Articles with the Tag Aquitania

Lusitania & Mauretania ‘Full Astern’

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Lusitania & Mauretania: ‘Full Astern’

During my lecture at the British Titanic Society’s convention in Belfast in April 2024, one of the themes I highlighted was how various criticisms of Titanic’s design are often made without reference to the broader context.

The ‘Olympic‘ class ships were triple screw steamers with reciprocating engines driving the port and starboard propellers and a low pressure turbine driving the centre propeller.  One such criticism of the ‘combination’ propelling machinery is that the centre propeller only operated ahead and could not be reversed.  The criticism was that this meant only the port and starboard propellers could be reversed in a scenario where a ‘full astern’ order was given.

However, those voicing this criticism have evidently paid little attention to competitors such as Lusitania and Mauretania.  The two Cunarders were quadruple screw steamers driven solely by turbine engines.  They entered service in 1907 and, by 1911, Cunard’s staff had plenty of experience from their day to day operation.  A memo entitled ‘New Fast Steamer’, dated 7 February 1911 and stamped with an Executive Committee stamp on 21 August 1912, noted a problem based on their experience to date.  Only the two inboard propellers [‘centre shafts’] were reversible:


When going full speed ahead and the order is given to go astern, the rotors on the centre shafts are going astern quite a time before the ahead rotors on the wing shafts have stopped going ahead.  This will retard the progress astern and of course there will be a little drag from the wing propellers after they have stopped going ahead.

As a result, it was suggested that the ‘new fast steamer’ (Aquitania) should be designed so that all four propellers could be reversed: ‘Astern rotors on the wing [propeller] shafts [as well] would overcome this difficulty and enable all four shafts to be revolved in the required direction, which of course would be a great advantage when manoeuvring’.

There are advantages and disadvantages between different propulsion systems.  One system might be superior in one aspect, whereas another might be better on another comparison.  Looking at twin screw ships such as Oceanic (1899), both propellers could be reversed.  Modern day analysis of Titanic‘s or any other vessel’s design simply needs to consider the broader context.  Not only did Lusitania and Mauretania have a similar issue in that only two of their four propellers could run in reverse, but Cunard’s own engineering staff noted that the two wing propellers were still going ahead for a period that the two inner propellers were running astern. 

‘Olympic & Aquitania: Eyeing up the Competition – Cunard’s “White Star Liner”‘

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‘Olympic & Aquitania: Eyeing Up the Competition – Cunard’s “White Star Liner” ’

 

 

 

While Olympic was under construction, White Star’s rival Cunard was not idle. They were planning their answer to the competition in the form of their new Aquitania. Unlike Lusitania and Mauretania, which were financed with state support, Cunard had to finance Aquitania on a commercial basis and opted for comfort and luxury rather than speed. That led them to design a ship whose key particulars were very close to Olympic in size and speed. Maritime historian John Maxtone-Graham called her Cunard’s ‘White Star Liner’. 

Cunard’s directors and engineering staff found out what they could about Olympic while she was being built and then their naval architect Leonard Peskett sailed on her in August 1911. He noted some features worth considering as Aquitania’s design was finalised, including bringing elements of her design more into line with Olympic.  My September 2022 presentation at PRONI covers the key details and provides ‘a brilliant insight’.

 

 

Above: Aquitania‘s first class grill room, with its Jacobean decor, had significant visual similarities with Olympic‘s first class dining saloon.  During the design phase in July 1913, Cunard actually opted for some slight changes to try and differentiate it.  (Author’s collection)