MIL-DTL-11891 Track Shoe Sets, Track Shoe Assemblies, Track Shoe Pads And Track Shoe Bushings, Vehicular: ElastomerizedThis specification identifies the requirements for qualification and production control of track systems supporting U.S. Military Tracked Vehicles. This specification is intended primarily for the qualification of elastomeric compounds used in the fabrication of track and track components and to ensure that the quality and performance established at qualification is maintained throughout production. The contractor is held fully responsible for the entire assembly/component including all non-elastomeric components and fasteners.

Pages 1 - - 64 - 65 - 66 - 67 - 68 - 69 - 70 - 71 - 72 - 73 - 74 - 75 - 76 - 77 - 78 - 79 - 80 - 81 - 82|||

MIL-DTL-11891G(AT)

APPENDIX C

C.3.16.3 Visual inspection. Between each division of the break-in run, a visual inspection

shall be made of the track and the component parts. The inspection shall be in accordance with

the inspection and replacement criteria found in the table IX. Hardware shall be re-torqued if

noticeably loose. After break-in, all hardware shall be torqued 100% to values specified in

C.3.15.

C.3.16.4 Track failures. Any track failures which occur during break-in do not count

towards the failure criteria. Further, any failures during break-in do not reduce the original

sample sizes. Track shoes failed during break-in shall be replaced with spares and noted on a Test

Incident Report (TIR). The track shoes comprising a strand after break-in (including the recorded

spares inserted for any failures during break-in) shall be denoted as the original strand sample at

the start of test. Break-in mileage shall be counted toward the qualification mileage requirement.

C.3.16.5 Spare track. All spare track shall be installed on a vehicle and broken in before

test start up. The break-in shall be performed in accordance with C.3.16. After completion of the

break-in run, the track shall be removed from the vehicle and stored for future use during the

qualification test.

C.3.17 Test procedure. After completion of the break-in run, the vehicle shall run to the

operational mode summary found in C.3.5.1 until the track being tested for qualification has met

the failure criteria (see C.3.19) or the 1200 mile requirement is exceeded. Testing may be stopped

at any time at the discretion of the test director.

C.3.17.1 Mission scenarios. During the test, operators are to run mission scenarios as

specified by the Preparing Activity.

C.3.17.2 Track switching. Upon completion of the first 500-mile mission scenario, the

track strands shall be removed from the vehicle, inspected for overall condition, and switched to

the opposite side. At 1000 miles, the track strands shall be removed from the vehicle, inspected

for overall condition, and switched to the opposite side. Repeat this switching procedure for

every 500 miles of testing.

C.3.18 Inspection and replacement criteria. Inspection and replacement criteria during

the on-vehicle test shall be in accordance with the table IX.

C.3.19 Failure criteria. Failure of a contractor's track will be established when 20% of its

total shoe samples have reached wearout and/or need replacement (see table IX).