Popular Science Monthly 



Vol. 9^2 



No. 2 



225 West Thirty-ninth Street, New York City 



February, 1918 



$1.50 



Annually 



Plugging a Torpedoed Ship 



When a hole is torn in the hull, the apron is 

 unrolled like a carpet and lowered over the side 



HOW many ships could be saved for 

 the world's commerce if there were 

 means immediately available to 

 plug ugly holes in their hulls, caused by 

 torpedoes, mines, explosive shells and col- 

 lisions? This is the question which con- 

 fronted a Wisconsin inventor and he 

 straightway set about to answer it by 

 inventing a metal apron which can be 

 rolled up and carried on the ship's deck 

 and immediately lowered to plug a hole 

 torn in the hull. 



The apron consists of a series of bulb 

 tee irons such as are used for deck beams 

 m sbips or as a part of the steel framework 

 in large buildings. The irons are held 

 together by means of flexible metal strips 

 bolted to their flanges. Between the 

 metal strips and the angle flanges are 

 strips of heavy tar paper or rubber com- 

 pound, to make the apron waterproof 

 when it is placed over 

 the hole. 



The flexible metal 

 strips which hold the 

 bulbs together per- 

 mit the entire apron 

 to be rolled up like a 

 carpet and to be car- 

 ried on the ship's 

 deck on a small 

 wheeled carriage. 

 When a hole is stove 

 in the ship's side, the 

 apron is rolled to the 

 nearest derrick, which 

 may be the mast boom 

 or a small steam 

 winch placed along 

 the side for the pur- 

 pose. The apron is 

 unrolled and lowered 



5team derrick 



iau't and fastened 

 to decK 



Derrick rope 



flexible air-pipe cushion 



Lowering the apron when the damaged 

 ship has a heavy Hst. The dotted line 

 shows the final position of the apron when 

 it is placed over the hole torn in the hull 



into the water and down to the hole, 

 where the inrushing water sucks it into 

 contact with the hull. A flexible rubber 

 or canvas pipe about eight inches in di- 

 ameter is attached to the side of the 

 apron. It comes into contact with the 

 ship's hull and extends clear around the 

 contour of the apron. This pipe is filled 

 with air pumped from machinery on 

 board, so that the apron fits the side of a 

 ragged hole so snugly that water can not 

 rush in around the edges. 



To locate the hole in the side, two heavy 

 hooks are first lowered by hand and 

 caught in the front and rear projecting 

 sides of the hole. A third and heavier 

 hook is then lowered midway between the 

 first two and it is made fast to the top 

 edge of the hole. The guy rope holding 

 this hook is firmly attached to the deck 

 and the apron slides down the rope until 

 notches on the supporting sling are 

 brought up against similar notches 

 OuideropeTrav^n in the upper end of 

 the hook bar. When 

 these notches meet, 

 the apron's downward 

 course is halted di- 

 rectly over the hole 

 and the inrush of the 

 water draws it se- 

 curely against the hull. 

 It is doubtful 

 whether the opera- 

 tion would be so sim- 

 ple if the vessel was 

 moving. Moreover, if 

 the hole torn in the 

 hull were of great 

 size, no such plugging 

 device could keep out 

 the water. 



Water pressure on 

 apron plugs hole 



163 



