This brilliant concept (called “The Sea Slipper”) by Johnn ‘Trike’ Schroeder uses underwater wings to stablize a catamaran. The wings allow to stablize the catamarn even by hard wind and removing the typical long keel used by RC Sailboat which limits where you can sail it.
The concept came Johnn while working on his model rocket car (did I mention he is a RC genius)! After some discussions on the concept he wrote me a fantastic 6 page article explaining it in every detail including drawings. I want to thank him again and again for this.
I will post this article in parts as it is simply to long for one blog post. If you want to get the full article immediately or have any questions on the concept contact me
SEA SLIPPER high performance catamaran top view
The Concept in detail
Sea Slipper Control system Figure 1
The idea is simple as a concept, the ‘wings’ are used to create a counter force to the heeling motion imparted to the hull by the wind loading the sail/rigging and tilting the boat over. This is usually countered by a deep bulb keel. If you wanted to sail a RC boat, in say a shallow reflecting pond, the deep keel boats might not be able to pull it off. To see how this works, let us look at the idea of a simple pendulum sensor to detect hull motion from side to side, but prevented from swinging fore and aft.
Sea Slipper Control system Figure 2
As the magnet swings over a hall-effect sensor, the magnetic field is detected, and a signal generated to tell the control circuit that a positional displacement has taken place. This signal is used to create a positional displacement of the wing on a hull, to compensate for the roll effect. A left leaning of the hull would cause the wing to create a right ‘lift’ to counter the displacement. A harder lean would generate a harder countering force to the right to keep the hull as close to vertical as possible. By how the sensors are located, and the number of ‘sensing’ steps used, a moderate heeling force would be allowed, and then a steady correction force can be generated to keep the hull firmly in control.
This same sensor system, using a pendulum fixed to swing only fore and aft, would adjust the wing sets to assist in smoothing the pitching motions of a small model in ‘non-scale’ waters (i.e. our world!) Or if used on a full sized boat, it would aid in the ride of increasing wave action. In this manner, 2-axis control would give the wings a dual action capability that would stabilize the craft and smooth the ride for better control (and for full-scale boats ease the motion for landlubbers like stabilizers on a cruise ship.)
As can been seen in the drawing of the model in Fig. 3, the craft has both a front and a rear set of split wings to give rapid easy control to sea conditions. The split wing design allows half the wing to go up while the other goes down to create the anti-heel response with smaller wing movements. Secondly, for a pitch correction (up or down) the wings will move together to counter pitch together as if a fixed wing.
The next part discusses how this control system can be realised with a RC Sailboat. If you want the full article immediately or have any questions on the concept contact me
About the Author/Designer of the Sea Slipper Concept:
I’m a Mechanical Designer with an electronics background and degree, so I married my work and hobbies for increased fun and develop new ways to spend my money in strange ways (according to my wife!)
This is a winter project with an eye towards exploring electronic control to ease the job of the skipper (be it RC or full-sized), and give them a fast, better controlled boat. The concept came to me as I developed a flap system for a model rocket car. See Fig. 1 (to keep the dang thing on the ground, instead of becoming airborne so easy. The last hit Mach 2 eighty feet off the ground!)