Figure 6-11. The ball breaker — principle of operation. 



being used with piston corers, it is attached to 

 the trigger Hne above the trigger weight. 



6-58 Operating (he Ball Breaker.— Once 

 the ball breaker is over the side and there is full 

 tension on the trigger the safety pin is removed. 

 During lowering a careful watch must be kept 

 to observe the signal. Upon contact with the 

 bottom, the slack produced in the wire allows 

 the ball breaker piston to be released from the 

 trigger and fall freely, imploding the glass ball. 

 The instant the implosion signal is received the 

 winch must be stopped. 



6-59 Receiving the Implosion Signal. — 

 Two methods of reporting the implosion signal 

 have been used successfully aboard Navy sur- 

 vey ships. One method is to connect a Brush 

 recorder to the echo sounder and observe the 

 signal from the pen trace. The other is to lis- 

 ten for the audible signal on the echo sounder. 

 The first method is recommended, as a com- 

 plete record of the direct signal and its echoes 

 are obtained as shown in figure 6-12. The 



IMPLOSION OF SPHERE HALFWAY DOWN TO BOTTOM (500 FATHOMS) 



CHART NO. BL 923 



THE BRUSH DEVELOPMENT CO. 



IMPLOSION OF SPHERE AT BOTTOM (1000 FATHOMS) 

 (SPEED OF BRUSH RECORDER SET AT 25mm/sec.) 



Figure 6-12. Recorder tapes showing ball breaker signals. 



H. O. 607 



