torn sampling instrument such as a snapper or 

 dredge. 



6-10 Corers Used by the Navy. — Aboard 

 the survey ships and associated vessels of the 

 U. S. Navy Hydrographic Office, three types of 

 coring devices are currently in use: The 

 Phleger corer, the Kullenberg piston corer, and 

 the Ewing piston corer. Detailed descriptions 

 of these coring devices are given in the follow- 

 ing pages (fig. 6-3). 



Figure 6-3. Coring devices - Phleger, Kullenberg, and 

 Ewing. 



6-11 INSTRUCTIONS FOR OPERATING 

 THE PHLEGER CORER.— Designed to obtain 

 cores up to about 4 feet in length, the Phleger 

 corer is utilized in cases where only the upper 

 layers of the sea bottom are to be analyzed. 

 Because of its small size and weight, the 

 Phleger corer is widely used. It may be 

 operated from an oceanographic winch, and 

 has been used successfully from a bathy- 

 thermograph winch in depths of less than 100 



fathoms. Coring tubes 12 and 36 inches in 

 length, a main body weight, an upper tube, 

 check valve, and tailfin assembly account for 

 an overall length of 3 to 5 feet for the corer 

 (fig. 6-4). The upper tube, main body weight, 

 check valve, and tailfin assembly comprise 

 the mainweight. The check valve, located at 

 the tailfin, is to prevent the flow of water into 

 the upper section and consequent washing out 

 of the core sample while hoisting the corer. 

 6-12 Equipment Needed to Operate the 

 Phleger Corer. — In addition to the mainweight 

 and coring tube mentioned above, the following 

 components are needed to operate the Phleger 

 corer: 



1. A plastic liner, which runs the entire 

 length of the inside of the corer. The liner is 

 used to retain and store the core. 



2. A core catcher, whose interleaved springs 

 fit inside the lower end of the liner. The core 

 catcher springs will allow sediment material 

 to enter but not leave the coring tube. 



3. A cutting edge, which holds the core 

 catcher and liner in the coring tube and has 

 a sharpened rim for penetrating the bottom. 

 It is attached to the coring tube with a bayonet- 

 type fitting. 



4. A release mechanism, from which the 

 corer is suspended and released for free fall to 

 the bottom. 



5. A trigger line, used to suspend the trigger 

 weight from the arm of the release mechanism. 

 This line has a suspended length of 15 feet. 

 Any light line, such as cotton heaving line or 

 9-thread manila, may be used. 



6. A trigger weight, which is suspended 

 from the end of the trigger line. It prevents 

 the release mechanism from dropping the corer 

 until the weight hits the bottom. The trigger 

 weight is usually a 14-pound sounding lead. 



7. A 20-foot length of galvanized steel chain, 

 which is attached to the release mechanism 

 and corer to retrieve the corer after the free 

 fall. Chain size: %6-inch BBB type. Two 

 shackles are needed to attach the chain. 



6-13 Spare Parts Needed for the Phleger 

 Corer. — The following spare parts are needed 

 to operate the Phleger corer: 



1. Coring tube. One extra. 



2. Core catcher. Four extra. 



3. Cutting edge. Four extra. 



4. Plastic liner. Enough lengths of iK-inch 

 (outside diameter) plastic liner as needed to 

 conduct the coring program for a survey cruise. 

 One liner is needed for each sample. 



5. Rubber stoppers or plastic caps (enough 

 rubber stoppers, size No. 7, as needed to con- 

 duct the coring program for a survey cruise). 



54 



H. O. 607 



