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AutorenbildHans Genthe

See me, feel me, fly me - indulging in an old love.

Aktualisiert: 15. Dez. 2020

The bow rises into the sky and then crashes into the wave´s valley. On impact I feel Hauke's legs coming off my shoulder - does he tip forward? When the boat hits the ground my thighs scream with pain - under my weight, I ease the mainsail, we accelerate. Everything disappears in spray ... nothing to see, but then I feel Hauke's leg back in its usual place on my shoulder - he has swung back.


Kieler Woche 2002. We sail with about 10 knots upwind. In windward Borowski, we are in a safe leewards position. It's all about the first or second place, the last race. The short Stollergrund wave doesn't fit to the length of the boat at all, to keep the speed we always drop a little bit while flying over the wave, to hit the next wave with a lot of pressure in the jib and get through with a lot of power. I pray fervently that nothing breaks. I just hang with my toes in the riding belt, upper body almost horizontal, keeping the boat exactly on a 5 degree heel, and was looking upwind via Hauke. Yes, we make every wave 10-20 centimeters against Borowski. Slowly we work our way forward. Andrenaline pure. The wind has oscillated around 10 degrees the whole race, when will the next shift come? Another high wave. Experience shows that they always come in threes. I drop down a little more, sail full on the genoa and we take off. After the impact again half a meter out - then the wind turns. Browoski sticks to the stern and gets bad winds. 2 minutes later we can turn around and approach the target. Won! Hauke and I fall into each other's arms after flying through the line - we finally won the Kieler Woche - a long-cherished dream. In the years before we failed again and again, with good 2nd and 3rd places.


Our boat is a KDV, in 1988 I optimized the construction with Johan Vels according to my wishes and upgraded and sold several boats. I wanted to go to the Olympics, had no money and had to be creative. In 1990 we fitted a new boat and sail it successfully for 20 years - now the boat sails my son. In the winter of 1999/2000 we gave the boat a total refit. The double bottom and centreboard box were made of wood, which had drawn water over the screws of the fittings. Again and again blocks flew out of the rotting wood, moreover the ship had in the meantime 3 kg overweight. The rest of the boat was made of carbon-kevlar, the deck was made of carbon sandwich, thus practically indestructible and bombproof.

So out with the wood scrap. We completely removed the double bottom and centreboard box and rebuilt it. The centreboard box has got an epoxy graphite coating inside, so that the centreboard axis can be adjusted even under wind pressure. The new double bottom is made of carbon sandwich, the rear last meter even of honeycomb. For this purpose 4cm of tough "submarine" foam is used at all places where fittings are mounted, so that the screws do not protrude into the double bottom, and it is 100% watertight. We also optimized the transom, remove struts and thereby reduce wind resistance. Tests on the 470 have shown that more than 50% of the total wind resistance is generated by wind resistance. This means that the brake plate in the transom must be removed.

In the bow, we removed the complete forestay suspension and installed a carbon double cross beam, to which we mount the jib furler and forestay. The cladding of this construction is also made of carbon. This saves 2 kg of weight in the bow and the annoying strut in the jib furler is no longer necessary. This makes setting and recovering the spinnaker faster. We also replace the tube for the spinnaker in the foreship - the new version made of Kevlar weighs only 1/3 of its predecessor.

The hatches in our boat are heavy, but 100% watertight and easy to use. Big enough to store spare parts and food.


The carbon framework in the center behind the mast is carrying a curry cleat base for the spinnaker pole hoisting rope - a perfect place and easy to access.

In the whole boat we optimised the adjustment possibilities, and can thus build up more shroud tension during sailing - this means the genoa is flatter in the luff - an advantage in heavy winds.


The modifications pay off, at the world championship in Gilleleje in Denmark in 2001 we became 6th, although with the only 77kg weight of my crew Henri we should not stand a chance in strong winds. In 2002 Hauke and I sail Kieler Woche together for the first time as a new team - with the 95kg weight of Hauke we are extremely fast. We lead, but fall behind in the penultimate race because of some tactical mistakes, our nerves are shattered. For the last day of racing we go to bed early, have breakfast and good mood, and start the last races with 18-22 knots wind - our dream conditions. What sailing. Sun, waves and a happy team. The old masters and GDR Olympic participant Borowski are tactically superior, but we sail a touch faster and are better in manoeuvres. Again and again changes in the lead, so the decision about the overall victory is really only made in the last meters.

