Mark Chirnside
Member
It seems interesting that although Olympic's wing propellers were apparently reconfigured to have a diameter of 22 feet 9 inches in 1913 (and a larger pitch), by the time Britannic's wing screws were fitted in September 1914 they were apparently designed with a diameter of 23 feet 9 inches, for a usual running speed of 77 r.p.m.
Although I have no idea of the pitch of these, the diameter of Britannic's propellers would seem to be even larger than Titanic's in 1912 or even Olympic's on her maiden voyage in 1911. Presumably the pitch would have been lower if the figure of 23 feet 9 inches is accurate, to compensate for the engines' increased efforts to turn larger diameter propellers.
It has always been my belief that Britannic would have proved to have been the fastest of the three sister ships had she survived to commercial service. Although I appreciate that her reciprocating engines were physically the same size, mechanical alterations raised the horsepower developed, while the turbine engine was the largest afloat, and more powerful than Olympic's, if not quite the most powerful afloat. I believe that as her horsepower increased quite considerably beyond that of her displacement compared to Olympic, even the slightly wider breadth might have been offset.
While Olympic's 'registered horsepower' of 50,000 i.h.p. was the same as Britannic's, Olympic's Chief Engineer estimated that the ship's engines could develop a maximum of 59,000 horsepower. (Whether s.h.p. or i.h.p.) Britannic's total would seem therefore to be closer to 65,000.
Olympic's engines worked 'exceptionally well' on her maiden voyage and in June 1911 additional steel plates were added along the sides of the bedplates. These remained until during the 1932-33 engine work more substantial plates were fitted, ensuring the engines' continued strong performance. I've often wondered if the bedplate design was altered on Titanic and Britannic, or if these plates were just incorporated into their designs from the start -- or rather July 1911 onwards.
Just a few thoughts, true or not.
Best regards,
Mark.
Although I have no idea of the pitch of these, the diameter of Britannic's propellers would seem to be even larger than Titanic's in 1912 or even Olympic's on her maiden voyage in 1911. Presumably the pitch would have been lower if the figure of 23 feet 9 inches is accurate, to compensate for the engines' increased efforts to turn larger diameter propellers.
It has always been my belief that Britannic would have proved to have been the fastest of the three sister ships had she survived to commercial service. Although I appreciate that her reciprocating engines were physically the same size, mechanical alterations raised the horsepower developed, while the turbine engine was the largest afloat, and more powerful than Olympic's, if not quite the most powerful afloat. I believe that as her horsepower increased quite considerably beyond that of her displacement compared to Olympic, even the slightly wider breadth might have been offset.
While Olympic's 'registered horsepower' of 50,000 i.h.p. was the same as Britannic's, Olympic's Chief Engineer estimated that the ship's engines could develop a maximum of 59,000 horsepower. (Whether s.h.p. or i.h.p.) Britannic's total would seem therefore to be closer to 65,000.
Olympic's engines worked 'exceptionally well' on her maiden voyage and in June 1911 additional steel plates were added along the sides of the bedplates. These remained until during the 1932-33 engine work more substantial plates were fitted, ensuring the engines' continued strong performance. I've often wondered if the bedplate design was altered on Titanic and Britannic, or if these plates were just incorporated into their designs from the start -- or rather July 1911 onwards.
Just a few thoughts, true or not.
Best regards,
Mark.
