set up with folding prop.

Hull shape is essentially a stretched platu Farr / Rachel and Pugh / Andrews influenced 1990s style without chines! Because we are making little concession to cruising, freeboard is relatively much the same as the smaller boats, going up to somewhere between 1.3 m and 1.6 m, tailing off to 90 cm on the transom and 1.4 about on the bow. The bow would most likely be plumb because we want max waterline upwind and there will be no bow work under normal conditions. Probably opting then for an above deck roller firling to reduce the hull work, and clean up the bow area vs the melges rather nasty little roller drum well. Hull construction may well be glass-kevlar single skin.

The main other construction feature would be aluminium sections which 1) hold the deck stepped mast 2) attach the shroud plates 3) transmit forces to the hull and keel. Thus the interior is devoid of a mast strut, and this allows for a slightly more creature comfort, open central area for sitting in a ring cracking a beer open to celebrate or to lick wounds. Aluminium box section also runs from the keel box forward to these lateral girdle structures. These also allow for options on where the shroud plates would be mounted, fully outboard to further in thus a small 110% genoa could be on the cards while on the design table for power and verticle centre of effort in the sail plan.

Rudder bearings would be much the same as the platu, carbon reinforced and the mast would be an aluminium skin with simple carbon pole inserts, tapered up the mast, and shimmed in place with nylon composite collars and cones at the head and foot of the mast. Boom by the same construction.

I do rather fancy using the Andrews 28 lifting rudder, but using a 29er style alumium skin, composite solution for cost and weight.  I am not a fan of transom hung rudders on anything over 25 feet. Look up the arguements about aquadynamics, loading, over/leverage and vulnerability yourself.

A nicety would be a hydraulic mast ram to avoid so much bottle screw nonsense, or a simpler hydraulic purchase on the forestay, taken as a stock item from a backstay equipment catalogue. Backstay on a simple cascade purchase with a big whipper on the top

Standard stays and shrouds, twin swept back aluminium spreaders. I would opt for a wire strop system to reduce the costs of installing a travellerr and keep the cockpit nice and open, with a forward sheeting position useable by helm or trimmer. Jib sheets maybe on a purchase a la b14 with cross sheeting set up, or with winches. A basic cabin top winch set up like the impala, with a cut away for the stb sheet aimed at crross winching would be a budget option, but the boat would have stregnthened positions ready for six winches. Outhail and reefing point on jammers hidden uynder the boom like proj 920, neat that idea. High boom to make for safe crewing and shove some sail area higher up there, while making for  a very usable amount of bend in the mast when using kicker.

Assy off a carbon pole. either in a deck box or just in collars and gusset seals throught the hull. Up wind probably about 13 m squre foresail, 19 main with an assy to somewhere around 60 to 70 for OD and a smaller no 2 for wind over 22 knts true and for IRC racing. Jb goes down to no 2 at the same range and becomes also IRC jib.  Main has reefing points because this is in my opinion a failing in the M24 because just as the wind is exciting for off wind, the main is being flogged and the boat is overpowered completely upwind.

Upwind, performance nothing spectacular, high fives low sixes. Off wind it would be notably a fast boat with the big kite up in One Design, but not planing as early in wind terms as her smaller cousins.

Target price? well inc VAT and sails and motor around 50 to 60 k euros, ex trailer and IRC No. 2 set of sails, being supplied with a No 3 and 3/4 ounce, smaller reacher as second A/sail.

IRC optimised sail set would need to count in at about 1.005 to 1.015 max, with the No 1s and big assy probably poking it up to 1.028.  Planing not really happening until 16 to 18 knots true on the smaller sails. Upwind max being maybe just 6 knots, relying on acceleration and quick tacking ability to make up time in what may often be IRC 3 to IRC 4 class banding.

Possible Concessions

1) Chines = cut off hull wetted area. Because the boat is very narrow, it may need more bouyant lever to make it stable and driving through the gusts. Also this will increase the planing area for off wind platform stability!

2) Diesel -Gennie Electric Drive  could be just an outboard in the well.

3) Higher freeboard for a sit in some more comfort cabin.

4) a fixed A frame instead of a bow sprit perhaps to simplyify and make the interior more water tight.

6) Transom hung rudder for cost

7) a non lifting keel

I think quite a few boats have compromised down the cruising interior to a stage where it is almost superflouos such as the smaller Arachambaults. the Grand Surprise , the Andrews 28 and so on, while the j88 and some Corby's have gone the other way, with just too few berths. I remember having a very good nights sleep indeed on an FC 8m on a blow up lilo down there with the petrol fumes even. Stoop and sleep rather than crawl in and sleep are just as good to my mind. Heads on a 28 footer become sensible, and I remember well the Figaro with its rather public heads.

In fact given the choice of an older boat to sail one design I would have to say the detuned masthead figaro II would be a top choice, all be that with a prodder protruding frm the pointy end.