Original Date: 02/28/2000
Revision Date: 01/18/2007
Information : Pellet Assembly
Crane Army Ammunition Activity was tasked with producing 155mm practice rounds. Since 41,000 pellets were needed to fulfill the requirements, the Activity developed a new process to meet the production requirement which reduced assembly times and labor cost.
Crane Army Ammunition Activity (CAAA) was tasked with producing 155mm practice rounds. The pellet that goes into the 155mm round had been a remote assembly operation due to safety concerns. The pellet is a high explosive that is placed into a canister that is then crimped to contain the explosive. Large presses were used for the crimping operation. The crimping operation is performed in two steps with two different sets of fixtures in two presses. The presses that were being used were so large that they could overcome the tooling and cause pressure ignition of the pellet. At times, the pellets would also become lodged in the tooling.
Since 41,000 pellets were needed to fulfill the requirements, CAAA needed to find a better and safer way of meeting the production requirement. The tooling was redesigned so that lower pressures could be used and a positive stop was designed into the fixturing eliminating the possibility of pressure ignition. Since lower pressures were required, the small Magna presses were used. The tooling was also designed to use air pressure to eject any lodged pellets. The Safety Office approved the new process as a non-remote operation.
The new process is safer, assembly times were reduced by 58 seconds per pellet, 70% of the total labor cost was saved, the production rate increased greater than 500% and quality was improved since there was less pellet breakage. The previous production rate was 50 units per hour and the new production rate is 250 units per hour after the initial process ramp-up.
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