When specified (see 6.2), provide the availability of air pressure for the tailgate trip
control only during the time that the driver presses down on the service brake air
treadle in the cab, thus preventing unintensional tailgate release.
Provide dump body load cover mechanism in compliance with all state laws
pertaining to highway transport of loose materials.
Provide a heavy weight elastomer plastic impregnated fabric tarpaulin
intended for dump usage, sized to completely cover a heaped payload of earth
and provide shock cord tie downs along the sides.
Provide a tarpaulin which will not adhere to or be damaged by hot-mix asphalt
up to 375 F.
Provide the cover mechanism, mounted on the front of the semitrailer that,
when actuated, will maintain the tarpaulin clear of the payload during
covering and only near the end of travel permit the tarpaulin to be dragged
over the aggregate.
Provide driver controls for covering and for uncovering the load, of the
manual, remote control types; location of controls for operation from the
front, roadside, while the driver remains safely standing on the ground.
Provide shock cords, preventing the air stream from lifting the tarpaulin and
blowing loose materials, along at least every 36 inches on the side of the
body; provide shock cord installation and removal method by the driver while
safely standing on the ground.
3.6 Hoist system. The dump semitrailer shall be equipped with a front mount, telescopic
ram, hydraulic system as specified herein and on the dump semitrailer specification sheet. The
classification of the hoist system shall be in accordance with the Hoist Classification Chart of the
Truck Body and Equipment Association (TBEA). The dump body shall hoist to the standard
dump angle of the semitrailer manufacturer; however, unless otherwise specified, (see 6.2 and
the applicable specification sheet), this angle shall be not less than 40 degrees. At least
6-1/2 inches of clearance shall be provided between hydraulic system components and lines and
any heat radiating part of engine exhaust systems. The hoist components shall not bellmouth,
bind, malfunction, or be damaged by the act of dumping the loaded semitrailer as specified
herein, including dumping on side slopes up to the limit shown in figure 2. Stroke limiting
hydraulic valve or other safe restraining devices shall be furnished to prevent overtravel of the
hoist mechanism. Semitrailers with dump bodies that are 20 feet long and longer shall be
equipped with either a hydraulic or cam stabilizing system or an air-spring suspension system
which shall prevent rear suspension oscillation and decrease the risk of laterial instability during
the dump cycle on firm ground.
3.6.1 Hoist actuation. Unless otherwise specified herein, the actuation of the body hoist
system shall be as specified in (a) as follows. When specified (see 6.2 and 6.4), the actuation of
the body hoist system shall be as specified in (b) as follows: