General Knowledge: Cargo And Vehicle Control
22 questions in the bank cover this topic. Everything below is drawn from the sources those questions cite.
Sources: 49 CFR 392.9, 49 CFR 393.102, 49 CFR 393.104, 49 CFR 393.106, 49 CFR 396 Appendix A
What you need to know
392.9(b)(2) requires inspection within the first 50 miles after beginning a trip.
The 150-mile figure appears in 392.9(b)(3) as one of the triggers for reexamination during the trip.
Inspect the cargo and the devices used to secure the cargo within the first 50 miles after beginning a trip and cause any adjustments to be made to the cargo or load securement devices as necessary.
49 CFR 392.9
392.9(b)(3) lists three triggers and requires action at whichever occurs first: a change of duty status, 3 hours driven, or 150 miles driven.
Reexamination and any necessary adjustments must be made whenever— (i) The driver makes a change of his/her duty status; or (ii) The commercial motor vehicle has been driven for 3 hours; or (iii) The commercial motor vehicle has been driven for 150 miles, whichever occurs first.
49 CFR 392.9
392.9(b)(4) exempts the driver of a sealed vehicle ordered not to open it, and the driver of a vehicle loaded so that inspecting the cargo is impracticable.
Trip length, cargo type and experience are not exemptions. For a sealed vehicle the driver must also have been ordered not to open it.
The rules in this paragraph (b) do not apply to the driver of a sealed commercial motor vehicle who has been ordered not to open it to inspect its cargo or to the driver of a commercial motor vehicle that has been loaded in a manner that makes inspection of its cargo impracticable.
49 CFR 392.9
392.9(a)(3) addresses obstruction of view, free movement of arms and legs, access to emergency accessories, and free exit from the cab.
There is no 80 percent volume rule in this provision.
The commercial motor vehicle's cargo or any other object does not obscure the driver's view ahead or to the right or left sides (except for drivers of self-steer dollies), interfere with the free movement of his/her arms or legs, prevent his/her free and ready access to accessories required for emergencies, or prevent the free and ready exit of any person from the commercial motor vehicle's cab or driver's compartment.
49 CFR 392.9
392.9(a)(1) refers to sections 393.100 through 393.136, the cargo securement standards in Part 393.
A driver may not operate a commercial motor vehicle and a motor carrier may not require or permit a driver to operate a commercial motor vehicle unless— (1) The commercial motor vehicle's cargo is properly distributed and adequately secured as specified in §§ 393.100 through 393.136 of this subchapter.
49 CFR 392.9
396 Appendix A item 6.a includes the spare tire and the dunnage, not just the cargo.
Anything that can reach the road is covered, which is why the spare carrier is part of a walk-around. The spare tire, load and dunnage are all named.
Part(s) of vehicle or condition of loading such that the spare tire or any part of the load or dunnage can fall onto the roadway.
49 CFR 396 Appendix A
396 Appendix A item 6.b fails a vehicle lacking the required front-end structure, the headache rack.
Under hard braking the load keeps moving forward, and that structure is what stands between it and the driver. Where one is required.
Protection Against Shifting Cargo—Any vehicle without a front-end structure or equivalent device as required.
49 CFR 396 Appendix A
393.106(d) sets one-half the cargo weight as the aggregate working load limit.
Working load limit is a safe working figure well below breaking strength, which is why half the weight is sufficient. Or of the group of articles secured together.
The aggregate working load limit of tiedowns used to secure an article or group of articles against movement must be at least one-half times the weight of the article or group of articles.
49 CFR 393.106
393.106(d)(3) counts the full figure for a tiedown anchored on both sides, against one-half in (d)(1) and (d)(2) for tiedowns anchored to the cargo or returning to the same side.
A tiedown working across the vehicle resists movement in both directions.
The working load limit for each tiedown that goes from an anchor point on the vehicle, through, over, or around the article of cargo, and then attaches to another anchor point on the other side of the vehicle.
49 CFR 393.106
393.106(d)(1) counts one-half.
The same halving applies under (d)(2) where a tiedown passes over the cargo and returns to an anchor on the SAME side of the vehicle.
One-half the working load limit of each tiedown that goes from an anchor point on the vehicle to an anchor point on an article of cargo
49 CFR 393.106
393.106(c)(1) requires a positive means of preventing roll, and adds that it must not be capable of becoming unintentionally unfastened or loose in transit.
Tiedowns stop vertical and longitudinal movement but not rotation. They must not be able to become unfastened in transit.
Articles of cargo that are likely to roll must be restrained by chocks, wedges, a cradle or other equivalent means to prevent rolling.
49 CFR 393.106
393.106(c)(2) gives two options.
A gap lets items gain momentum before colliding, which can break the securement and shift the load suddenly.
Articles or cargo placed beside each other and secured by transverse tiedowns must either: (i) Be placed in direct contact with each other, or (ii) Be prevented from shifting towards each other while in transit.
49 CFR 393.106
393.104(f)(1) prohibits knots outright.
A knot concentrates stress and can reduce a strap's strength by half or more, so the marked working load limit no longer applies. A knot is a weak point and can work loose.
