Swede 55 Development

wede 55 Team left to right: Börje Larsson, Berit Mellkvist, Leif Yxfeld, Carin Hildebrand, Gunnar Francke, Knud H. Reimers and initiator Olof Hildebrand 1975
Swede 55 Team left to right: Börje Larsson, Berit Mellkvist, Leif Yxfeld, Carin Hildebrand, Gunnar Francke, Knud H. Reimers and initiator Olof Hildebrand 1975 © Swedesail Archive

Inspired by the popular cruising Skärgårdskryssare S30, Rolly Taskers offshore racing experience with modified 40 sqm boat Siska in Australia and Fidelis’ success at the Sydney-Hobert race, the Swede 55 project started in 1974.

Accoarding to Reimers’ drawings dated March 1974, Swede 55 was first planned as International Onedesign 40 sqm class with nominal 40 square metres. Reimers had planned a longkeeled underwater body. The rudder attached to the keel was still common at traditional yachts at the time and it was prescribed by the swedish square metre rule. On the other hand, eagerly sailed boats like Swede 55 forerunners Siska, Fidelis or Bacchant already had keel and rudder separated.

Accomodation of International Onedesign 40 Quare metre boat by Knud Reimers dated March 1974 - Source SSHM Stockholm
Accomodation of International Onedesign 40 Quaremetreboat by Knud Reimers dated March 1974 – CC BY-SA 4.0 Sjöhistoriska museet

Note the tiller or wheel arrangement to steer the boat as alternative. During summer 74, the project became a slightly longer Onedesign 55 square metre class.

Further steps to Swede 55

Initial Swede 55 design dated January 1975 with conventional keel & rudder © Sjöhistoriska museet
Initial Swede 55 design dated 5th January 1975 with conventional keel & rudder – CC BY-SA 4.0 Sjöhistoriska museet

The remarks in red of the drawing below show the transition to a modern keel and rudder configuration, a slight extension of the boat and other alterations. The up-to-date appendages came as input by Prof. Sven Olof Ridder of Stockholm by means of specific NACA sections and a carefully balanced rudder. As expert in low speed aerodynamics, inventor of the Windex wind indicator and consulting the design of SAAB airplanes, Ridder was quite a capacity.

Alterations as discussed early 1975 © Sjöhistoriska museet
Alterations as discussed early 1975 – CC BY-SA 4.0 Sjöhistoriska museet

Accoarding to Reimers’ drawings dated January 1975 and remarks on it, the general design was modified then in 75 and more or less completed in summer that year. Now the hull was extended from 51’7“ by 11“ (15.72 to 16 m). The centre cockpit with steering position and later the engine compartment were altered. The headstay was moved forward.

The separation of keel and rudder provides good directional stability. The distance between the fins help to control of the boat in a turbulent sea state and safe steering at high speed under spinnaker. The cleverly designed skegless rudder with carefully chosen balance enables the helmsman to turn the boat instantly and safely handle the 52 footer in narrow waters. However the free standing rudder was considered to be risky at the time.

Floor reinforcements with keel suspension and engine bed as specified by Reimers Januar 1976 - source SSHM Stockholm
Floor reinforcements with tank/engine beds and keel suspension by Reimers January 1976 – CC BY-SA 4.0 Sjöhistoriska museet

A folder introduced the project, followed by a Gylling/Fisksätra brochure.

Boat # 2 being covered in swedish magazine På Kryss & Till Rors in 1976, the first series of 15 boats were quickly sold. Here more about the Swede 55 fleet and here details regarding the construction of Swede 55.

Swede 55 Introduction, Knud Reimers, Swede 55 Exterior, Swede 55 Accomodation, Swede 55 Forerunners, Swede 55 Registry, Swede 55 Successors