| Abstract |
The life test on the 152-mm, XM162, gun-launcher was conducted to determine the safe-life data for various components, i.e., chamber and coupling, recoil - mount, and tubes. Essentially the criterion used was to fire two items at the most severe (highest) chamber pressure expected in service until one fails; divide the least number of rounds to failure by three to obtain the safe-life recommendation for troop training and service board tests. If no failure is experienced, then the safe-life recommendation is 1/3 of the least number of rounds demonstrated on either of the two items. The latter criterion was used on this test. Based upon the results obtained, the recommendations concerning the interim safe life of the major pressure-vessel components were as follows: gun tube, XM162, 800 rounds; standard breech chamber and modified (closed breech scavenger system), autofrettaged, 800 rounds; coupling, XM162, standard and modified (Closed breech scavenger system), 1600 rounds. Recommendations concerning the recoil nut remain the same as previously established, 2000 rounds. The reliability obtained with the closed-breech scavenger components is contained in Table 1.5-1. Two nonautofrettaged breech chambers were fired 802 rounds to obtain firing data that could be used in conjunction with laboratory hydraulic cycling as a means of qualifying this manufacturing process change on the breech chambers. These two breech chambers will be returned to Watervliet Arsenal for laboratory cycle testing until failure. In addition, six additional breech chambers (nonautofrettaged) will be cycled until failure, at Watervliet Arsenal. |
