MIL-DTL-62049 Semitrailer, Van: For Installation Of Special Equipment, Military DesignThis specification covers eight models of special purpose 6 ton, tactical, 2- and 4-wheel van semitrailers, herein referred to as semitrailers. The semitrailers are used primarily to transport and house repair parts and shop equipment \(electrical or mechanical\) over all types of roads and limited cross-country terrain and under extreme climate conditions.

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MIL-DTL-62049G

semitrailer body undercarriage frame assembly (including kingpin), semitrailer bogie structure

(including suspension brackets), semitrailer suspension and (b) performance requirements

specified herein. A failure also includes weld cracks, base metal cracks, and permanent

deformation of items. The prime manufacturer shall be responsible to correct and repair any

failure(s) that occurred during testing on each semitrailer produced at no additional cost to the

Government and no modification in the contract delivery schedule.

4.5.8.3 Expansibility reliability. The shop equipment shall be tested for a total of

12 operations with zero chargeable failure. A chargeable failure is defined as any malfunction

which cannot be corrected by an organizational repair or replacement action (using controls on

equipment, tool, or parts).

4.5.9 Maintainability. To determine conformance to 3.5, a maintenance ratio less than or

equal to that specified shall be demonstrated during testing. The maintenance ratio will be

calculated using the total cumulative maintenance manhours, except those incurred through

maintenance induced errors.

4.5.10 Performance. To determine conformance to 3.6, the semitrailer shall be operated

for a distance of not less than 50 miles. Test course shall be smooth, approximately level, hard

surfaced road.

4.5.10.1 Environmental operation. To determine conformance to 3.6.1, operate the

semitrailer and store it at the temperatures specified. The semitrailer shall evidence no

deterioration of operation and performance, or failure of any component.

4.5.10.2 Brakes.

4.5.10.2.1 Service brake test. To determine conformance to 3.6.3.1, the loaded

semitrailer and towing vehicle combination shall be operated as specified and the performance

measured. The vehicle combination shall control, decelerate, and stop the semitrailer within

30 feet from a speed of 20 miles per hour on a dry, hard, paved, level, smooth surface. Brakes

shall apply evenly on all semitrailer and towing vehicle wheels and maintain the vehicle

combination within a 12 foot wide lane. The service brake test shall also be conducted on

acceptance test with the semitrailer, van without payload and the same performance measured.

4.5.10.3 Automatic brake actuation test. To determine conformance to 3.6.3.2, the

semitrailer and towing vehicle shall be placed on the specified grade and the automatic

breakaway device actuated. Brakes shall hold the semitrailer stationary for the specified time. A

satisfactory test technique for this test shall be developed by the tester whereby a simulation of

the breakaway is accomplished without complete mechanical disconnect of the semitrailer from

the prime mover. A satisfactory technique shall be one that assures safety of manpower and

equipment in the event of brake system failure.