296 DESIGN AND CONSTRUCTION OF PASSENGER STEAMERS. 



gard to watertube boilers. On page 279 he says : "The claims of the watertube boiler over 

 the Scotch for high-speed ships have made good to such an extent that they will feature more 

 largely in future ships." And, on page 282, he says : "As regards weights, it is clear that 

 warship practice rather than merchant would have to be followed for machinery design" on 

 high-powered vessels. That is, of course, something that the makers of watertube boilers 

 have been preaching for a great many years, and it is interesting to reflect on the fact that 

 some of the large passenger vessels today are using watertube boilers. As Mr. Rigg says in 

 the paper, the vessels built at his yard, the New York Shipbuilding Corporation, and the ones 

 built at Newport News, have watertube boilers, Babcock and Wilcox type, and those built 

 for Bethlehem at Sparrow's Point have the Yarrow boilers. It is also probably known that 

 the three big former German vessels, the Berengaria (Imperator), Leviathan (Vaterland) and 

 Majestic (Bismarck), all have watertube boilers, which, I understand, are of the Thomycroft- 

 Schulz type. 



The new Holland-American ship to which Mr. Rigg refers will be supplied with Bab- 

 cock and Wilcox boilers, built in England ; and I may add that the International Mercantile 

 Marine is also building two 20,000-ton vessels at Harland and Wolff's, which will also have 

 Babcock and Wilcox boilers in them. I am not sure that Mr. Rigg has this information, but 

 it must give him some satisfaction to have his predictions verified so completely and so soon. 



The question of weight is one which is very striking indeed. I remember that almost 

 ten years ago, one of the last papers written by my dear old chief, Admiral Melville, discussed 

 this question of the watertube boiler and the saving of weight by its use. I will put the figures 

 in my remarks when revised, but my recollection is he made a comparison about the saving 

 of weight, that would have occurred on the Mauretania and Lusitania, if watertube boilers 

 had been used, instead of having Scotch boilers, and my recollection is that the saving was 

 somewhere between 1,500 and 2,000 tons. (Melville's paper gives the figures as 1,950 tons 

 for watertube boilers against 4,000 tons for Scotch boilers.) They are vessels of large power, 

 70,000 horse-power. When we run into such large horse-powers as Mr. Rigg has given in 

 the paper, where there is a possibility of 163,000 horse-power, we can see that in such vessels 

 it will be necessary to use the very lightest type of boiler. 



You all know that our battle cruisers which are building, even if they are going to be 

 scrapped, would have 180,000 horse-power, and obviously in that case it was necessary to 

 use watertube boilers as has for years been the practice with all naval vessels. 



I want to express my appreciation of Mr. Rigg's paper, which is an admirable one and 

 which I have greatly enjoyed. 



I would be remiss in giving these data about watertube boilers in passenger vessels if I 

 failed to remind you of the fine record of the Great Northern and Northern Pacific, whose 

 boilers were built by my company for Cramps, who built the vessels. Their service as trans- 

 ports during the war was very arduous. The Great Northern holds the record for long- 

 distance, high-speed steaming, and naturally all concerned in her building are very proud of it. 



It may interest you to know that when Sir Wm. White read his paper on "Size of Trans- 

 atlantic Steamers" at our 1911 meeting, and referred to a new one then under consideration, 

 he had planned a slightly smaller Mauretania, made possible by the use of Babcock and Wil- 

 cox boilers. 



Commander T. Kawahigashi, C. C, I. J. N. (Communicated) : — Mr. Chairman and 

 gentlemen, it is indeed, a very great privilege to be permitted to say a few words about the 



