Airplane Steering

From Wiki

Jump to: navigation, search

The TriFoiler is steered with a rudder control bar that is operated by the skippers feet. The factory configuration for steering is to have the rudder control bar act like a bicycle front wheel and is called "bicycle steering" i.e. pushing the right foot forward on the rudder pedal causes the boat to turn left.

Several owners have converted their boats to "airplane steering". In this configuration, pressing forward with the right foot turns the boat to the right. This may be more intuitive for those skippers who are trained as pilots. It also may be argued that airplane steering is more intuitive for small craft sailors as well. While located on the windward side of a boat, pushing the tiller away causes the boat to steer upwind "toward" the skipper; this would seem to parallel pushing with the windward foot in order to head up. If one takes this view, it becomes a bit of a puzzle that the boat's designers chose bicycle steering at all.

A side benefit of converting from bicycle to airplane steering is that the shear stresses are reduced where the steering cable pulley blocks are glued to the inside of the boat deck. The reduction in shear force on these blocks is simply due to the reduction in the angle of redirection of the steering cable. A diagram or pics further describing the geometry change and quantifying the stress reduction will be added here.

Note that it is worthwhile to inspect the condition of the adhesion of these blocks at least annually as there is at least one known case in which a block fell off and led to the catastrophic loss of a rudder.Neuperg 06:28, 29 May 2009 (UTC) - Aha! This is where we link to the story, once the boat's owner has added it to the owners/boats/mishaps section(s). Jonathan 12:37, 29 May 2009 (UTC)

Airplane steering conversion with controls moved aft by 250 mm (click to enlarge)

There is at least one known boat that was converted to airplane steering simply to facilitate locating the rudder bar further aft as the skipper had difficulty reaching the rudder pedals. The picture to the left is of this conversion. Note that in this photo, the rudder control assembly has been moved aft ~250 mm towards the camera. With the aft relocation of the rudder assembly, the geometry of the cables is different and there is no benefit of stress reduction on the pulley blocks.

The conversion between bicycle and airplane steering takes only about an hour and no parts need to be cut or permanently modified. As such the conversion is easily reversible.

Personal tools