Infidel and Inspiration
In the 1950’s, a New Zealand architect who was passionate about sailing started designing boats. His name was John Spencer; and his work inspires a lot of what we’re doing at Puur Sailboats.
Two of Spencer’s driving passions in boat design stand out to me: integration and simplicity. Many boat designers today are neither experienced builders nor experienced sailors, because industrial specialization has driven a segregation of expertise. On the contrary, Spencer was a designer, builder, and sailor. So, he saw design, construction, and operation as equal pillars of a great boat; his goal was a fast, lovely boat that would be easy to build and easy to sail. This holistic focus on simplicity is remarkable, firstly as it required an intimate understanding of all three domains and secondly as it produced some boats radically ahead of their time. And, my siren is his design originally named Infidel.
A sexy 60’ hard-chine plywood sloop, built single-handed by one man in a shed, twice winner of the Transpac, still sailing 50 years later? That’s Infidel. That’s Spencer’s genius.
Here are a few of the many ways we find inspiration for a 17’ daysailer in Spencer’s big sled.
A Practical Starting Point
He wanted it to fit in his shed. According to Spencer, “the length was chosen as coinciding with the overall length of the workshop.” You need a place to build it! We chose a 17’ model for the first Puur sailboat because we wanted a boat that could be built in and later parked in a normal garage.
Affordable and Buildable
Spencer built Infidel, largely by himself. It had to be affordable and easy to build. He chose plywood as the material and designed the assembly process to eliminate unnecessary woodwork. You can see in the attached image from Spencer’s original write-up that he did not even notch the transverse ribs to allow the stringers to be inserted into them.
This would certainly have stuck traditional boat-builders as odd, but Spencer wanted a design that was durable yet easy to build. Notching ribs for stringers is time-consuming and imprecise, so he designed a way around it. At Puur today, we have robotic manufacturing capabilities that allow us to improve on Spencer’s approach, by precisely machining joints in multiple plywood structural systems so that parts like ribs and stringers can mate tightly and strongly without any work by the builder.
Built to Last
Spencer wanted Infidel to endure. He specifically stated his design goal was “immense strength compared to conventional methods of construction.” Spencer designed full-length/full-width truss structures into the hull skeleton, including full ring frames forward, full u-frames aft, flooring as a box-frame member, and longitudinal stringers for the hull and deck. We employed a very similar approach in the design of the Puur 17, for the same reason: we want your boat to last a lifetime and more.
A side note: Some people wonder “will a plywood boat last?” After literally five decades of harsh offshore racing, Infidel is a pretty good answer: yes, plywood boats can last.
Easy to Sail
He gave Infidel a simple, rig, a flat foredeck, and a large cockpit area, to make sailing operations easier.
We gave the Puur 17 a cockpit that is half the size of the boat, a flat foredeck, and a simple rig that’s easy to raise/stow for trailering.
Taking the philosophy in a slightly different direction, we gave the Puur 17 a self-tacking jib system that allowed us to balance the sail plan by increasing the size of the headsail, which in turn simplified downwind sailing for single- and short-handed crews.
Beautiful Sailboat
It’s obvious Spencer wanted a beautiful boat. The photos of Infidel and the Puur 17 show how beautiful hard-chine plywood sailboats can be.
Fast but Stable
Spencer wanted Infidel to be light, stable, and fast. After all, she was commissioned by a professional auto racer. For a 60’ boat of her day, 10 tons was light; but with 40% of her weight in the 9’ draft keel, Infidel had the necessary stability to handle offshore weather. Aside from the keel, Spencer kept Infidel’s hull form relatively shallow and narrow.
Following Spencer’s lead, we used a similar 40-50% ballast target for the Puur 17, including crew weight – which is a significant source of righting moment in a small sailboat. Then, we gave the Puur 17 a very shallow underbody as well, so she will exceed hull speed even in very lights winds.
In a departure from Spencer’s approach with Infidel, we wanted the Puur 17 to have great pointing ability and great maneuverability, so we moved the CLR forward and gave her a relatively deep rudder. We also made the Puur17 relatively wider, as crew weight is a significant portion of her righting moment.
Of course, it’s obvious that our 17’ daysailer is no 60’ Transpac winner. But, I wanted to pay a little tribute to an amazing designer and an amazing boat, both of which inspired us to do something different from what everyone else is doing.
PS. If you have a few more minutes, you can read the origin story of Infidel in Spencer’s words here.