These objects are identified as "the inside of a power turbine" in the book "The Story of the Unsinkable Titanic" by Michael Wilkinson and Robert Hamilton. The picture and description are on page 109.

Despite what Wilkinson and Hamilton might choose to believe, I can assure any interested parties that the structure of those objects has absolutely nothing to do with the inside of any turbine. Incidentally, lest I be doubted, the RMS Titanic was fitted with one steam turbine made by the British manufacturer Parsons, and none of its internal or external components resembled the objects in the photograph.

I believe this stack of objects is the remains of one of the feed water filters. Their purpose was to clean the fresh water coming from the condensers of grease, oil and other impurities before it was cycled back to the boilers. Originally, it probably looked like a cylindrical tank, this stack of round grates would have been inside and held filter material between them. Just a guess....