"garry crothers" wrote in message
...

I believe that the advantage with two rams is that, because one cylinder
pushes aft, while the other pulls forward with the same force, the only
force on the rudder stock is the desired twisting, and no side loading is
imposed, as the case would be with the use of a single cylinder.

Ok, you're right. But my gut feeling tells me that this side load is
relatively small, especially compared to the side load induced by the water
pressure against the rudder.

Meindert