måndag 23 april 2012


1881 America's Cup winner, Mischief
From a poster by Tre Tryckare, Göteborg 1962
Viewed in profile, the America's Cup defender in 1881, Mischief, was strikingly similar to Pilot Cutters from Falmouth, Britain. (Interestingly, with its clipper bow, the British challenger, Atalanta, resembled an American yacht of the time. From a distance, the tables must have appeared to be turned.)

In fact, Mishchief was nothing like the narrow, deep-draft cutters or fishing trawlers of England with their full bows and narrow sterns. She was decidedly different and rather radical, to the extent that there was nothing really like her in Europe at that time. 

Mischief was unusually beamy, of extremely shallow draft, with a centreboard, and very heavy (probably helped to a few extra tons because of the materials used - she was built of iron). The traditional craft that spring to my mind would be the catboats of New England. 
Mischief as a yacht, probably in the 1890s

From Howard Chapelle, History of American Sailing Ships 
Looking through Chapelle's History of American Sailing Ships I always admired her lines. Because apart from being beamy, shallow and shapely, with a long, efficient waterline, she had a lovely distribution of displacement - sharp forward, beamy aft. Very efficient, and in fact almost modern.

A new 'Mischief'
When I was approached a few years ago for the design of a 108' performance yacht with a traditional pilot boat character, I could think of no better inspiration than the 67' Mischief
Mischief 108' interpretation

The inefficient flat-plate centreboard is substituted for a modern bulb keel which will keep the ballast weight low. The original boat relied on a heavy displacement for its stability. With its centre of gravity pushed down, the modern version can get away with much less displacement, offering the same degree of performance as any well-designed modern cruiser / racer.
Mischief 108' interpretation

The rig shown is more for illustration purposes - on a 100' hull, such a gaff rig would be rather impractical. Mischief has not yet been built.

The new Mischief is does not pretend to be a replica, but a modern interpretation, inspired by the original. She is much larger,  with very different hull and appendages configuration, deck layout, interior layout and even aesthetics. The preferred building material would be a carbon composite.

The original seems to have been painted black in 1881 and later repainted white, for example in the photo above which I believe could have been taken in the 1890s. 

With a sail area of 550 square metres, the sail area / displacement ratio (SA /D) will be the same highish 26,4 for both boats. However, the displacement / length ratio (D /L) will be a high 349 for the old boat and a very low 109 for the modern variant. This means the two boats will have completely different sets of characteristics. 

Dimensions original Mischief             new Mischief
L.O.A.:          20.57 m                            32.80 m     
L.W.L.:          18.59 m                            29.10 m
Beam:            6.00 m                              9.00 m
Draft:             1.62 m (centerboard up)     3.50 m
Displacement: 79.2 tons                             95 tons
Sail area:       487 m2                              550 m2
SA /D             26,4                                  26,4
D /L                349                                   109

fredag 20 april 2012


Sailing Faster & Staying Overnight

Design contests are fun.
I remember three sailboat design contests since I started out professionally in 1991.
* One was in Yachting World 1995
* One in Yachting Monthly 2000
* And last year this oneDesign Challenge III, in Professional BoatBuilder together with its sister publication WoodenBoat.

The theme for this contest seemed interesting and, as it happened, I had had a boat in mind which was very much in line with the ideas behind the competition. Still, we were busy with other work and with only a few weeks to go before the closing date, we sat down to put this new design on paper.  

The Baby Celeste
picture by Christian Wallgren

There is something about certain boats, like they seem to talk to you. You see a sailboat moving slowly in the morning breeze, yanking her mooring lines a little, anxious to get out on the bay. And you feel this urge to join her, to hop onboard and cast off.

Fast, responsive, simple, immensely fun and very versatile – this must be tempting for many people. Young couples, sailors with little time, people in the cities, Wednesday night racers. Or sailors who have already had a serious cruising yacht which took an hour to get underway, despite a couple of extra hands onboard.

For some time, I have had this vision of an utterly modern, responsive sportsboat with a big, inviting cockpit for long summer days. But, no matter how fun this boat would be to sail, she would only be half if she didn’t have a cosy little shelter, some basic comfort and a good, warm and dry berth inviting you to stay overnight. A little boat for those among us who still appreciate the basic joys of life.

