The actual shape of the hull may not be all that different whether you have a single or twin prop set-up. As long as there's clearance room for the props, that is. But the chances are that a twin prop set-up will use smaller props that when only a single is fitted. Also be careful not to let the props "overhang" the hull. It would still work ok, but the chances of damaging a prop are much greater.
As for handling. Both my cable ships (I sailed in both) had twin screws and a single rudder and both handle well in both real and model guise."Bluebird of Chelsea" has twin screws and twin rudders. Handles even better! Twin screws with either single or twin rudders handle better than a single prop....mainly because you can use the tansverse thrust of the props to advantage when berthing or manoeuvring in confined or crowded spaces.
I'm a bit curious about the Admirals Barge with twin screws. If the real one had deisel engines then OK, but Stapletons book on steam pinances makes no mention of twin screwd steam boats. That could be because of my memory! But looking plans etc. for the steamers I wouldn't have thought that the engine/boiler room space was big enough to hold 2 steam engines. Cheers. BY.
