Thule
Latest updated Monday, February 5, 2024, 12 comments
Images | Particulars | More about | Background and history
Plans, Thule - 125 EUR
Purchase
Thule is a fast and roomy expedition and touring kayak, designed to provide a dry ride, ample storage and an ability to press on even in adverse weather conditions.
To achieve this the kayak is fine-ended, has rounded chines and just a trace of deadrise.
High stability (very high secondary) means that inexperienced paddlers quickly learn to handle the kayak in waves and that skilled paddlers can keep going comfortably when the weather refuses to cooperate.
Thule is a large and roomy kayak and works best with a tall paddler who has enough strength and weight to make full use of the kayaks potential.
In spite of its length, Thule turns easily. In a hard beam wind, though, all but the really experienced paddler would need some additional help to stay on course. Most Thule´s are built with rudders, but an adjustable skeg will work nicely to neutralize weathercocking if the kayak is used for cruising rather than rockhopping (both options shown on the plans). Also shown are bulkheads and hatches, but Thule can be built without those if the builders prefer a simple layout – with the high deck and large cockpit it is easy to pack from the cockpit which is a reliable, inexpensive and light option.
Particulars
| Length¹ |
550/523 cm (overall/WL) |
| Beam |
57/54 cm (overall/WL) |
| Draft |
11 cm |
| Cockpit¹ |
80x40 cm |
| Height¹ |
29.5/22 cm (in front of/behind the cockpit) |
| Weight² |
18-23 kg |
| Displacement/volume⁶ |
150 kg/420 litre |
| Speed³ |
7.4/10.8 km/h |
| Prismatic coefficient |
0.55 |
| Wetted surface |
2.23 m² |
| Drag⁴ |
1.64/3 kp |
| Stability⁵ |
4/5 (initial/secondary stability) |
| Intended use |
Expedition and touring, coastal and open sea. Day tours and exercise. |
* These dimensions can be adapted to suit personal needs or wishes.
** Depending on type of wood, equipment, care with epoxy usage, sanding etc. etc.
*** The speed numbers are based on mathematical standard formulas (175 lb paddler + 30 lb carco weight) and corrected from the kayaks actual performance om trials, on tours and in races.
⁴ Calculated resistance in 4 and 5 knots (at nominal load capacity).
⁵ Initial stability and secondary stability on a subjective scale, where 1 is very tippy and 5 is very stable.
⁶ Displacement is kayak + paddler + load. Count off the kayak weight to get the load capacity.
Stability
The curve shows the calculated stability with a static load, and therefore of limited use for a real paddler. The part of the curve near zero degrees indicates the initial (primary) stability – the steeper the curve, the more stable. The part of the curve left of the peak indicates end (secondary) stability – the higher and wider, the safer you feel edging the kayak. The position of the peak shows also how much the kayak can be leaned without tipping over. The part of the curve to the right of the peak with rapidly decreasing righting moment is almost impossible to take advantage of.
Plans
The plan sheets contain the information needed to build the kayak/canoe. Station molds, stems and construction details are full scale. For kayaks the recommended cockpit size is shown half scale with offsets for a full scale drawing and advice on altering the size. On the plans you will also find advice on how to shorten or lengthen the craft. Lines and construction drawings are in metric scale 1:10.
The illustrated step-by-step building manual is in Swedish only, but it is available online in English: it covers all steps in detail and will guide first-time builders through the project.
Plans, Thule - 125 EUR
Purchase
Minimum window dimensions to get your kayak out from the workshop:
57x34cm
More about Thule
Thule is a fast sea kayak for touring and expeditions, designed to permit a high mean speed over time with little effort, even in difficult conditions and with a full load. The hull, rounded with sharp stems, enables Thule to go smoothly and dry in steep waves, with easily controlled movements and without being slowed down much in a head sea.
Good stability (very high secondary) gives even inexperienced paddlers the confidence to tackle waves, and helps experienced paddlers press on with speed and safety in bad conditions. The initial stability is high and braces are rare. With the knee supports shown on the plan, Thule is easy to roll even with the optional large cockpit. Vertical sides mean that the stability is almost the same with or without load and the flat bottom makes for great surfs. The midship shape is also important for the initial stability – the seat can be placed low, which together with the beam is the most important stability factor. Round and v-shaped bottoms force the seat up which decreases stability, which then has to be restored with more beam or ballast – both of which is detrimental to paddling efficiency.
Thule is a large volume kayak with ample room for knees, feet and payload, and I had large paddlers in mind when designing (>185 cm and 80 kg) – but in practice Thule has been popular with much smaller paddlers (though they might need some ballast when paddling without load, to control windage).
The volume is adequate for expeditions, or for extra gear such as diving or fishing equipment or extra food rations for areas with few opportunities for provisioning.
In spite of the length Thule is quite easily handled, but compared to Njord, Frej and others, some maneuverability is sacrificed for tracking. Rather long distance touring than rock-hopping. To counter weathercocking a rudder or an adjustable skeg is recommended.
Thule can be built with or without bulkheads and hatches. The deck configuration makes packing from the cockpit easy, so the choice is mostly about habits, weight, safety and convenience.
Background and history
Thule, designed 1997, was born from the need to have more packing volume than the original Kavat. I had the notion of bringing diving equipment for shorter trips and be entirely self-supporting on longer. At the same time, I wanted a fast and able kayak for any conditions around the coast.
At the time Ted Moores ordered a touring kayak from naval architect Steve Killing. It was named Endeavour 17 and was presented in Teds Book Kayak Craft. I liked the lines and gave my Thule similar lines.
Endeavour 17
Thule
What I did not like was the beam and deck height (many American kayaks at the time were really large) and the bell-shaped deck profile that in my opinion limited the room for knees in spite of a visually very high deck. With the high aft deck, the kayak was also very hard to roll.
So when my Thule neared completion there were, as usual, not much remaining of the inspirational lines. And so it should be: you find inspiration somewhere, add you input and end up with something that for the intended use is significantly improved. Thule has more volume in the ends and the total drag was down by 8% at 5 knots compared to the Endeavour (according to the presented figures and with the usual warning that they may be defined differently by different software), is narrower midships for a more comfortable and efficient stroke geometry, has a lower deck but more room for knee and feet (the deck has an elliptical cross section instead of the bell shape that has volume only in the middle), lower aft deck to simplify rolling, and slightly more rocker to improve maneuvering. What is left is a pretty profile and a healthy load capacity (though not quite as impressive as the Endeavour).
In my first presentation, I wrote that Thule suits tall and heavy paddlers – the normal consequence of generous load capacity. A small and light paddler will float high and be at the mercy of winds. But I learned soon that also short and light paddlers found Thule easily maneuvered and handled, so I had to adjust my prejudices ;-)
The name Thule has nothing to do with the air base in northern Greenland or the medieval Thule culture that once colonized Greenland. My thoughts went instead to the Romans who used the name Thule for the territory that is modern Sweden.
