TABLE III. Semitrailer specifications (continued).
Unless otherwise specified, furnish front vertical supports (semitrailer
landing gear) per TTMA RP No. 4.
Twin vertical lift, telescopic, non-rotating type supports with two
speed gearbox and folding handcrank equipped with holder.
Leg travel min. 17-in., providing upper coupler-plate- to-ground
clearance range of at least 46-in. thru 58-in. at the kingpin centerline.
Full skirt type support legs.
Provide longitudinal bracing and transverse bracing.
Support withstand loaded, free-fall drop of at least 4-in. height without
Gearboxes filled with reopectate silicone base grease per TMC-ATA
Advisory AV 7-5.
When specified (see 6.2), furnish front supports of the adjustable
stiff-leg type having captive chained securing lock-pins and
manufacturer's standard sand shoes.
Provide equalizing sand shoes on each leg having turned-up edges.
Min. 120-sq. inch area for each shoe.
Upper Coupler Assembly
Upper coupler assembly per DOT FMCSR 393.70, TTMA RP No. 6,
and No. 19, TOFC rated.
Kingpin of 2-in. dia. throat per SAE J700, SAE J133, and AAR Spec.
Kingpin of alloy steel having either flame hardening or induction
hardening types of heat treatment in the jaw wearing contact area of
Front coupling ramp, min. 2-in. vertical height, fabricated of slit pipe
or beveled plate with gussets and cover, no standing water traps.
Coupler top plate of ASTM A242 or SAE J410 HSLA steel for both
steel and aluminum dump bodies.
Size min. 42-in. wide and completly cover a 36-in. dia., lower 5th
Coupler top plate min. 1/4-in. thick.
Plate and kingpin reinforcement of egg-crate type stiffener.