WoodenBoat’s and Professional BoatBuilder’s Design Challenge strikes a very keen note for a seasoned sailor. There may also be a commercial potential in this kind of boat; indeed, this is just one more reason that I find the thought of it rather thrilling. So much that I decided to enter a design competition after having managed to stay away from them for 12½ years.

The Baby Celeste may be a slightly different interpretation of the ideas behind the Design Challenge. I decided to pack her into a somewhat traditional folklore ballad kind of composition. Too conventional perhaps? Maybe, but she is still very unusual, there is nothing like her on the market, is there? Too complex? Well, she is still a very simple boat… Too basic? For some, absolutely, because her comfort is rather primitive, there is no shower, no standing headroom. She certainly is not for everybody.

Some details of the design may need a comment:

Hull concept

Under water, the Baby Celeste has a sharper bow than almost any boat of similar proportions. Her waterline entry angle is a mere 10 degrees. This makes her able to slice through waves at speed, and with great ease.
But the most outstanding feature of this design must surely be her length / beam ratio, in particular at the waterline, at a whooping 5,4. Why not make a shorter, planing hull? This is all about high average speeds. The  Baby Celeste  will be extremely swift on all points of sailing, not just downwind. She will have a smooth transition to speeds higher than hull speed and thus will be equally happy at 6½ knots on the wind as she will at 12 knots on a reach.
The downside to this hull shape is stability of form, and she will depend on her deep T- keel for stability. A beamy boat of the same length would have had greater wetted surface, required more sail, would need heavier scantlings because both hull and deck panels are bigger. Such a boat would, effectively, have been a much bigger boat. 

Keel arrangement
The keel can be lifted for trailering, or for motoring into shallow anchorages.
The lifting keel is mounted in a carefully cast square shaped moulding which is fixed to the hull and deck, with the adjoining main bulkhead completing the box-like, self supporting structure. This arrangement gives excellent strength and stiffness to the part of the boat which carries the greatest loads, and eliminates the need for further stiffeners or structural members.
To improve things a little further, as can be seen in the drawings, there are also elastic sliders mounted onto bumpers at the corners of the square top of the keel. This will both ensure that the keel is hoisted without much friction, and allow it to move a little at impact. Even a slight movement will reduce the energy to a fraction, possibly eliminating the risk of damage completely, if for example one hits a rock.
The keel is hoisted by means of an 8:1 tackle with blocks either side of the top of the keel case. The line is lead via a jammer to a dedicated winch and cleat. The rudder kicks up as well and can be controlled via a lever through the rudder head.


The chainplates are near the deck edge, anchored in the main bulkhead, giving the mast a wide base for the shrouds. This allows for a thin and light mast section, and for single spreaders to be used. Aluminium spars.
The mast step has a hinge at the back side, like a tabernacle, so the mast can be set up on the boat. When doing so, it is held in place by the (rather common) arrangement consisting of two removable stanchions holding the lower shrouds. Lifting is done by means of the jib halyard, boomed out at the mast step. Once the spar is in place, the upper shrouds are set, the stanchions are removed, the lowers are lengthened and attached to their turnbuckles.
Sail handling is straightforward. The mainsheet is on a padeye in the cockpit floor. The jib is on a furler, sheeted to a ‘Hoyt’-type boom which makes it exceedingly efficient on a reach. The jibsheets lead aft each side under the cosmetic roof. On the aft face of the cabin there is a group of clutches recessed on each side; these are not shown in the drawings. A gennaker can be flown from the bow.
The  Baby Celeste is a very fast, very responsive and rather tender boat and will be at her best in summer winds. For crossing the Channel in September, one should look for another kind of boat. But with her easily driven hull shape, she will offer a civilised ride home in a blow, under a very deep reef.

