Several sailboats offer emergency steering apparatus. Usually its a pipe of some design that will slip over the rudder shaft under the helmsman seat. (Clever designs have used a table leg from the saloon table or similar.) This type of emergency steering can work with a cable/quadrant system or a tiller steered sailboat. I know that Island Packet designs their rudder with a hole in the top aft end of the rudder that a rope can be passed through in order to turn the rudder with a rope in the event of steerage loss. In the event of loss of the rudder, I've read of sailors using (jury rigging) their saloon table as a rudder.