Mauretania was 5 feet longer than Lusitania, thanks to a differently-shaped stern (Lucy's was squared off; Maury's is rounder). The bulwarks on the forward end of the superstructure were vastly different, with Maury's bridge extending ahead over the deck below by a couple of feet; Lucy's was pushed back. A few other changes:
-Maury had a longer set of bulwarks along the forward end of the bow; Lucy had only her forepeak bulwarked.
-Maury had a full compliment of cowl (or gooseneck) vents on her "top-of-house" structure, around the funnels. Lucy had stove-top vents, with hinged lids (which were prone to loss from heavy seas).
-Maury's upper skylights were pyramidal in shape; Lucy's were barrel-shaped.
-Second class lounge atop the aft Second class deckhouse was round on Mary; Lucy's was square with diagonal-cut corners.
That's only the tip of the iceberg as far as external differences go. Lusitania's interiors were described as a sunny country home, while Mauretania's interiors were more along the lines of a comfortable gentleman's club.
Matt, one major difference between the Lusitania and Mauretania were the interiors. Lusitania`s public rooms had a lighter feel to them due to the extensive use of plaster work. In contrast Mauretania`s public rooms has a somewhat denser feel to them due to the extensive use of wood in it`s public rooms. Compare for example Lusitania`s and Mauretania`s first class lounges and dining rooms.
Adam Leet is quite correct to point out the difference of the vents. In addition Maury`s large number of cowl vents gave her a somewhat cluttered appearance compared to the Lucy. And gave the the false impression that Laucy`s`s four funnels were higher than the Maury`s (they were exactly the same)
In addition the windows on the Lusitania were slightly rounded on the top and bottom whilst Mauritania`s were true rectangles.
See also the superb book "Lusitania triumph of the Edwardian Age" by Eric Sauder (1993).
going on the style and construction of ventillater intakes in general for liners of this period,it does seem odd to me that only the lusitania appeard to deviate in what was a readily tried and tested design in the cowling construction on the upper works.I must admitt i have never seen any other ventillators to match those which adam describes(the stove pipe vents with lids on),which were obviously inferior to the conventional gooseneck type.
Could anyone enlighten me as to why then such ventillators were incorporated into the construction plans of such a grand liner as the lusitania,.when the goosneck type was certainly more popular for ocean going vessels.
The promenade deck on Maury was a little extended in the breadth , increasing the deck area.
Maury's props were changed in 1909 , from 3 bladed to 4 bladed , to lessen the vibrations.
Same changes were brought on Lucy , as the tests were concluding.
this is why the Lusitania's 4 bladed prop on show at Southampton is different from the shipyard's pictures , showing her building.
Also , while I was getting thoroughly into research , it appears that the outer props of Maury were put 15 feet more forward than on Lucy.But I couldn't determinate if maury's outer shafts were put more offset than on Lucy.
From what I could see in my books , the hull lines were also different , the tumblehome on Lucy was a little "rounder" than Maury's.
While deck machinery , steering gear apparatus , pumps & other machinery features are the same , some castings were different , as the rudder blade & the main condensors for example...
The hull test procedures were different at the two shipyards , John brown used a towed basin scale model , while Swan hunter used a electric powered wooden launch.
So , we can assume they were sisters , but they differed a lot from each other.