294 DESIGN AND CONSTRUCTION OF PASSENGER STEAMERS. 



midway between the old parallel shipbuilding channel and the extreme taper of the present 

 American structural channeL It should be noted that British standard sections are common 

 to all users of structural mild steel, including shipbuilders, bridgebuilders, etc., while here in 

 America we have two distinct standards for channels, the structural channel and the ship- 

 building channel. The bulb angle, which has distinct advantages over the channel for ship- 

 building purposes from the point of view of upkeep, is used more than the channel in British 

 shipyards, while exactly the opposite holds here, due probably to the extra cost of bulb angles 

 as compared with channels. 



The adoption of a single line of up-to-date channel sections for all structural purposes 

 in this country would be a distinct gain to both American shipbuilders and structural engi- 

 neers, and it is hoped that our steel manufacturers may be persuaded that this course will 

 also be to their advantage, as the American shipbuilder is already sufficiently handicapped by 

 high labor costs without being at the further disadvantage of having to use, in shipbuilding 

 construction, shapes which are relatively less efficient than the corresponding shapes available 

 to his foreign competitors. 



Mr. Rigg draws attention to other aspects of standardization as applied to shipbuilding 

 and engineering, such as that of Scotch boilers, marine reciprocating engines, ship fittings, etc. 

 Lloyd's Register, the British Corporation and the Board of Trade now have common rules 

 and regulations for the construction of ordinary Scotch boilers, which is a distinct gain to 

 the shipbuilders and shipowners of the United Kingdom. Since 1917 Germany also has 

 taken up the question of industrial standardization with characteristic thoroughness, and it 

 would not only appear that the matter is worthy of the very earnest consideration of Ameri- 

 can shipbuilders and engineers, but that now is the time to go into this important matter, when 

 business is dull, rather than wait for a revival of the shipbuilding industry. 



It is refreshing to have Mr. Rigg's opinion that the recent revision of the rules of the 

 classification societies has placed in the hands of the shipyards methods of designing struc- 

 ture and details which enable much quicker and better work to be done. That is entirely 

 as it should be, as a classification society, in the modem sense as distinct from the old idea 

 of a purely underwriter's registry, is a technical organization, whose only excuse for exist- 

 ence is in the authoritative and impartial service which it may render to shipping, shipbuild- 

 ing and underwriting interests. All the stockholders are interested in those allied activities, 

 and the capital is represented by the knowledge and experience of the staff. 



I feel that the thanks of this Society are due Mr. Rigg for presenting a paper which 

 must have involved considerable expenditure of time and labor. 



Mr. William W. Smith, Member: — Referring to page 276 of the paper, the author 

 states that electric drive was first contemplated for these vessels. No doubt this type of ma- 

 chinery would make a good installation and would work satisfactorily. However, it is con- 

 siderably heavier and more expensive than gea red-turbine machinery. In view of the per- 

 formance of the Hood and many other high-powered vessels equipped with geared turbines, 

 there is little room to doubt that this type of machinery would prove entirely satisfactory for 

 an installation of this kind. 



It would be particularly interesting if the author would give comparative data for these 

 two types of machinery, provided it is available. From my investigation of this subject, I would 

 estimate roughly that the weight and cost of the corresponding electric-drive machinery would 

 be from 70 to 80 per cent more than the geared -turbine propelling units, and that the steam 



