Initial design of a 40 cruising square metre boat by Knud Reimers March 1974 © Sjöhistoriska Museet Stockholm

Initial design of a 40 cruising square metre boat by Knud Reimers March 1974 © Sjöhistoriska Museet Stockholm

As the drawing of March 1974 shows, the initial idea was for a cruising square metre boat with nominal sail area of 40 square metres. This became a slightly longer 55 square metre class. The plans from January 1975 show that Swede 55 was initially intended to be a long keeler, just like the 75 sqm boat Bacchant. The rudder blade attached to the keel was common at the time and also prescribed by the swedish square metre class rules.

Development and construction of Swede 55

The first Swede 55 design with rudder attached to the keel © Sjöhistoriska museet Stockholm

First Swede 55-design with rudder attached to the keel. Note the mizzen right behind the wheel © Sjöhistoriska museet Stockholm

The changes sketched in red in the next drawing below document the step towards the separate keel and rudder configuration as suggested and designed by Stockholm low speed aerodynamics expert Prof. Sven Olof Ridder (Windex inventor and Saab planes) with special NACA profiles. Further the hull was lengthened from the initially planned 15.72 m to 16 m. The headstay was moved forward. The cockpit and the steering position, later the engine room, were altered as well. The 55- square metre skerrycruiser accoarding to Swedish sqm boat regulations evolved towards a modern Onedesign 55 cruising square metre boat with a nominal sail area of 55 square metres. It was named Swede 55.

Swede 55 drawing with red marked alterations © Sjöhistoriska museet Stockholm

Swede 55 drawing with red marked alterations © Sjöhistoriska museet Stockholm

By the summer of 1975, the construction was largely complete. The plans of the revised keel and rudder configuration date from September 1976.  The separation of keel and rudder provides course stability, as well as manoeuvrability at sea and when manoeuvring in narrow harbours. The large distance between keel fin and rudder blade offers the pleasure of sensitive steering.

Revised keel and rudder of Swede 55

The free-standing, skeg-less rudder blade aft was considered a risk at the time, as was the single-masted rigging with 30 to 48 square metres of cloth. The sail plan followed in March 1977. Modern sail handling systems such as headsail furling systems or self-tailing winches, were not yet common at the time. It is interesting to note that a two-masted ketch rig was considered at the time, but never built. The position of the mizzen mast on the bench seat for the helmsman would have neither been practical nor comfortable.

Floor reinforcements with keel suspension and engine bed as specified by Reimers Januar 1976 - source SSHM Stockholm

Drawing of the stringers with tank/engine bed foundations, keel suspension and steering gear by Knud Reimers January 1976 © Sjöhistoriska museet Stockholm