Steve -- Any breakdown of a hydraulic system should be immediately apparent by the "feel" of the steering wheel. Just what a 1912-era telemotor would feel like, though, I don't know because I've not used one.
On one ferry that I ran a few years ago the master hydraulic pump leaked. If we did not fill it every morning, we would discover that it took more and more turns of the steering wheel to obtain the same rudder angle. With a full reservoir, there were 8 turns "lock to lock." After two days of innatention, you could crank 40 turns without ever getting hard over in either direction. Needless to say, we replaced the leaking bearing.
The loss of the steering engine would not be "felt" by the QM. He would note quickly, however, that the ship was not responding to the helm. This would be obvious even at night in the enclosed wheelhouse because the compass reading would not change, or would change in the wrong direction.
I'm not sure about the half-circle display you mentioned. The electric rudder angle/position indicator on
Olympic's bridge looks like any large electric meter of the period. In fact, the guts inside were probably identical to the meters on the electrical switchboard. The only difference was the face, which on the rudder indicator was graduated in degrees left or right of center.
The mechanical rudder angle/position indicator on the telemotor that I have studied is a half-circle graduated in degrees left and right from center. A large bronze pointer shows the amount of helm applied. This pointer is driven mechanically through gearing from the steering wheel shaft.
Keep in mind that the indicator on the telemotor does not really say anything about the rudder. It only indicates the amount of helm that has been called for by the QM turning the wheel. That is why the electrical indicator was needed, to provide the true rudder angle.
On the subject of failure -- both the wheelhouse wheel and the auxiliary steering wheel on the bridge would have been incapacitated by a failure of the hydraulic system. Steering would have been shifted to the so-called "docking bridge." In the unlikely event that both steering engines should fail, the rudder could have been controlled by by block and tackle.
More than likely, however, if the both steering engines had failed at sea, the rudder would have been secured amidships. Titanic could have been "aimed" sufficiently well to make New York by using only its reciprocating engines. If the port engine were run slower than the starboard, the ship would turn left. The reverse would be true if the starboard engine were slowed. About two weeks ago I talked to a German captain who brought his ship into harbor using this technique.
-- David G. Brown
