ELECTRIC AUXILIARIES ON MERCHANT SHIPS. 



169 



Fuel Per Shaft Horse-power Hour: 



2,340 

 2,500 



Fuel in Barrels Per Knot: 



= 0.936 pound. 



7.33 



Assuming a speed of 10.5 knots, ' = 0.698 barrel per knot. 



These estimates show the saving in fuel consumption by the use of electric auxiliaries, 

 as follows : 



Scming in Fuel Consumption (at sea) : 

 Steam auxiliaries, 230 barrels. 

 Electric auxiliaries, 189 barrels, 17.3 per cent. 

 Electric auxiliaries, with 200° P., 176 barrels, 23.5 per cent. 



Solving Per Year: 



208 days at sea, oil at $1.50 per barrel. 



Electric auxiliaries, 8,320 barrels at $1.50 = $12,480. 



Electric auxiliaries, with 200° F. superheat, 11,250 barrels at $1.50 = $16,900. 



In the estimate, an allowance was made of 40 barrels per day in port. With electric 

 auxiliaries and economic engine-room machinery, it should be possible to reduce this by one- 

 half. 



157 days X 20 pounds X $1-50 = $4,710. 



With a good system in the engine room, the lubricating oil required would be greatly 

 reduced. 



2. Port Charges. — In giving thoughtful consideration to improving the earning power 

 of a ship, it will be recognized as essential to decrease its idle time, as certain charges are 

 continuous, whereas the ship is actually earning money only when traveling between ports. 

 When it is realized that the average cargo ship makes only about 36,000 miles per year and 

 that at an average speed of 10 knots, which means that she is at sea only about 150 days out 

 of a year, it is very evident that there is a big field for improvement. 



Port charges estimated for the coastwise schedule mentioned above are as follows : 



(a) Wharfage 



(b) Lighterage 



(c) Piloti' fees 



(d) Stevedoring 



(e) Tugboat charges 



(f ) Canal dues 



New York 



$7, 800 



202.56 

 7,800 

 100 



Colon 



$4,150 



Los 

 Angeles 



$\, 560 



200 

 1,560 



San 

 Francisco 



$3,120 



250 



3,120 



200 



Seattle 



$3,120 



3,120 



Total 



$15, 600 



652.66 

 15, 600 

 300 

 4,150 



Total per trip $ 36,302.56 



Total per year (four round trips) 290, 420.48 



