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Q1. In a four-ram hydraulic steering gear the centre line of the rams is 0.9m from the centreline

of the rudder stock. The diameter of the rams is 280mm and the diameter of the rudder stock is 390mm. When in the mid-ships position, the rudder is struck by a heavy sea which causes the relief

valves of the ram cylinders to operate. The relief valves are set to operate at 4MN/m².

Calculate EACH of the following:

(a) the maximum shearing stress imposed on the rudder stock;

(b) the percentage increase in shearing stress imposed on the rudder stock if the relief valves are set at 4.2 MN/m².