Now, 20 years later, I have the opportunity to bring the experience and some new ideas into a Flying Dutchman production. Over the last years I have gained a lot of practical and theoretical knowledge about yacht design and composite manufacturing - in addition to my 4 semesters of shipbuilding studies. Since October 2019 I live in Dubai - a Mecca of possibilities: Qualified workforce, low corporate taxes and a worldwide logistics. So why not develop and build a FD? The latest developments in the FD have driven up the price - in my opinion, that doesn't have to happen. The shape is optimized to the limit - according to CFD software, modifications only bring speed increases in the per mille range. The shape of the new boats from Planatech and Mader use tolerances down to one millimeter - anyway, only +/- 6mm are possible. An FD should be maximally full in the bow (Section 9), maximally narrow in the middle (Section 5) and maximally wide in the transom, with as little curvature as possible in the longitudinal direction. This results in so little further room for manoeuvre that resistance changes are no longer measurable.

Picture above: The magenta zone (line thickness) is exact the tolerance, which is possible inside the measurement rules. Compared to the original plans from 1956 the aft section can be flat up to 2,2m length, which optimizes (theoretically) the planning abilities. The difference in the angle of the exit lines in the transom is max. 0,25 degrees. The possibilities in optimizing a modern FD lines plan are less than 0,05 degrees, that means, the change in resistance is not longer relevant ... we can be sure, that a Flying Dutchman offers fair and competitive sailing for decades.

Aspects leading to victories The following factors offer far more potential for optimisation: - Reliability (finish all races, do as little tinkering as possible and train a lot) - Easy maintenance (all lines and fittings are accessible and quickly replaceable) - Wind resistance (from 10 knots wind upwind more than 50% of the total resistance) - Handling (All trim devices can be operated with little friction and are optimally arranged) - Durability (being able to sail as long as possible with his proven boat) - Possibilities for upgrades (new trimming devices are easy to install) - Cost (makes the class more attractive and brings larger fields) - Optics (gives pleasure)

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The new Flying Dutchman For the following boat I made a calculation and have experienced production partners. It will become reality, if I get 6 preorders collected. The new Flying Dutchman will be delivered always as a full carbon epoxy boat. It can be ordered without any fittings or fully equipped without mast, boom, spinnaker pole. We developed some individual solutions: Carbon cleat boards, a carbon mainsheet cleat bracket which supports the traveller, very strong and light Carbon jib leads arms, a Carbon shroud track and last but not least high duty rudder fittings. Most blocks are Dyneema rope mounted, fixed at carbon loop padeyes or rounded fender eyes. The boat will be produced in an industrial organized series production, certified ISO 9001:2015.


Material/production in CNC milled moulds - Carbon epoxy vacuum infusion (no glass, only carbon!) - The whole boat will be tempered in a big oven - Polyester gelcoat (20 years well proven) with thin vinylester contact skin/layer (no UV-problems and easy to repair) - Foam without water absorption, exact CNC cutting - Only carbon and high density foam for reinforcements, no wood or alloy - Exact jigs for mounting of all structure and parts Hull design - Maximum girth/volume in the bow - Maximum width in the transom. - Minimum rocker in the transom section - Minimum width/girth in the mid section

- extreme weight concentration in the center of movement (traveller)


To avoid mistakes I´ve added all measurement rules and illustrations in our plans and visualized the tolerances:

Cockpit design - Optimized cockpit ergonomics - Open transom, only 10cm deck/bridge at the transom a) minimum wind resistance

b) water is out faster

c) you can see through the transom - so you can see if you're sitting too far back

d) It's easy to get the rudder mounted - Less buoyancy in the transom means much better behaviour when capsized: a) turns to 180 degrees much slower b) you get on your centreboard better - Best maintenance, easy access on all the lines - Long rubbercords up to the transom, so the cords last longer - Easy mounting of individual fittings: big areas of high density foam in the center of gravity

Strongback - The structure of longitudinal stringers and frames absorbs all forces. The hull is only a shell. - The second longitudinal stringers (yellow) are high to stiffen the boat - Exact CNC cutting of all parts - Carbon biaxial fabric with additional unidirectional layers - 20mm foam without water absorption - The structure is glued in: secondary bonding with a hollow joint and 45 degree biaxial carbon tapes - The centreboard case is optimally stiffened in the area of the axle with extra bulkhead

Double bottom - The double bottom is extremely rigid/stiff due to the framework - The double bottom is as deep as possible at the transom

a) offers the helmsman a better hanging position b) the water flows off faster due to the stronger inclination - The double bottom is raised below the side decks - The water under the side deck runs off more quickly, especially when heeling

Foreship - The foreship is extremely stiff - bulkhead made of unidirectionally reinforced carbon - The longitudinal stringers run out in the front smoothly (support where the ship hits the waves hardest) - The forestay and genoa reel are attached to a carbon crossbar (10 years well proven) - The spinnaker trumpet is max. large in the front, the spi goes in and out easily

