power package 



safe-and-arm 

 device 



magnetic switch 



weighted touchdown rod 



the 1,100-psi nitrogen for extended periods of time. 

 Also, when the gas bottle was punctured with the 

 inflator, the small metal piece that sealed the bottle 

 would pass into the solenoid valving assembly and 

 cause the solenoids to leak. Thus, a successful bench 

 firing of the assembly was not a suitable guarantee of 

 success. These problems were eliminated by replacing 

 the gas bottle/inflator assembly with a fabricated 

 refillable gas canister with a one-way filling valve on 

 top. The modified upper gas assembly is shown in 

 Figure 16. 



Other modifications were made to the gas 

 assembly to improve reliability. The first involved 

 combining the two solenoid valves into one body to 

 shorten the unit and eliminate connective piping; the 

 second involved the activation time phasing for the 

 two valves. Originally, there was a 30-msec delay 

 between the time the first (three-way) valve and the 

 second (two-way) valve were activated. This was to 

 ensure that the three-way valve was closed to the S/A 

 chamber and open to the shear disk prior to 

 activating the two-way valve and releasing the nitro- 

 gen pressure. Additional testing showed this delay, 

 which was provided by an electronic circuit in the 

 power package, to be unnecessary. This change most 

 likely occurred because of the larger volume of gas 

 stored in the reusable gas canister as compared to the 

 throw-away gas bottle previously used. 



The ordnance S/A assembly did create a problem 

 during the testing phase that would be of no concern 

 if the system were totally expended. The S/A base 

 would expand during firing, making retraction 

 extremely difficult. To eliminate this problem and 

 also to reduce cost and simplify operations in shallow 

 water where the gun assembly is recovered and 

 refurbished, a new nonordnance S/A was developed 

 (Figure 17). The system costs 20% more than the 

 ordnance S/A, but it can be used 20 to 30 times 

 before the aluminum housing is worn. Stainless steel 

 components could increase its use even further. As 

 mentioned, the firing pin directly detonates the M58 

 primer in the cartridge. Above 50 feet, the pin 

 is mechanically blocked by the hydrostatically acti- 

 vated plunger. 



Figure 14. Firing mechanism for CEL 20K anchor. 



13 



