With fixed fixed keels, there was no point in having lifting rudders. In any case, the lifting rudders were equal contributors with the daggerboards to producing rattles, and they were far from balanced.
Our first plan was to change to spade rudders, ie rudders constructed round a strong rudderstock rotating on bearings built into the bottom of the hull. However, Darren suggested that the stocks should be 60mm diameter solid aluminium, and Mark's calculations confirmed that, even though the present transom-hung rudders were strongly enough mounted swinging on a 12mm s/s rod, a spade would need at least 60mm. The expense in material and labour looked frightening, so we decided to go with balanced, transom-hung rudders, still swinging on the 12mm rod.
The design is shown below, on the left. Mark and Ted decided they could use the old rudders as a
starting point, and the picture on the right shows the rudders in build.
|
|
|
| Rudder design | Rudders in build |