There is an interesting article re Titanic in the Saturday Mail of 31st showing the photo posted above,of the central prop being clearly 4 bladed. It also states that the sternmost funnel of the four, is a "false" one and not connected to the boilers in any way.It states that this fourth funnel was purely cosmetic,as she "looked better" with four rather than three.I hadn't heard of this before,but agree she wouldn't have looked right with three,but perhaps that is because I cant actually visualise it.I would have thought the funnels would have been bigger,and spaced differently if only three were used?
Mick