The Baby Celeste has watertight compartments forward and aft, meaning that there are no deck hatches. However, there is one in the port cockpit seat, for dry storage like sails and cushions, and one in the cockpit floor, for things like an outboard.
And of course there is a hatch in the foredeck, offering light and air to the berth below.
Installations forward, like the bearings for the jib boom, can be accessed through a hatch set in the forward watertight bulkhead.
picture by Christian Wallgren
Depending on where you measure, the cockpit is 3,15 – 3,60 metres (10-12 feet) long and laid out for 1-6 persons. Surrounding the cockpit, there is a low pushpit onto which is attached comfortable backrests for the sofas, modern daysailer style. The helmsman sits aft, or on the sofa. The sofas are long enough to sleep on in fine weather and a fine place to sit in port. There is room for a small table in the middle.
The transom is open for easy access from a dock or dinghy, for swimming, and for the simplest possible rigging of an outboard. Still, a little electric engine and a folding propeller is a nice option.
Such a propulsion system is completely silent, clean and odourless, and is at your service at the touch of the control lever. It reaches full thrust, 60 kgs (130 lbs), in less than two revolutions. One of the beauties of the propulsion system is that, because it is electric, it allows the incorporation of other electric creature comforts. The system is ‘refuelled’ by plugging in the cord. It can be kept topped up by a sun panel.
The clue to this system’s efficiency is in the speed control, the refrigeration technology and the optimising and careful integration of the components. The system is provided by Oz Marine in Sweden; on other markets there may be other suppliers of similar systems although I believe their fridge is a very remarkable thing.
Nobody needs to be on deck unless you want to hoist the gennaker. Thus, there are no lifelines, and the jib boom is arranged to almost sweep the deck. The deck is big and clean, surrounded only by a pretty little varnished teak toe rail.

Staying overnight

I did not want to simply tuck in four berths but instead accomplish some more comfort, without adding kilos – but remember, this is a small boat on the inside! Headroom is only about 1,32 metres (4’4”).
There is a generous double forward with a deck hatch above to give light and ventilation. On the starboard side the bulkhead can be opened, forming a counter space above the w.c., or closed, separating these two compartments. To port, the double berth may be curtained off from the rest of the boat to give some privacy.
Further aft, there is a galley to port and the w.c. to starboard, together with the sink. The w.c. can be made completely private by means of another curtain, arranged to extend from the aft of the keel trunk towards the side of the boat. There is room for a very small water tank under the forward berth. A battery goes in the cockpit stow room. This is charged from shore and used for the few LEDs on board.

The electric installation can also integrate things like a music system, sailing instruments, a chart plotter and an 18 l (2cu.ft.) refrigerator, drawing only 4 watts. 
Aft, there are two ‘easy chairs’ under deck, extending a little way aft under the side decks where the winches are placed. Further aft, the starboard seat is converted into a berth to sleep one more person. To port there is room for bags and sails, also accessible from the cockpit.
Light and ventilation is provided via the forward hatch, a transparent entrance hatch with washboards, and the opening port in the starboard side of the cockpit. In addition to the two fixed ports, Baby Celeste also has two opening ports in the cabin, concealed behind louvered glass grilles which keep rain out, so the boat can be left until the next sail, with windows open.
The visible part of the interior extends 5 metres (16½ ft) forward and aft and 2 metres (7 ft) across.
A square boom tent is attached to the pushpit and could almost make the little Neo appear spacious. It offers a little more headroom in the cockpit (1,6 m) and in the entrance (2 m). The opening part of the bulkhead forward doubles as the cockpit table.

Making it all work
A concept like the Baby Celeste will be possible only if weight is strictly controlled. At the same time, I believe that exotic materials must be avoided in order to keep production cost within reasonable limits.
The Design Challenge called for a simple boat, which is good. Simplicity is a corner stone of any good design. But how does one define simple? As a designer, should you focus on simple handling, or a simple build schedule, or a lack of features, or simplistic / minimalistic shapes? Difficult balance.
Using Vinylester infusion of multi-directional glass rovings on a closed cell PVC core, the construction is made of four basic parts:
1 - The hull, which uses a split mould but is laminated in one piece
2 - The deck and cockpit, including the part of the cabin which is just under the cosmetic roof and houses the keel lifting blocks and all control lines 
3 - The keel casing, which extends forward like an overturned ‘L’ right under the cabin top. This goes together with the deck part, above, to make a proper beam, forming the mast step
4 - The cosmetic roof, which does nothing except look sweet
You could perhaps say that the complication of the design lies in engineering and 3D-modelling the necessary plugs and moulds. Once done, the build process should be straightforward, and handling will be a doddle.
picture by Christian Wallgren
Availability and price
A carbon spar on the Baby Celeste would be an interesting option. And customers will be able to choose the colour of their boat and its roof, the rig, the propulsion, the way it is equipped, sails, cushions, boom tent and the colour of its specially made trailer.
A prototype will start building after summer 2012. 
Price and availability to be annonunced. Please let us know of your possible interest.