(Carbon with Teflon-coated surface) - No corners/edges where the spinnaker can get caught - The spinnaker tube is made of kevlar - no fractures/leaking - Forestay & jib furler line run through the spinnaker tube - further weight saving - Small hole in the bow for a bow line / tow line

Transom - The transom is maximally open and reduces wind resistance

(upwind wind resistance is more than 50% of total resistance) - The center stringer supports the upper rudder fitting - The rudder fittings are optimally accessible

Rudder

- The classic "one piece" rudder is extremely strong and reliable

- Profile optimized by VPP/CFD technology

- Produced in heated alloy moulds with 120t press

- Carbon tiller and carbon tiller extension

- New developed heavy duty rudder fittings

- the rudder blade starts less than 1mm behind the hull -> less ventilation

Gybing Centreboard - Self-adjusting angle of attack, 1,6 degrees to each side - Extremely high carbon ratio: 80% unidirectional carbon, 20% biaxial carbon - Critical area head/outside hull massive unidirectional carbon layers 30 degrees angle - Strong high density core (no wood) - Profile optimized by VPP/CFD technology - Produced in heated alloy moulds with 120t press

Centreboard case - inside epoxy-graphite coating - the centreboard axis can be moved under pressure - reinforced with extra strong biaxial carbon layers - The centreboard case is self draining due to it´s shape

Fittings

The basic version is fitted with Allen blocks and fittings. We developed a more simple layout which reduces the costs but offers all functions with less friction. We got great support from Allen (UK), they improved their fittings a lot. For example Petticrow Dragons are fitted with Allen now. In 2018 Allen takes huge investments in their machining centres and design & CAD modelling software. The new patented Allen Dynamic bearing system provides an unrivalled weight to performance ratio. For the Allen Flying Dutchman version we worked close together to find the best solutions. This results in reduced friction, which means you are able to produce higher tension in the rig without increasing the ratio - a huge advantage in handling and speed.

Trimm and Handling of the Basic Version - Jib sheet ratchet blocks switchable with one curry cleat per side (see options)

- Endless jib sheet - Adjustable Carbon jib arm with ball bearing sheaves - Recess in the double bottom to allow max. deep jib lead prosition - Spinnaker sheet system with automatic ratchet blocks

- Tapered endless Dyneema spinnaker sheet with balls

- Main sheet 1:4 with automatic ratchet block

- Raised main sheet curry cleat base on carbon rack

- Bended traveller with ball bearing high load car - Barber hauler (3 versions possible for operation by crew, helmsman or automatic with balls) - Mast saver 1:4 - Jib furler high load with ball bearings

- 15m ø8mm towing rope Center cleat console The following trim ropes are guided to starboard/port through hard anodized cleats on a carbon console, all ropes are pulled below deck with extra long elastic cords for long durability. The ClamCleats offers the advantage that you can´t open the cleat by mistake or forget to push the rope in the curry cleat. At other positions you want to let the rope unfixed in some situations, like centreboard or boom vang. All ropes listed from front to back:

1) centreboard up/down 1:4, curry cleat

2) spinnaker pole lift (1:2 in mast), clamcleat 3) cunningham 1:4, clamcleat 4) jib lead adjustment vertical 1:12, clamcleat

5) jib lead adjustment sidewards 1:8 (each from windward side adjustable), clamcleat 6) lower shrouds 1:24, clamcleat 7) shrouds 1:24, clamcleat 8) jib/forstay adjustment rough 1:12 big curry cleat and fine 1:24, clamcleat 9) see option below 10) see option below 11) boom vang 1:12, curry cleat, easy to access on heavy wind downwind reaches

12) traveller - due to the elastic cord mounted blocks the leeward cleat can be opened in full hanging position if you forgot to open the sheet during tacking. In light air this system works better than an expensive automatic traveller (which blocks if insufficient pressure is applied to the mainsheet). Options on cleat board 9) centreboard on two ball bearing cars on track 1:3, curry cleat

10) spinnaker sheet adjustment 1:12 (9. position) clamcleat The spinnaker lead blocks at the transom are adjustable. Solves some problems in heavy wind on a fast spinnaker run- On a tight run you can get the boom away from the forestay and you can roll the jib. No additional blocks on the sheet (no additional friction) or expensive tracks. I have it since 15 years in my boat, simple, reliable, effective.

Further options - 2 additional jib cleats per side (accessible by the helmsman, recommended) - upgrade central cleats rack with ball bearing curry cleats (not recommended) - upgrade to Harken automatic traveller (not recommended) - double speed endless mainsheet system with double cleats (recommended) - 2 carbon paddles (nice to have) - 2 helmsman cushions (recommended, offers a better hanging position) - 2 carbon bottle holders (nice to have)

The red areas port side in the illustration below show the 50mm (!) thick high density foam. So you are free to mount fittings in this sections without any problems - just drill and screw.



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