the applied conditions with no additional application and despite the depletion of all air pressure.
Parking brakes shall conform to Federal Motor Carrier Safety Regulation 393.41.
* 3.10 Upper fifth wheel. The upper fifth wheel plate shall completely cover a 36 inch
diameter lower fifth wheel when the lower fifth wheel is coupled to the kingpin of the upper fifth
wheel and the semitrailer is turned at all angles. The upper fifth wheel shall conform to Federal
Motor Carrier Safety Regulation 399.70(b).
* 3.10.1 Upper fifth wheel plate. The upper fifth wheel plate shall be not less than 0.25 inch
thick. The plate shall be reinforced on the upper surface through the use of commercial steel
angles, channels, and ribs. The plate shall include an access hole to permit servicing the brake
connections and electrical connectors when these components are not serviceable from the top.
* 3.10.2 Pickup plate. A turned up lip pickup plate, compatible with the size (payload) of the
semitrailer, shall be provided as an extension of the upper fifth wheel plate. The pickup plate
shall have a turned up lip not less than 2 inches high. The pickup plate shall extend sufficiently
forward to protect the semi trailer from damage during coupling and uncoupling operations to
and from a truck tractor. The pickup plate shall be integral with the upper fifth wheel plate.
* 3.10.3 Kingpin. A 2-inch diameter kingpin conforming to SAE J700 shall be furnished. The
kingpin shall be fabricated of heat treated alloy steel.
* 3.11 Lighting. The lighting system shall be of 12-volt potential and shall conform to Federal
Motor Carrier Safety Regulations 393.14, 393.20, 393.22, 393.23, 393.25, and 393.26. The
brake lights shall override the four-way emergency flasher or the two systems shall be
independent of each other. All lights and reflectors shall be protected from operational hazards
by mounting in recessed or otherwise guarded locations. Lights and reflectors shall not be
mounted on vertical surfaces of the rub rails (unless recessed and fully protected) or semitrailer
bumper. The front of the semitrailer shall be equipped with a receptacle conforming to
SAE J560 with the conductors connected and color coded as specified therein. The receptacle
shall be located in accordance with SAE J702. Clearance lights shall be constructed for easy
removal and replacement of lamps and lenses without the use of hand tools. Turn signal lamps
shall conform to SAE J588.
3.11.1 Wiring. Wiring shall conform to SAE J1292, type Heavy Duty Thermoplastic (HDT)
or Heavy Duty Rubber Single Braid (HDB), and to Federal Motor Carrier Safety Regulations
393.27 through 393.30, 393.32 and 393.33. All wiring shall be firmly attached to the semitrailer.
Wiring shall be in rubber covered cable and individual lines shall be run in plastic tubing or
metal conduit. Junction boxes shall be of vaporproof design.