THE SUBMARINE OF TO-DAY AND TO-MORROW. 203 



Table III. 



English German German 



Type "B" Type "E" " U-2t to 0-32' ' ' ' U-33 toU-42" 



Length 230' 6" 175' 213' 223' 



Surface displacement, tons 663 730 640 665 



Submerged displacement, tons 912 825 787 822 



Engines Diesel Diesel Diesel Diesel 



Horse-power, surface 2,000 1,600 1,800 2,300 



Speed, surface, knots 17 15-16 16 17 



Speed, submerged, knots 10% 9-10 10 10 



Armament, torpedo tubes 8 6* 4* 5* 



Armament, guns o 2 2 2 



Counting then only such boats as are actually in active commission and of 

 proved qualities, we may sum up this phase of the subject by saying that from the 

 point of view of mechanical development "the submarine of to-day" connotes a 

 vessel of the following approximate characteristics: 



Surface displacement 650 to 750 tons. 



Submerged displacement 800 to 900 tons. 



Surface horse-power 1,600 to 2,300. 



Surface speed 15 to 17 knots. 



Submerged speed 9 to 1 1 knots. 



Armament 2 guns of from 3 to 4 inches caliber 



and 4 to 8 torpedo tubes. 



The wide radius of action of such boats and their efficiency when operating 

 submerged at long distances from their base have been amply demonstrated in the 

 present war. The exploits of the English "E" boats in the Dardanelles, the Baltic 

 and the North Sea, and the similar work of the German boats "U-21 to U-41" in 

 the North Sea, the Atlantic and Turkish waters, are too well known to call for 

 detailed mention here, but it may be well to point out that the natural difficulties 

 overcome by both sides have been enormously increased by the fact that the boats 

 in order to reach their objectives have been required to make long voyages through 

 waters controlled and closely patrolled on the surface by the enemy. 



Having thus briefly examined the development so far accomplished on the 

 engineering side, it is now in order to consider the present status from a purely 

 military standpoint. From what has been said above, it is obvious that if smaller 

 surface displacements than 650 to 750 tons are found in strictly modern boats, 

 the reason must be sought on the military or financial side rather than on the en- 

 gineering side. As a matter of fact, an examination of the characteristics of boats 

 laid down during the past four years shows surface displacements ranging from 

 35 to 1,100 tons. Those of 800 tons and up properly belong among "the subma- 



*Doubtful. 



