SELECTION OF THE BEST KIND OF PROPELLING MACHINERY. 227 
The initial cost listed in Plate 63 may be open to criticism, owing to prices being so 
spotty and varied at the present time. These prices are based on firm quotations of the low- 
est reputable bidder and include machinery installed ready for use. The same remark applies 
to weight. Different builders vary considerably, but, whatever error there is, the percentage 
of error will be the same for all types and will be in the same direction; and as it is the differ- 
ence in cost and the difference in weight which we are most interested in, the percentage of 
error will be very small. 
The machinery weights do not include hull engineering or any portion of the machinery 
usually located in the engine room but necessary for deck machinery only, such as auxiliary 
generating sets for generating electricity to be used on electric deck machinery. 
I have not given the cubic required for the machinery space, because in all cases the 
space required is so near the 13 per cent required by the U. S. Tonnage Rules as not to 
justify the loss of the 33 per cent deduction to gross tonnage, which is permitted when 
machinery space is at least 13 per cent of the cubic of the ship. 
I have not dealt with the engines which offer the greatest saving in space and weight, 
because up to the present time none have been built in this country, but it would appear to me 
that the opposed piston type of engines like the Fullagar and the Doxford offer many advan- 
tages that cannot be overlooked by the prospective shipowner. 
From reports available, the Yngaren, fitted with a 3,000-horse-power opposed piston- 
type engine, made by the Doxford Company, has given an excellent account of herself for 
her maiden voyage from the British Isles to Australia and back. This engine offers one or 
two very desirable features, viz., a slow-running engine for comparatively large powers, with 
the consequent efficient propeller, considerably smaller engine-room space and one shaft alley 
only. 
Owing to the Diesel engine builders standardizing around an engine of 2,500 shaft horse- 
power, I have used this power upon ships of 7,500 to 8,800 tons and on a 10,500-ton tanker. 
This assumption makes machinery for these types cost and weigh about the same but give 
us slightly different speeds. (The above figures hold good only so far as new machinery is 
concerned. ) 
It so happens, however, that at the present time there is hanging over the market a very 
large tonnage owned by the Emergency Fleet Corporation and available at very much lower 
prices than the present actual costs for replacing the same. 
To convert any one of these 7,500 to 12,000-ton steamers into Diesel engine-driven 
boats, with 2,500 shaft horse-power Diesel engines, maintaining the existing auxiliary steam- 
driven machinery and deck machinery, would cost approximately $400,000, and this same 
change, together with changing the auxiliaries and deck machinery to the electric drive, would 
cost in the neighborhood of $550,000. 
The first proposal would save the shipowner approximately 18 tons of oil a day; the 
second would save him about 22 tons of oil aday. For 200 days a year at sea and 165 days 
in port at $10 a ton for oil, the total saving for steam auxiliaries and Diesel propelling engines 
in oil would be about $36,000, and the extra for fixed charges would be $60,000. For Diesel 
propelling engines and electric deck machinery the initial cost would be in the neighborhood of 
$550,000. Saving in fuel oil would be 22 tons for 200 days and 5 tons for 165 days at $10 
a ton—$53,000—and the extra due to fixed charges would be $83,000. The extra cost of 
lubricating oil for the Diesel engine will be offset by the decrease in cost of operating per- 
