FINE TUNING
Soldiers from 3rd Battalion, 7th Field Artillery Regiment, 3rd Brigade Combat Team (BCT), 25th Infantry Division adjust their M119A3 howitzer as they occupy a firing point on Area X-Ray during Exercise Lightning Forge in March. High-angle, high-charge firing showed the recoil system on the earlier iteration of the howitzer to be its Achilles’ heel. The M119A3 improves the recoil system using existing parts. (U.S. Army photo by SGT Brian C. Erickson, 3rd BCT Public Affairs)
the system, absorbs the reaction forces of the firing howitzer and brings it to a con- trolled rest within a determined length along the sleigh, the part of the carriage that provides immediate support for the howitzer tube and houses the recoil sys- tem. Te recuperator, precharged with gas, uses the rearward movement of the cannon to increase its gas pressure, creat- ing the energy to return the cannon to its original firing position.
Te redesigned system modifies and
simplifies some of the components, but operates on the same fundamentals as the legacy system. Te new design modifies
the buffer by splitting the front head of the legacy buffer into two pieces, compen- sating for potential misalignment within the system and internal recoil length. Te redesigned recuperator is a modified ver- sion of the legacy version with a majority of the components removed. Tis is pos- sible because of the Suspension Lockout System (SLOS) and fixing the recoil length at 25 inches. Te SLOS is an eas- ily installable, field-deployable device used to stabilize the M119 during high- angle firing. It removes the problematic variable-recoil hardware, and works in conjunction with the fixed recoil system to reduce accelerations and stresses on the
carriage and lower buffer rod forces. In the legacy recoil system, recoil length varied from 14.5 inches to 42 inches depending on the elevation of the gun. Te combi- nation provides more stability by reducing platform displacement, resulting in more responsive fires and making it safer for the Soldier to operate.
During the prototyping, PM TAS, the program manager, ARDEC and RIA-JMTC developed a partnership approach that leveraged each group’s strengths: The ARDEC engineers provided technical and engineering support, while RIA-JMTC provided manufacturing process support and valuable feedback on the technical data package.
COMPONENT REUSE CUTS COST When redesigning a system as complex as the M119 recoil system, the challenge is to improve reliability, availability and performance to meet threshold require- ments while controlling the overall cost. In addition to increasing reliability and stability and eliminating the frequent need to add or remove oil, the recoil rede- sign also reduces the overall weight of the system by approximately 45 pounds, a significant weight reduction. Using a combination of unmodified and modi- fied legacy parts along with the newly manufactured ones reduced overall costs. Te legacy system consists of approxi- mately 124 total parts. Te redesign will reduce that number by 40 percent to approximately 75, reusing 47 parts from the legacy system—65 percent—and manufacturing 28 new parts. Te rede- sign efforts will reduce the estimated cost
ASC.ARMY.MIL
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ACQUISITION
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