MIL-S-62549 Semitrailer, Low Bed, 40 Ton Nominal Payload For Transportation Of Heavy Engineer Construction Equipment, M870A2This specification covers a level frame, low bed semitrailer equipped with a folding gooseneck for front loading and movement of heavy engineer construction equipment.

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 - 30 - 31 - 32 - 33 - 34 - 35 - 36 - 37 - 38 - 39

MIL-S-62549(AT)

3.5.3 Side slopes. The loaded semitrailer when towed by the specified truck-tractors shall be capable of operating on a 20% side slope without slipping or upsetting.

3.5.3.1 Gradeability. Semitrailer shall be capable of operating on a 0 to 20% grade heading up and down the respective grades without malfunction. When the semitrailer is on any incline specified herein, the semitrailer shall not interfere with any component of the truck-tractor, except where the upper fifth wheel plate is coupled to the truck-tractor fifth wheel plate.

3.5.4 Fording ability. The semitrailer shall ford salt and fresh water to a depth of 18 inches without any special servicing or protection before fording. No evidence of water leakage or moisture penetration into sealed wheel bearings, shall be permitted.

3.5.5 Braking. The service brakes shall stop the semitrailer-tractor combination, with the semitrailer loaded with specified payload, within the stopping distance requirements of FMVSS 121.

3.5.6 Tracking ability. The semitrailer shall conform to the tracking requirements of FMCSR

393.70.

3.5.7 Folding gooseneck ability. The gooseneck shall be capable of folding to the ground and of being raised and locked with the semitrailer fully loaded without any evidence of component failure, deformation or misalignment.

3.5.8 Rear and side loadings. The semitrailer, coupled with truck-tractors, shall be capable of being loaded from both the rear and the side when they are in a position adjacent to earth ramps.

3.5.9 Ozone resistance. All rubber components and accessories shall be ozone resistant and shall be tested in accordance with suffix letter C of ASTM D2000.

3.6 MANPRINT.

3.6.1 Safety. The semitrailer shall comply with all FMCSR and FMVSS regulations applicable to a vehicle of this weight class at the time of manufacture. it shall be free of sharp projections or edges that may cause the operator or maintainer injury. Operators and maintenance personnel shall not be unknowingly exposed to rotating or moving parts, hot surfaces, electrically energized components, components containing high pressures or other inherently hazardous components or systems. Consideration should be given to expected failure mode situation in addition to normal operations.

3.6.2 Human factor engineering (HFE). All subsystems and components of the semitrailer shall meet all safety and HFE requirements specified in MIL-STD-1472.