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.

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MIL-DTL-11891G(AT)

APPENDIX B

B.3.17.2.1 Track roadwheel path surface. The track roadwheel path surface shall be

cooled to the point where the palm of the hand can be held to the surface backing in excess of

10 seconds.

B.3.17.2.2 Cool down. Cool down between speed changes shall require the use of a

device used to measure the temperature of the rubber pads (see figure 7 for a diagrammed

example of this type of device). Measurements should be taken from both the roadwheel side and

the road side. A reading of 130 degrees or less should be recorded prior to restart of the break-in.

B.3.17.3 Visual inspection of track. 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 VII. Hardware shall be

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

specified in B.3.16.

B.3.17.4 Track or pad failures. Any track or pad 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/pads 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.

B.3.17.5 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 B.3.17. After completion of the

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

qualification test.

B.3.18 Test procedure. After completion of the break-in run, the vehicle shall be run to

the operational mode summary found in 30.6 until the track and/or pads being tested for

qualification have met the failure criteria (see B.3.20) or have exceeded the qualification

requirements of 5000 miles track life and/or 1000 miles pad life. Testing may be stopped at any

time at the discretion of the test director.