Tiedowns and securing devices must not contain knots.
49 CFR 393.104
393.104(f)(4) requires it wherever abrasion or cutting could occur, and the protection itself must resist abrasion, cutting and crushing.
A sharp edge can cut through a strap in a few miles of vibration. The protection goes at the point of contact. Protection goes at the point of contact.
Edge protection must be used whenever a tiedown would be subject to abrasion or cutting at the point where it touches an article of cargo. The edge protection must resist abrasion, cutting and crushing.
49 CFR 393.104
393.104(f)(3) names all four.
Working loose is listed first because it is the usual failure: vibration slackens the tiedown and the load starts to move before anything breaks. All while in transit.
Each tiedown must be attached and secured in a manner that prevents it from becoming loose, unfastening, opening or releasing while the vehicle is in transit.
49 CFR 393.104
393.104(b) bars damaged or weakened components, naming cracks and cuts as examples that can reduce the working load limit.
A cut strap still carrying load is rated for a figure it can no longer meet. Cracks and cuts are the examples given.
All tiedowns, cargo securement systems, parts and components used to secure cargo must be in proper working order when used to perform that function with no damaged or weakened components, such as, but not limited to, cracks or cuts that will adversely affect their performance
49 CFR 393.104
393.104(c) covers the whole load path.
The strongest strap is useless if the pocket it anchors to is cracked, so the structure is held to the same 393.102 performance criteria. Floors, walls, decks, anchor points, headerboards, bulkheads, stakes, posts and mounting pockets all count.
Vehicle structures, floors, walls, decks, tiedown anchor points, headerboards, bulkheads, stakes, posts, and associated mounting pockets used to contain or secure articles of cargo must be strong enough to meet the performance criteria of § 393.102, with no damaged or weakened components
49 CFR 393.104
393.102(a)(1) applies 0.8 g forward, 0.5 g rearward and 0.5 g lateral, each applied separately, against the manufacturer's breaking strength rating.
Forward is highest because hard braking is the most common severe load case.
(i) 0.8 g deceleration in the forward direction;
(ii) 0.5 g acceleration in the rearward direction; and
(iii) 0.5 g acceleration in a lateral direction.
49 CFR 393.102
393.102(a)(2) uses 0.435 g forward, 0.5 g rearward and 0.25 g lateral.
These are LOWER than the breaking strength figures in (a)(1) because working load limit is a safe everyday rating, while breaking strength is the point of failure. Confusing the two sets is an easy mistake.
(i) 0.435 g deceleration in the forward direction;
(ii) 0.5 g acceleration in the rearward direction; and
(iii) 0.25 g acceleration in a lateral direction.
49 CFR 393.102
393.106(b) lists several and expressly allows combinations.
Blocking and bracing that immobilises the load can do as much as a tiedown, and often more for cargo that would otherwise shift. Dunnage bags count as dunnage.
Cargo must be firmly immobilized or secured on or within a vehicle by structures of adequate strength, dunnage or dunnage bags, shoring bars, tiedowns or a combination of these.
49 CFR 393.106
393.106(a) gives precedence to the commodity-specific rules where they add requirements.
Logs, metal coils, concrete pipe, vehicles and similar loads each have their own section for good reason.
The commodity-specific rules take precedence over the general requirements of this section when additional requirements are given for a commodity listed in those sections.
49 CFR 393.106
393.102(b) requires at least 20 percent of the cargo's weight pressing down, for anything not fully contained by the vehicle's own structure.
Cargo inside a closed van body may instead be secured under 393.106(b). None of the figures offered is the one the rule gives.
Securement systems must provide a downward force equivalent to at least 20 percent of the weight of the article of cargo if the article is not fully contained within the structure of the vehicle.
49 CFR 393.102
Check yourself
- Within what distance after beginning a trip must you inspect your cargo securement?
- During the trip, the rule requires your cargo to be reexamined whenever which of these occurs first?
- When do the en-route cargo inspection rules not apply to you?
- What is NOT one of the conditions the rule requires regarding cargo placement?
- What is the part of the regulations that sets the cargo securement standards?
- What loading condition is a listed defect?
- What protects the cab from cargo moving forward?
- What is the minimum aggregate working load limit for tiedowns?
- How much of a tiedown's working load limit counts when it runs over the cargo to the other side?
- How much of a tiedown's working load limit counts when it anchors to the cargo itself?
- How must cargo that is likely to roll be restrained?
- What is required of two items sitting side by side under transverse tiedowns?
- What must you avoid in a tiedown or securing device?
- When is edge protection required on your tiedown?
- What four outcomes must your tiedown's attachment prevent?
- What is the tiedown condition that may not be used?
- What three vehicle structures must be undamaged?
- Against the BREAKING STRENGTH criterion in the rule, what forces must a securement system withstand?
- Against the WORKING LOAD LIMIT criterion in the rule, what forces apply?
- What five means may be used to prevent forward cargo movement?
- Which rule applies to a commodity with its own securement rule in the appendix?
- What downward force must secure cargo that is NOT fully contained within the vehicle structure?
Answers are in the practice test for this topic.