On Mon, 15 Dec 2003 12:54:24 -0000, "garry crothers"
wrote:

I am do the sums to calculate the required size of hydraulic ram need to
drive a transom hung rudder.

I read somewhere that it is preferable to use two rams (one on each side )
to minimise the amount of twisting forces on a rudder.

If I decide to go for this method, is it acceptable to divide the torque
requirement by two.

I.E
If I need a 90KgM torque to drive the rudder, can I size the rams for 2 x
45, or should I use 2 x 90 ?

garry

If you are visualizing what I am visualizing, then two single acting
rams can substiture for one double acting ram.
Each s.a. ram needs to develop the full torque: one to starboard, the
other to port. There is no difference on the torque experienced by
the rudder post, as far as I can see.

Brian W