If Olympic was originally supplied with compasses as was Titanic, then she would have had three main compasses:I don't think so Jim. Under the W-Comp. heading there were two columns, one marked course and the other marked deviation.
Gyro repeaters don't have deviation error. I suspect that the W-Comp was originally for the magnetic compass on top of the wheelhouse.
There were also 2 pelorus equipped, one on each bridge wing.
1: The mid-ship Standard Compass.
2: The Steering Compass in the wheelhouse and
3: The Steering Compass on the captain's bridge located directly in front of the enclosed wheelhouse.
The Standard was as named. The other two would be used according to the situation...i.e. when under pilotage or when on ocean passage.
Perhaps that's what the three headings were?
PS. As young Cadets we were very much aware of "Lecky's Wrinkles" A lot of his pronouncements were taken with a pinch of salt. That non- sense about the compensators affecting each other was a wrinkle too far. The farmer's Almanac said it but I think he was the one who wrote "The Sun Always Shines at Noon"