Baby Celeste, specifications:

L.O.A.                                         9,25 m      30,3'
D.W.L.                                         8,81 m      28,9'
Beam, maximum                         2,28 m        7,5'
Beam, waterline                          1,64 m        5,4'
Draft                                            2,00 m        6,6'
Displacement, light                      1550 kg     2700 lbs
Disp., w. 2 persons + light load 1760 kg     3100 lbs
Ballast                                         650 kg      990 lbs
Sail areas:
Sail area 100%                            38,6 m²     415 sq.ft.
True sail area                               40,8 m²     439 sq.ft
Mainsail, true area     27,0 m²     290 sq.ft.
Jib, true area              13,8 m²     148 sq.ft.
Gennaker                                     42 m²        452 sq.ft.

D/L                                              73
SA/D, upwind                             26,5
SA/D, downwind                         57
Ballast ratio                                 42 %
WL. entry                                    10,0°

torsdag 19 april 2012


18' Sport Boat

At 18 feet, this little boat is by far the smallest one-off designed by Heyman Yacht Design. Still, she makes a lot of sense and there is nothing like her on the market - please correct me if we have missed something out there!

She was designed for a sailor in Dubai, a father of five. The requirements was for a competitive sportboat / daysailer with room for the children, easy to sail single-handed and without need for hiking out.

Added to this, this boat had to be easy to pull onto a trailer and to raise the keel and be beached for a picnic ashore. And, when the wind dies in the evening, to be rowed home in the setting sun.

Sit back - Sail away
The nicest thing about this little boat is how she invites you to sit down and lean back. She takes care of you like a traditional sailing skiff, or, on the Swedish coast, much like a Bohusjulle.

This is my older brother Jon and me sailing our bohusjulle, Bums, in 1956. I am the toddler between the oarlocks, barely tall enough to look out when sitting on the floor-boards.

Same thing, almost...
Hoisting for the first time in Långedrag harbour

Watching these pictures in 2012, it is suddenly apparent to me that the Maha Dubai, designed some 50 years later, must have been inspired by Bums, at least on a subconscious level. Even her square head mainsail is reminiscent of the older boat.

But this is where their similarities end. 
The Maha Dubai will glide along at very good speed, without fuss. Her underwater shape is very slender. In proportion, she is more like an America's Cup IACC boat than anything else. 
So there she is, the first offspring to a bohusjulle and an IACC boat. This is what she looks like underneath:

At 18 ft, her keel is 2 m deep, made of a slender aluminium extrusion, with a bulb of 50 kgs. 

This makes her, not stiff, but less tippy and much more forgiving.

She was beautifully built by Torsten Sörvik in Göteborg, builder of the finest sailing canoes. 
For this boat, he used Divinycell planks and multidirectional E-glass. Project Management was handled by Pelle Fälth.

The rig is carbon, from Marström Composite.

Nicolas Bathfield, Naval Architect (left), Pontus Wennerlund (right)
Although the Maha Dubai was conceived as an open boat, she has a sunk deck forward. This is a lovely place for younger kids to sit, or for sunbathing. 

Underneath, and under the aft thwart, are dry storage / floatation compartments.  
The fixed bowsprit is for flying the asymmetric.
The floor is an integral part of the construction, and offers a little extra floatation. In the centre is a well for bailing. There are also Elvström Bailers each side. 

For rowing, the central floorboard is lifted out, inverted and used as a thwart. Underneath, in the well, are supports for feet when rowing.

The boat was called Maha Dubai - the symbol in the mainsail is the Arabian Oryx, a unicorn antelope, called Maha.
Mr Alhamli test sailing Maha
So, how did she turn out?
Her owner says she carries up to four people without any serious impact on speed, and that she has topped 13 or 14 knots.

Torsten Sörvik, builder, and Pelle Fälth, project manager
Torsten Sörvik and Pelle Fälth
Torsten Sörvik, builder

Maha Dubai, particulars
Length 18.7 feet.
Beam 5.24 feet.
Draft 6 ½ feet. 
Weight : 260 KG.