From the statute - the applicable rules in full
government speak.
Vehicles, equipment and
machinery which is lighter than 4,536 kg (10,000
lbs) may also be secured in accordance with the
provisions of this section, with ｧ393.128, or in
accordance with the provisions of ｧｧ393.100
through 393.114.
ｧ393.110 What else do I have to do to determine the
minimum number of tiedowns?
(a) In addition to the requirements of ｧ393.106, the
minimum number of tiedowns required to secure an
article or group of articles against movement
depends on the length of the article(s) being
secured, and the requirements of paragraphs (b)
and (c) of this section.
(b) When an article is not blocked or positioned to
prevent movement in the forward direction by a
headerboard, bulkhead, other cargo that is
positioned to prevent movement, or other
appropriate blocking devices, it must be secured by
at least:
(1) One tiedown for articles 5 feet (1.52 meters) or
less in length, and 1,100 lbs (500 kg) or less in
weight;
(2) Two tiedowns if the article is:
(i) 5 feet (1.52 meters) or less in length and
more than 1,100 lbs (500 kg) in weight; or
(ii) Longer than 5 feet (1.52 meters) but less
than or equal to 10 feet (3.04 meters) in
length, irrespective of the weight.
(3) Two tiedowns if the article is longer than 10 feet
(3.04 meters), and one additional tiedown for
every 10 feet (3.04 meters) of article length, or
fraction thereof, beyond the first 10 feet (3.04
meters) of length.
(c) If an individual article is required to be blocked,
braced or immobilized to prevent movement in the
forward direction by a headerboard, bulkhead, other
articles which are adequately secured or by an
appropriate blocking or immobilization method, it
must be secured by at least one tiedown for every
3.04 meters (10 feet) or article length, or fraction
thereof.
(d) Special rule for special purpose vehicles.
The rules in this section do not apply to a
vehicle transporting one or more articles of
cargo such as, but not limited to, machinery or
fabricated structural items (e.g., steel or concrete
beams, crane booms, girders, and trusses, etc.)
which, because of their design, size, shape, or
weight, must be fastened by special methods.
However, any article of cargo carried on that
vehicle must be securely and adequately
fastened to the vehicle.
ｧ393.112 Must a tiedown be adjustable?
Each tiedown, or its associated connectors, or
its attachment mechanisms must be designed,
constructed, and maintained so the driver of an in-
transit commercial motor vehicle can tighten them.
However, this requirement does not apply to the use
of steel strapping.
ｧ393.114 What are the requirements for front end
structures used as part of a cargo securement system?
(a) Applicability. The rules in this section are applicable
to commercial motor vehicles transporting articles
of cargo that are in contact with the front end
structure of the vehicle. The front end structure on
these cargo-carrying vehicles must meet the
performance requirements of this section.
(b) Height and width.
(1) The front end structure must extend either to a
height of 4 feet above the floor of the vehicle or
to a height at which it blocks forward movement
of any item of article of cargo being carried on
the vehicle, whichever is lower.
(2) The front end structure must have a width which
is at least equal to the width of the vehicle or
which blocks forward movement of any article of
cargo being transported on the vehicle,
whichever is narrower.
(c) Strength. The front end structure must be capable of
withstanding the following horizontal forward static
load:
(1) For a front end structure less than 6 feet in
height, a horizontal forward static load equal to
one-half (0.5) of the weight of the articles
of cargo being transported on the vehicle
uniformly distributed over the entire portion
of the front end structure that is within 4 feet
above the vehicle痴 floor or that is at or below a
height above the vehicle痴 floor at which it
blocks forward movement of any article of the
vehicle痴 cargo, whichever is less; or
(2) For a front end structure 6 feet in height
or higher, a horizontal forward static load equal
to four-tenths (0.4) of the weight of
the articles of cargo being transported on
the vehicle uniformly distributed over the entire
front end structure.
(d) Penetration resistance. The front end structure
must be designed, constructed, and maintained
so that it is capable of resisting penetration
by any article of cargo that contacts it when
the vehicle decelerates at a rate of 20 feet per
second, per second. The front end structure must
have no aperture large enough to permit any
article of cargo in contact with the structure to
pass through it.
(e) Substitute devices. The requirements of this
section may be met by the use of devices
performing the same functions as a front end
structure, if the devices are at least as strong as,
and provide protection against shifting articles
of cargo at least equal to, a front end structure
which conforms to those requirements.
