Going backwards in technology? Decisions were made for good reasons at the time they were made. Richard simply ignored the fact that we now have primary source evidence of the propeller configuration on Titanic as well as that on Olympic, including the changes made to Olympic's over the years. The Drawing Office notebook, as Mark said, documented the changes made to Olympic. The relevant pages are shown below. On the right is the original spec for Olympic. The pitch value crossed out and replaced was the modification made in Jan 1912. On the left is the changes made in Mar 1913. Nobody seems to question what was documented here, or the fact that Olympic was fitted with a 3-bladed center prop in 1913, but some just seem to ignore it, just like they ignore the what was documented in the H&W engineering notebook that Mark uncovered in 2008.The more a propeller has propeller blades, the more its efficiency will decrease. Hence, in terms of perfomance, I don't believe that a three bladed propeller is "going backwards". Nevertheless, it surely does in terms of comfort. Like Mark said in his article, it's all about finding the balance between those two factors. It also depends on what kind of ship you want to build I guess.